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Parallax CR servo speed modifications? — Parallax Forums

Parallax CR servo speed modifications?

RahkshiPartyRahkshiParty Posts: 3
edited 2014-02-04 11:31 in Robotics
Hello, I am new here.
I joined because I have been using parallax CR servos in my combat robot projects. I was wondering if it was possible to change the gearing of the servo to upgrade the "zippyness factor" of my robot. Poor thing would be slaughtered at its current speed, and I really don't have any way to obtain high speed servos. So, can you chaps help me? The robot is an antweight-class combat machine, it uses dual stick "tank drive" systems for steering.

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-02-03 21:53
    RahkshiParty wrote: »
    Hello, I am new here.
    I joined because I have been using parallax CR servos in my combat robot projects. I was wondering if it was possible to change the gearing of the servo to upgrade the "zippyness factor" of my robot. Poor thing would be slaughtered at its current speed, and I really don't have any way to obtain high speed servos. So, can you chaps help me? The robot is an antweight-class combat machine, it uses dual stick "tank drive" systems for steering.

    The short answer is no there isn't a way to change the speed of the servo. You can't change the gears around in the servo and still have them fit in the gearbox. You could add gears outside the servo's gearbox to increase the speed at the cost of lower torque. If you used a largish gear where the wheel normally connected to the servo and had the large gear drive a small gear on the wheel, then the wheel should spin faster. You might be able to do this with Lego gears. Here's a picture of a gear I added to a servo.

    attachment.php?attachmentid=85924&d=1318473673

    The gear attached to the wheel needs to be smaller than the gear attached to the servo in order to increase the speed of the wheel.

    Parallax sells new "high speed" servos. It's a much easier way to increase the speed of your robot than adding gears.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-02-03 22:05
    RahkshiParty wrote:
    ... I really don't have any way to obtain high speed servos.
    'Not sure what you mean by that, since Parallax also sells high-speed CR servos:

    -Phil
  • ercoerco Posts: 20,256
    edited 2014-02-03 22:25
    Bigger wheels.

    What's next?
  • Martin_HMartin_H Posts: 4,051
    edited 2014-02-04 01:54
    I've driven both the Parallax CR servos and GWS BB CR servos at up to 7.5 volts without a problem. Both seem to handle it fine and the extra voltage noticeably increases the speed and power of the servos. I imagine that this might shorten the life of the motor contacts, but it hasn't been a problem with my CBA robot which I've been using for several years.
  • RahkshiPartyRahkshiParty Posts: 3
    edited 2014-02-04 10:22
    I am using a 27 MHZ transmitter and receiver set, meant for RC aircraft. Parallax CR motors work fine, but they are just slower, especially by today's USA antweight criteria. @Martin, could you post or send me a video of your robot, I would like to see how fast it travels.

    Thanks
  • RahkshiPartyRahkshiParty Posts: 3
    edited 2014-02-04 10:43
    Meaning that I don't have enough cash to buy a couple. I didn't buy the CR ones, They borrowed/permanent loaned to me.
  • Martin_HMartin_H Posts: 4,051
    edited 2014-02-04 11:31
    Here's a video of it wall following:
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