Re: pic: CGX-108 front
 

Why not just use a stock versaplanetary?

Re: pic: CGX-108 front
 

Why not use a single 33:1 stage instead of a 3:1 stage and a 10:1 stage? Also, I'm a fan of non-backdriving gearboxes, and this is a much more robust option over the window motors.

Re: pic: CGX-108 front
 

One has thousands and thousands of hours of FRC in competition testing, the other does not.

Easy enough for me.

Re: pic: CGX-108 front
 

Every new design has to start somewhere. When Versaplanetaries first came out they didn't have nearly the testing hours they do now.

Re: pic: CGX-108 front
 

They may not have had the amount of testing they do now. But I'm certain that a company as large as vex would have done some pretty in depth testing before putting it in the hands of first teams. That being said I do agree that this would still be a cool thing to see produced and used on an frc bot.

Re: pic: CGX-108 front
 

The only reason this wouldn't back drive would be inefficiency. Cycloidal drives DO backdrive. :)

Single stage cycloid backdriving!

Re: pic: CGX-108 front
 

I agree that non-backdrivable cycloids are more inefficient. The efficiency is related to the friction the angle of contact between the the teeth, and I think the offset as well, and the static coefficient of friction between the ring teeth and wobble gear teeth is what causes the ability to non-backdrive while lowering the efficiency. IIRC cycloidal drives with static teeth are extremely unlikely to backdrive at the cost of reduced efficiency, while ball-bearing ring teeth allow it to have just enough efficiency to be backdrivable, albeit not without lots of friction.

As a side note, that is a beautiful cycloid box! What kind of efficiency did you get out of it in the end?

Re: pic: CGX-108 front
 

Didn't get to measure it unfortunately. It's in the field and operational though.

Re: pic: CGX-108 front
 

Also bumping this thread because I still love this design.

There are ways to work around backdriving, but backlash is a much nastier problem to extinguish from high-reduction precision systems. This is one area where cycloidal components excite me. Granted, if you put any additional mechanical reductions after the output shaft, you're re-introducing the possibility of backlash. Thus right now we'd be limited by what the Versa output shaft can support.

Even still, this would be one of the few products I'd push to become an "early adopter" of (even if just on practice/demo machines).