[asid61]

Originally Posted by marshall

This is really cool. How are the gearboxes holding up? Any interesting failure modes observed so far?

Thanks! The "good" failure mode is just a ratcheting due to the plastic teeth skipping, and the gearbox still runs afterwards. The more common "bad" failure mode is when the plastic gears go skew on the shaft, locking up the gearbox. Using metal hubs or bearings should fix these issues. I would not use the gearboxes on a robot right now, as the tolerances are all over the place. I'll be fixing that next week.

Originally Posted by nuclearnerd

This is a really cool project, and I'm anxious to see the final result commercially available. Although I would be even more excited if you could make your own final stage as well. The Vex final stage has really insufficient mounting strength at high ratios. Two #10 bolts isn't enough to hold the reaction torque (above 100:1 on a bag motor) in our experience.

Thank you, I hope to be able to make this a commercial thing eventually.
We have used the side mounting holes in the past to hold our VPs, so doing that could help. You could also cut 2 more mounting holes such that it holds the VP together; you would use the 2 corner holes that currently house #8 bolts that hold the VP together.

Originally Posted by Chris Endres

Nice! Ever since you posted the CAD a few months ago, I was eager to see it come to life.

Good luck on the final iteration! Hopefully this will be something VEXPro will look into in the future, it really is a nice way to get a compact and high reduction stage for Versa Planetaries.

Originally Posted by cbale2000

While I'm still of the opinion that cycloidal gearboxs are magic, the thought of a 20:1 or higher reduction with limited or zero backdrive in a VersaPlanetary form factor is VERY appealing to me. It could also be a way more flexible and compact solution for applications that many teams currently use worm gearboxes for.

My thoughts exactly! Using the plastic gears allows for ratcheting, so the gearbox doesn't get destroyed by over-torquing the output (like in a collision with another robot), but metal gears if properly constructed would be able to shear the 1/2" hex output before the gearbox fails.