Cycloid drive

This is a 31.5x reduction cycloid gear.  It is backdrivable. 

BOM:

4x M3 screws 20-25mm

6x 6700 bearings (10x15x4mm)

2x 6806 bearings (30x42x7mm)

link to video

https://photos.app.goo.gl/pRLiKd7gytNQXL9h7

Putting together is pretty straighforward.  The shaft is a little tricky.  Insert 2x 6700 bearing into each gear.  Each gear goes on each half of the  shaft little-gear first.  Then, the two halves of the shaft should mate.  Note, the shaft is eccentric with each gear 180 degress opposite.  The two halves of the shaft can be held together with an M3 bolt.  The center hole in the shaft is sized so the m3 bolt sill self-thread.  One half of the shaft has a 3mm hex to mate with a power source.  The other half has a chamfered edge to fit a countersunk head of an m3 bolt.