KAP Gear Sources

Our KAP activities have spawned ingenious and affordable products to make KAPing easier and/or more enjoyable. Post/Find information on KAP-worthy products here.

Gears for micro servos

I am building a KAP rig with micro servos. The pan micro servo is a continuous rotation servo. The servo has a 21 tooth spline, 4.8mm in diameter. Most standard servo gears are either 24 or 25 tooth, and of course larger in diameter. Many KAPers print their own gears; I do not have this ability. What have any of you found that works reliably as micro servo gears? I am tempted to get a 4mm pinion gear and carefully ream out the shaft hole to accommodate the micro servo spline; the locking screw might give me the reliability I need for the servo to function as designed.


  • edited January 11

    I don't have a direct answer, but I have used Hitec HS-65HB micro servos for KAP rigs with good results (for tilt and shutter actuation, not for panning). They have strong "karbonite" gears, whatever that means. They are not continuous rotation servos, but maybe you could cannibalize one for the gears you need?

    Edit: to my surprise, there is a Wikipedia entry dedicated to karbonite gears: https://en.wikipedia.org/wiki/Karbonite_gears

  • edited January 11

    Which brand servo are you using ? Most/many servos seem to come with an "X" or crosspiece, splined for
    that servo. You may need to use it as an " interface " between servo and most any gear. The gear is attached to the
    "X" with small screws, concentric with the center of the servo shaft.
    Have you tried Servocity.com ?

  • I agree with Paul. See zenoshrdlu.com/KAPDSMTX2/AKRig.html for pictures of gears screwed to servo horns.

  • David, Paul, Montagdude: Thanks for responding. I have seen pictures of gears attached with the micro servo horn. It appears that this is my best (and only) option. I plan to use a Tower Pro MG90S micro servo for the tilt function and a Feetech FS90R for the pan function, though if I follow some of David’s ideas (previously published) I may use the metal geared Tower Pro for the pan function also and reverse the gearing to get 360 degrees of rotation from a 90 degree servo operation. I am experimenting with a rig design using wrapped carbon tubes, supported in small wooden blocks, and some thin aluminum for the arms of the tilt platform. I am considering venturing into the area of RC for remote control (David’s work in this area is inspiring). Will see how successful I am. Previously my rigs have been the typical double-U design from thin aluminum, using standard servos activated with an AuRiCo controller (autoKAP).

Sign In or Register to comment.