Cycloidal Gearboxes, a game changer?

[Kevin Leonard]

Originally Posted by BBray_T1296

I just drew up and 3d printed a 6.66:1 one for a CIM, and it works like a charm. I can put enough torque on it I am worried the solid PLA will break and cannot backdrive it. With the drawing I was happy with, by swapping out 2 small parts I could easily change it to 5:1, 10.5:1, or 22:1. it is also super compact, being only 2x2x0.9", it is comparable in size to a versa-planetary and if made from alum/steel could easily handle more force*.

Another interesting point about this transmission is while the output is coaxial the input, they are counter-rotating

*Planetary gearboxes generally fail under load when teeth shear off inside. All failure points inside this gearbox are much thicker than the tiny gears we generally see and in theory would handle more force before shearing

Can you post a picture of this? And perhaps a video of it handling decent amounts of torque?
I'm very curious about how this 3d printed version holds up. If that can handle certain loads, there's no reason a metal equivalent wouldn't work fantastic.

[tafipapi]

Originally Posted by BBray_T1296

I just drew up and 3d printed a 6.66:1 one for a CIM, and it works like a charm. I can put enough torque on it I am worried the solid PLA will break and cannot backdrive it. With the drawing I was happy with, by swapping out 2 small parts I could easily change it to 5:1, 10.5:1, or 22:1. it is also super compact, being only 2x2x0.9", it is comparable in size to a versa-planetary and if made from alum/steel could easily handle more force*.g

Did you use the hypocycloidal ecuation to draw the profile of the gear??
I just designed one using tangent semicircles and im planning to build it, but im concerned that this characteristic may not contribute to the non-backdrivable feature.

[asid61]

Originally Posted by tafipapi

Did you use the hypocycloidal ecuation to draw the profile of the gear??
I just designed one using tangent semicircles and im planning to build it, but im concerned that this characteristic may not contribute to the non-backdrivable feature.

The zip file here: http://www.chiefdelphi.com/forums/sh...47&postcount=7
Has SolidWorks parts and equations and stuff to generate the correct cycloidal profile/ make a cycloidal gear. Semicircles may not work properly.