Harmonic Drive

cults3d

This is a 94.5 : 1 gearbox that is entirely preassembled and requires no support to print. It is a type of harmonic drive, which uses a flexible output ring to attain a high gear reduction. My design is unique (as far as I know) in that it also incorporates a planetary gearset for further reduction. Instead of a toothed belt for the flexible coupling, I use a crinkled shape that forms involute gear teeth on both the inside and outside. The edges of the teeth taper down in order to keep the belt from stretching. The herringbone teeth keep all the gears from falling out. You can see a description and demo here: http://youtu.be/vzc53n0ssik