Dave,do you have any info/links to good cheap bipolar drive and motors???
that can be used with a stamp/pic/????
I have found one it looks good also good price but the documentation really
is poor.
www.futurlec.com look under stepper motors.
at $17.00 the price is hard to beat.
maybe someone on the list has used one of these and can comment on it maybe
some example code???
regards
victor
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, November 29, 2002 8:26 AM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses in
> the motor increase with the square of the voltage. At some point the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
> Mostly because the PC timings. that's 10kH pulses, into a 200 step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so much
> umph per minute regardless of speed. double the speed, and you halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
> could say you have 25/1. At high speed, say 50 RPM, you have 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You may
> be surprised to find that you are running one of these puppies at 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> > Why it overheats?
> > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> designed to
> > handle about 500ma tops.
> > 12v at 3.5 ohms would be about 3.4 amps.
> > The 75ohm stepper that came with the NS1000 would be about 66ma,
> which is
> > less than the max for the ULN2003, so it would work OK.
> >
> > Normally you limit the max current that the stepper motor can
> handle,
> > otherwise it overheats and you risk burning out a coil.
> >
> > Small steppers can be driven with the ULN2003 but not the more
> powerful
> > ones.
> > You'll need more poewerful power transistors to handle the heavier
> stepper
> > motor.
> >
> > I think that maybe your speed value is set too fast.
> > The ULN2003 is getting overloaded and your power supply may be too
> weak for
> > the big stepper.
> > Thus you tend to get twitching.
> > Steppers typically run at less than 100 rpm. You can get some
> steppers to
> > run faster, but you have to carefully ramp up the speed from slow
> to fast.
> > But a fast running stepper has little or no torque at high rpms.
> > I'd probably start at 1/2 second steps and see what happens, having
> it turn
> > slow is easier to watch.
> >
> >
> >
> >
Original Message
> > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > Sent: Thursday, November 28, 2002 8:28 PM
> > To: basicstamps@y...
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram should
> list
> > > where the center taps go (power) and where the legs go. All you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque things
> move
> > > with running the motor at the nameplate voltages. One good test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is annoying to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages. some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage, but
> are
> > > limited to nameplate amps. You really don't get the power from a
> > > stepper until you jack up the voltage. and when/if you looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code. The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
I hooked the commons up to 5v on the breadboard
and left the legs hooked to the 2803. It spins!
I really appreciate your help on this.
The motor spun good with the 5v. However,
the heatsink on the NX-1000 started to get
warm similarly to the 2803.
I got the motor to go around and that was my
goal - i think I will not hook it up to my
nx-1000 board again though.
I am learning a good bit about stepper
motors and measuring volts/ohms/amps
although it is still hazy to me how to
think ahead accurately.
I think with this motor in general, I am not
driving it with enough amps so it is drawing
too hard on my power source. I am guessing
if i found a power supply rated at ~3.5 amps
it would run fine.
I am wondering - the 2803 pulses the legs at
less than 1v. Why do you need an IC to do this?
Could you not just throw a resistor in line
with a stamp pin to knock the volts down some
and just pulse the legs from a stamp pin?
Also, in general, do you usually purchase a
stepper motor and driver together as a package
thus avioding all of the current matching
problems i am having or should one be good enough
to take just any stepper motor and basically
make their own driver?
mkl
Original Message
From: Dave Mucha <davemucha@j...>
Date: Friday, November 29, 2002 7:26 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses
> in
> the motor increase with the square of the voltage. At some point
> the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge
> the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
>
> Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it
> goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so
> much
> umph per minute regardless of speed. double the speed, and you
> halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> you
> could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it
> away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You
> may
> be surprised to find that you are running one of these puppies at
> 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
> get
> away from the uni-polar style.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> > Why it overheats?
> > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> designed to
> > handle about 500ma tops.
> > 12v at 3.5 ohms would be about 3.4 amps.
> > The 75ohm stepper that came with the NS1000 would be about 66ma,
> which is
> > less than the max for the ULN2003, so it would work OK.
> >
> > Normally you limit the max current that the stepper motor can
> handle,
> > otherwise it overheats and you risk burning out a coil.
> >
> > Small steppers can be driven with the ULN2003 but not the more
> powerful
> > ones.
> > You'll need more poewerful power transistors to handle the
> heavier
> stepper
> > motor.
> >
> > I think that maybe your speed value is set too fast.
> > The ULN2003 is getting overloaded and your power supply may be
> too
> weak for
> > the big stepper.
> > Thus you tend to get twitching.
> > Steppers typically run at less than 100 rpm. You can get some
> steppers to
> > run faster, but you have to carefully ramp up the speed from
> slow
> to fast.
> > But a fast running stepper has little or no torque at high rpms.
> > I'd probably start at 1/2 second steps and see what happens,
> having
> it turn
> > slow is easier to watch.
> >
> >
> >
> >
Original Message
> > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > Sent: Thursday, November 28, 2002 8:28 PM
> > To: basicstamps@y...
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
>
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram
> should
> list
> > > where the center taps go (power) and where the legs go. All
> you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque
> things
> move
> > > with running the motor at the nameplate voltages. One good
> test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is
> annoying to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages. some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage,
> but
> are
> > > limited to nameplate amps. You really don't get the power
> from a
> > > stepper until you jack up the voltage. and when/if you
> looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code. The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
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Driving a Darlington like a TP120 will carry the current for low
power steppers. under 1.5 A. you can drive it from a Stamp directly
for step control. 4 units would allow you to as a chopper.
Allegro makes a surface mount H-Bridge chip the A3977 also good for
up to 35 volts and 1.5 amps.
You might want to check out Allegro UNC5804 too.
Generally speaking you can make a full H-Bridge circuit to drive a
stepper, or use a pre-packaged chip. These take 2 pins, one for
pulse and one for direction.
There are also some circuits that allow you to vari the voltage or
use a pot to change speed. If you are driving a robot and are just
looking for a motor, the voltage/pot style is fine. If you need to
know where the shaft is then you need to count pulses.
There are quite a few drives, kits, chips and circuits floating
around. Figure out what your maximum motor size is and design around
that that.
btw, are you experimenting ? making a robot? or getting started in
CNC ?
Dave
--- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> Dave,do you have any info/links to good cheap bipolar drive and
motors???
> that can be used with a stamp/pic/????
> I have found one it looks good also good price but the
documentation really
> is poor.
> www.futurlec.com look under stepper motors.
> at $17.00 the price is hard to beat.
> maybe someone on the list has used one of these and can comment on
it maybe
> some example code???
> regards
> victor
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Friday, November 29, 2002 8:26 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> >
> > You must limit the power.
> >
> > I had made a mistake in an earlier post.
> >
> > Power output increases proportionally with supply voltage. Losses
in
> > the motor increase with the square of the voltage. At some point
the
> > motor just gets too hot.
> >
> > I think I wrote that speed increases as the square of voltage.
> >
> > Motor speed is dependant on how fast you can charge and discharge
the
> > coils. at some point, you cannot make the unit move any faster.
> > Typically on PC based stepper controlles, 10kH is the best you do.
> > Mostly because the PC timings. that's 10kH pulses, into a 200
step
> > per rev motor. Smaller motors can spin faster than large ones.
> >
> > The point about loss of power at high speed is correct, but it
goes
> > to constant power. Output power is independant of speed.
> > since the stepper will deliver constant power, you only get so
much
> > umph per minute regardless of speed. double the speed, and you
halve
> > the torque. At low speed that means X amount of torque at low
> > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
you
> > could say you have 25/1. At high speed, say 50 RPM, you have
25/50
> > so the motor is very weak.
> >
> > Stepper MOTORS are designed to run HOT, put you hand and pull it
away
> > hot. not sizzling. electronics are designed to run cool. it
> > shouldn't be the other way around.
> >
> > and don't forget to calculate power consumption and watts. You
may
> > be surprised to find that you are running one of these puppies at
30
> > watts or more. even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
get
> > away from the uni-polar style.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
wrote:
> > > Why it overheats?
> > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > designed to
> > > handle about 500ma tops.
> > > 12v at 3.5 ohms would be about 3.4 amps.
> > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > which is
> > > less than the max for the ULN2003, so it would work OK.
> > >
> > > Normally you limit the max current that the stepper motor can
> > handle,
> > > otherwise it overheats and you risk burning out a coil.
> > >
> > > Small steppers can be driven with the ULN2003 but not the more
> > powerful
> > > ones.
> > > You'll need more poewerful power transistors to handle the
heavier
> > stepper
> > > motor.
> > >
> > > I think that maybe your speed value is set too fast.
> > > The ULN2003 is getting overloaded and your power supply may be
too
> > weak for
> > > the big stepper.
> > > Thus you tend to get twitching.
> > > Steppers typically run at less than 100 rpm. You can get some
> > steppers to
> > > run faster, but you have to carefully ramp up the speed from
slow
> > to fast.
> > > But a fast running stepper has little or no torque at high rpms.
> > > I'd probably start at 1/2 second steps and see what happens,
having
> > it turn
> > > slow is easier to watch.
> > >
> > >
> > >
> > >
Original Message
> > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > Sent: Thursday, November 28, 2002 8:28 PM
> > > To: basicstamps@y...
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > Dave,
> > >
> > > I have taken your suggestions and found out
> > > a good bit about the motor but still cannot make
> > > it rotate.
> > >
> > > I have also read many of the websites people have suggested
> > > and I do have a pretty good idea of the theory of how
> > > these stepper motors work. What i really do not know is
> > > how to tell if a certain driver (the one on the nx-1000) will
drive
> > > an arbitrary stepper motor I come up with. I think this might
> > > boil down to a basic electronics question but i'm not certain.
> > >
> > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > >
> > > I am connecting it to the 12V ouputs on the NX-1000.
> > >
> > > I have deduced the following from your suggested
> > > ohm readings:
> > >
> > > blue leg
> > > yellow leg
> > > black common
> > >
> > > brown leg
> > > red leg
> > > white common
> > >
> > > I have no idea which is leg A and which is leg B.
> > >
> > > Firstly, I am curious to know why when I try to run
> > > this motor does it overheat the 2003AN IC? I would
> > > think that if i'm pumping 12V into a 3V motor it would
> > > overheat the motor if anything. Also, the "known
> > > good motor (the one that came with stampworks)" reads
> > > at like 75+ ohms.
> > >
> > > This means the stampworks motor is running about 160mA
> > > where this other motor is running say 3430mA which is
> > > 7* tollerance according to the nx-1000 specs.
> > >
> > > Is it the lack of resistance the new motor has that
> > > makes the IC get too hot and should I try adding
> > > resistors to correct for this?
> > >
> > > I know the IC is still good because I keep switching
> > > back to the "known good" motor and it still works. On
> > > the IC I did fry whichever pin is connected to output
> > > 1 on the 7-CH stepper motor driver, but I just moved
> > > up to 4,5,6,7.
> > >
> > > At any rate, following is the code i'm running and
> > > several different wiring configs i have tried, all
> > > of which behave about the same. Also this is a
> > > bench test with no load whatsoever on the motor.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirA = %1111
> > > speed = 20
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > pause speed
> > > coils = %1001
> > > pause speed
> > > next
> > > 'go ahead and end so as not to
> > > 'keep trying and hurt something
> > >
> > > end
> > >
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p2--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p3--5--brown
> > > p2--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p2--6--yellow
> > > p1--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > >
Original Message
> > > From: "Dave Mucha" <davemucha@j...>
> > > To: <basicstamps@y...>
> > > Sent: Thursday, November 28, 2002 10:40 AM
> > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > > <snip>
> > > >
> > > > The cogging you describe is either that the motor is way under
> > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
should
> > be at
> > > > least 5 times the motor nameplate voltage.
> > > >
> > > > or, the load it too great to allow it to start
> > > >
> > > > or, the ramp up speed it too great
> > > >
> > > > or, the motor it not wired correctly.
> > > >
> > > >
> > > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> > bench
> > > > test is pretty easy.
> > > >
> > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > have 2
> > > > sets of windings and each set can be tested with an ohm meter.
> > The
> > > > center tap of each circuit will be half the max for that
> > circuit. If
> > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
ohms, 2
> > and
> > > > 3 should be 5 ohms. 3 then is the center tap.
> > > >
> > > > Do the same for 4,5 and 6. the board connection diagram
should
> > list
> > > > where the center taps go (power) and where the legs go. All
you
> > need
> > > > to do is to switch one pair of windings.
> > > >
> > > > example : if 1 and 2 are legs and 3 is center/power
> > > > and 4 and 5 are legs and 6 is center/power
> > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > >
> > > > For hobby purposes, you should be able to make low torque
things
> > move
> > > > with running the motor at the nameplate voltages. One good
test
> > is
> > > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > > and you can get about as much torque as it takes to stop the
> > motor by
> > > > hand. the cogging will not damage anything, but it is
annoying to
> > > > listen to.
> > > >
> > > > hope this helps.
> > > >
> > > > one additional piece of data, most motor manufacturers put the
> > > > voltage on the namplate that is used to calculate voltages.
some,
> > > > like Pacific Scientific list the proper running voltage. your
> > higher
> > > > voltage motors may be such units.
> > > >
> > > > You can run motors from 5 to 25 times the nameplate voltage,
but
> > are
> > > > limited to nameplate amps. You really don't get the power
from a
> > > > stepper until you jack up the voltage. and when/if you
looking
> > doing
> > > > any real power applications, look into bi-polar wiring of your
> > motors
> > > > and get away from using a resitor in the power line. the high
> > > > voltages would need huge resistors and need to dump lots of
heat.
> > > >
> > > > Dave
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > I am able to hook it up similarly to the motor that came
with
> > > > stampworks, but on the breadboard and run the following
code. The
> > > > motor does not rotate but I can feel it pulsing as if it would
> > rotate
> > > > if only i had the sequence correct.
> > > > >
> > > > > Any help would be appreciated. Also, if i'm a fool for even
> > trying
> > > > this please say so.
> > > > >
> > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > I also tried using outL and adjusting DirL and Coils
> > accordingly to
> > > > try to use that 5th wire and got
> > > > > the same result - a pulsing motor with no rotation.
> > > > >
> > > > > '{$STAMP BS2}
> > > > > Coils VAR OutA 'output to stepper coils
> > > > >
> > > > > speed var word
> > > > > times var word
> > > > >
> > > > > dirL = %1111
> > > > > speed = 10
> > > > >
> > > > > main:
> > > > >
> > > > > for times = 1 to 25
> > > > > coils = %1001
> > > > > pause speed
> > > > > coils = %1100
> > > > > pause speed
> > > > > coils = %0110
> > > > > pause speed
> > > > > coils = %0011
> > > > > next
> > > > > pause 200
> > > > > goto main
> > > > >
> > > > >
> > > > >
> > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
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> > > Body of the message will be ignored.
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> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
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> > > >
> > >
> > >
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> >
> >
it is always neat to have a thing work after all the energy you put
into it.
about Power supplys,
first, a transformer with enough amps to handle 66% of the total motor
(S) amps.
a full bridge rectifier or diodes rated at 150% or twice the desired
voltage.
remember your AC, once rectified and filtered will yield 1.414 times
AC suppy. so your 10V AC will become 14.14 volts DC.
Caps need to be huge. Figure C=((80,000 * I)/V) C=uF Jameco sells
10,000uF,50V caps for $4.99.
I am doing CNC work with NEMA34 steppers, 4.7A, 1.7V driving them at
36VDC, 4 motors on the power supply. I use GECKO stepper
controllers. These are $115.00 per motor units that take one signal
to control forward or reverse and another signal in pulse to control
steps, well, actually, micro-steps. (10 micro-steps per motor step)
These can control up to 7 amp motors.
good site for information on power supplies www.geckodrives.com and
also where I got the formulas. The guy who makes them is one of
those EE's that forgets more than most of us know. And a neat thing
about him (like Tracy here) is that he can explain it to you so you
can understand it. sometimes that is a trick all to itself.
And if you are into designing your own power supplies, or stepper
controllers or want more technical data (we are getting a little
close to off topic on this list) check out
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> I hooked the commons up to 5v on the breadboard
> and left the legs hooked to the 2803. It spins!
>
> I really appreciate your help on this.
>
> The motor spun good with the 5v. However,
> the heatsink on the NX-1000 started to get
> warm similarly to the 2803.
>
> I got the motor to go around and that was my
> goal - i think I will not hook it up to my
> nx-1000 board again though.
>
> I am learning a good bit about stepper
> motors and measuring volts/ohms/amps
> although it is still hazy to me how to
> think ahead accurately.
>
> I think with this motor in general, I am not
> driving it with enough amps so it is drawing
> too hard on my power source. I am guessing
> if i found a power supply rated at ~3.5 amps
> it would run fine.
>
> I am wondering - the 2803 pulses the legs at
> less than 1v. Why do you need an IC to do this?
> Could you not just throw a resistor in line
> with a stamp pin to knock the volts down some
> and just pulse the legs from a stamp pin?
>
> Also, in general, do you usually purchase a
> stepper motor and driver together as a package
> thus avioding all of the current matching
> problems i am having or should one be good enough
> to take just any stepper motor and basically
> make their own driver?
>
> mkl
>
>
Original Message
> From: Dave Mucha <davemucha@j...>
> Date: Friday, November 29, 2002 7:26 am
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> >
> > You must limit the power.
> >
> > I had made a mistake in an earlier post.
> >
> > Power output increases proportionally with supply voltage. Losses
> > in
> > the motor increase with the square of the voltage. At some point
> > the
> > motor just gets too hot.
> >
> > I think I wrote that speed increases as the square of voltage.
> >
> > Motor speed is dependant on how fast you can charge and discharge
> > the
> > coils. at some point, you cannot make the unit move any faster.
> > Typically on PC based stepper controlles, 10kH is the best you
do.
> >
> > Mostly because the PC timings. that's 10kH pulses, into a 200
> > step
> > per rev motor. Smaller motors can spin faster than large ones.
> >
> > The point about loss of power at high speed is correct, but it
> > goes
> > to constant power. Output power is independant of speed.
> > since the stepper will deliver constant power, you only get so
> > much
> > umph per minute regardless of speed. double the speed, and you
> > halve
> > the torque. At low speed that means X amount of torque at low
> > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> > you
> > could say you have 25/1. At high speed, say 50 RPM, you have
> > 25/50
> > so the motor is very weak.
> >
> > Stepper MOTORS are designed to run HOT, put you hand and pull it
> > away
> > hot. not sizzling. electronics are designed to run cool. it
> > shouldn't be the other way around.
> >
> > and don't forget to calculate power consumption and watts. You
> > may
> > be surprised to find that you are running one of these puppies at
> > 30
> > watts or more. even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
> > get
> > away from the uni-polar style.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
wrote:
> > > Why it overheats?
> > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > designed to
> > > handle about 500ma tops.
> > > 12v at 3.5 ohms would be about 3.4 amps.
> > > The 75ohm stepper that came with the NS1000 would be about
66ma,
> > which is
> > > less than the max for the ULN2003, so it would work OK.
> > >
> > > Normally you limit the max current that the stepper motor can
> > handle,
> > > otherwise it overheats and you risk burning out a coil.
> > >
> > > Small steppers can be driven with the ULN2003 but not the more
> > powerful
> > > ones.
> > > You'll need more poewerful power transistors to handle the
> > heavier
> > stepper
> > > motor.
> > >
> > > I think that maybe your speed value is set too fast.
> > > The ULN2003 is getting overloaded and your power supply may be
> > too
> > weak for
> > > the big stepper.
> > > Thus you tend to get twitching.
> > > Steppers typically run at less than 100 rpm. You can get some
> > steppers to
> > > run faster, but you have to carefully ramp up the speed from
> > slow
> > to fast.
> > > But a fast running stepper has little or no torque at high rpms.
> > > I'd probably start at 1/2 second steps and see what happens,
> > having
> > it turn
> > > slow is easier to watch.
> > >
> > >
> > >
> > >
Original Message
> > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > Sent: Thursday, November 28, 2002 8:28 PM
> > > To: basicstamps@y...
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > Dave,
> > >
> > > I have taken your suggestions and found out
> > > a good bit about the motor but still cannot make
> > > it rotate.
> > >
> > > I have also read many of the websites people have suggested
> > > and I do have a pretty good idea of the theory of how
> > > these stepper motors work. What i really do not know is
> > > how to tell if a certain driver (the one on the nx-1000) will
drive
> > > an arbitrary stepper motor I come up with. I think this might
> > > boil down to a basic electronics question but i'm not certain.
> > >
> > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > >
> > > I am connecting it to the 12V ouputs on the NX-1000.
> > >
> > > I have deduced the following from your suggested
> > > ohm readings:
> > >
> > > blue leg
> > > yellow leg
> > > black common
> > >
> > > brown leg
> > > red leg
> > > white common
> > >
> > > I have no idea which is leg A and which is leg B.
> > >
> > > Firstly, I am curious to know why when I try to run
> > > this motor does it overheat the 2003AN IC? I would
> > > think that if i'm pumping 12V into a 3V motor it would
> > > overheat the motor if anything. Also, the "known
> > > good motor (the one that came with stampworks)" reads
> > > at like 75+ ohms.
> > >
> > > This means the stampworks motor is running about 160mA
> > > where this other motor is running say 3430mA which is
> > > 7* tollerance according to the nx-1000 specs.
> > >
> > > Is it the lack of resistance the new motor has that
> > > makes the IC get too hot and should I try adding
> > > resistors to correct for this?
> > >
> > > I know the IC is still good because I keep switching
> > > back to the "known good" motor and it still works. On
> > > the IC I did fry whichever pin is connected to output
> > > 1 on the 7-CH stepper motor driver, but I just moved
> > > up to 4,5,6,7.
> > >
> > > At any rate, following is the code i'm running and
> > > several different wiring configs i have tried, all
> > > of which behave about the same. Also this is a
> > > bench test with no load whatsoever on the motor.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirA = %1111
> > > speed = 20
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > pause speed
> > > coils = %1001
> > > pause speed
> > > next
> > > 'go ahead and end so as not to
> > > 'keep trying and hurt something
> > >
> > > end
> > >
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p2--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p3--5--brown
> > > p2--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p2--6--yellow
> > > p1--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > >
Original Message
> > > From: "Dave Mucha" <davemucha@j...>
> > > To: <basicstamps@y...>
> > > Sent: Thursday, November 28, 2002 10:40 AM
> > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > > <snip>
> > > >
> > > > The cogging you describe is either that the motor is way under
> > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> > should
> > be at
> > > > least 5 times the motor nameplate voltage.
> > > >
> > > > or, the load it too great to allow it to start
> > > >
> > > > or, the ramp up speed it too great
> > > >
> > > > or, the motor it not wired correctly.
> > > >
> > > >
> > > > since a 3.5 volt motor will turn with 3.5 volts and no load,
a
> > bench
> > > > test is pretty easy.
> > > >
> > > > Since you stated 6 wires, you have a uni-polar stepper.
these
> > have 2
> > > > sets of windings and each set can be tested with an ohm
meter.
> >
> > The
> > > > center tap of each circuit will be half the max for that
> > circuit. If
> > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> > ohms, 2
> > and
> > > > 3 should be 5 ohms. 3 then is the center tap.
> > > >
> > > > Do the same for 4,5 and 6. the board connection diagram
> > should
> > list
> > > > where the center taps go (power) and where the legs go. All
> > you
> > need
> > > > to do is to switch one pair of windings.
> > > >
> > > > example : if 1 and 2 are legs and 3 is center/power
> > > > and 4 and 5 are legs and 6 is center/power
> > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > >
> > > > For hobby purposes, you should be able to make low torque
> > things
> > move
> > > > with running the motor at the nameplate voltages. One good
> > test
> > is
> > > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > > and you can get about as much torque as it takes to stop the
> > motor by
> > > > hand. the cogging will not damage anything, but it is
> > annoying to
> > > > listen to.
> > > >
> > > > hope this helps.
> > > >
> > > > one additional piece of data, most motor manufacturers put the
> > > > voltage on the namplate that is used to calculate voltages.
some,
> > > > like Pacific Scientific list the proper running voltage. your
> > higher
> > > > voltage motors may be such units.
> > > >
> > > > You can run motors from 5 to 25 times the nameplate voltage,
> > but
> > are
> > > > limited to nameplate amps. You really don't get the power
> > from a
> > > > stepper until you jack up the voltage. and when/if you
> > looking
> > doing
> > > > any real power applications, look into bi-polar wiring of
your
> > motors
> > > > and get away from using a resitor in the power line. the high
> > > > voltages would need huge resistors and need to dump lots of
heat.
> > > >
> > > > Dave
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > I am able to hook it up similarly to the motor that came
with
> > > > stampworks, but on the breadboard and run the following
code. The
> > > > motor does not rotate but I can feel it pulsing as if it
would
> > rotate
> > > > if only i had the sequence correct.
> > > > >
> > > > > Any help would be appreciated. Also, if i'm a fool for
even
> > trying
> > > > this please say so.
> > > > >
> > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > I also tried using outL and adjusting DirL and Coils
> > accordingly to
> > > > try to use that 5th wire and got
> > > > > the same result - a pulsing motor with no rotation.
> > > > >
> > > > > '{$STAMP BS2}
> > > > > Coils VAR OutA 'output to stepper coils
> > > > >
> > > > > speed var word
> > > > > times var word
> > > > >
> > > > > dirL = %1111
> > > > > speed = 10
> > > > >
> > > > > main:
> > > > >
> > > > > for times = 1 to 25
> > > > > coils = %1001
> > > > > pause speed
> > > > > coils = %1100
> > > > > pause speed
> > > > > coils = %0110
> > > > > pause speed
> > > > > coils = %0011
> > > > > next
> > > > > pause 200
> > > > > goto main
> > > > >
> > > > >
> > > > >
> > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@y...
> > > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
Quote "even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style."
This brings up a confusing point for me about chopper driving a stepper.
If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
I correct in my assumption that since the resistance across the coils cannot
change, the amperage will increase along with the chosen chopper voltage? Do
I need to upgrade my transistors to handle this increase in amperage or do I
size my transistors by multiplying the calculated amperage by the duty
cycle?
For example:
Stepper Specs- 3.25v, 13watt stepper.
4 amps = calculated amperage at this voltage.
.8125 Ohms = Calculated resistance across coil
If I plug the extrapolated resistance figure into ohms law, my amperage
requirement at 24 volts will be 29 amps. Is this correct?
Power output increases proportionally with supply voltage. Losses in
the motor increase with the square of the voltage. At some point the
motor just gets too hot.
I think I wrote that speed increases as the square of voltage.
Motor speed is dependant on how fast you can charge and discharge the
coils. at some point, you cannot make the unit move any faster.
Typically on PC based stepper controlles, 10kH is the best you do.
Mostly because the PC timings. that's 10kH pulses, into a 200 step
per rev motor. Smaller motors can spin faster than large ones.
The point about loss of power at high speed is correct, but it goes
to constant power. Output power is independant of speed.
since the stepper will deliver constant power, you only get so much
umph per minute regardless of speed. double the speed, and you halve
the torque. At low speed that means X amount of torque at low
rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
could say you have 25/1. At high speed, say 50 RPM, you have 25/50
so the motor is very weak.
Stepper MOTORS are designed to run HOT, put you hand and pull it away
hot. not sizzling. electronics are designed to run cool. it
shouldn't be the other way around.
and don't forget to calculate power consumption and watts. You may
be surprised to find that you are running one of these puppies at 30
watts or more. even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style.
Dave
--- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> Why it overheats?
> 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
designed to
> handle about 500ma tops.
> 12v at 3.5 ohms would be about 3.4 amps.
> The 75ohm stepper that came with the NS1000 would be about 66ma,
which is
> less than the max for the ULN2003, so it would work OK.
>
> Normally you limit the max current that the stepper motor can
handle,
> otherwise it overheats and you risk burning out a coil.
>
> Small steppers can be driven with the ULN2003 but not the more
powerful
> ones.
> You'll need more poewerful power transistors to handle the heavier
stepper
> motor.
>
> I think that maybe your speed value is set too fast.
> The ULN2003 is getting overloaded and your power supply may be too
weak for
> the big stepper.
> Thus you tend to get twitching.
> Steppers typically run at less than 100 rpm. You can get some
steppers to
> run faster, but you have to carefully ramp up the speed from slow
to fast.
> But a fast running stepper has little or no torque at high rpms.
> I'd probably start at 1/2 second steps and see what happens, having
it turn
> slow is easier to watch.
>
>
>
>
Original Message
> From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> Sent: Thursday, November 28, 2002 8:28 PM
> To: basicstamps@y...
> Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@y...
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
To UNSUBSCRIBE, just send mail to: basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Yes trying an xy table.
I know there are quite a few drives for a pc but I"m trying to do it with a
micro controller.
regards
victor
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, November 29, 2002 12:49 PM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are just
> looking for a motor, the voltage/pot style is fine. If you need to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
>
>
>
>
>
>
>
> --- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> > Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> > that can be used with a stamp/pic/????
> > I have found one it looks good also good price but the
> documentation really
> > is poor.
> > www.futurlec.com look under stepper motors.
> > at $17.00 the price is hard to beat.
> > maybe someone on the list has used one of these and can comment on
> it maybe
> > some example code???
> > regards
> > victor
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Friday, November 29, 2002 8:26 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > >
> > > You must limit the power.
> > >
> > > I had made a mistake in an earlier post.
> > >
> > > Power output increases proportionally with supply voltage. Losses
> in
> > > the motor increase with the square of the voltage. At some point
> the
> > > motor just gets too hot.
> > >
> > > I think I wrote that speed increases as the square of voltage.
> > >
> > > Motor speed is dependant on how fast you can charge and discharge
> the
> > > coils. at some point, you cannot make the unit move any faster.
> > > Typically on PC based stepper controlles, 10kH is the best you do.
> > > Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> > > per rev motor. Smaller motors can spin faster than large ones.
> > >
> > > The point about loss of power at high speed is correct, but it
> goes
> > > to constant power. Output power is independant of speed.
> > > since the stepper will deliver constant power, you only get so
> much
> > > umph per minute regardless of speed. double the speed, and you
> halve
> > > the torque. At low speed that means X amount of torque at low
> > > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> you
> > > could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> > > so the motor is very weak.
> > >
> > > Stepper MOTORS are designed to run HOT, put you hand and pull it
> away
> > > hot. not sizzling. electronics are designed to run cool. it
> > > shouldn't be the other way around.
> > >
> > > and don't forget to calculate power consumption and watts. You
> may
> > > be surprised to find that you are running one of these puppies at
> 30
> > > watts or more. even the limiting resistor my be sized for 30-50
> > > watts. at that point, look into chopper drives and H-Bridges and
> get
> > > away from the uni-polar style.
> > >
> > > Dave
> > >
> > >
> > >
> > > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
> wrote:
> > > > Why it overheats?
> > > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > > designed to
> > > > handle about 500ma tops.
> > > > 12v at 3.5 ohms would be about 3.4 amps.
> > > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > > which is
> > > > less than the max for the ULN2003, so it would work OK.
> > > >
> > > > Normally you limit the max current that the stepper motor can
> > > handle,
> > > > otherwise it overheats and you risk burning out a coil.
> > > >
> > > > Small steppers can be driven with the ULN2003 but not the more
> > > powerful
> > > > ones.
> > > > You'll need more poewerful power transistors to handle the
> heavier
> > > stepper
> > > > motor.
> > > >
> > > > I think that maybe your speed value is set too fast.
> > > > The ULN2003 is getting overloaded and your power supply may be
> too
> > > weak for
> > > > the big stepper.
> > > > Thus you tend to get twitching.
> > > > Steppers typically run at less than 100 rpm. You can get some
> > > steppers to
> > > > run faster, but you have to carefully ramp up the speed from
> slow
> > > to fast.
> > > > But a fast running stepper has little or no torque at high rpms.
> > > > I'd probably start at 1/2 second steps and see what happens,
> having
> > > it turn
> > > > slow is easier to watch.
> > > >
> > > >
> > > >
> > > >
Original Message
> > > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > > Sent: Thursday, November 28, 2002 8:28 PM
> > > > To: basicstamps@y...
> > > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > Dave,
> > > >
> > > > I have taken your suggestions and found out
> > > > a good bit about the motor but still cannot make
> > > > it rotate.
> > > >
> > > > I have also read many of the websites people have suggested
> > > > and I do have a pretty good idea of the theory of how
> > > > these stepper motors work. What i really do not know is
> > > > how to tell if a certain driver (the one on the nx-1000) will
> drive
> > > > an arbitrary stepper motor I come up with. I think this might
> > > > boil down to a basic electronics question but i'm not certain.
> > > >
> > > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > > >
> > > > I am connecting it to the 12V ouputs on the NX-1000.
> > > >
> > > > I have deduced the following from your suggested
> > > > ohm readings:
> > > >
> > > > blue leg
> > > > yellow leg
> > > > black common
> > > >
> > > > brown leg
> > > > red leg
> > > > white common
> > > >
> > > > I have no idea which is leg A and which is leg B.
> > > >
> > > > Firstly, I am curious to know why when I try to run
> > > > this motor does it overheat the 2003AN IC? I would
> > > > think that if i'm pumping 12V into a 3V motor it would
> > > > overheat the motor if anything. Also, the "known
> > > > good motor (the one that came with stampworks)" reads
> > > > at like 75+ ohms.
> > > >
> > > > This means the stampworks motor is running about 160mA
> > > > where this other motor is running say 3430mA which is
> > > > 7* tollerance according to the nx-1000 specs.
> > > >
> > > > Is it the lack of resistance the new motor has that
> > > > makes the IC get too hot and should I try adding
> > > > resistors to correct for this?
> > > >
> > > > I know the IC is still good because I keep switching
> > > > back to the "known good" motor and it still works. On
> > > > the IC I did fry whichever pin is connected to output
> > > > 1 on the 7-CH stepper motor driver, but I just moved
> > > > up to 4,5,6,7.
> > > >
> > > > At any rate, following is the code i'm running and
> > > > several different wiring configs i have tried, all
> > > > of which behave about the same. Also this is a
> > > > bench test with no load whatsoever on the motor.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirA = %1111
> > > > speed = 20
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > pause speed
> > > > coils = %1001
> > > > pause speed
> > > > next
> > > > 'go ahead and end so as not to
> > > > 'keep trying and hurt something
> > > >
> > > > end
> > > >
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p2--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p3--5--brown
> > > > p2--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p2--6--yellow
> > > > p1--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > >
Original Message
> > > > From: "Dave Mucha" <davemucha@j...>
> > > > To: <basicstamps@y...>
> > > > Sent: Thursday, November 28, 2002 10:40 AM
> > > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > > <snip>
> > > > >
> > > > > The cogging you describe is either that the motor is way under
> > > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> > > be at
> > > > > least 5 times the motor nameplate voltage.
> > > > >
> > > > > or, the load it too great to allow it to start
> > > > >
> > > > > or, the ramp up speed it too great
> > > > >
> > > > > or, the motor it not wired correctly.
> > > > >
> > > > >
> > > > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> > > bench
> > > > > test is pretty easy.
> > > > >
> > > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > > have 2
> > > > > sets of windings and each set can be tested with an ohm meter.
> > > The
> > > > > center tap of each circuit will be half the max for that
> > > circuit. If
> > > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> > > and
> > > > > 3 should be 5 ohms. 3 then is the center tap.
> > > > >
> > > > > Do the same for 4,5 and 6. the board connection diagram
> should
> > > list
> > > > > where the center taps go (power) and where the legs go. All
> you
> > > need
> > > > > to do is to switch one pair of windings.
> > > > >
> > > > > example : if 1 and 2 are legs and 3 is center/power
> > > > > and 4 and 5 are legs and 6 is center/power
> > > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > > >
> > > > > For hobby purposes, you should be able to make low torque
> things
> > > move
> > > > > with running the motor at the nameplate voltages. One good
> test
> > > is
> > > > > to see if you can spin the thing by hand. ie: wheels spin
> freely.
> > > > > and you can get about as much torque as it takes to stop the
> > > motor by
> > > > > hand. the cogging will not damage anything, but it is
> annoying to
> > > > > listen to.
> > > > >
> > > > > hope this helps.
> > > > >
> > > > > one additional piece of data, most motor manufacturers put the
> > > > > voltage on the namplate that is used to calculate voltages.
> some,
> > > > > like Pacific Scientific list the proper running voltage. your
> > > higher
> > > > > voltage motors may be such units.
> > > > >
> > > > > You can run motors from 5 to 25 times the nameplate voltage,
> but
> > > are
> > > > > limited to nameplate amps. You really don't get the power
> from a
> > > > > stepper until you jack up the voltage. and when/if you
> looking
> > > doing
> > > > > any real power applications, look into bi-polar wiring of your
> > > motors
> > > > > and get away from using a resitor in the power line. the high
> > > > > voltages would need huge resistors and need to dump lots of
> heat.
> > > > >
> > > > > Dave
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > I am able to hook it up similarly to the motor that came
> with
> > > > > stampworks, but on the breadboard and run the following
> code. The
> > > > > motor does not rotate but I can feel it pulsing as if it would
> > > rotate
> > > > > if only i had the sequence correct.
> > > > > >
> > > > > > Any help would be appreciated. Also, if i'm a fool for even
> > > trying
> > > > > this please say so.
> > > > > >
> > > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > > I also tried using outL and adjusting DirL and Coils
> > > accordingly to
> > > > > try to use that 5th wire and got
> > > > > > the same result - a pulsing motor with no rotation.
> > > > > >
> > > > > > '{$STAMP BS2}
> > > > > > Coils VAR OutA 'output to stepper coils
> > > > > >
> > > > > > speed var word
> > > > > > times var word
> > > > > >
> > > > > > dirL = %1111
> > > > > > speed = 10
> > > > > >
> > > > > > main:
> > > > > >
> > > > > > for times = 1 to 25
> > > > > > coils = %1001
> > > > > > pause speed
> > > > > > coils = %1100
> > > > > > pause speed
> > > > > > coils = %0110
> > > > > > pause speed
> > > > > > coils = %0011
> > > > > > next
> > > > > > pause 200
> > > > > > goto main
> > > > > >
> > > > > >
> > > > > >
> > > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > > >
> > > > >
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>
I think I am just expirementing with the idea of
making a robot in the future.
I'm really a computer programmer dealing with PC's
and IBM Mainframe.
Where I work we store a lot of our data on tapes.
That might sound archaic but it is still the most
affordable long term storage as far as i know.
Well we used to have a crew of "tape mounters"
working in the data center 24/7. One day a truck
pulled up and they unloaded the 'robots'. These
were basically big long black library cases that
housed the tapes and there were two robots inside
each case that would fetch and mount the tapes.
One day i put my nose up to the glass and watched
the robots for about 15 min. and ever since then
I just want to know more about how to interface
computers with anything robotic or electronic.
Well that is really just as easy as learning the
commands the robot expects - that is no fun - it
is the same as sending print commands to a printer.
So I guess my overall goal is to learn the basic
pieces of robotics and then 'use them on my own.'
Stampworks makes this very attainable; however, I
am always left with more curiousity. Sure I can
follow the directions and make their stepper motor
run fast, slow, forward and backwards, but i'm
the type that has to really build my confidence up
by trying 3 or more different stepper motors until
i'm pretty sure I could use about any stepper motor.
I do like the idea of using a steper motor to
drive a robot because I imagine i could count the
revs in a variable and always 'get back home' with
some math - assuming the bot did not coggle. Besides
they are way quieter than servos which really get
on my nerves.
Again - thanks for all your help.
mkl
Original Message
From: Dave Mucha <davemucha@j...>
Date: Friday, November 29, 2002 11:49 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp
> directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good
> for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are
> just
> looking for a motor, the voltage/pot style is fine. If you need
> to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design
> around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
>
>
>
>
>
>
>
> --- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> > Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> > that can be used with a stamp/pic/????
> > I have found one it looks good also good price but the
> documentation really
> > is poor.
> > www.futurlec.com look under stepper motors.
> > at $17.00 the price is hard to beat.
> > maybe someone on the list has used one of these and can comment
> on
> it maybe
> > some example code???
> > regards
> > victor
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Friday, November 29, 2002 8:26 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > >
> > > You must limit the power.
> > >
> > > I had made a mistake in an earlier post.
> > >
> > > Power output increases proportionally with supply voltage.
> Losses
> in
> > > the motor increase with the square of the voltage. At some
> point
> the
> > > motor just gets too hot.
> > >
> > > I think I wrote that speed increases as the square of voltage.
> > >
> > > Motor speed is dependant on how fast you can charge and
> discharge
> the
> > > coils. at some point, you cannot make the unit move any faster.
> > > Typically on PC based stepper controlles, 10kH is the best you do.
> > > Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> > > per rev motor. Smaller motors can spin faster than large ones.
> > >
> > > The point about loss of power at high speed is correct, but it
> goes
> > > to constant power. Output power is independant of speed.
> > > since the stepper will deliver constant power, you only get so
> much
> > > umph per minute regardless of speed. double the speed, and
> you
> halve
> > > the torque. At low speed that means X amount of torque at low
> > > rpm's. say you are delivering 25 oz/in at the shaft. at 1
> rpm
> you
> > > could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> > > so the motor is very weak.
> > >
> > > Stepper MOTORS are designed to run HOT, put you hand and pull
> it
> away
> > > hot. not sizzling. electronics are designed to run cool. it
> > > shouldn't be the other way around.
> > >
> > > and don't forget to calculate power consumption and watts.
> You
> may
> > > be surprised to find that you are running one of these puppies
> at
> 30
> > > watts or more. even the limiting resistor my be sized for 30-50
> > > watts. at that point, look into chopper drives and H-Bridges
> and
> get
> > > away from the uni-polar style.
> > >
> > > Dave
> > >
> > >
> > >
> > > --- In basicstamps@y..., "Earl Bollinger"
> <earlwbollinger@a...>
> wrote:
> > > > Why it overheats?
> > > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > > designed to
> > > > handle about 500ma tops.
> > > > 12v at 3.5 ohms would be about 3.4 amps.
> > > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > > which is
> > > > less than the max for the ULN2003, so it would work OK.
> > > >
> > > > Normally you limit the max current that the stepper motor can
> > > handle,
> > > > otherwise it overheats and you risk burning out a coil.
> > > >
> > > > Small steppers can be driven with the ULN2003 but not the more
> > > powerful
> > > > ones.
> > > > You'll need more poewerful power transistors to handle the
> heavier
> > > stepper
> > > > motor.
> > > >
> > > > I think that maybe your speed value is set too fast.
> > > > The ULN2003 is getting overloaded and your power supply may
> be
> too
> > > weak for
> > > > the big stepper.
> > > > Thus you tend to get twitching.
> > > > Steppers typically run at less than 100 rpm. You can get some
> > > steppers to
> > > > run faster, but you have to carefully ramp up the speed from
> slow
> > > to fast.
> > > > But a fast running stepper has little or no torque at high rpms.
> > > > I'd probably start at 1/2 second steps and see what happens,
> having
> > > it turn
> > > > slow is easier to watch.
> > > >
> > > >
> > > >
> > > >
Original Message
> > > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > > Sent: Thursday, November 28, 2002 8:28 PM
> > > > To: basicstamps@y...
> > > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > Dave,
> > > >
> > > > I have taken your suggestions and found out
> > > > a good bit about the motor but still cannot make
> > > > it rotate.
> > > >
> > > > I have also read many of the websites people have suggested
> > > > and I do have a pretty good idea of the theory of how
> > > > these stepper motors work. What i really do not know is
> > > > how to tell if a certain driver (the one on the nx-1000)
> will
> drive
> > > > an arbitrary stepper motor I come up with. I think this might
> > > > boil down to a basic electronics question but i'm not certain.
> > > >
> > > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > > >
> > > > I am connecting it to the 12V ouputs on the NX-1000.
> > > >
> > > > I have deduced the following from your suggested
> > > > ohm readings:
> > > >
> > > > blue leg
> > > > yellow leg
> > > > black common
> > > >
> > > > brown leg
> > > > red leg
> > > > white common
> > > >
> > > > I have no idea which is leg A and which is leg B.
> > > >
> > > > Firstly, I am curious to know why when I try to run
> > > > this motor does it overheat the 2003AN IC? I would
> > > > think that if i'm pumping 12V into a 3V motor it would
> > > > overheat the motor if anything. Also, the "known
> > > > good motor (the one that came with stampworks)" reads
> > > > at like 75+ ohms.
> > > >
> > > > This means the stampworks motor is running about 160mA
> > > > where this other motor is running say 3430mA which is
> > > > 7* tollerance according to the nx-1000 specs.
> > > >
> > > > Is it the lack of resistance the new motor has that
> > > > makes the IC get too hot and should I try adding
> > > > resistors to correct for this?
> > > >
> > > > I know the IC is still good because I keep switching
> > > > back to the "known good" motor and it still works. On
> > > > the IC I did fry whichever pin is connected to output
> > > > 1 on the 7-CH stepper motor driver, but I just moved
> > > > up to 4,5,6,7.
> > > >
> > > > At any rate, following is the code i'm running and
> > > > several different wiring configs i have tried, all
> > > > of which behave about the same. Also this is a
> > > > bench test with no load whatsoever on the motor.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirA = %1111
> > > > speed = 20
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > pause speed
> > > > coils = %1001
> > > > pause speed
> > > > next
> > > > 'go ahead and end so as not to
> > > > 'keep trying and hurt something
> > > >
> > > > end
> > > >
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p2--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p3--5--brown
> > > > p2--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p2--6--yellow
> > > > p1--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > >
Original Message
> > > > From: "Dave Mucha" <davemucha@j...>
> > > > To: <basicstamps@y...>
> > > > Sent: Thursday, November 28, 2002 10:40 AM
> > > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > > <snip>
> > > > >
> > > > > The cogging you describe is either that the motor is way under
> > > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> > > be at
> > > > > least 5 times the motor nameplate voltage.
> > > > >
> > > > > or, the load it too great to allow it to start
> > > > >
> > > > > or, the ramp up speed it too great
> > > > >
> > > > > or, the motor it not wired correctly.
> > > > >
> > > > >
> > > > > since a 3.5 volt motor will turn with 3.5 volts and no
> load, a
> > > bench
> > > > > test is pretty easy.
> > > > >
> > > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > > have 2
> > > > > sets of windings and each set can be tested with an ohm meter.
> > > The
> > > > > center tap of each circuit will be half the max for that
> > > circuit. If
> > > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> > > and
> > > > > 3 should be 5 ohms. 3 then is the center tap.
> > > > >
> > > > > Do the same for 4,5 and 6. the board connection diagram
> should
> > > list
> > > > > where the center taps go (power) and where the legs go.
> All
> you
> > > need
> > > > > to do is to switch one pair of windings.
> > > > >
> > > > > example : if 1 and 2 are legs and 3 is center/power
> > > > > and 4 and 5 are legs and 6 is center/power
> > > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > > >
> > > > > For hobby purposes, you should be able to make low torque
> things
> > > move
> > > > > with running the motor at the nameplate voltages. One
> good
> test
> > > is
> > > > > to see if you can spin the thing by hand. ie: wheels spin
> freely.
> > > > > and you can get about as much torque as it takes to stop the
> > > motor by
> > > > > hand. the cogging will not damage anything, but it is
> annoying to
> > > > > listen to.
> > > > >
> > > > > hope this helps.
> > > > >
> > > > > one additional piece of data, most motor manufacturers put the
> > > > > voltage on the namplate that is used to calculate
> voltages.
> some,
> > > > > like Pacific Scientific list the proper running voltage. your
> > > higher
> > > > > voltage motors may be such units.
> > > > >
> > > > > You can run motors from 5 to 25 times the nameplate
> voltage,
> but
> > > are
> > > > > limited to nameplate amps. You really don't get the power
> from a
> > > > > stepper until you jack up the voltage. and when/if you
> looking
> > > doing
> > > > > any real power applications, look into bi-polar wiring of your
> > > motors
> > > > > and get away from using a resitor in the power line. the high
> > > > > voltages would need huge resistors and need to dump lots
> of
> heat.
> > > > >
> > > > > Dave
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > I am able to hook it up similarly to the motor that came
> with
> > > > > stampworks, but on the breadboard and run the following
> code. The
> > > > > motor does not rotate but I can feel it pulsing as if it would
> > > rotate
> > > > > if only i had the sequence correct.
> > > > > >
> > > > > > Any help would be appreciated. Also, if i'm a fool for even
> > > trying
> > > > > this please say so.
> > > > > >
> > > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > > I also tried using outL and adjusting DirL and Coils
> > > accordingly to
> > > > > try to use that 5th wire and got
> > > > > > the same result - a pulsing motor with no rotation.
> > > > > >
> > > > > > '{$STAMP BS2}
> > > > > > Coils VAR OutA 'output to stepper coils
> > > > > >
> > > > > > speed var word
> > > > > > times var word
> > > > > >
> > > > > > dirL = %1111
> > > > > > speed = 10
> > > > > >
> > > > > > main:
> > > > > >
> > > > > > for times = 1 to 25
> > > > > > coils = %1001
> > > > > > pause speed
> > > > > > coils = %1100
> > > > > > pause speed
> > > > > > coils = %0110
> > > > > > pause speed
> > > > > > coils = %0011
> > > > > > next
> > > > > > pause 200
> > > > > > goto main
> > > > > >
> > > > > >
> > > > > >
> > > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > > >
> > > > >
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the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
> I correct in my assumption that since the resistance across the coils cannot
> change, the amperage will increase along with the chosen chopper voltage? Do
> I need to upgrade my transistors to handle this increase in amperage or do I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
> I correct in my assumption that since the resistance across the coils cannot
> change, the amperage will increase along with the chosen chopper voltage? Do
> I need to upgrade my transistors to handle this increase in amperage or do I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
At 01:34 PM 11/29/2002 -0500, you wrote:
>Yes trying an xy table.
>I know there are quite a few drives for a pc but I"m trying to do it with a
>micro controller.
>regards
>victor
Me too .. but .. a 'translator' chip like the L297 can sure make life easier
by eliminating the repetitive task of telling the motor coils which
sequence to
step in. All it needs is an enable flag, a direction flag, and a pulse stream
from the PIC (which, remember, isn't especially great at generating accurate
timing info if it's using a ceramic resonator).
The logic in the L297 eliminates worry about missed sequence info (the motor
likes that a LOT) . missing pulses/motor steps is another kettle o' fish,
tho. [noparse]:)[/noparse]
the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle?
Am
> I correct in my assumption that since the resistance across the coils
cannot
> change, the amperage will increase along with the chosen chopper voltage?
Do
> I need to upgrade my transistors to handle this increase in amperage or do
I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
> <snip>
To UNSUBSCRIBE, just send mail to: basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
with a current limited power source, you use the resistor, when using
a chopper style, you monitor the current an with a pwm style output,
cut the power when you reached your amps.
what you are doing is trying to inject as much power as fast as you
can. the R/C time will be such that the cap will charge at a rate of
I/uF volts per second.
With a chopper drive, you have zero resistance so your time is zero
as well.
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Thanks for your reply Dave.
> So what you are saying is...I will need current limiting resistors
even
> with the chopper drive?
>
> Jeff
>
>
Original Message
> From: Dave Mucha [noparse][[/noparse]mailto:davemucha@j...]
> Sent: Friday, November 29, 2002 3:32 PM
> To: basicstamps@y...
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> Hi Jeff,
>
> the stepper motor can only handle the 'nameplate' amps. since your
> motor is listed with part of the numbers, you calculated the amps
for
> the basic unit. if you power at 1 volt or 60 volts, the amps (4
amps
> per your example) is the max amps regardless of voltage you use to
> drive the motor.
>
> Verify the resistance to prove the calculation. Seems like a lare
> stepper. NEMA34 (3.4" dia or 3.4 square)
>
> Dave
>
>
>
> --- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> > Quote "even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
get
> > away from the uni-polar style."
> >
> > This brings up a confusing point for me about chopper driving a
stepper.
> > If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10%
duty cycle?
> Am
> > I correct in my assumption that since the resistance across the
coils
> cannot
> > change, the amperage will increase along with the chosen chopper
voltage?
> Do
> > I need to upgrade my transistors to handle this increase in
amperage or do
> I
> > size my transistors by multiplying the calculated amperage by the
duty
> > cycle?
> >
> > For example:
> >
> > Stepper Specs- 3.25v, 13watt stepper.
> >
> > 4 amps = calculated amperage at this voltage.
> > .8125 Ohms = Calculated resistance across coil
> >
> > If I plug the extrapolated resistance figure into ohms law, my
amperage
> > requirement at 24 volts will be 29 amps. Is this correct?
> >
> > Jeff
>
>
> > <snip>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@y...
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
hope you don't mind too much if I take the lazy approach, but this
was covered in the last few weeks.
search the group for stepper and you'll find lots of data.
Dave
--- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> does anyone know how to controll stepper motors with the BS2. any
> info. will be helpfull.
>
> Eric
This may come off looking like a mess - i dunno. At any rate there are
some explanations, a little code, and some web links in here.
Eric, here is pretty much everything that was said about steppers
last week:
Quote "even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style."
This brings up a confusing point for me about chopper driving a
stepper.
If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty
cycle? Am
I correct in my assumption that since the resistance across the coils
cannot
change, the amperage will increase along with the chosen chopper
voltage? Do
I need to upgrade my transistors to handle this increase in amperage or
do I
size my transistors by multiplying the calculated amperage by the duty
cycle?
For example:
Stepper Specs- 3.25v, 13watt stepper.
4 amps = calculated amperage at this voltage.
.8125 Ohms = Calculated resistance across coil
If I plug the extrapolated resistance figure into ohms law, my amperage
requirement at 24 volts will be 29 amps. Is this correct?
Driving a Darlington like a TP120 will carry the current for low
power steppers. under 1.5 A. you can drive it from a Stamp directly
for step control. 4 units would allow you to as a chopper.
Allegro makes a surface mount H-Bridge chip the A3977 also good for
up to 35 volts and 1.5 amps.
You might want to check out Allegro UNC5804 too.
Generally speaking you can make a full H-Bridge circuit to drive a
stepper, or use a pre-packaged chip. These take 2 pins, one for
pulse and one for direction.
There are also some circuits that allow you to vari the voltage or
use a pot to change speed. If you are driving a robot and are just
looking for a motor, the voltage/pot style is fine. If you need to
know where the shaft is then you need to count pulses.
There are quite a few drives, kits, chips and circuits floating
around. Figure out what your maximum motor size is and design around
that that.
btw, are you experimenting ? making a robot? or getting started in
CNC ?
I hooked the commons up to 5v on the breadboard
and left the legs hooked to the 2803. It spins!
I really appreciate your help on this.
The motor spun good with the 5v. However,
the heatsink on the NX-1000 started to get
warm similarly to the 2803.
I got the motor to go around and that was my
goal - i think I will not hook it up to my
nx-1000 board again though.
I am learning a good bit about stepper
motors and measuring volts/ohms/amps
although it is still hazy to me how to
think ahead accurately.
I think with this motor in general, I am not
driving it with enough amps so it is drawing
too hard on my power source. I am guessing
if i found a power supply rated at ~3.5 amps
it would run fine.
I am wondering - the 2803 pulses the legs at
less than 1v. Why do you need an IC to do this?
Could you not just throw a resistor in line
with a stamp pin to knock the volts down some
and just pulse the legs from a stamp pin?
Also, in general, do you usually purchase a
stepper motor and driver together as a package
thus avioding all of the current matching
problems i am having or should one be good enough
to take just any stepper motor and basically
make their own driver?
Dave,do you have any info/links to good cheap bipolar drive and
motors???
that can be used with a stamp/pic/????
I have found one it looks good also good price but the documentation
really
is poor.
www.futurlec.com look under stepper motors.
at $17.00 the price is hard to beat.
maybe someone on the list has used one of these and can comment on it
maybe
some example code???
regards
victor
Power output increases proportionally with supply voltage. Losses in
the motor increase with the square of the voltage. At some point the
motor just gets too hot.
I think I wrote that speed increases as the square of voltage.
Motor speed is dependant on how fast you can charge and discharge the
coils. at some point, you cannot make the unit move any faster.
Typically on PC based stepper controlles, 10kH is the best you do.
Mostly because the PC timings. that's 10kH pulses, into a 200 step
per rev motor. Smaller motors can spin faster than large ones.
The point about loss of power at high speed is correct, but it goes
to constant power. Output power is independant of speed.
since the stepper will deliver constant power, you only get so much
umph per minute regardless of speed. double the speed, and you halve
the torque. At low speed that means X amount of torque at low
rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
could say you have 25/1. At high speed, say 50 RPM, you have 25/50
so the motor is very weak.
Stepper MOTORS are designed to run HOT, put you hand and pull it away
hot. not sizzling. electronics are designed to run cool. it
shouldn't be the other way around.
and don't forget to calculate power consumption and watts. You may
be surprised to find that you are running one of these puppies at 30
watts or more. even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style.
Why it overheats?
5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only designed
to
handle about 500ma tops.
12v at 3.5 ohms would be about 3.4 amps.
The 75ohm stepper that came with the NS1000 would be about 66ma, which
is
less than the max for the ULN2003, so it would work OK.
Normally you limit the max current that the stepper motor can handle,
otherwise it overheats and you risk burning out a coil.
Small steppers can be driven with the ULN2003 but not the more powerful
ones.
You'll need more poewerful power transistors to handle the heavier
stepper
motor.
I think that maybe your speed value is set too fast.
The ULN2003 is getting overloaded and your power supply may be too weak
for
the big stepper.
Thus you tend to get twitching.
Steppers typically run at less than 100 rpm. You can get some steppers
to
run faster, but you have to carefully ramp up the speed from slow to
fast.
But a fast running stepper has little or no torque at high rpms.
I'd probably start at 1/2 second steps and see what happens, having it
turn
slow is easier to watch.
first is that you must do the ohm's law calc on motor amps and supply
voltage to determine what size resistor to use. both watts as well as
resistsnce.
Second, you are pumping current into an inductive load.
Theroretically, zero speed will yield zero resistance and infinate
amps. when the motor is not spinning, you basically have a dead
short. once you start spinning the motor your volts/amps/resistance
falls in line.
Working with 5 volts is fine to test, and you should get the motor to
spin easily at 5 volts. higher voltages is needed to increase power
of the stepper. power increases as the square of the voltage, so you
can see that low voltage will offer low power.
Regarding leads into the motor, since you know the power lines, the
rest is simple. A resistor on the power supply to limit the total
amps as you determined from calculating the known desired current and
known supply voltage and subrtracting the motor resistance from the
calculated total loop resistance.
if leads
blue = 1
yellow = 2
black (common) = 3
brown = 1a
red = 2a
white (common) = 3a
if the power supply is working properly and you have limited the
current to the stepper and the motor is still cogging (not spinning
but making a grinding noise) then swaping 1a and 2a would allow the
motor to spin. you have not figured out direction. it may be that
the motor is spinning in reverse. if that is the case, swap 1 and 2
and 1a and 2a.
I'm thinking that you are offering unlimited power to the motor, the
motor is shorting out the power and your darlintons are over heating
as a result.
I have taken your suggestions and found out
a good bit about the motor but still cannot make
it rotate.
I have also read many of the websites people have suggested
and I do have a pretty good idea of the theory of how
these stepper motors work. What i really do not know is
how to tell if a certain driver (the one on the nx-1000) will drive
an arbitrary stepper motor I come up with. I think this might
boil down to a basic electronics question but i'm not certain.
I stand corrected - it is 3v, 3.5ohm, 1.8step.
I am connecting it to the 12V ouputs on the NX-1000.
I have deduced the following from your suggested
ohm readings:
blue leg
yellow leg
black common
brown leg
red leg
white common
I have no idea which is leg A and which is leg B.
Firstly, I am curious to know why when I try to run
this motor does it overheat the 2003AN IC? I would
think that if i'm pumping 12V into a 3V motor it would
overheat the motor if anything. Also, the "known
good motor (the one that came with stampworks)" reads
at like 75+ ohms.
This means the stampworks motor is running about 160mA
where this other motor is running say 3430mA which is
7* tollerance according to the nx-1000 specs.
Is it the lack of resistance the new motor has that
makes the IC get too hot and should I try adding
resistors to correct for this?
I know the IC is still good because I keep switching
back to the "known good" motor and it still works. On
the IC I did fry whichever pin is connected to output
1 on the 7-CH stepper motor driver, but I just moved
up to 4,5,6,7.
At any rate, following is the code i'm running and
several different wiring configs i have tried, all
of which behave about the same. Also this is a
bench test with no load whatsoever on the motor.
'{$STAMP BS2}
Coils VAR OutA 'output to stepper coils
speed var word
times var word
dirA = %1111
speed = 20
main:
for times = 1 to 25
coils = %1100
pause speed
coils = %0110
pause speed
coils = %0011
pause speed
coils = %1001
pause speed
next
'go ahead and end so as not to
'keep trying and hurt something
end
twitches and 2003AN IC gets hot
p0--7--blue
p1--6--yellow
p2--5--brown
p3--4--red
3
2
1
V--black-white
twitches and 2003AN IC gets hot
p0--7--blue
p1--6--yellow
p3--5--brown
p2--4--red
3
2
1
V--black-white
twitches and 2003AN IC gets hot
p0--7--blue
p2--6--yellow
p1--5--brown
p3--4--red
3
2
1
V--black-white
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, November 28, 2002 10:40 AM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> <snip>
>
> The cogging you describe is either that the motor is way under
> powered, ie: feeding a 3.5 volt motor only 5 volts. It should be at
> least 5 times the motor nameplate voltage.
>
> or, the load it too great to allow it to start
>
> or, the ramp up speed it too great
>
> or, the motor it not wired correctly.
>
>
> since a 3.5 volt motor will turn with 3.5 volts and no load, a bench
> test is pretty easy.
>
> Since you stated 6 wires, you have a uni-polar stepper. these have 2
> sets of windings and each set can be tested with an ohm meter. The
> center tap of each circuit will be half the max for that circuit. If
> you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2 and
> 3 should be 5 ohms. 3 then is the center tap.
>
> Do the same for 4,5 and 6. the board connection diagram should list
> where the center taps go (power) and where the legs go. All you need
> to do is to switch one pair of windings.
>
> example : if 1 and 2 are legs and 3 is center/power
> and 4 and 5 are legs and 6 is center/power
> all you need to do is swap 4 and 5 to 5 and 4.
>
> For hobby purposes, you should be able to make low torque things move
> with running the motor at the nameplate voltages. One good test is
> to see if you can spin the thing by hand. ie: wheels spin freely.
> and you can get about as much torque as it takes to stop the motor by
> hand. the cogging will not damage anything, but it is annoying to
> listen to.
>
> hope this helps.
>
> one additional piece of data, most motor manufacturers put the
> voltage on the namplate that is used to calculate voltages. some,
> like Pacific Scientific list the proper running voltage. your higher
> voltage motors may be such units.
>
> You can run motors from 5 to 25 times the nameplate voltage, but are
> limited to nameplate amps. You really don't get the power from a
> stepper until you jack up the voltage. and when/if you looking doing
> any real power applications, look into bi-polar wiring of your motors
> and get away from using a resitor in the power line. the high
> voltages would need huge resistors and need to dump lots of heat.
>
> Dave
>
>
> > I am able to hook it up similarly to the motor that came with
> stampworks, but on the breadboard and run the following code. The
> motor does not rotate but I can feel it pulsing as if it would rotate
> if only i had the sequence correct.
> >
> > Any help would be appreciated. Also, if i'm a fool for even trying
> this please say so.
> >
> > I have the wires hooked to pins 0 - 5 on the stamp.
> > I also tried using outL and adjusting DirL and Coils accordingly to
> try to use that 5th wire and got
> > the same result - a pulsing motor with no rotation.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirL = %1111
> > speed = 10
> >
> > main:
> >
> > for times = 1 to 25
> > coils = %1001
> > pause speed
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > next
> > pause 200
> > goto main
> >
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
To UNSUBSCRIBE, just send mail to: basicstamps-unsubscribe@yahoogroups.com
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Original Message
From: Dave Mucha <davemucha@j...>
Date: Thursday, December 5, 2002 9:28 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Hi Eric,
>
> hope you don't mind too much if I take the lazy approach, but this
> was covered in the last few weeks.
>
> search the group for stepper and you'll find lots of data.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> > does anyone know how to controll stepper motors with the BS2.
> any
> > info. will be helpfull.
> >
> > Eric
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
Search the Parallax site for data sheets on how to get started. Most
of what we did last week was pretty indepth and for someone who is
pretty well versed on the software side and experianced with the
electronics, not too easy for a beginner.
Dave
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> I saved most of those off to the side.
>
> This may come off looking like a mess - i dunno. At any rate there
are
> some explanations, a little code, and some web links in here.
>
> Eric, here is pretty much everything that was said about steppers
> last week:
>
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a
> stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty
> cycle? Am
> I correct in my assumption that since the resistance across the
coils
> cannot
> change, the amperage will increase along with the chosen chopper
> voltage? Do
> I need to upgrade my transistors to handle this increase in
amperage or
> do I
> size my transistors by multiplying the calculated amperage by the
duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my
amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
>
> ***********************************************************
> ***********************************************************
>
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp
directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are just
> looking for a motor, the voltage/pot style is fine. If you need to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design
around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
> ************************************************************
> ************************************************************
>
> I hooked the commons up to 5v on the breadboard
> and left the legs hooked to the 2803. It spins!
>
> I really appreciate your help on this.
>
> The motor spun good with the 5v. However,
> the heatsink on the NX-1000 started to get
> warm similarly to the 2803.
>
> I got the motor to go around and that was my
> goal - i think I will not hook it up to my
> nx-1000 board again though.
>
> I am learning a good bit about stepper
> motors and measuring volts/ohms/amps
> although it is still hazy to me how to
> think ahead accurately.
>
> I think with this motor in general, I am not
> driving it with enough amps so it is drawing
> too hard on my power source. I am guessing
> if i found a power supply rated at ~3.5 amps
> it would run fine.
>
> I am wondering - the 2803 pulses the legs at
> less than 1v. Why do you need an IC to do this?
> Could you not just throw a resistor in line
> with a stamp pin to knock the volts down some
> and just pulse the legs from a stamp pin?
>
> Also, in general, do you usually purchase a
> stepper motor and driver together as a package
> thus avioding all of the current matching
> problems i am having or should one be good enough
> to take just any stepper motor and basically
> make their own driver?
>
> mkl
>
> *************************************************************
> *************************************************************
>
> Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> that can be used with a stamp/pic/????
> I have found one it looks good also good price but the
documentation
> really
> is poor.
> www.futurlec.com look under stepper motors.
> at $17.00 the price is hard to beat.
> maybe someone on the list has used one of these and can comment on
it
> maybe
> some example code???
> regards
> victor
>
>
**********************************************************************
>
**********************************************************************
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses in
> the motor increase with the square of the voltage. At some point the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge
the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
> Mostly because the PC timings. that's 10kH pulses, into a 200 step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so much
> umph per minute regardless of speed. double the speed, and you
halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
> could say you have 25/1. At high speed, say 50 RPM, you have 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it
away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You may
> be surprised to find that you are running one of these puppies at 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
get
> away from the uni-polar style.
>
> Dave
>
>
>
>
>
**********************************************************************
>
**********************************************************************
>
>
> Why it overheats?
> 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
designed
> to
> handle about 500ma tops.
> 12v at 3.5 ohms would be about 3.4 amps.
> The 75ohm stepper that came with the NS1000 would be about 66ma,
which
> is
> less than the max for the ULN2003, so it would work OK.
>
> Normally you limit the max current that the stepper motor can
handle,
> otherwise it overheats and you risk burning out a coil.
>
> Small steppers can be driven with the ULN2003 but not the more
powerful
> ones.
> You'll need more poewerful power transistors to handle the heavier
> stepper
> motor.
>
> I think that maybe your speed value is set too fast.
> The ULN2003 is getting overloaded and your power supply may be too
weak
> for
> the big stepper.
> Thus you tend to get twitching.
> Steppers typically run at less than 100 rpm. You can get some
steppers
> to
> run faster, but you have to carefully ramp up the speed from slow
to
> fast.
> But a fast running stepper has little or no torque at high rpms.
> I'd probably start at 1/2 second steps and see what happens, having
it
> turn
> slow is easier to watch.
>
> *************************************************************
> *************************************************************
>
>
**********************************************************************
>
**********************************************************************
>
> Interesting results.
>
> first is that you must do the ohm's law calc on motor amps and
supply
> voltage to determine what size resistor to use. both watts as well
as
> resistsnce.
>
> Second, you are pumping current into an inductive load.
> Theroretically, zero speed will yield zero resistance and infinate
> amps. when the motor is not spinning, you basically have a dead
> short. once you start spinning the motor your volts/amps/resistance
> falls in line.
>
> Working with 5 volts is fine to test, and you should get the motor
to
> spin easily at 5 volts. higher voltages is needed to increase power
> of the stepper. power increases as the square of the voltage, so
you
> can see that low voltage will offer low power.
>
> Regarding leads into the motor, since you know the power lines, the
> rest is simple. A resistor on the power supply to limit the total
> amps as you determined from calculating the known desired current
and
> known supply voltage and subrtracting the motor resistance from the
> calculated total loop resistance.
>
> if leads
> blue = 1
> yellow = 2
> black (common) = 3
> brown = 1a
> red = 2a
> white (common) = 3a
>
> if the power supply is working properly and you have limited the
> current to the stepper and the motor is still cogging (not spinning
> but making a grinding noise) then swaping 1a and 2a would allow the
> motor to spin. you have not figured out direction. it may be that
> the motor is spinning in reverse. if that is the case, swap 1 and 2
> and 1a and 2a.
>
> I'm thinking that you are offering unlimited power to the motor, the
> motor is shorting out the power and your darlintons are over heating
> as a result.
>
> Hope this made some sense.
>
> Dave
>
> ************************************************************
> ************************************************************
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
>
>
> --- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will
drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms,
2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram should
> list
> > > where the center taps go (power) and where the legs go. All you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque things
> move
> > > with running the motor at the nameplate voltages. One good test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is annoying
to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages.
some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage, but
> are
> > > limited to nameplate amps. You really don't get the power from
a
> > > stepper until you jack up the voltage. and when/if you looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of
heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code.
The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@y...
> from the same email address that you subscribed. Text in the
Subject
> and Body
> of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
>
>
>
>
Original Message
> From: Dave Mucha <davemucha@j...>
> Date: Thursday, December 5, 2002 9:28 am
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> > Hi Eric,
> >
> > hope you don't mind too much if I take the lazy approach, but
this
> > was covered in the last few weeks.
> >
> > search the group for stepper and you'll find lots of data.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> > > does anyone know how to controll stepper motors with the BS2.
> > any
> > > info. will be helpfull.
> > >
> > > Eric
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
Comments
that can be used with a stamp/pic/????
I have found one it looks good also good price but the documentation really
is poor.
www.futurlec.com look under stepper motors.
at $17.00 the price is hard to beat.
maybe someone on the list has used one of these and can comment on it maybe
some example code???
regards
victor
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, November 29, 2002 8:26 AM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses in
> the motor increase with the square of the voltage. At some point the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
> Mostly because the PC timings. that's 10kH pulses, into a 200 step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so much
> umph per minute regardless of speed. double the speed, and you halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
> could say you have 25/1. At high speed, say 50 RPM, you have 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You may
> be surprised to find that you are running one of these puppies at 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> > Why it overheats?
> > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> designed to
> > handle about 500ma tops.
> > 12v at 3.5 ohms would be about 3.4 amps.
> > The 75ohm stepper that came with the NS1000 would be about 66ma,
> which is
> > less than the max for the ULN2003, so it would work OK.
> >
> > Normally you limit the max current that the stepper motor can
> handle,
> > otherwise it overheats and you risk burning out a coil.
> >
> > Small steppers can be driven with the ULN2003 but not the more
> powerful
> > ones.
> > You'll need more poewerful power transistors to handle the heavier
> stepper
> > motor.
> >
> > I think that maybe your speed value is set too fast.
> > The ULN2003 is getting overloaded and your power supply may be too
> weak for
> > the big stepper.
> > Thus you tend to get twitching.
> > Steppers typically run at less than 100 rpm. You can get some
> steppers to
> > run faster, but you have to carefully ramp up the speed from slow
> to fast.
> > But a fast running stepper has little or no torque at high rpms.
> > I'd probably start at 1/2 second steps and see what happens, having
> it turn
> > slow is easier to watch.
> >
> >
> >
> >
Original Message
> > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > Sent: Thursday, November 28, 2002 8:28 PM
> > To: basicstamps@y...
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram should
> list
> > > where the center taps go (power) and where the legs go. All you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque things
> move
> > > with running the motor at the nameplate voltages. One good test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is annoying to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages. some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage, but
> are
> > > limited to nameplate amps. You really don't get the power from a
> > > stepper until you jack up the voltage. and when/if you looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code. The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
and left the legs hooked to the 2803. It spins!
I really appreciate your help on this.
The motor spun good with the 5v. However,
the heatsink on the NX-1000 started to get
warm similarly to the 2803.
I got the motor to go around and that was my
goal - i think I will not hook it up to my
nx-1000 board again though.
I am learning a good bit about stepper
motors and measuring volts/ohms/amps
although it is still hazy to me how to
think ahead accurately.
I think with this motor in general, I am not
driving it with enough amps so it is drawing
too hard on my power source. I am guessing
if i found a power supply rated at ~3.5 amps
it would run fine.
I am wondering - the 2803 pulses the legs at
less than 1v. Why do you need an IC to do this?
Could you not just throw a resistor in line
with a stamp pin to knock the volts down some
and just pulse the legs from a stamp pin?
Also, in general, do you usually purchase a
stepper motor and driver together as a package
thus avioding all of the current matching
problems i am having or should one be good enough
to take just any stepper motor and basically
make their own driver?
mkl
Original Message
From: Dave Mucha <davemucha@j...>
Date: Friday, November 29, 2002 7:26 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses
> in
> the motor increase with the square of the voltage. At some point
> the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge
> the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
>
> Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it
> goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so
> much
> umph per minute regardless of speed. double the speed, and you
> halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> you
> could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it
> away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You
> may
> be surprised to find that you are running one of these puppies at
> 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
> get
> away from the uni-polar style.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> > Why it overheats?
> > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> designed to
> > handle about 500ma tops.
> > 12v at 3.5 ohms would be about 3.4 amps.
> > The 75ohm stepper that came with the NS1000 would be about 66ma,
> which is
> > less than the max for the ULN2003, so it would work OK.
> >
> > Normally you limit the max current that the stepper motor can
> handle,
> > otherwise it overheats and you risk burning out a coil.
> >
> > Small steppers can be driven with the ULN2003 but not the more
> powerful
> > ones.
> > You'll need more poewerful power transistors to handle the
> heavier
> stepper
> > motor.
> >
> > I think that maybe your speed value is set too fast.
> > The ULN2003 is getting overloaded and your power supply may be
> too
> weak for
> > the big stepper.
> > Thus you tend to get twitching.
> > Steppers typically run at less than 100 rpm. You can get some
> steppers to
> > run faster, but you have to carefully ramp up the speed from
> slow
> to fast.
> > But a fast running stepper has little or no torque at high rpms.
> > I'd probably start at 1/2 second steps and see what happens,
> having
> it turn
> > slow is easier to watch.
> >
> >
> >
> >
Original Message
> > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > Sent: Thursday, November 28, 2002 8:28 PM
> > To: basicstamps@y...
> > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
>
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram
> should
> list
> > > where the center taps go (power) and where the legs go. All
> you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque
> things
> move
> > > with running the motor at the nameplate voltages. One good
> test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is
> annoying to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages. some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage,
> but
> are
> > > limited to nameplate amps. You really don't get the power
> from a
> > > stepper until you jack up the voltage. and when/if you
> looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code. The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
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> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> http://docs.yahoo.com/info/terms/
>
>
>
power steppers. under 1.5 A. you can drive it from a Stamp directly
for step control. 4 units would allow you to as a chopper.
Allegro makes a surface mount H-Bridge chip the A3977 also good for
up to 35 volts and 1.5 amps.
You might want to check out Allegro UNC5804 too.
Generally speaking you can make a full H-Bridge circuit to drive a
stepper, or use a pre-packaged chip. These take 2 pins, one for
pulse and one for direction.
There are also some circuits that allow you to vari the voltage or
use a pot to change speed. If you are driving a robot and are just
looking for a motor, the voltage/pot style is fine. If you need to
know where the shaft is then you need to count pulses.
There are quite a few drives, kits, chips and circuits floating
around. Figure out what your maximum motor size is and design around
that that.
btw, are you experimenting ? making a robot? or getting started in
CNC ?
Dave
--- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> Dave,do you have any info/links to good cheap bipolar drive and
motors???
> that can be used with a stamp/pic/????
> I have found one it looks good also good price but the
documentation really
> is poor.
> www.futurlec.com look under stepper motors.
> at $17.00 the price is hard to beat.
> maybe someone on the list has used one of these and can comment on
it maybe
> some example code???
> regards
> victor
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Friday, November 29, 2002 8:26 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> >
> > You must limit the power.
> >
> > I had made a mistake in an earlier post.
> >
> > Power output increases proportionally with supply voltage. Losses
in
> > the motor increase with the square of the voltage. At some point
the
> > motor just gets too hot.
> >
> > I think I wrote that speed increases as the square of voltage.
> >
> > Motor speed is dependant on how fast you can charge and discharge
the
> > coils. at some point, you cannot make the unit move any faster.
> > Typically on PC based stepper controlles, 10kH is the best you do.
> > Mostly because the PC timings. that's 10kH pulses, into a 200
step
> > per rev motor. Smaller motors can spin faster than large ones.
> >
> > The point about loss of power at high speed is correct, but it
goes
> > to constant power. Output power is independant of speed.
> > since the stepper will deliver constant power, you only get so
much
> > umph per minute regardless of speed. double the speed, and you
halve
> > the torque. At low speed that means X amount of torque at low
> > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
you
> > could say you have 25/1. At high speed, say 50 RPM, you have
25/50
> > so the motor is very weak.
> >
> > Stepper MOTORS are designed to run HOT, put you hand and pull it
away
> > hot. not sizzling. electronics are designed to run cool. it
> > shouldn't be the other way around.
> >
> > and don't forget to calculate power consumption and watts. You
may
> > be surprised to find that you are running one of these puppies at
30
> > watts or more. even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
get
> > away from the uni-polar style.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
wrote:
> > > Why it overheats?
> > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > designed to
> > > handle about 500ma tops.
> > > 12v at 3.5 ohms would be about 3.4 amps.
> > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > which is
> > > less than the max for the ULN2003, so it would work OK.
> > >
> > > Normally you limit the max current that the stepper motor can
> > handle,
> > > otherwise it overheats and you risk burning out a coil.
> > >
> > > Small steppers can be driven with the ULN2003 but not the more
> > powerful
> > > ones.
> > > You'll need more poewerful power transistors to handle the
heavier
> > stepper
> > > motor.
> > >
> > > I think that maybe your speed value is set too fast.
> > > The ULN2003 is getting overloaded and your power supply may be
too
> > weak for
> > > the big stepper.
> > > Thus you tend to get twitching.
> > > Steppers typically run at less than 100 rpm. You can get some
> > steppers to
> > > run faster, but you have to carefully ramp up the speed from
slow
> > to fast.
> > > But a fast running stepper has little or no torque at high rpms.
> > > I'd probably start at 1/2 second steps and see what happens,
having
> > it turn
> > > slow is easier to watch.
> > >
> > >
> > >
> > >
Original Message
> > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > Sent: Thursday, November 28, 2002 8:28 PM
> > > To: basicstamps@y...
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > Dave,
> > >
> > > I have taken your suggestions and found out
> > > a good bit about the motor but still cannot make
> > > it rotate.
> > >
> > > I have also read many of the websites people have suggested
> > > and I do have a pretty good idea of the theory of how
> > > these stepper motors work. What i really do not know is
> > > how to tell if a certain driver (the one on the nx-1000) will
drive
> > > an arbitrary stepper motor I come up with. I think this might
> > > boil down to a basic electronics question but i'm not certain.
> > >
> > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > >
> > > I am connecting it to the 12V ouputs on the NX-1000.
> > >
> > > I have deduced the following from your suggested
> > > ohm readings:
> > >
> > > blue leg
> > > yellow leg
> > > black common
> > >
> > > brown leg
> > > red leg
> > > white common
> > >
> > > I have no idea which is leg A and which is leg B.
> > >
> > > Firstly, I am curious to know why when I try to run
> > > this motor does it overheat the 2003AN IC? I would
> > > think that if i'm pumping 12V into a 3V motor it would
> > > overheat the motor if anything. Also, the "known
> > > good motor (the one that came with stampworks)" reads
> > > at like 75+ ohms.
> > >
> > > This means the stampworks motor is running about 160mA
> > > where this other motor is running say 3430mA which is
> > > 7* tollerance according to the nx-1000 specs.
> > >
> > > Is it the lack of resistance the new motor has that
> > > makes the IC get too hot and should I try adding
> > > resistors to correct for this?
> > >
> > > I know the IC is still good because I keep switching
> > > back to the "known good" motor and it still works. On
> > > the IC I did fry whichever pin is connected to output
> > > 1 on the 7-CH stepper motor driver, but I just moved
> > > up to 4,5,6,7.
> > >
> > > At any rate, following is the code i'm running and
> > > several different wiring configs i have tried, all
> > > of which behave about the same. Also this is a
> > > bench test with no load whatsoever on the motor.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirA = %1111
> > > speed = 20
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > pause speed
> > > coils = %1001
> > > pause speed
> > > next
> > > 'go ahead and end so as not to
> > > 'keep trying and hurt something
> > >
> > > end
> > >
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p2--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p3--5--brown
> > > p2--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p2--6--yellow
> > > p1--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > >
Original Message
> > > From: "Dave Mucha" <davemucha@j...>
> > > To: <basicstamps@y...>
> > > Sent: Thursday, November 28, 2002 10:40 AM
> > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > > <snip>
> > > >
> > > > The cogging you describe is either that the motor is way under
> > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
should
> > be at
> > > > least 5 times the motor nameplate voltage.
> > > >
> > > > or, the load it too great to allow it to start
> > > >
> > > > or, the ramp up speed it too great
> > > >
> > > > or, the motor it not wired correctly.
> > > >
> > > >
> > > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> > bench
> > > > test is pretty easy.
> > > >
> > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > have 2
> > > > sets of windings and each set can be tested with an ohm meter.
> > The
> > > > center tap of each circuit will be half the max for that
> > circuit. If
> > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
ohms, 2
> > and
> > > > 3 should be 5 ohms. 3 then is the center tap.
> > > >
> > > > Do the same for 4,5 and 6. the board connection diagram
should
> > list
> > > > where the center taps go (power) and where the legs go. All
you
> > need
> > > > to do is to switch one pair of windings.
> > > >
> > > > example : if 1 and 2 are legs and 3 is center/power
> > > > and 4 and 5 are legs and 6 is center/power
> > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > >
> > > > For hobby purposes, you should be able to make low torque
things
> > move
> > > > with running the motor at the nameplate voltages. One good
test
> > is
> > > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > > and you can get about as much torque as it takes to stop the
> > motor by
> > > > hand. the cogging will not damage anything, but it is
annoying to
> > > > listen to.
> > > >
> > > > hope this helps.
> > > >
> > > > one additional piece of data, most motor manufacturers put the
> > > > voltage on the namplate that is used to calculate voltages.
some,
> > > > like Pacific Scientific list the proper running voltage. your
> > higher
> > > > voltage motors may be such units.
> > > >
> > > > You can run motors from 5 to 25 times the nameplate voltage,
but
> > are
> > > > limited to nameplate amps. You really don't get the power
from a
> > > > stepper until you jack up the voltage. and when/if you
looking
> > doing
> > > > any real power applications, look into bi-polar wiring of your
> > motors
> > > > and get away from using a resitor in the power line. the high
> > > > voltages would need huge resistors and need to dump lots of
heat.
> > > >
> > > > Dave
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > I am able to hook it up similarly to the motor that came
with
> > > > stampworks, but on the breadboard and run the following
code. The
> > > > motor does not rotate but I can feel it pulsing as if it would
> > rotate
> > > > if only i had the sequence correct.
> > > > >
> > > > > Any help would be appreciated. Also, if i'm a fool for even
> > trying
> > > > this please say so.
> > > > >
> > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > I also tried using outL and adjusting DirL and Coils
> > accordingly to
> > > > try to use that 5th wire and got
> > > > > the same result - a pulsing motor with no rotation.
> > > > >
> > > > > '{$STAMP BS2}
> > > > > Coils VAR OutA 'output to stepper coils
> > > > >
> > > > > speed var word
> > > > > times var word
> > > > >
> > > > > dirL = %1111
> > > > > speed = 10
> > > > >
> > > > > main:
> > > > >
> > > > > for times = 1 to 25
> > > > > coils = %1001
> > > > > pause speed
> > > > > coils = %1100
> > > > > pause speed
> > > > > coils = %0110
> > > > > pause speed
> > > > > coils = %0011
> > > > > next
> > > > > pause 200
> > > > > goto main
> > > > >
> > > > >
> > > > >
> > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@y...
> > > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
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> > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
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> >
> >
> > To UNSUBSCRIBE, just send mail to:
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Subject and
> Body of the message will be ignored.
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> >
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http://docs.yahoo.com/info/terms/
> >
> >
GREAT !!!!!
it is always neat to have a thing work after all the energy you put
into it.
about Power supplys,
first, a transformer with enough amps to handle 66% of the total motor
(S) amps.
a full bridge rectifier or diodes rated at 150% or twice the desired
voltage.
remember your AC, once rectified and filtered will yield 1.414 times
AC suppy. so your 10V AC will become 14.14 volts DC.
Caps need to be huge. Figure C=((80,000 * I)/V) C=uF Jameco sells
10,000uF,50V caps for $4.99.
Check out Russ's tutorial. This will give you an idea on the ways to
control a stepper. simple layout and good gradient of information.
http://209.41.165.153/stepper/Tutorials/UniTutor.htm
I am doing CNC work with NEMA34 steppers, 4.7A, 1.7V driving them at
36VDC, 4 motors on the power supply. I use GECKO stepper
controllers. These are $115.00 per motor units that take one signal
to control forward or reverse and another signal in pulse to control
steps, well, actually, micro-steps. (10 micro-steps per motor step)
These can control up to 7 amp motors.
good site for information on power supplies www.geckodrives.com and
also where I got the formulas. The guy who makes them is one of
those EE's that forgets more than most of us know. And a neat thing
about him (like Tracy here) is that he can explain it to you so you
can understand it. sometimes that is a trick all to itself.
And if you are into designing your own power supplies, or stepper
controllers or want more technical data (we are getting a little
close to off topic on this list) check out
http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/
Dave
=============
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> I hooked the commons up to 5v on the breadboard
> and left the legs hooked to the 2803. It spins!
>
> I really appreciate your help on this.
>
> The motor spun good with the 5v. However,
> the heatsink on the NX-1000 started to get
> warm similarly to the 2803.
>
> I got the motor to go around and that was my
> goal - i think I will not hook it up to my
> nx-1000 board again though.
>
> I am learning a good bit about stepper
> motors and measuring volts/ohms/amps
> although it is still hazy to me how to
> think ahead accurately.
>
> I think with this motor in general, I am not
> driving it with enough amps so it is drawing
> too hard on my power source. I am guessing
> if i found a power supply rated at ~3.5 amps
> it would run fine.
>
> I am wondering - the 2803 pulses the legs at
> less than 1v. Why do you need an IC to do this?
> Could you not just throw a resistor in line
> with a stamp pin to knock the volts down some
> and just pulse the legs from a stamp pin?
>
> Also, in general, do you usually purchase a
> stepper motor and driver together as a package
> thus avioding all of the current matching
> problems i am having or should one be good enough
> to take just any stepper motor and basically
> make their own driver?
>
> mkl
>
>
Original Message
> From: Dave Mucha <davemucha@j...>
> Date: Friday, November 29, 2002 7:26 am
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> >
> > You must limit the power.
> >
> > I had made a mistake in an earlier post.
> >
> > Power output increases proportionally with supply voltage. Losses
> > in
> > the motor increase with the square of the voltage. At some point
> > the
> > motor just gets too hot.
> >
> > I think I wrote that speed increases as the square of voltage.
> >
> > Motor speed is dependant on how fast you can charge and discharge
> > the
> > coils. at some point, you cannot make the unit move any faster.
> > Typically on PC based stepper controlles, 10kH is the best you
do.
> >
> > Mostly because the PC timings. that's 10kH pulses, into a 200
> > step
> > per rev motor. Smaller motors can spin faster than large ones.
> >
> > The point about loss of power at high speed is correct, but it
> > goes
> > to constant power. Output power is independant of speed.
> > since the stepper will deliver constant power, you only get so
> > much
> > umph per minute regardless of speed. double the speed, and you
> > halve
> > the torque. At low speed that means X amount of torque at low
> > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> > you
> > could say you have 25/1. At high speed, say 50 RPM, you have
> > 25/50
> > so the motor is very weak.
> >
> > Stepper MOTORS are designed to run HOT, put you hand and pull it
> > away
> > hot. not sizzling. electronics are designed to run cool. it
> > shouldn't be the other way around.
> >
> > and don't forget to calculate power consumption and watts. You
> > may
> > be surprised to find that you are running one of these puppies at
> > 30
> > watts or more. even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
> > get
> > away from the uni-polar style.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
wrote:
> > > Why it overheats?
> > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > designed to
> > > handle about 500ma tops.
> > > 12v at 3.5 ohms would be about 3.4 amps.
> > > The 75ohm stepper that came with the NS1000 would be about
66ma,
> > which is
> > > less than the max for the ULN2003, so it would work OK.
> > >
> > > Normally you limit the max current that the stepper motor can
> > handle,
> > > otherwise it overheats and you risk burning out a coil.
> > >
> > > Small steppers can be driven with the ULN2003 but not the more
> > powerful
> > > ones.
> > > You'll need more poewerful power transistors to handle the
> > heavier
> > stepper
> > > motor.
> > >
> > > I think that maybe your speed value is set too fast.
> > > The ULN2003 is getting overloaded and your power supply may be
> > too
> > weak for
> > > the big stepper.
> > > Thus you tend to get twitching.
> > > Steppers typically run at less than 100 rpm. You can get some
> > steppers to
> > > run faster, but you have to carefully ramp up the speed from
> > slow
> > to fast.
> > > But a fast running stepper has little or no torque at high rpms.
> > > I'd probably start at 1/2 second steps and see what happens,
> > having
> > it turn
> > > slow is easier to watch.
> > >
> > >
> > >
> > >
Original Message
> > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > Sent: Thursday, November 28, 2002 8:28 PM
> > > To: basicstamps@y...
> > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > Dave,
> > >
> > > I have taken your suggestions and found out
> > > a good bit about the motor but still cannot make
> > > it rotate.
> > >
> > > I have also read many of the websites people have suggested
> > > and I do have a pretty good idea of the theory of how
> > > these stepper motors work. What i really do not know is
> > > how to tell if a certain driver (the one on the nx-1000) will
drive
> > > an arbitrary stepper motor I come up with. I think this might
> > > boil down to a basic electronics question but i'm not certain.
> > >
> > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > >
> > > I am connecting it to the 12V ouputs on the NX-1000.
> > >
> > > I have deduced the following from your suggested
> > > ohm readings:
> > >
> > > blue leg
> > > yellow leg
> > > black common
> > >
> > > brown leg
> > > red leg
> > > white common
> > >
> > > I have no idea which is leg A and which is leg B.
> > >
> > > Firstly, I am curious to know why when I try to run
> > > this motor does it overheat the 2003AN IC? I would
> > > think that if i'm pumping 12V into a 3V motor it would
> > > overheat the motor if anything. Also, the "known
> > > good motor (the one that came with stampworks)" reads
> > > at like 75+ ohms.
> > >
> > > This means the stampworks motor is running about 160mA
> > > where this other motor is running say 3430mA which is
> > > 7* tollerance according to the nx-1000 specs.
> > >
> > > Is it the lack of resistance the new motor has that
> > > makes the IC get too hot and should I try adding
> > > resistors to correct for this?
> > >
> > > I know the IC is still good because I keep switching
> > > back to the "known good" motor and it still works. On
> > > the IC I did fry whichever pin is connected to output
> > > 1 on the 7-CH stepper motor driver, but I just moved
> > > up to 4,5,6,7.
> > >
> > > At any rate, following is the code i'm running and
> > > several different wiring configs i have tried, all
> > > of which behave about the same. Also this is a
> > > bench test with no load whatsoever on the motor.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirA = %1111
> > > speed = 20
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > pause speed
> > > coils = %1001
> > > pause speed
> > > next
> > > 'go ahead and end so as not to
> > > 'keep trying and hurt something
> > >
> > > end
> > >
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p2--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p1--6--yellow
> > > p3--5--brown
> > > p2--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > > twitches and 2003AN IC gets hot
> > > p0--7--blue
> > > p2--6--yellow
> > > p1--5--brown
> > > p3--4--red
> > > 3
> > > 2
> > > 1
> > > V--black-white
> > >
> > >
Original Message
> > > From: "Dave Mucha" <davemucha@j...>
> > > To: <basicstamps@y...>
> > > Sent: Thursday, November 28, 2002 10:40 AM
> > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > >
> > >
> > > > <snip>
> > > >
> > > > The cogging you describe is either that the motor is way under
> > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> > should
> > be at
> > > > least 5 times the motor nameplate voltage.
> > > >
> > > > or, the load it too great to allow it to start
> > > >
> > > > or, the ramp up speed it too great
> > > >
> > > > or, the motor it not wired correctly.
> > > >
> > > >
> > > > since a 3.5 volt motor will turn with 3.5 volts and no load,
a
> > bench
> > > > test is pretty easy.
> > > >
> > > > Since you stated 6 wires, you have a uni-polar stepper.
these
> > have 2
> > > > sets of windings and each set can be tested with an ohm
meter.
> >
> > The
> > > > center tap of each circuit will be half the max for that
> > circuit. If
> > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> > ohms, 2
> > and
> > > > 3 should be 5 ohms. 3 then is the center tap.
> > > >
> > > > Do the same for 4,5 and 6. the board connection diagram
> > should
> > list
> > > > where the center taps go (power) and where the legs go. All
> > you
> > need
> > > > to do is to switch one pair of windings.
> > > >
> > > > example : if 1 and 2 are legs and 3 is center/power
> > > > and 4 and 5 are legs and 6 is center/power
> > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > >
> > > > For hobby purposes, you should be able to make low torque
> > things
> > move
> > > > with running the motor at the nameplate voltages. One good
> > test
> > is
> > > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > > and you can get about as much torque as it takes to stop the
> > motor by
> > > > hand. the cogging will not damage anything, but it is
> > annoying to
> > > > listen to.
> > > >
> > > > hope this helps.
> > > >
> > > > one additional piece of data, most motor manufacturers put the
> > > > voltage on the namplate that is used to calculate voltages.
some,
> > > > like Pacific Scientific list the proper running voltage. your
> > higher
> > > > voltage motors may be such units.
> > > >
> > > > You can run motors from 5 to 25 times the nameplate voltage,
> > but
> > are
> > > > limited to nameplate amps. You really don't get the power
> > from a
> > > > stepper until you jack up the voltage. and when/if you
> > looking
> > doing
> > > > any real power applications, look into bi-polar wiring of
your
> > motors
> > > > and get away from using a resitor in the power line. the high
> > > > voltages would need huge resistors and need to dump lots of
heat.
> > > >
> > > > Dave
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > I am able to hook it up similarly to the motor that came
with
> > > > stampworks, but on the breadboard and run the following
code. The
> > > > motor does not rotate but I can feel it pulsing as if it
would
> > rotate
> > > > if only i had the sequence correct.
> > > > >
> > > > > Any help would be appreciated. Also, if i'm a fool for
even
> > trying
> > > > this please say so.
> > > > >
> > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > I also tried using outL and adjusting DirL and Coils
> > accordingly to
> > > > try to use that 5th wire and got
> > > > > the same result - a pulsing motor with no rotation.
> > > > >
> > > > > '{$STAMP BS2}
> > > > > Coils VAR OutA 'output to stepper coils
> > > > >
> > > > > speed var word
> > > > > times var word
> > > > >
> > > > > dirL = %1111
> > > > > speed = 10
> > > > >
> > > > > main:
> > > > >
> > > > > for times = 1 to 25
> > > > > coils = %1001
> > > > > pause speed
> > > > > coils = %1100
> > > > > pause speed
> > > > > coils = %0110
> > > > > pause speed
> > > > > coils = %0011
> > > > > next
> > > > > pause 200
> > > > > goto main
> > > > >
> > > > >
> > > > >
> > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@y...
> > > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> > Subject and
> > > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
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> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style."
This brings up a confusing point for me about chopper driving a stepper.
If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
I correct in my assumption that since the resistance across the coils cannot
change, the amperage will increase along with the chosen chopper voltage? Do
I need to upgrade my transistors to handle this increase in amperage or do I
size my transistors by multiplying the calculated amperage by the duty
cycle?
For example:
Stepper Specs- 3.25v, 13watt stepper.
4 amps = calculated amperage at this voltage.
.8125 Ohms = Calculated resistance across coil
If I plug the extrapolated resistance figure into ohms law, my amperage
requirement at 24 volts will be 29 amps. Is this correct?
Jeff
Original Message
From: Dave Mucha [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XaFjq5xiqvY5-G-1W1Z6v3Juc8ruhR7V1rcb7f-0vMCQ1UfsAPfRQcVd5iUG80IRAa7dPNL4CpernmIN]davemucha@j...[/url
Sent: Friday, November 29, 2002 8:26 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
You must limit the power.
I had made a mistake in an earlier post.
Power output increases proportionally with supply voltage. Losses in
the motor increase with the square of the voltage. At some point the
motor just gets too hot.
I think I wrote that speed increases as the square of voltage.
Motor speed is dependant on how fast you can charge and discharge the
coils. at some point, you cannot make the unit move any faster.
Typically on PC based stepper controlles, 10kH is the best you do.
Mostly because the PC timings. that's 10kH pulses, into a 200 step
per rev motor. Smaller motors can spin faster than large ones.
The point about loss of power at high speed is correct, but it goes
to constant power. Output power is independant of speed.
since the stepper will deliver constant power, you only get so much
umph per minute regardless of speed. double the speed, and you halve
the torque. At low speed that means X amount of torque at low
rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
could say you have 25/1. At high speed, say 50 RPM, you have 25/50
so the motor is very weak.
Stepper MOTORS are designed to run HOT, put you hand and pull it away
hot. not sizzling. electronics are designed to run cool. it
shouldn't be the other way around.
and don't forget to calculate power consumption and watts. You may
be surprised to find that you are running one of these puppies at 30
watts or more. even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style.
Dave
--- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...> wrote:
> Why it overheats?
> 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
designed to
> handle about 500ma tops.
> 12v at 3.5 ohms would be about 3.4 amps.
> The 75ohm stepper that came with the NS1000 would be about 66ma,
which is
> less than the max for the ULN2003, so it would work OK.
>
> Normally you limit the max current that the stepper motor can
handle,
> otherwise it overheats and you risk burning out a coil.
>
> Small steppers can be driven with the ULN2003 but not the more
powerful
> ones.
> You'll need more poewerful power transistors to handle the heavier
stepper
> motor.
>
> I think that maybe your speed value is set too fast.
> The ULN2003 is getting overloaded and your power supply may be too
weak for
> the big stepper.
> Thus you tend to get twitching.
> Steppers typically run at less than 100 rpm. You can get some
steppers to
> run faster, but you have to carefully ramp up the speed from slow
to fast.
> But a fast running stepper has little or no torque at high rpms.
> I'd probably start at 1/2 second steps and see what happens, having
it turn
> slow is easier to watch.
>
>
>
>
Original Message
> From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> Sent: Thursday, November 28, 2002 8:28 PM
> To: basicstamps@y...
> Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@y...
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
>
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I know there are quite a few drives for a pc but I"m trying to do it with a
micro controller.
regards
victor
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, November 29, 2002 12:49 PM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are just
> looking for a motor, the voltage/pot style is fine. If you need to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
>
>
>
>
>
>
>
> --- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> > Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> > that can be used with a stamp/pic/????
> > I have found one it looks good also good price but the
> documentation really
> > is poor.
> > www.futurlec.com look under stepper motors.
> > at $17.00 the price is hard to beat.
> > maybe someone on the list has used one of these and can comment on
> it maybe
> > some example code???
> > regards
> > victor
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Friday, November 29, 2002 8:26 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > >
> > > You must limit the power.
> > >
> > > I had made a mistake in an earlier post.
> > >
> > > Power output increases proportionally with supply voltage. Losses
> in
> > > the motor increase with the square of the voltage. At some point
> the
> > > motor just gets too hot.
> > >
> > > I think I wrote that speed increases as the square of voltage.
> > >
> > > Motor speed is dependant on how fast you can charge and discharge
> the
> > > coils. at some point, you cannot make the unit move any faster.
> > > Typically on PC based stepper controlles, 10kH is the best you do.
> > > Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> > > per rev motor. Smaller motors can spin faster than large ones.
> > >
> > > The point about loss of power at high speed is correct, but it
> goes
> > > to constant power. Output power is independant of speed.
> > > since the stepper will deliver constant power, you only get so
> much
> > > umph per minute regardless of speed. double the speed, and you
> halve
> > > the torque. At low speed that means X amount of torque at low
> > > rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm
> you
> > > could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> > > so the motor is very weak.
> > >
> > > Stepper MOTORS are designed to run HOT, put you hand and pull it
> away
> > > hot. not sizzling. electronics are designed to run cool. it
> > > shouldn't be the other way around.
> > >
> > > and don't forget to calculate power consumption and watts. You
> may
> > > be surprised to find that you are running one of these puppies at
> 30
> > > watts or more. even the limiting resistor my be sized for 30-50
> > > watts. at that point, look into chopper drives and H-Bridges and
> get
> > > away from the uni-polar style.
> > >
> > > Dave
> > >
> > >
> > >
> > > --- In basicstamps@y..., "Earl Bollinger" <earlwbollinger@a...>
> wrote:
> > > > Why it overheats?
> > > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > > designed to
> > > > handle about 500ma tops.
> > > > 12v at 3.5 ohms would be about 3.4 amps.
> > > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > > which is
> > > > less than the max for the ULN2003, so it would work OK.
> > > >
> > > > Normally you limit the max current that the stepper motor can
> > > handle,
> > > > otherwise it overheats and you risk burning out a coil.
> > > >
> > > > Small steppers can be driven with the ULN2003 but not the more
> > > powerful
> > > > ones.
> > > > You'll need more poewerful power transistors to handle the
> heavier
> > > stepper
> > > > motor.
> > > >
> > > > I think that maybe your speed value is set too fast.
> > > > The ULN2003 is getting overloaded and your power supply may be
> too
> > > weak for
> > > > the big stepper.
> > > > Thus you tend to get twitching.
> > > > Steppers typically run at less than 100 rpm. You can get some
> > > steppers to
> > > > run faster, but you have to carefully ramp up the speed from
> slow
> > > to fast.
> > > > But a fast running stepper has little or no torque at high rpms.
> > > > I'd probably start at 1/2 second steps and see what happens,
> having
> > > it turn
> > > > slow is easier to watch.
> > > >
> > > >
> > > >
> > > >
Original Message
> > > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > > Sent: Thursday, November 28, 2002 8:28 PM
> > > > To: basicstamps@y...
> > > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > Dave,
> > > >
> > > > I have taken your suggestions and found out
> > > > a good bit about the motor but still cannot make
> > > > it rotate.
> > > >
> > > > I have also read many of the websites people have suggested
> > > > and I do have a pretty good idea of the theory of how
> > > > these stepper motors work. What i really do not know is
> > > > how to tell if a certain driver (the one on the nx-1000) will
> drive
> > > > an arbitrary stepper motor I come up with. I think this might
> > > > boil down to a basic electronics question but i'm not certain.
> > > >
> > > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > > >
> > > > I am connecting it to the 12V ouputs on the NX-1000.
> > > >
> > > > I have deduced the following from your suggested
> > > > ohm readings:
> > > >
> > > > blue leg
> > > > yellow leg
> > > > black common
> > > >
> > > > brown leg
> > > > red leg
> > > > white common
> > > >
> > > > I have no idea which is leg A and which is leg B.
> > > >
> > > > Firstly, I am curious to know why when I try to run
> > > > this motor does it overheat the 2003AN IC? I would
> > > > think that if i'm pumping 12V into a 3V motor it would
> > > > overheat the motor if anything. Also, the "known
> > > > good motor (the one that came with stampworks)" reads
> > > > at like 75+ ohms.
> > > >
> > > > This means the stampworks motor is running about 160mA
> > > > where this other motor is running say 3430mA which is
> > > > 7* tollerance according to the nx-1000 specs.
> > > >
> > > > Is it the lack of resistance the new motor has that
> > > > makes the IC get too hot and should I try adding
> > > > resistors to correct for this?
> > > >
> > > > I know the IC is still good because I keep switching
> > > > back to the "known good" motor and it still works. On
> > > > the IC I did fry whichever pin is connected to output
> > > > 1 on the 7-CH stepper motor driver, but I just moved
> > > > up to 4,5,6,7.
> > > >
> > > > At any rate, following is the code i'm running and
> > > > several different wiring configs i have tried, all
> > > > of which behave about the same. Also this is a
> > > > bench test with no load whatsoever on the motor.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirA = %1111
> > > > speed = 20
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > pause speed
> > > > coils = %1001
> > > > pause speed
> > > > next
> > > > 'go ahead and end so as not to
> > > > 'keep trying and hurt something
> > > >
> > > > end
> > > >
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p2--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p3--5--brown
> > > > p2--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p2--6--yellow
> > > > p1--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > >
Original Message
> > > > From: "Dave Mucha" <davemucha@j...>
> > > > To: <basicstamps@y...>
> > > > Sent: Thursday, November 28, 2002 10:40 AM
> > > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > > <snip>
> > > > >
> > > > > The cogging you describe is either that the motor is way under
> > > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> > > be at
> > > > > least 5 times the motor nameplate voltage.
> > > > >
> > > > > or, the load it too great to allow it to start
> > > > >
> > > > > or, the ramp up speed it too great
> > > > >
> > > > > or, the motor it not wired correctly.
> > > > >
> > > > >
> > > > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> > > bench
> > > > > test is pretty easy.
> > > > >
> > > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > > have 2
> > > > > sets of windings and each set can be tested with an ohm meter.
> > > The
> > > > > center tap of each circuit will be half the max for that
> > > circuit. If
> > > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> > > and
> > > > > 3 should be 5 ohms. 3 then is the center tap.
> > > > >
> > > > > Do the same for 4,5 and 6. the board connection diagram
> should
> > > list
> > > > > where the center taps go (power) and where the legs go. All
> you
> > > need
> > > > > to do is to switch one pair of windings.
> > > > >
> > > > > example : if 1 and 2 are legs and 3 is center/power
> > > > > and 4 and 5 are legs and 6 is center/power
> > > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > > >
> > > > > For hobby purposes, you should be able to make low torque
> things
> > > move
> > > > > with running the motor at the nameplate voltages. One good
> test
> > > is
> > > > > to see if you can spin the thing by hand. ie: wheels spin
> freely.
> > > > > and you can get about as much torque as it takes to stop the
> > > motor by
> > > > > hand. the cogging will not damage anything, but it is
> annoying to
> > > > > listen to.
> > > > >
> > > > > hope this helps.
> > > > >
> > > > > one additional piece of data, most motor manufacturers put the
> > > > > voltage on the namplate that is used to calculate voltages.
> some,
> > > > > like Pacific Scientific list the proper running voltage. your
> > > higher
> > > > > voltage motors may be such units.
> > > > >
> > > > > You can run motors from 5 to 25 times the nameplate voltage,
> but
> > > are
> > > > > limited to nameplate amps. You really don't get the power
> from a
> > > > > stepper until you jack up the voltage. and when/if you
> looking
> > > doing
> > > > > any real power applications, look into bi-polar wiring of your
> > > motors
> > > > > and get away from using a resitor in the power line. the high
> > > > > voltages would need huge resistors and need to dump lots of
> heat.
> > > > >
> > > > > Dave
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > I am able to hook it up similarly to the motor that came
> with
> > > > > stampworks, but on the breadboard and run the following
> code. The
> > > > > motor does not rotate but I can feel it pulsing as if it would
> > > rotate
> > > > > if only i had the sequence correct.
> > > > > >
> > > > > > Any help would be appreciated. Also, if i'm a fool for even
> > > trying
> > > > > this please say so.
> > > > > >
> > > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > > I also tried using outL and adjusting DirL and Coils
> > > accordingly to
> > > > > try to use that 5th wire and got
> > > > > > the same result - a pulsing motor with no rotation.
> > > > > >
> > > > > > '{$STAMP BS2}
> > > > > > Coils VAR OutA 'output to stepper coils
> > > > > >
> > > > > > speed var word
> > > > > > times var word
> > > > > >
> > > > > > dirL = %1111
> > > > > > speed = 10
> > > > > >
> > > > > > main:
> > > > > >
> > > > > > for times = 1 to 25
> > > > > > coils = %1001
> > > > > > pause speed
> > > > > > coils = %1100
> > > > > > pause speed
> > > > > > coils = %0110
> > > > > > pause speed
> > > > > > coils = %0011
> > > > > > next
> > > > > > pause 200
> > > > > > goto main
> > > > > >
> > > > > >
> > > > > >
> > > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > > >
> > > > >
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>
making a robot in the future.
I'm really a computer programmer dealing with PC's
and IBM Mainframe.
Where I work we store a lot of our data on tapes.
That might sound archaic but it is still the most
affordable long term storage as far as i know.
Well we used to have a crew of "tape mounters"
working in the data center 24/7. One day a truck
pulled up and they unloaded the 'robots'. These
were basically big long black library cases that
housed the tapes and there were two robots inside
each case that would fetch and mount the tapes.
One day i put my nose up to the glass and watched
the robots for about 15 min. and ever since then
I just want to know more about how to interface
computers with anything robotic or electronic.
Well that is really just as easy as learning the
commands the robot expects - that is no fun - it
is the same as sending print commands to a printer.
So I guess my overall goal is to learn the basic
pieces of robotics and then 'use them on my own.'
Stampworks makes this very attainable; however, I
am always left with more curiousity. Sure I can
follow the directions and make their stepper motor
run fast, slow, forward and backwards, but i'm
the type that has to really build my confidence up
by trying 3 or more different stepper motors until
i'm pretty sure I could use about any stepper motor.
I do like the idea of using a steper motor to
drive a robot because I imagine i could count the
revs in a variable and always 'get back home' with
some math - assuming the bot did not coggle. Besides
they are way quieter than servos which really get
on my nerves.
Again - thanks for all your help.
mkl
Original Message
From: Dave Mucha <davemucha@j...>
Date: Friday, November 29, 2002 11:49 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp
> directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good
> for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are
> just
> looking for a motor, the voltage/pot style is fine. If you need
> to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design
> around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
>
>
>
>
>
>
>
> --- In basicstamps@y..., "Victor Faria" <victorf@g...> wrote:
> > Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> > that can be used with a stamp/pic/????
> > I have found one it looks good also good price but the
> documentation really
> > is poor.
> > www.futurlec.com look under stepper motors.
> > at $17.00 the price is hard to beat.
> > maybe someone on the list has used one of these and can comment
> on
> it maybe
> > some example code???
> > regards
> > victor
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Friday, November 29, 2002 8:26 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > >
> > > You must limit the power.
> > >
> > > I had made a mistake in an earlier post.
> > >
> > > Power output increases proportionally with supply voltage.
> Losses
> in
> > > the motor increase with the square of the voltage. At some
> point
> the
> > > motor just gets too hot.
> > >
> > > I think I wrote that speed increases as the square of voltage.
> > >
> > > Motor speed is dependant on how fast you can charge and
> discharge
> the
> > > coils. at some point, you cannot make the unit move any faster.
> > > Typically on PC based stepper controlles, 10kH is the best you do.
> > > Mostly because the PC timings. that's 10kH pulses, into a 200
> step
> > > per rev motor. Smaller motors can spin faster than large ones.
> > >
> > > The point about loss of power at high speed is correct, but it
> goes
> > > to constant power. Output power is independant of speed.
> > > since the stepper will deliver constant power, you only get so
> much
> > > umph per minute regardless of speed. double the speed, and
> you
> halve
> > > the torque. At low speed that means X amount of torque at low
> > > rpm's. say you are delivering 25 oz/in at the shaft. at 1
> rpm
> you
> > > could say you have 25/1. At high speed, say 50 RPM, you have
> 25/50
> > > so the motor is very weak.
> > >
> > > Stepper MOTORS are designed to run HOT, put you hand and pull
> it
> away
> > > hot. not sizzling. electronics are designed to run cool. it
> > > shouldn't be the other way around.
> > >
> > > and don't forget to calculate power consumption and watts.
> You
> may
> > > be surprised to find that you are running one of these puppies
> at
> 30
> > > watts or more. even the limiting resistor my be sized for 30-50
> > > watts. at that point, look into chopper drives and H-Bridges
> and
> get
> > > away from the uni-polar style.
> > >
> > > Dave
> > >
> > >
> > >
> > > --- In basicstamps@y..., "Earl Bollinger"
> <earlwbollinger@a...>
> wrote:
> > > > Why it overheats?
> > > > 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
> > > designed to
> > > > handle about 500ma tops.
> > > > 12v at 3.5 ohms would be about 3.4 amps.
> > > > The 75ohm stepper that came with the NS1000 would be about 66ma,
> > > which is
> > > > less than the max for the ULN2003, so it would work OK.
> > > >
> > > > Normally you limit the max current that the stepper motor can
> > > handle,
> > > > otherwise it overheats and you risk burning out a coil.
> > > >
> > > > Small steppers can be driven with the ULN2003 but not the more
> > > powerful
> > > > ones.
> > > > You'll need more poewerful power transistors to handle the
> heavier
> > > stepper
> > > > motor.
> > > >
> > > > I think that maybe your speed value is set too fast.
> > > > The ULN2003 is getting overloaded and your power supply may
> be
> too
> > > weak for
> > > > the big stepper.
> > > > Thus you tend to get twitching.
> > > > Steppers typically run at less than 100 rpm. You can get some
> > > steppers to
> > > > run faster, but you have to carefully ramp up the speed from
> slow
> > > to fast.
> > > > But a fast running stepper has little or no torque at high rpms.
> > > > I'd probably start at 1/2 second steps and see what happens,
> having
> > > it turn
> > > > slow is easier to watch.
> > > >
> > > >
> > > >
> > > >
Original Message
> > > > From: Matt Lorenz [noparse][[/noparse]mailto:mklorenz@c...]
> > > > Sent: Thursday, November 28, 2002 8:28 PM
> > > > To: basicstamps@y...
> > > > Subject: Re: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > Dave,
> > > >
> > > > I have taken your suggestions and found out
> > > > a good bit about the motor but still cannot make
> > > > it rotate.
> > > >
> > > > I have also read many of the websites people have suggested
> > > > and I do have a pretty good idea of the theory of how
> > > > these stepper motors work. What i really do not know is
> > > > how to tell if a certain driver (the one on the nx-1000)
> will
> drive
> > > > an arbitrary stepper motor I come up with. I think this might
> > > > boil down to a basic electronics question but i'm not certain.
> > > >
> > > > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> > > >
> > > > I am connecting it to the 12V ouputs on the NX-1000.
> > > >
> > > > I have deduced the following from your suggested
> > > > ohm readings:
> > > >
> > > > blue leg
> > > > yellow leg
> > > > black common
> > > >
> > > > brown leg
> > > > red leg
> > > > white common
> > > >
> > > > I have no idea which is leg A and which is leg B.
> > > >
> > > > Firstly, I am curious to know why when I try to run
> > > > this motor does it overheat the 2003AN IC? I would
> > > > think that if i'm pumping 12V into a 3V motor it would
> > > > overheat the motor if anything. Also, the "known
> > > > good motor (the one that came with stampworks)" reads
> > > > at like 75+ ohms.
> > > >
> > > > This means the stampworks motor is running about 160mA
> > > > where this other motor is running say 3430mA which is
> > > > 7* tollerance according to the nx-1000 specs.
> > > >
> > > > Is it the lack of resistance the new motor has that
> > > > makes the IC get too hot and should I try adding
> > > > resistors to correct for this?
> > > >
> > > > I know the IC is still good because I keep switching
> > > > back to the "known good" motor and it still works. On
> > > > the IC I did fry whichever pin is connected to output
> > > > 1 on the 7-CH stepper motor driver, but I just moved
> > > > up to 4,5,6,7.
> > > >
> > > > At any rate, following is the code i'm running and
> > > > several different wiring configs i have tried, all
> > > > of which behave about the same. Also this is a
> > > > bench test with no load whatsoever on the motor.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirA = %1111
> > > > speed = 20
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > pause speed
> > > > coils = %1001
> > > > pause speed
> > > > next
> > > > 'go ahead and end so as not to
> > > > 'keep trying and hurt something
> > > >
> > > > end
> > > >
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p2--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p1--6--yellow
> > > > p3--5--brown
> > > > p2--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > > twitches and 2003AN IC gets hot
> > > > p0--7--blue
> > > > p2--6--yellow
> > > > p1--5--brown
> > > > p3--4--red
> > > > 3
> > > > 2
> > > > 1
> > > > V--black-white
> > > >
> > > >
Original Message
> > > > From: "Dave Mucha" <davemucha@j...>
> > > > To: <basicstamps@y...>
> > > > Sent: Thursday, November 28, 2002 10:40 AM
> > > > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> > > >
> > > >
> > > > > <snip>
> > > > >
> > > > > The cogging you describe is either that the motor is way under
> > > > > powered, ie: feeding a 3.5 volt motor only 5 volts. It
> should
> > > be at
> > > > > least 5 times the motor nameplate voltage.
> > > > >
> > > > > or, the load it too great to allow it to start
> > > > >
> > > > > or, the ramp up speed it too great
> > > > >
> > > > > or, the motor it not wired correctly.
> > > > >
> > > > >
> > > > > since a 3.5 volt motor will turn with 3.5 volts and no
> load, a
> > > bench
> > > > > test is pretty easy.
> > > > >
> > > > > Since you stated 6 wires, you have a uni-polar stepper. these
> > > have 2
> > > > > sets of windings and each set can be tested with an ohm meter.
> > > The
> > > > > center tap of each circuit will be half the max for that
> > > circuit. If
> > > > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5
> ohms, 2
> > > and
> > > > > 3 should be 5 ohms. 3 then is the center tap.
> > > > >
> > > > > Do the same for 4,5 and 6. the board connection diagram
> should
> > > list
> > > > > where the center taps go (power) and where the legs go.
> All
> you
> > > need
> > > > > to do is to switch one pair of windings.
> > > > >
> > > > > example : if 1 and 2 are legs and 3 is center/power
> > > > > and 4 and 5 are legs and 6 is center/power
> > > > > all you need to do is swap 4 and 5 to 5 and 4.
> > > > >
> > > > > For hobby purposes, you should be able to make low torque
> things
> > > move
> > > > > with running the motor at the nameplate voltages. One
> good
> test
> > > is
> > > > > to see if you can spin the thing by hand. ie: wheels spin
> freely.
> > > > > and you can get about as much torque as it takes to stop the
> > > motor by
> > > > > hand. the cogging will not damage anything, but it is
> annoying to
> > > > > listen to.
> > > > >
> > > > > hope this helps.
> > > > >
> > > > > one additional piece of data, most motor manufacturers put the
> > > > > voltage on the namplate that is used to calculate
> voltages.
> some,
> > > > > like Pacific Scientific list the proper running voltage. your
> > > higher
> > > > > voltage motors may be such units.
> > > > >
> > > > > You can run motors from 5 to 25 times the nameplate
> voltage,
> but
> > > are
> > > > > limited to nameplate amps. You really don't get the power
> from a
> > > > > stepper until you jack up the voltage. and when/if you
> looking
> > > doing
> > > > > any real power applications, look into bi-polar wiring of your
> > > motors
> > > > > and get away from using a resitor in the power line. the high
> > > > > voltages would need huge resistors and need to dump lots
> of
> heat.
> > > > >
> > > > > Dave
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > > I am able to hook it up similarly to the motor that came
> with
> > > > > stampworks, but on the breadboard and run the following
> code. The
> > > > > motor does not rotate but I can feel it pulsing as if it would
> > > rotate
> > > > > if only i had the sequence correct.
> > > > > >
> > > > > > Any help would be appreciated. Also, if i'm a fool for even
> > > trying
> > > > > this please say so.
> > > > > >
> > > > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > > > I also tried using outL and adjusting DirL and Coils
> > > accordingly to
> > > > > try to use that 5th wire and got
> > > > > > the same result - a pulsing motor with no rotation.
> > > > > >
> > > > > > '{$STAMP BS2}
> > > > > > Coils VAR OutA 'output to stepper coils
> > > > > >
> > > > > > speed var word
> > > > > > times var word
> > > > > >
> > > > > > dirL = %1111
> > > > > > speed = 10
> > > > > >
> > > > > > main:
> > > > > >
> > > > > > for times = 1 to 25
> > > > > > coils = %1001
> > > > > > pause speed
> > > > > > coils = %1100
> > > > > > pause speed
> > > > > > coils = %0110
> > > > > > pause speed
> > > > > > coils = %0011
> > > > > > next
> > > > > > pause 200
> > > > > > goto main
> > > > > >
> > > > > >
> > > > > >
> > > > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > > >
> > > > >
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>
the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
> I correct in my assumption that since the resistance across the coils cannot
> change, the amperage will increase along with the chosen chopper voltage? Do
> I need to upgrade my transistors to handle this increase in amperage or do I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
> <snip>
the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle? Am
> I correct in my assumption that since the resistance across the coils cannot
> change, the amperage will increase along with the chosen chopper voltage? Do
> I need to upgrade my transistors to handle this increase in amperage or do I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
> <snip>
>Yes trying an xy table.
>I know there are quite a few drives for a pc but I"m trying to do it with a
>micro controller.
>regards
>victor
Me too .. but .. a 'translator' chip like the L297 can sure make life easier
by eliminating the repetitive task of telling the motor coils which
sequence to
step in. All it needs is an enable flag, a direction flag, and a pulse stream
from the PIC (which, remember, isn't especially great at generating accurate
timing info if it's using a ceramic resonator).
The logic in the L297 eliminates worry about missed sequence info (the motor
likes that a LOT) . missing pulses/motor steps is another kettle o' fish,
tho. [noparse]:)[/noparse]
Ron Yost
So what you are saying is...I will need current limiting resistors even
with the chopper drive?
Jeff
Original Message
From: Dave Mucha [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9EbKZrBQPm2utUMUO8T_cTGIPghxizNSIvbYAoybO-m1OIsS4jTSL5QIXzyJ7_k06qKbsiyff9p5jw]davemucha@j...[/url
Sent: Friday, November 29, 2002 3:32 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
Hi Jeff,
the stepper motor can only handle the 'nameplate' amps. since your
motor is listed with part of the numbers, you calculated the amps for
the basic unit. if you power at 1 volt or 60 volts, the amps (4 amps
per your example) is the max amps regardless of voltage you use to
drive the motor.
Verify the resistance to prove the calculation. Seems like a lare
stepper. NEMA34 (3.4" dia or 3.4 square)
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty cycle?
Am
> I correct in my assumption that since the resistance across the coils
cannot
> change, the amperage will increase along with the chosen chopper voltage?
Do
> I need to upgrade my transistors to handle this increase in amperage or do
I
> size my transistors by multiplying the calculated amperage by the duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
> <snip>
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with a current limited power source, you use the resistor, when using
a chopper style, you monitor the current an with a pwm style output,
cut the power when you reached your amps.
what you are doing is trying to inject as much power as fast as you
can. the R/C time will be such that the cap will charge at a rate of
I/uF volts per second.
With a chopper drive, you have zero resistance so your time is zero
as well.
Dave
--- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> Thanks for your reply Dave.
> So what you are saying is...I will need current limiting resistors
even
> with the chopper drive?
>
> Jeff
>
>
Original Message
> From: Dave Mucha [noparse][[/noparse]mailto:davemucha@j...]
> Sent: Friday, November 29, 2002 3:32 PM
> To: basicstamps@y...
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> Hi Jeff,
>
> the stepper motor can only handle the 'nameplate' amps. since your
> motor is listed with part of the numbers, you calculated the amps
for
> the basic unit. if you power at 1 volt or 60 volts, the amps (4
amps
> per your example) is the max amps regardless of voltage you use to
> drive the motor.
>
> Verify the resistance to prove the calculation. Seems like a lare
> stepper. NEMA34 (3.4" dia or 3.4 square)
>
> Dave
>
>
>
> --- In basicstamps@y..., "Jeff Mitchell" <EL-JEFE@P...> wrote:
> > Quote "even the limiting resistor my be sized for 30-50
> > watts. at that point, look into chopper drives and H-Bridges and
get
> > away from the uni-polar style."
> >
> > This brings up a confusing point for me about chopper driving a
stepper.
> > If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10%
duty cycle?
> Am
> > I correct in my assumption that since the resistance across the
coils
> cannot
> > change, the amperage will increase along with the chosen chopper
voltage?
> Do
> > I need to upgrade my transistors to handle this increase in
amperage or do
> I
> > size my transistors by multiplying the calculated amperage by the
duty
> > cycle?
> >
> > For example:
> >
> > Stepper Specs- 3.25v, 13watt stepper.
> >
> > 4 amps = calculated amperage at this voltage.
> > .8125 Ohms = Calculated resistance across coil
> >
> > If I plug the extrapolated resistance figure into ohms law, my
amperage
> > requirement at 24 volts will be 29 amps. Is this correct?
> >
> > Jeff
>
>
> > <snip>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@y...
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Subject and
> Body of the message will be ignored.
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>
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
info. will be helpfull.
Eric
hope you don't mind too much if I take the lazy approach, but this
was covered in the last few weeks.
search the group for stepper and you'll find lots of data.
Dave
--- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> does anyone know how to controll stepper motors with the BS2. any
> info. will be helpfull.
>
> Eric
This may come off looking like a mess - i dunno. At any rate there are
some explanations, a little code, and some web links in here.
Eric, here is pretty much everything that was said about steppers
last week:
Quote "even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style."
This brings up a confusing point for me about chopper driving a
stepper.
If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty
cycle? Am
I correct in my assumption that since the resistance across the coils
cannot
change, the amperage will increase along with the chosen chopper
voltage? Do
I need to upgrade my transistors to handle this increase in amperage or
do I
size my transistors by multiplying the calculated amperage by the duty
cycle?
For example:
Stepper Specs- 3.25v, 13watt stepper.
4 amps = calculated amperage at this voltage.
.8125 Ohms = Calculated resistance across coil
If I plug the extrapolated resistance figure into ohms law, my amperage
requirement at 24 volts will be 29 amps. Is this correct?
Jeff
***********************************************************
***********************************************************
Driving a Darlington like a TP120 will carry the current for low
power steppers. under 1.5 A. you can drive it from a Stamp directly
for step control. 4 units would allow you to as a chopper.
Allegro makes a surface mount H-Bridge chip the A3977 also good for
up to 35 volts and 1.5 amps.
You might want to check out Allegro UNC5804 too.
Generally speaking you can make a full H-Bridge circuit to drive a
stepper, or use a pre-packaged chip. These take 2 pins, one for
pulse and one for direction.
There are also some circuits that allow you to vari the voltage or
use a pot to change speed. If you are driving a robot and are just
looking for a motor, the voltage/pot style is fine. If you need to
know where the shaft is then you need to count pulses.
There are quite a few drives, kits, chips and circuits floating
around. Figure out what your maximum motor size is and design around
that that.
btw, are you experimenting ? making a robot? or getting started in
CNC ?
Dave
************************************************************
************************************************************
I hooked the commons up to 5v on the breadboard
and left the legs hooked to the 2803. It spins!
I really appreciate your help on this.
The motor spun good with the 5v. However,
the heatsink on the NX-1000 started to get
warm similarly to the 2803.
I got the motor to go around and that was my
goal - i think I will not hook it up to my
nx-1000 board again though.
I am learning a good bit about stepper
motors and measuring volts/ohms/amps
although it is still hazy to me how to
think ahead accurately.
I think with this motor in general, I am not
driving it with enough amps so it is drawing
too hard on my power source. I am guessing
if i found a power supply rated at ~3.5 amps
it would run fine.
I am wondering - the 2803 pulses the legs at
less than 1v. Why do you need an IC to do this?
Could you not just throw a resistor in line
with a stamp pin to knock the volts down some
and just pulse the legs from a stamp pin?
Also, in general, do you usually purchase a
stepper motor and driver together as a package
thus avioding all of the current matching
problems i am having or should one be good enough
to take just any stepper motor and basically
make their own driver?
mkl
*************************************************************
*************************************************************
Dave,do you have any info/links to good cheap bipolar drive and
motors???
that can be used with a stamp/pic/????
I have found one it looks good also good price but the documentation
really
is poor.
www.futurlec.com look under stepper motors.
at $17.00 the price is hard to beat.
maybe someone on the list has used one of these and can comment on it
maybe
some example code???
regards
victor
**********************************************************************
**********************************************************************
You must limit the power.
I had made a mistake in an earlier post.
Power output increases proportionally with supply voltage. Losses in
the motor increase with the square of the voltage. At some point the
motor just gets too hot.
I think I wrote that speed increases as the square of voltage.
Motor speed is dependant on how fast you can charge and discharge the
coils. at some point, you cannot make the unit move any faster.
Typically on PC based stepper controlles, 10kH is the best you do.
Mostly because the PC timings. that's 10kH pulses, into a 200 step
per rev motor. Smaller motors can spin faster than large ones.
The point about loss of power at high speed is correct, but it goes
to constant power. Output power is independant of speed.
since the stepper will deliver constant power, you only get so much
umph per minute regardless of speed. double the speed, and you halve
the torque. At low speed that means X amount of torque at low
rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
could say you have 25/1. At high speed, say 50 RPM, you have 25/50
so the motor is very weak.
Stepper MOTORS are designed to run HOT, put you hand and pull it away
hot. not sizzling. electronics are designed to run cool. it
shouldn't be the other way around.
and don't forget to calculate power consumption and watts. You may
be surprised to find that you are running one of these puppies at 30
watts or more. even the limiting resistor my be sized for 30-50
watts. at that point, look into chopper drives and H-Bridges and get
away from the uni-polar style.
Dave
**********************************************************************
**********************************************************************
Why it overheats?
5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only designed
to
handle about 500ma tops.
12v at 3.5 ohms would be about 3.4 amps.
The 75ohm stepper that came with the NS1000 would be about 66ma, which
is
less than the max for the ULN2003, so it would work OK.
Normally you limit the max current that the stepper motor can handle,
otherwise it overheats and you risk burning out a coil.
Small steppers can be driven with the ULN2003 but not the more powerful
ones.
You'll need more poewerful power transistors to handle the heavier
stepper
motor.
I think that maybe your speed value is set too fast.
The ULN2003 is getting overloaded and your power supply may be too weak
for
the big stepper.
Thus you tend to get twitching.
Steppers typically run at less than 100 rpm. You can get some steppers
to
run faster, but you have to carefully ramp up the speed from slow to
fast.
But a fast running stepper has little or no torque at high rpms.
I'd probably start at 1/2 second steps and see what happens, having it
turn
slow is easier to watch.
*************************************************************
*************************************************************
**********************************************************************
**********************************************************************
Interesting results.
first is that you must do the ohm's law calc on motor amps and supply
voltage to determine what size resistor to use. both watts as well as
resistsnce.
Second, you are pumping current into an inductive load.
Theroretically, zero speed will yield zero resistance and infinate
amps. when the motor is not spinning, you basically have a dead
short. once you start spinning the motor your volts/amps/resistance
falls in line.
Working with 5 volts is fine to test, and you should get the motor to
spin easily at 5 volts. higher voltages is needed to increase power
of the stepper. power increases as the square of the voltage, so you
can see that low voltage will offer low power.
Regarding leads into the motor, since you know the power lines, the
rest is simple. A resistor on the power supply to limit the total
amps as you determined from calculating the known desired current and
known supply voltage and subrtracting the motor resistance from the
calculated total loop resistance.
if leads
blue = 1
yellow = 2
black (common) = 3
brown = 1a
red = 2a
white (common) = 3a
if the power supply is working properly and you have limited the
current to the stepper and the motor is still cogging (not spinning
but making a grinding noise) then swaping 1a and 2a would allow the
motor to spin. you have not figured out direction. it may be that
the motor is spinning in reverse. if that is the case, swap 1 and 2
and 1a and 2a.
I'm thinking that you are offering unlimited power to the motor, the
motor is shorting out the power and your darlintons are over heating
as a result.
Hope this made some sense.
Dave
************************************************************
************************************************************
Dave,
I have taken your suggestions and found out
a good bit about the motor but still cannot make
it rotate.
I have also read many of the websites people have suggested
and I do have a pretty good idea of the theory of how
these stepper motors work. What i really do not know is
how to tell if a certain driver (the one on the nx-1000) will drive
an arbitrary stepper motor I come up with. I think this might
boil down to a basic electronics question but i'm not certain.
I stand corrected - it is 3v, 3.5ohm, 1.8step.
I am connecting it to the 12V ouputs on the NX-1000.
I have deduced the following from your suggested
ohm readings:
blue leg
yellow leg
black common
brown leg
red leg
white common
I have no idea which is leg A and which is leg B.
Firstly, I am curious to know why when I try to run
this motor does it overheat the 2003AN IC? I would
think that if i'm pumping 12V into a 3V motor it would
overheat the motor if anything. Also, the "known
good motor (the one that came with stampworks)" reads
at like 75+ ohms.
This means the stampworks motor is running about 160mA
where this other motor is running say 3430mA which is
7* tollerance according to the nx-1000 specs.
Is it the lack of resistance the new motor has that
makes the IC get too hot and should I try adding
resistors to correct for this?
I know the IC is still good because I keep switching
back to the "known good" motor and it still works. On
the IC I did fry whichever pin is connected to output
1 on the 7-CH stepper motor driver, but I just moved
up to 4,5,6,7.
At any rate, following is the code i'm running and
several different wiring configs i have tried, all
of which behave about the same. Also this is a
bench test with no load whatsoever on the motor.
'{$STAMP BS2}
Coils VAR OutA 'output to stepper coils
speed var word
times var word
dirA = %1111
speed = 20
main:
for times = 1 to 25
coils = %1100
pause speed
coils = %0110
pause speed
coils = %0011
pause speed
coils = %1001
pause speed
next
'go ahead and end so as not to
'keep trying and hurt something
end
twitches and 2003AN IC gets hot
p0--7--blue
p1--6--yellow
p2--5--brown
p3--4--red
3
2
1
V--black-white
twitches and 2003AN IC gets hot
p0--7--blue
p1--6--yellow
p3--5--brown
p2--4--red
3
2
1
V--black-white
twitches and 2003AN IC gets hot
p0--7--blue
p2--6--yellow
p1--5--brown
p3--4--red
3
2
1
V--black-white
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, November 28, 2002 10:40 AM
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> <snip>
>
> The cogging you describe is either that the motor is way under
> powered, ie: feeding a 3.5 volt motor only 5 volts. It should be at
> least 5 times the motor nameplate voltage.
>
> or, the load it too great to allow it to start
>
> or, the ramp up speed it too great
>
> or, the motor it not wired correctly.
>
>
> since a 3.5 volt motor will turn with 3.5 volts and no load, a bench
> test is pretty easy.
>
> Since you stated 6 wires, you have a uni-polar stepper. these have 2
> sets of windings and each set can be tested with an ohm meter. The
> center tap of each circuit will be half the max for that circuit. If
> you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2 and
> 3 should be 5 ohms. 3 then is the center tap.
>
> Do the same for 4,5 and 6. the board connection diagram should list
> where the center taps go (power) and where the legs go. All you need
> to do is to switch one pair of windings.
>
> example : if 1 and 2 are legs and 3 is center/power
> and 4 and 5 are legs and 6 is center/power
> all you need to do is swap 4 and 5 to 5 and 4.
>
> For hobby purposes, you should be able to make low torque things move
> with running the motor at the nameplate voltages. One good test is
> to see if you can spin the thing by hand. ie: wheels spin freely.
> and you can get about as much torque as it takes to stop the motor by
> hand. the cogging will not damage anything, but it is annoying to
> listen to.
>
> hope this helps.
>
> one additional piece of data, most motor manufacturers put the
> voltage on the namplate that is used to calculate voltages. some,
> like Pacific Scientific list the proper running voltage. your higher
> voltage motors may be such units.
>
> You can run motors from 5 to 25 times the nameplate voltage, but are
> limited to nameplate amps. You really don't get the power from a
> stepper until you jack up the voltage. and when/if you looking doing
> any real power applications, look into bi-polar wiring of your motors
> and get away from using a resitor in the power line. the high
> voltages would need huge resistors and need to dump lots of heat.
>
> Dave
>
>
> > I am able to hook it up similarly to the motor that came with
> stampworks, but on the breadboard and run the following code. The
> motor does not rotate but I can feel it pulsing as if it would rotate
> if only i had the sequence correct.
> >
> > Any help would be appreciated. Also, if i'm a fool for even trying
> this please say so.
> >
> > I have the wires hooked to pins 0 - 5 on the stamp.
> > I also tried using outL and adjusting DirL and Coils accordingly to
> try to use that 5th wire and got
> > the same result - a pulsing motor with no rotation.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirL = %1111
> > speed = 10
> >
> > main:
> >
> > for times = 1 to 25
> > coils = %1001
> > pause speed
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > next
> > pause 200
> > goto main
> >
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
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Original Message
From: Dave Mucha <davemucha@j...>
Date: Thursday, December 5, 2002 9:28 am
Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> Hi Eric,
>
> hope you don't mind too much if I take the lazy approach, but this
> was covered in the last few weeks.
>
> search the group for stepper and you'll find lots of data.
>
> Dave
>
>
>
> --- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> > does anyone know how to controll stepper motors with the BS2.
> any
> > info. will be helpfull.
> >
> > Eric
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
Search the Parallax site for data sheets on how to get started. Most
of what we did last week was pretty indepth and for someone who is
pretty well versed on the software side and experianced with the
electronics, not too easy for a beginner.
Dave
--- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> I saved most of those off to the side.
>
> This may come off looking like a mess - i dunno. At any rate there
are
> some explanations, a little code, and some web links in here.
>
> Eric, here is pretty much everything that was said about steppers
> last week:
>
> Quote "even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
get
> away from the uni-polar style."
>
> This brings up a confusing point for me about chopper driving a
> stepper.
> If I drive a 2.5 volt stepper with 24volts, do I pwm at a 10% duty
> cycle? Am
> I correct in my assumption that since the resistance across the
coils
> cannot
> change, the amperage will increase along with the chosen chopper
> voltage? Do
> I need to upgrade my transistors to handle this increase in
amperage or
> do I
> size my transistors by multiplying the calculated amperage by the
duty
> cycle?
>
> For example:
>
> Stepper Specs- 3.25v, 13watt stepper.
>
> 4 amps = calculated amperage at this voltage.
> .8125 Ohms = Calculated resistance across coil
>
> If I plug the extrapolated resistance figure into ohms law, my
amperage
> requirement at 24 volts will be 29 amps. Is this correct?
>
> Jeff
>
> ***********************************************************
> ***********************************************************
>
> Driving a Darlington like a TP120 will carry the current for low
> power steppers. under 1.5 A. you can drive it from a Stamp
directly
> for step control. 4 units would allow you to as a chopper.
>
> Allegro makes a surface mount H-Bridge chip the A3977 also good for
> up to 35 volts and 1.5 amps.
>
> You might want to check out Allegro UNC5804 too.
>
> Generally speaking you can make a full H-Bridge circuit to drive a
> stepper, or use a pre-packaged chip. These take 2 pins, one for
> pulse and one for direction.
>
> There are also some circuits that allow you to vari the voltage or
> use a pot to change speed. If you are driving a robot and are just
> looking for a motor, the voltage/pot style is fine. If you need to
> know where the shaft is then you need to count pulses.
>
> There are quite a few drives, kits, chips and circuits floating
> around. Figure out what your maximum motor size is and design
around
> that that.
>
> btw, are you experimenting ? making a robot? or getting started in
> CNC ?
>
> Dave
>
> ************************************************************
> ************************************************************
>
> I hooked the commons up to 5v on the breadboard
> and left the legs hooked to the 2803. It spins!
>
> I really appreciate your help on this.
>
> The motor spun good with the 5v. However,
> the heatsink on the NX-1000 started to get
> warm similarly to the 2803.
>
> I got the motor to go around and that was my
> goal - i think I will not hook it up to my
> nx-1000 board again though.
>
> I am learning a good bit about stepper
> motors and measuring volts/ohms/amps
> although it is still hazy to me how to
> think ahead accurately.
>
> I think with this motor in general, I am not
> driving it with enough amps so it is drawing
> too hard on my power source. I am guessing
> if i found a power supply rated at ~3.5 amps
> it would run fine.
>
> I am wondering - the 2803 pulses the legs at
> less than 1v. Why do you need an IC to do this?
> Could you not just throw a resistor in line
> with a stamp pin to knock the volts down some
> and just pulse the legs from a stamp pin?
>
> Also, in general, do you usually purchase a
> stepper motor and driver together as a package
> thus avioding all of the current matching
> problems i am having or should one be good enough
> to take just any stepper motor and basically
> make their own driver?
>
> mkl
>
> *************************************************************
> *************************************************************
>
> Dave,do you have any info/links to good cheap bipolar drive and
> motors???
> that can be used with a stamp/pic/????
> I have found one it looks good also good price but the
documentation
> really
> is poor.
> www.futurlec.com look under stepper motors.
> at $17.00 the price is hard to beat.
> maybe someone on the list has used one of these and can comment on
it
> maybe
> some example code???
> regards
> victor
>
>
**********************************************************************
>
**********************************************************************
>
> You must limit the power.
>
> I had made a mistake in an earlier post.
>
> Power output increases proportionally with supply voltage. Losses in
> the motor increase with the square of the voltage. At some point the
> motor just gets too hot.
>
> I think I wrote that speed increases as the square of voltage.
>
> Motor speed is dependant on how fast you can charge and discharge
the
> coils. at some point, you cannot make the unit move any faster.
> Typically on PC based stepper controlles, 10kH is the best you do.
> Mostly because the PC timings. that's 10kH pulses, into a 200 step
> per rev motor. Smaller motors can spin faster than large ones.
>
> The point about loss of power at high speed is correct, but it goes
> to constant power. Output power is independant of speed.
> since the stepper will deliver constant power, you only get so much
> umph per minute regardless of speed. double the speed, and you
halve
> the torque. At low speed that means X amount of torque at low
> rpm's. say you are delivering 25 oz/in at the shaft. at 1 rpm you
> could say you have 25/1. At high speed, say 50 RPM, you have 25/50
> so the motor is very weak.
>
> Stepper MOTORS are designed to run HOT, put you hand and pull it
away
> hot. not sizzling. electronics are designed to run cool. it
> shouldn't be the other way around.
>
> and don't forget to calculate power consumption and watts. You may
> be surprised to find that you are running one of these puppies at 30
> watts or more. even the limiting resistor my be sized for 30-50
> watts. at that point, look into chopper drives and H-Bridges and
get
> away from the uni-polar style.
>
> Dave
>
>
>
>
>
**********************************************************************
>
**********************************************************************
>
>
> Why it overheats?
> 5v at 3.5 ohms translates to about 1.4 amps. A ULN2003 is only
designed
> to
> handle about 500ma tops.
> 12v at 3.5 ohms would be about 3.4 amps.
> The 75ohm stepper that came with the NS1000 would be about 66ma,
which
> is
> less than the max for the ULN2003, so it would work OK.
>
> Normally you limit the max current that the stepper motor can
handle,
> otherwise it overheats and you risk burning out a coil.
>
> Small steppers can be driven with the ULN2003 but not the more
powerful
> ones.
> You'll need more poewerful power transistors to handle the heavier
> stepper
> motor.
>
> I think that maybe your speed value is set too fast.
> The ULN2003 is getting overloaded and your power supply may be too
weak
> for
> the big stepper.
> Thus you tend to get twitching.
> Steppers typically run at less than 100 rpm. You can get some
steppers
> to
> run faster, but you have to carefully ramp up the speed from slow
to
> fast.
> But a fast running stepper has little or no torque at high rpms.
> I'd probably start at 1/2 second steps and see what happens, having
it
> turn
> slow is easier to watch.
>
> *************************************************************
> *************************************************************
>
>
**********************************************************************
>
**********************************************************************
>
> Interesting results.
>
> first is that you must do the ohm's law calc on motor amps and
supply
> voltage to determine what size resistor to use. both watts as well
as
> resistsnce.
>
> Second, you are pumping current into an inductive load.
> Theroretically, zero speed will yield zero resistance and infinate
> amps. when the motor is not spinning, you basically have a dead
> short. once you start spinning the motor your volts/amps/resistance
> falls in line.
>
> Working with 5 volts is fine to test, and you should get the motor
to
> spin easily at 5 volts. higher voltages is needed to increase power
> of the stepper. power increases as the square of the voltage, so
you
> can see that low voltage will offer low power.
>
> Regarding leads into the motor, since you know the power lines, the
> rest is simple. A resistor on the power supply to limit the total
> amps as you determined from calculating the known desired current
and
> known supply voltage and subrtracting the motor resistance from the
> calculated total loop resistance.
>
> if leads
> blue = 1
> yellow = 2
> black (common) = 3
> brown = 1a
> red = 2a
> white (common) = 3a
>
> if the power supply is working properly and you have limited the
> current to the stepper and the motor is still cogging (not spinning
> but making a grinding noise) then swaping 1a and 2a would allow the
> motor to spin. you have not figured out direction. it may be that
> the motor is spinning in reverse. if that is the case, swap 1 and 2
> and 1a and 2a.
>
> I'm thinking that you are offering unlimited power to the motor, the
> motor is shorting out the power and your darlintons are over heating
> as a result.
>
> Hope this made some sense.
>
> Dave
>
> ************************************************************
> ************************************************************
> Dave,
>
> I have taken your suggestions and found out
> a good bit about the motor but still cannot make
> it rotate.
>
> I have also read many of the websites people have suggested
> and I do have a pretty good idea of the theory of how
> these stepper motors work. What i really do not know is
> how to tell if a certain driver (the one on the nx-1000) will drive
> an arbitrary stepper motor I come up with. I think this might
> boil down to a basic electronics question but i'm not certain.
>
> I stand corrected - it is 3v, 3.5ohm, 1.8step.
>
> I am connecting it to the 12V ouputs on the NX-1000.
>
> I have deduced the following from your suggested
> ohm readings:
>
> blue leg
> yellow leg
> black common
>
> brown leg
> red leg
> white common
>
> I have no idea which is leg A and which is leg B.
>
> Firstly, I am curious to know why when I try to run
> this motor does it overheat the 2003AN IC? I would
> think that if i'm pumping 12V into a 3V motor it would
> overheat the motor if anything. Also, the "known
> good motor (the one that came with stampworks)" reads
> at like 75+ ohms.
>
> This means the stampworks motor is running about 160mA
> where this other motor is running say 3430mA which is
> 7* tollerance according to the nx-1000 specs.
>
> Is it the lack of resistance the new motor has that
> makes the IC get too hot and should I try adding
> resistors to correct for this?
>
> I know the IC is still good because I keep switching
> back to the "known good" motor and it still works. On
> the IC I did fry whichever pin is connected to output
> 1 on the 7-CH stepper motor driver, but I just moved
> up to 4,5,6,7.
>
> At any rate, following is the code i'm running and
> several different wiring configs i have tried, all
> of which behave about the same. Also this is a
> bench test with no load whatsoever on the motor.
>
> '{$STAMP BS2}
> Coils VAR OutA 'output to stepper coils
>
> speed var word
> times var word
>
> dirA = %1111
> speed = 20
> main:
>
> for times = 1 to 25
> coils = %1100
> pause speed
> coils = %0110
> pause speed
> coils = %0011
> pause speed
> coils = %1001
> pause speed
> next
> 'go ahead and end so as not to
> 'keep trying and hurt something
>
> end
>
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p2--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p1--6--yellow
> p3--5--brown
> p2--4--red
> 3
> 2
> 1
> V--black-white
>
> twitches and 2003AN IC gets hot
> p0--7--blue
> p2--6--yellow
> p1--5--brown
> p3--4--red
> 3
> 2
> 1
> V--black-white
>
>
Original Message
> From: "Dave Mucha" <davemucha@j...>
> To: <basicstamps@y...>
> Sent: Thursday, November 28, 2002 10:40 AM
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
>
> > <snip>
> >
> > The cogging you describe is either that the motor is way under
> > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
be at
> > least 5 times the motor nameplate voltage.
> >
> > or, the load it too great to allow it to start
> >
> > or, the ramp up speed it too great
> >
> > or, the motor it not wired correctly.
> >
> >
> > since a 3.5 volt motor will turn with 3.5 volts and no load, a
bench
> > test is pretty easy.
> >
> > Since you stated 6 wires, you have a uni-polar stepper. these
have 2
> > sets of windings and each set can be tested with an ohm meter.
The
> > center tap of each circuit will be half the max for that
circuit. If
> > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms, 2
and
> > 3 should be 5 ohms. 3 then is the center tap.
> >
> > Do the same for 4,5 and 6. the board connection diagram should
list
> > where the center taps go (power) and where the legs go. All you
need
> > to do is to switch one pair of windings.
> >
> > example : if 1 and 2 are legs and 3 is center/power
> > and 4 and 5 are legs and 6 is center/power
> > all you need to do is swap 4 and 5 to 5 and 4.
> >
> > For hobby purposes, you should be able to make low torque things
move
> > with running the motor at the nameplate voltages. One good test
is
> > to see if you can spin the thing by hand. ie: wheels spin freely.
> > and you can get about as much torque as it takes to stop the
motor by
> > hand. the cogging will not damage anything, but it is annoying to
> > listen to.
> >
> > hope this helps.
> >
> > one additional piece of data, most motor manufacturers put the
> > voltage on the namplate that is used to calculate voltages. some,
> > like Pacific Scientific list the proper running voltage. your
higher
> > voltage motors may be such units.
> >
> > You can run motors from 5 to 25 times the nameplate voltage, but
are
> > limited to nameplate amps. You really don't get the power from a
> > stepper until you jack up the voltage. and when/if you looking
doing
> > any real power applications, look into bi-polar wiring of your
motors
> > and get away from using a resitor in the power line. the high
> > voltages would need huge resistors and need to dump lots of heat.
> >
> > Dave
> >
> >
> > > I am able to hook it up similarly to the motor that came with
> > stampworks, but on the breadboard and run the following code. The
> > motor does not rotate but I can feel it pulsing as if it would
rotate
> > if only i had the sequence correct.
> > >
> > > Any help would be appreciated. Also, if i'm a fool for even
trying
> > this please say so.
> > >
> > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > I also tried using outL and adjusting DirL and Coils
accordingly to
> > try to use that 5th wire and got
> > > the same result - a pulsing motor with no rotation.
> > >
> > > '{$STAMP BS2}
> > > Coils VAR OutA 'output to stepper coils
> > >
> > > speed var word
> > > times var word
> > >
> > > dirL = %1111
> > > speed = 10
> > >
> > > main:
> > >
> > > for times = 1 to 25
> > > coils = %1001
> > > pause speed
> > > coils = %1100
> > > pause speed
> > > coils = %0110
> > > pause speed
> > > coils = %0011
> > > next
> > > pause 200
> > > goto main
> > >
>
>
> --- In basicstamps@y..., Matt Lorenz <mklorenz@c...> wrote:
> > Dave,
> >
> > I have taken your suggestions and found out
> > a good bit about the motor but still cannot make
> > it rotate.
> >
> > I have also read many of the websites people have suggested
> > and I do have a pretty good idea of the theory of how
> > these stepper motors work. What i really do not know is
> > how to tell if a certain driver (the one on the nx-1000) will
drive
> > an arbitrary stepper motor I come up with. I think this might
> > boil down to a basic electronics question but i'm not certain.
> >
> > I stand corrected - it is 3v, 3.5ohm, 1.8step.
> >
> > I am connecting it to the 12V ouputs on the NX-1000.
> >
> > I have deduced the following from your suggested
> > ohm readings:
> >
> > blue leg
> > yellow leg
> > black common
> >
> > brown leg
> > red leg
> > white common
> >
> > I have no idea which is leg A and which is leg B.
> >
> > Firstly, I am curious to know why when I try to run
> > this motor does it overheat the 2003AN IC? I would
> > think that if i'm pumping 12V into a 3V motor it would
> > overheat the motor if anything. Also, the "known
> > good motor (the one that came with stampworks)" reads
> > at like 75+ ohms.
> >
> > This means the stampworks motor is running about 160mA
> > where this other motor is running say 3430mA which is
> > 7* tollerance according to the nx-1000 specs.
> >
> > Is it the lack of resistance the new motor has that
> > makes the IC get too hot and should I try adding
> > resistors to correct for this?
> >
> > I know the IC is still good because I keep switching
> > back to the "known good" motor and it still works. On
> > the IC I did fry whichever pin is connected to output
> > 1 on the 7-CH stepper motor driver, but I just moved
> > up to 4,5,6,7.
> >
> > At any rate, following is the code i'm running and
> > several different wiring configs i have tried, all
> > of which behave about the same. Also this is a
> > bench test with no load whatsoever on the motor.
> >
> > '{$STAMP BS2}
> > Coils VAR OutA 'output to stepper coils
> >
> > speed var word
> > times var word
> >
> > dirA = %1111
> > speed = 20
> > main:
> >
> > for times = 1 to 25
> > coils = %1100
> > pause speed
> > coils = %0110
> > pause speed
> > coils = %0011
> > pause speed
> > coils = %1001
> > pause speed
> > next
> > 'go ahead and end so as not to
> > 'keep trying and hurt something
> >
> > end
> >
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p2--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p1--6--yellow
> > p3--5--brown
> > p2--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> > twitches and 2003AN IC gets hot
> > p0--7--blue
> > p2--6--yellow
> > p1--5--brown
> > p3--4--red
> > 3
> > 2
> > 1
> > V--black-white
> >
> >
Original Message
> > From: "Dave Mucha" <davemucha@j...>
> > To: <basicstamps@y...>
> > Sent: Thursday, November 28, 2002 10:40 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
> >
> >
> > > <snip>
> > >
> > > The cogging you describe is either that the motor is way under
> > > powered, ie: feeding a 3.5 volt motor only 5 volts. It should
> be at
> > > least 5 times the motor nameplate voltage.
> > >
> > > or, the load it too great to allow it to start
> > >
> > > or, the ramp up speed it too great
> > >
> > > or, the motor it not wired correctly.
> > >
> > >
> > > since a 3.5 volt motor will turn with 3.5 volts and no load, a
> bench
> > > test is pretty easy.
> > >
> > > Since you stated 6 wires, you have a uni-polar stepper. these
> have 2
> > > sets of windings and each set can be tested with an ohm meter.
> The
> > > center tap of each circuit will be half the max for that
> circuit. If
> > > you check wire 1 and 2 and get 10 ohms, and 1 and 3 are 5 ohms,
2
> and
> > > 3 should be 5 ohms. 3 then is the center tap.
> > >
> > > Do the same for 4,5 and 6. the board connection diagram should
> list
> > > where the center taps go (power) and where the legs go. All you
> need
> > > to do is to switch one pair of windings.
> > >
> > > example : if 1 and 2 are legs and 3 is center/power
> > > and 4 and 5 are legs and 6 is center/power
> > > all you need to do is swap 4 and 5 to 5 and 4.
> > >
> > > For hobby purposes, you should be able to make low torque things
> move
> > > with running the motor at the nameplate voltages. One good test
> is
> > > to see if you can spin the thing by hand. ie: wheels spin
freely.
> > > and you can get about as much torque as it takes to stop the
> motor by
> > > hand. the cogging will not damage anything, but it is annoying
to
> > > listen to.
> > >
> > > hope this helps.
> > >
> > > one additional piece of data, most motor manufacturers put the
> > > voltage on the namplate that is used to calculate voltages.
some,
> > > like Pacific Scientific list the proper running voltage. your
> higher
> > > voltage motors may be such units.
> > >
> > > You can run motors from 5 to 25 times the nameplate voltage, but
> are
> > > limited to nameplate amps. You really don't get the power from
a
> > > stepper until you jack up the voltage. and when/if you looking
> doing
> > > any real power applications, look into bi-polar wiring of your
> motors
> > > and get away from using a resitor in the power line. the high
> > > voltages would need huge resistors and need to dump lots of
heat.
> > >
> > > Dave
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > > I am able to hook it up similarly to the motor that came with
> > > stampworks, but on the breadboard and run the following code.
The
> > > motor does not rotate but I can feel it pulsing as if it would
> rotate
> > > if only i had the sequence correct.
> > > >
> > > > Any help would be appreciated. Also, if i'm a fool for even
> trying
> > > this please say so.
> > > >
> > > > I have the wires hooked to pins 0 - 5 on the stamp.
> > > > I also tried using outL and adjusting DirL and Coils
> accordingly to
> > > try to use that 5th wire and got
> > > > the same result - a pulsing motor with no rotation.
> > > >
> > > > '{$STAMP BS2}
> > > > Coils VAR OutA 'output to stepper coils
> > > >
> > > > speed var word
> > > > times var word
> > > >
> > > > dirL = %1111
> > > > speed = 10
> > > >
> > > > main:
> > > >
> > > > for times = 1 to 25
> > > > coils = %1001
> > > > pause speed
> > > > coils = %1100
> > > > pause speed
> > > > coils = %0110
> > > > pause speed
> > > > coils = %0011
> > > > next
> > > > pause 200
> > > > goto main
> > > >
> > > >
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@y...
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
>
>
> To UNSUBSCRIBE, just send mail to:
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>
>
>
>
>
>
Original Message
> From: Dave Mucha <davemucha@j...>
> Date: Thursday, December 5, 2002 9:28 am
> Subject: [noparse][[/noparse]basicstamps] Re: stepper motors
>
> > Hi Eric,
> >
> > hope you don't mind too much if I take the lazy approach, but
this
> > was covered in the last few weeks.
> >
> > search the group for stepper and you'll find lots of data.
> >
> > Dave
> >
> >
> >
> > --- In basicstamps@y..., "Eric" <morpheus358@c...> wrote:
> > > does anyone know how to controll stepper motors with the BS2.
> > any
> > > info. will be helpfull.
> > >
> > > Eric
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
> >