I’ve avoided 3D printing for as long as I can. Now that I’m away from a marvelous school machine shop, though, I thought I’d finally take the dive after some of the success that [JB] has been having with functional prints.
This project is a bit of an old hat. Since [JB] first pointed us to using servo replacement gears as mini-combat-robot transmissions, I’ve been dropping them into project after project whenever I need a little gear reduction. Compound gears–especially the kind that can take a bit of torque in small projects–are pretty annoying to source. This all-in-one set of servo replacement gears gives us a kit that works pretty well for many simple applications.
These replacement gears have a bit of magic “zen” in that the rest of the parts needed to work with them are all stock from McMaster-Carr. It just so happens that M2 and M3 dowel pins will slip-fit into the gear bores almost perfectly (the smaller bore needs to be hand-widened with a 2mm drill bit), and two metric bearings on the output gear enable smooth and high-speed output via the spline.
(For more details on actually doing something with that spline, see [JB’s] spline adapter post.)