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Servos

ArchiverArchiver Posts: 46,084
edited 2002-07-17 03:50 in General Discussion
Is the pwm/potentiometer system used by the Futaba servos limited to
hobby servos, or are there other manufacturers that will let me use
the same code to operate larger pieces? I am building a gadget for a
quadreplegic friend of mine. I made a mock up using the hobby servos
that is working pretty well, however the end product will require the
servos to be able to rotate a balanced ten pound mass about it's
axis. If servos are not an option is the bs2 compatible with stepper
motors?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-05-24 18:03
    Go to http://www.hobbyclub.com/framespage.htm and click on the products
    button. Then go to R/C systems and select Tonegawa Industrial Type Servos

    The specs for torque are: Starting torque:

    Ms 65.33 Kg/cm (907 oz/in) @ 6.0 VDC

    91.50 Kg/cm (1271 oz/in) @ 8.4 VDC

    Hope that helps if you want to stick with servos.

    Tim
    [noparse][[/noparse]Denver, CO]

    Original Message
    From: <EL-JEFE@P...>
    To: <basicstamps@egroups.com>
    Sent: Wednesday, May 24, 2000 10:42 AM
    Subject: [noparse][[/noparse]basicstamps] Servos


    > Is the pwm/potentiometer system used by the Futaba servos limited to
    > hobby servos, or are there other manufacturers that will let me use
    > the same code to operate larger pieces? I am building a gadget for a
    > quadreplegic friend of mine. I made a mock up using the hobby servos
    > that is working pretty well, however the end product will require the
    > servos to be able to rotate a balanced ten pound mass about it's
    > axis. If servos are not an option is the bs2 compatible with stepper
    > motors?
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-24 19:29
    Look:
    http://www.vantec.com/ssps105.htm

    World strongest RC Servo.
    ACJacques

    EL-JEFE@P... wrote:

    > Is the pwm/potentiometer system used by the Futaba servos limited to
    > hobby servos, or are there other manufacturers that will let me use
    > the same code to operate larger pieces? I am building a gadget for a
    > quadreplegic friend of mine. I made a mock up using the hobby servos
    > that is working pretty well, however the end product will require the
    > servos to be able to rotate a balanced ten pound mass about it's
    > axis. If servos are not an option is the bs2 compatible with stepper
    > motors?
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-25 01:22
    I realize there have been several other options posted for more powerful
    servos, but based on your specs some of these may be overkill. Good quality
    (futaba) 1/4 scale servos have torque figures in excess of 200 oz/inch and
    can be had fairly cheaply at any local RC model shop. They *are* bigger
    than standard servos though. Standard size, hi-torque, metal geared servos
    from the big manufacturers (JR, Hitec, Futaba) max out at about 130 oz/inch.

    Best, Duncan
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-26 21:15
    For a wide choice of very powerful actuators and servos that respond to
    standard "hobby servo" PWM see:
    http://hometown.aol.com/Ckdesign1/actuator.html
    These have a very long life, are very robust, and are very expensive also!

    >
    > From: EL-JEFE@P...
    > Reply To: basicstamps@egroups.com
    > Sent: Wednesday, May 24, 2000 9:42 am
    > To: basicstamps@egroups.com
    > Subject: [noparse][[/noparse]basicstamps] Servos
    >
    > Is the pwm/potentiometer system used by the Futaba servos limited to
    > hobby servos, or are there other manufacturers that will let me use
    > the same code to operate larger pieces? I am building a gadget for a
    > quadreplegic friend of mine. I made a mock up using the hobby servos
    > that is working pretty well, however the end product will require the
    > servos to be able to rotate a balanced ten pound mass about it's
    > axis. If servos are not an option is the bs2 compatible with stepper
    > motors?
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 12:44
    I am trying to make a servo work with a Stamp2-SX. I have tried the
    code for the Stamp1, but itndon't work on the servo. I don't know if
    the servo is defective or if the code won't work.
    Any Ideas?

    Thanks
    Doug Simpson
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 13:10
    Are you using two power supplies? Are the grounds connected? What exactly
    isn't working?
    -William


    Original Message
    From: <veewee77@a...>
    To: <basicstamps@egroups.com>
    Sent: Monday, October 23, 2000 7:44 AM
    Subject: [noparse][[/noparse]basicstamps] servos


    > I am trying to make a servo work with a Stamp2-SX. I have tried the
    > code for the Stamp1, but itndon't work on the servo. I don't know if
    > the servo is defective or if the code won't work.
    > Any Ideas?
    >
    > Thanks
    > Doug Simpson
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 18:26
    Actually, one power supply. It is a 6V gel-cell that powers the
    whole thing but the servo + line is connected directly to the +on the
    battery ahead of the Stamp2SX regulator. The grounds are connected.
    And the pulse line is connected through a 1K resistor to the pin on
    the Stamp2SX.

    The code looks like this:

    dirs %0000000000010000
    servo:
    pulsout 4,150
    pause 20
    goto servo

    This is the same basic code in the manual to control a servo with the
    Stamp1. An LED connected to the pulse line glows very dimly, so I
    know the pulses are there, I just don't know about the rate, length,
    etc.

    Thanks.
    Doug


    > To: <basicstamps@egroups.com>
    > From: "William Cox" <william@c...>
    > Date: Mon, 23 Oct 2000 08:10:26 -0400
    > Reply-to: basicstamps@egroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] servos

    > Are you using two power supplies? Are the grounds connected? What exactly
    > isn't working?
    > -William
    >
    >
    >
    Original Message
    > From: <veewee77@a...>
    > To: <basicstamps@egroups.com>
    > Sent: Monday, October 23, 2000 7:44 AM
    > Subject: [noparse][[/noparse]basicstamps] servos
    >
    >
    > > I am trying to make a servo work with a Stamp2-SX. I have tried the
    > > code for the Stamp1, but itndon't work on the servo. I don't know if
    > > the servo is defective or if the code won't work.
    > > Any Ideas?
    > >
    > > Thanks
    > > Doug Simpson
    > >
    > >
    > >
    > >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-24 01:30
    Original message from: "Doug Simpson" <veewee77@a...>
    >
    >Actually, one power supply. It is a 6V gel-cell that powers the
    >whole thing but the servo + line is connected directly to the +on the
    >battery ahead of the Stamp2SX regulator. The grounds are connected.
    >And the pulse line is connected through a 1K resistor to the pin on
    >the Stamp2SX.
    >
    >The code looks like this:
    >
    >dirs %0000000000010000
    >servo:
    >pulsout 4,150
    >pause 20
    >goto servo
    >
    >This is the same basic code in the manual to control a servo with the
    >Stamp1. An LED connected to the pulse line glows very dimly, so I
    >know the pulses are there, I just don't know about the rate, length,
    >etc.
    >
    >Thanks.
    >Doug
    >

    The Stamp2SX uses different timing values than the Stamp1. In many
    cases you cannot use code meant for a Stamp1 with a Stamp2SX, at least
    not without some conversion.

    In the pulsout command you should be using "1875" in place of "150".
    1875 should centre a servo connected to a Stamp2SX.


    Jason

    __________________________________________________________________
    Get your free Australian email account at http://www.start.com.au
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-24 15:17
    >The Stamp2SX uses different timing values than the Stamp1. In many
    >cases you cannot use code meant for a Stamp1 with a Stamp2SX, at least
    >not without some conversion.
    >
    >In the pulsout command you should be using "1875" in place of "150".
    >1875 should centre a servo connected to a Stamp2SX.
    >
    >
    >Jason

    Jason is EXACTLY right, with the StampI operating at 4MHz, the StampII
    operating at 20MHz and the StampII-SX operating at 50MHz ALL of the
    timing functions will be different.
    ^^^^^^^^^

    The values below correspond to a "Center" position with each Stamp.

    Stamp1 = 150
    Stamp2 = 750
    Stamp2-SX = 1875


    Conversion Table:

    Stamp1 --> Stamp2 multiply by 5
    Stamp1 --> Stamp2-SX multiply by 12.5

    Stamp2 --> Stamp1 divide by 5
    Stamp2 --> Stamp2-SX multiply by 2.5

    Stamp2-SX --> Stamp1 divide by 12.5
    Stamp2-SX --> Stamp2 divide by 2.5

    Beau Schwabe IC Mask Designer
    National Semiconductor Network Products Division
    500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-25 04:18
    Original message from: Beau Schwabe <bschwabe@a...>
    >
    >
    >>The Stamp2SX uses different timing values than the Stamp1. In many
    >>cases you cannot use code meant for a Stamp1 with a Stamp2SX, at
    least
    >>not without some conversion.
    >>
    >>In the pulsout command you should be using "1875" in place of
    "150".
    >>1875 should centre a servo connected to a Stamp2SX.
    >>
    >>
    >>Jason
    >
    >Jason is EXACTLY right, with the StampI operating at 4MHz, the
    StampII
    >operating at 20MHz and the StampII-SX operating at 50MHz ALL of the
    >timing functions will be different.
    > ^^^^^^^^^

    I'm don't think ALL the timing functions are different between the
    stamps. I suggest anyone who is using the SX should go to
    www.parallaxinc.com and download both the StampII as well as the
    StamIISX addendum manuals.

    Quote from the stampSX addendum manual:

    "Of the 39 BS2-SX commands available, 3 are new, 25 are
    identical in function as with the BS2, and 11 vary from the BS2-IC
    only in their timing."

    With regards to the coding used for the servo(by Doug I think), the
    PULSOUT command uses differing timing depending on which stamp you
    have. But the PAUSE has the same timing units on both BS2 and BSSX.

    Jason

    __________________________________________________________________
    Get your free Australian email account at http://www.start.com.au
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-29 02:03
    Just a practical question:

    How do you guys attach servos under the base of your robot?

    Nicolas
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-29 03:00
    Foam double sided tape works wonders. ....
    -William

    Original Message
    From: Nicolas Fournel <Nicolas.Fournel@f...>
    To: <basicstamps@egroups.com>
    Sent: Tuesday, November 28, 2000 9:03 PM
    Subject: [noparse][[/noparse]basicstamps] Servos


    > Just a practical question:
    >
    > How do you guys attach servos under the base of your robot?
    >
    > Nicolas
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-30 20:40
    Hello
    You can use dubbelsided tape or wirestraps, or both.
    Maybe glue them on the base?
    But the best way is probably to bolt them on that way they do not move at all.
    Regards Ken J
    Original Message
    From: "Nicolas Fournel" <Nicolas.Fournel@f...>
    To: <basicstamps@egroups.com>
    Sent: Wednesday, November 29, 2000 3:03 AM
    Subject: [noparse][[/noparse]basicstamps] Servos


    > Just a practical question:
    >
    > How do you guys attach servos under the base of your robot?
    >
    > Nicolas
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 10:05
    With difficulty.

    Ive tried double sided tape and they tend to wobble about.

    The little clamps you get from model shops dont seem to fit all Servos.

    The best ive done so far on my last platform was to use a couple of
    posts and stretch a piece of aluminium across them to clamp them on.
    My servos were back to back so I also taped them together with insulating
    tape so they were properly lined up.

    Now if only I could glue the wheels on to the servo arms straight, I could
    get it to go in a straight line.

    Gordon


    Original Message
    From: Nicolas Fournel [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=pp6VlnpZzssDuednOQ7ZfGB2KkeoRcEQNthuhYMUGNxtJNjT6uDBREsDc71LHEkBYZEldBWc4ydBfWF-STPeg62p]Nicolas.Fournel@f...[/url
    Sent: 29 November 2000 02:04
    To: basicstamps@egroups.com
    Subject: [noparse][[/noparse]basicstamps] Servos


    Just a practical question:

    How do you guys attach servos under the base of your robot?

    Nicolas
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 10:21
    At 05:05 AM Friday 12/1/2000 -0500, you wrote:

    >With difficulty.
    >
    >Ive tried double sided tape and they tend to wobble about.
    >
    >The little clamps you get from model shops dont seem to fit all Servos.
    >
    >The best ive done so far on my last platform was to use a couple of
    >posts and stretch a piece of aluminium across them to clamp them on.
    >My servos were back to back so I also taped them together with insulating
    >tape so they were properly lined up.
    >
    >Now if only I could glue the wheels on to the servo arms straight, I could
    >get it to go in a straight line.
    >
    >Gordon


    >Hi Gordon -
    >
    >If the wheels have solid hubs (not spoked) why not SCREW them, not GLUE
    >them ? That would seem to provide a firmer foundation.

    Regards,

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 10:26
    Gordon,

    I have used double-sided tape before as well, but wasn't too happy with
    the results. You might want to try this web site http://www.servocity.com/

    They carry servo mounts, gears & sprockets that are molded to fit
    directly onto the servo output shafts, and chains to build tracked
    robotic vehicles. For just a couple bucks -- you can have everything
    you need to put together some really solid servo platforms.

    Hope this helps...

    Bruce
    webmaster@r...


    Original Message
    From: "Endersby, Gordon" <gordon.endersby@m...>
    To: <basicstamps@egroups.com>
    Sent: Friday, December 01, 2000 3:05 AM
    Subject: RE: [noparse][[/noparse]basicstamps] Servos


    >
    > With difficulty.
    >
    > Ive tried double sided tape and they tend to wobble about.
    >
    > The little clamps you get from model shops dont seem to fit all Servos.
    >
    > The best ive done so far on my last platform was to use a couple of
    > posts and stretch a piece of aluminium across them to clamp them on.
    > My servos were back to back so I also taped them together with insulating
    > tape so they were properly lined up.
    >
    > Now if only I could glue the wheels on to the servo arms straight, I could
    > get it to go in a straight line.
    >
    > Gordon
    >
    >
    >
    Original Message
    > From: Nicolas Fournel [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=GA18pl3eTTXwMNZlz9tJVwc7RrwX5BbORTdH_XOAkrb5VNM0A5e3-SYQ9ckOxStOUcNqYt3ptHFxdd7AbasMhv1WvOHyyQ]Nicolas.Fournel@f...[/url
    > Sent: 29 November 2000 02:04
    > To: basicstamps@egroups.com
    > Subject: [noparse][[/noparse]basicstamps] Servos
    >
    >
    > Just a practical question:
    >
    > How do you guys attach servos under the base of your robot?
    >
    > Nicolas
    >
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 10:29
    Hi Bruce

    Ive had a bit of trouble finding good wheels.

    What Ive found so far are some nice balloon tyres from R/C plane landing
    gear.
    They have aluminium centres. But the centres are domed.

    I found some nice wheels at B&Q last weekend. nice size and a nice tyre on
    them.
    But it was designed to go on a spindle and didnt have a surface at all on
    the inside.
    So i built up the hollow spindle with lots of hot glue and managed to
    balance one of the
    round servo actuators on the hollow spindle for the best result so far.

    Where do you get your wheels ?

    Im also having trouble getting an IR proximity detector.
    Ive tried Totalrobots, milford instruments and technology information
    exchange.
    There dont seem to be any kits in the UK at the moment.
    I would have a go a making one from scratch but im no electronic engineer
    and cant
    find a set of idiot instructions that dont require scopes and other "Expert"
    knowledge.


    Gordon Endersby
    A Newbie without enough electronics knowledge.


    Original Message
    From: Bruce Bates [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9pg7pafJdC75GM2_ri41_RF8peRKmgo-RJI2fUY0COYsippqYE-PCmziO5f4y_itV7tENooSWcn4Lxp0Vyw]bvbates@u...[/url
    Sent: 01 December 2000 10:22
    To: basicstamps@egroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Servos


    At 05:05 AM Friday 12/1/2000 -0500, you wrote:

    >With difficulty.
    >
    >Ive tried double sided tape and they tend to wobble about.
    >
    >The little clamps you get from model shops dont seem to fit all Servos.
    >
    >The best ive done so far on my last platform was to use a couple of
    >posts and stretch a piece of aluminium across them to clamp them on.
    >My servos were back to back so I also taped them together with insulating
    >tape so they were properly lined up.
    >
    >Now if only I could glue the wheels on to the servo arms straight, I could
    >get it to go in a straight line.
    >
    >Gordon


    >Hi Gordon -
    >
    >If the wheels have solid hubs (not spoked) why not SCREW them, not GLUE
    >them ? That would seem to provide a firmer foundation.

    Regards,

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 13:35
    At 05:29 AM Friday 12/1/2000 -0500, you wrote:

    >Hi Bruce
    >
    >Ive had a bit of trouble finding good wheels.
    >DuBro has the BEST wheels I've seen NEW, but there are MANY surplus
    >resources, at least here in the US.
    >What Ive found so far are some nice balloon tyres from R/C plane landing gear.
    >They have aluminium centres. But the centres are domed.
    >
    >I found some nice wheels at B&Q last weekend. nice size and a nice tyre on
    >them.

    >But it was designed to go on a spindle and didnt have a surface at all on
    >the inside. So i built up the hollow spindle with lots of hot glue and
    >managed to balance one of the round servo actuators on the hollow spindle
    >for the best result so far.
    >DuBro has "super strength" actuator arms which you can assemble as you see
    >fit :

    >[noparse][[/noparse] http://www.probuild-uk.co.uk/products/servo_arms.php3 ]

    >Where do you get your wheels ? DuBro, naturally, via Tower Hobbies [noparse][[/noparse]
    >http://www.towerhobbies.com ] : ) Yours can be obtained directly from [noparse][[/noparse]
    >http://www.probuild-uk.co.uk/index.php3 ] ! You may be looking in the
    >wrong places.
    >
    >Im also having trouble getting an IR proximity detector.
    >Ive tried Totalrobots, milford instruments and technology information
    >exchange.

    These additional references SHOULD help : )

    >There dont seem to be any kits in the UK at the moment.
    >I would have a go a making one from scratch but im no electronic engineer
    >and cant find a set of idiot instructions that dont require scopes and
    >other "Expert" knowledge.

    >Bruce Reynold's FireStick is the BEST Ir tx rx setup that can be had [noparse][[/noparse]
    >http://www.rentron.com ]. That's one method, and other method, which has
    >the additional advantage of measuring the actual distance is the IRODS
    >sensor which can be obtained from [noparse][[/noparse] http://www.hvwtech.com/sensors ].

    I hope that gets you going in a better direction.


    >Gordon Endersby
    >A Newbie without enough electronics knowledge.
    Regards,

    Bruce Bates
    More bookmarks then
    he OUGHT to have !
  • ArchiverArchiver Posts: 46,084
    edited 2000-12-01 13:44
    Thanks Bruce that lot will help me a lot.
    Not my bank balance though [noparse]:)[/noparse]

    Gordon


    Original Message
    From: Bruce Bates [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=4bWmx9fTmr6HMLZKpoWr4DreQunm3mphAPNyW24q8f1FDN7oEXppTmQ0eHyPy3SHXthGzx92kvR7cq_6og]bvbates@u...[/url
    Sent: 01 December 2000 13:36
    To: basicstamps@egroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Servos


    At 05:29 AM Friday 12/1/2000 -0500, you wrote:

    >Hi Bruce
    >
    >Ive had a bit of trouble finding good wheels.
    >DuBro has the BEST wheels I've seen NEW, but there are MANY surplus
    >resources, at least here in the US.
    >What Ive found so far are some nice balloon tyres from R/C plane landing
    gear.
    >They have aluminium centres. But the centres are domed.
    >
    >I found some nice wheels at B&Q last weekend. nice size and a nice tyre on
    >them.

    >But it was designed to go on a spindle and didnt have a surface at all on
    >the inside. So i built up the hollow spindle with lots of hot glue and
    >managed to balance one of the round servo actuators on the hollow spindle
    >for the best result so far.
    >DuBro has "super strength" actuator arms which you can assemble as you see
    >fit :

    >[noparse][[/noparse] http://www.probuild-uk.co.uk/products/servo_arms.php3 ]

    >Where do you get your wheels ? DuBro, naturally, via Tower Hobbies [noparse][[/noparse]
    >http://www.towerhobbies.com ] : ) Yours can be obtained directly from [noparse][[/noparse]
    >http://www.probuild-uk.co.uk/index.php3 ] ! You may be looking in the
    >wrong places.
    >
    >Im also having trouble getting an IR proximity detector.
    >Ive tried Totalrobots, milford instruments and technology information
    >exchange.

    These additional references SHOULD help : )

    >There dont seem to be any kits in the UK at the moment.
    >I would have a go a making one from scratch but im no electronic engineer
    >and cant find a set of idiot instructions that dont require scopes and
    >other "Expert" knowledge.

    >Bruce Reynold's FireStick is the BEST Ir tx rx setup that can be had [noparse][[/noparse]
    >http://www.rentron.com ]. That's one method, and other method, which has
    >the additional advantage of measuring the actual distance is the IRODS
    >sensor which can be obtained from [noparse][[/noparse] http://www.hvwtech.com/sensors ].

    I hope that gets you going in a better direction.


    >Gordon Endersby
    >A Newbie without enough electronics knowledge.
    Regards,

    Bruce Bates
    More bookmarks then
    he OUGHT to have !
  • ArchiverArchiver Posts: 46,084
    edited 2002-07-17 03:50
    Another question on this topic,I seem to be having a problem
    powering my servos on a loaded circuit. I have a 5 sensor array
    breadboarded and I'm powering it with a 9V battery going through a
    5V regulator and all is well. Most of the articles and basic lessons
    on this kinda "robot" use a 9V feeding the stamp and detectors, and
    4x1.5AA to run the servos, is this the norm or can you use the same
    supply voltage,maybe 2x9V in paralell going through the
    regulator,and some kinda motor driver ie. H bridge?
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