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Do I need a 360 servo or stepper motor?

  1. Oct 31, 2014 #1
    Hey guys. Jarfi here,

    I'm working on some gear, a system powered by a rotation that needs to move at least 360 degrees.


    Fast rotations(used for stabilization)
    Fast response time
    needs to be able to hold a position like servos do
    needs to be not too big, under 5x5cm area and under <3,5cm height
    -okay with not too much precicion, it's not a 3d printer
    -okay with not too much torque, it's not a robotic arm

    Servo; larger area and small height, Ideal for the situation. Holds position, fast rotation/response time
    but the only con was that a 360 degree servo is expensive and there aren't many out there, it's 90% 180°.

    Stepper motor; ????

    I just know that a stepper motor has continuous rotation, so that it's not limited to 180° like standard servos are. But is it good for the task? is it more or less expensive than a 360° servo? I've never worked with one so I'm a bit hazy on all this.

    My thanks in advance
  2. jcsd
  3. Nov 1, 2014 #2


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    Gold Member

    I really know very little about stepper motors, but from what I've read I believe that such is the appropriate device for your purposes. Don't take my word for it, though.
  4. Nov 3, 2014 #3


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    Science Advisor

    I would have thought that a DC motor would have met the requirement.
    Do you really need digital step control or just a DC servo?
  5. Nov 5, 2014 #4
    Off the top of my head from the info on your post that precision or torque aren't critical but holding is just use a 90 or 180 servo with a 4 or 2:1 speed increaser. (the opposite of a reducer) . Bear in mind you will lose torque proportionally to the change in speed plus some inefficiencies in the power transmission through the gears.
  6. Nov 6, 2014 #5
    Ah yes, that is wise... I ended up doing something similar, just narrowed down the rotation required from around 250° to under 180° by modifying the gears
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