I need a supplier for steppers
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Hey everyone,
Where do you buy your stepper motors? I need a 12VDC one the is
pretty powerful. What specs do I look at for the turning torque?
Thanks,
Greg
Where do you buy your stepper motors? I need a 12VDC one the is
pretty powerful. What specs do I look at for the turning torque?
Thanks,
Greg
Comments
Andy
wrote:
> Hey everyone,
> Where do you buy your stepper motors? I need a 12VDC one the is
> pretty powerful. What specs do I look at for the turning torque?
> Thanks,
> Greg
Hi Greg,
To offer more guidance, you need to offer lots more information.
For a CNC milling machine, we use steppers that are the size of a
quart of milk, are rated for 3.57 volts and 6 amps, but I run them on
70 volts. Chopper style driver.
Since they weigh around 20 pounds, I think they are pretty powerful.
I also have some that I pulled from old floppy drives, the old 5.25
drives. These are 1.7" square and in comparison are iddiy-biddy
motors. but are neat for hobby stuff.
motors are NEMA rated, (National Electric Motor Association) for
physical size. the common ratings are 17, 23 and 34. each being the
approximate size of the motor housing in inches. 1.7", 2.3" and 3.4"
Then the length indicates how many sets of motors are in the case. a
NEMA23 is typically found in an old LaserJet printer and is about 2.3
inches long. A similar sized unit that is about 4 inches long is a
DoubeStack and has double the power. one that is about 6 inches long
is a triple stack. yup, 3 times as strong.
Dot matrix motors are pressed steel and are often poor candidates as
the number of steps per rotation is low and the tolerances are poor
meaning the efficiency is poor as well. But, the low cost and
availability make them fun to work with. And they work well in many
porjects.
If you plan on a uni-polar or simple H-Bridge driver, you need to use
line voltage that is the same as the motor, with resistors that limit
the current. Do the math on current and wattage to see the heat load
of the resistors. it can be HIGH and those power resistors can be
expensive.
Stay away from wire wound for current limiting on steppers as the
wire wound is a coil, ie: inductor. it WILL adversely effect your
operation.
Check Jameco for a pretty wide listing of motors to get a better idea
what size and power you need.
Create a spreadsheet to convert Newton meters to inch pounds to do a
simple check of the torque available.
Bty, 800 inch pounds is about the ratings of the triple stack
NEMA34's above.
My PCB (t-Tech) etching machine uses NEMA23's single stack and the
are rated for about 35 ounce inches. A note is that there is no
real standard and the old round motors are not as efficient as the
newer square body ones. And, to make it worse, a NEMA23 – single
stack, may have a 3 /4 inch coil or a 1.5" coil. So, each motor may
be slightly different.
Other sources are MPJA.com AllElectronics.com and junk printers,
copiers, scanners, fax machines....oh, yeah, E-Bay for the larger
ones.
Hope that helps.
Ask if you need more information.
Dave