pic: CGX-108 front

[AdamHeard]

Originally Posted by Cothron Theiss

This is a bit of a resurrection, but has there been any progress on this design? I think this could be a great option for teams wanting to power arms or winches or a host of other subsystems.

Why not just use a stock versaplanetary?

[Cothron Theiss]

Originally Posted by AdamHeard

Why not just use a stock versaplanetary?

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.

[AdamHeard]

Originally Posted by Cothron Theiss

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.

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

Easy enough for me.

[cbale2000]

Originally Posted by AdamHeard

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

Easy enough for me.

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

[cad321]

Originally Posted by cbale2000

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

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.

[ajlapp]

.I'm a fan of non-backdriving gearboxes, and this is a much more robust option over the window motors.

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

Single stage cycloid backdriving!

[asid61]

Originally Posted by ajlapp

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

Single stage cycloid backdriving!

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?

[ajlapp]

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

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

[Lil' Lavery]

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).