10:1 Cycloid Heli Gearbox

thingiverse

It's always cycloids with me lately, isn't it? This is my second attempt at making a gearbox which fits motors from a crashed RC heli, the first which works acceptably: Note I do not say fly as much as "whirl its blades around alarmingly". Unlike my previous attempts it has no preferred rotation of direction. It cannot be backdriven -- if you try and let the motor freewheel, it will just seize! Required vitamins: 1 x 625 ball bearing Probably epoxy, to hold the cam in place 30mm M3 and 14mm M3 bolts, 4 x M3 nut Main motor and mounting bolts from "Sanhuan 8827 RC Helicopter", aka Pioneer X8 Mounting bolts and pair of "A" or "B" blades from above helicopter A mess of 4.5 mm ammunition Four 4.5mm balls are used to join the wobbling gear to the output plate as shown in picture 3. A bunch more are used in a thrust bearing as shown in the cutaway view. Source files at http://burningsmell.org/3d/heli/