NeveRest 60 in FRC

[EricDrost]

We've been doing FTC for three years and I think we've seen every possible failure these motors can have. Less common failures I've seen are magic smoke (only once and it was totally our fault), and cold solder joints under the black plastic caps (two times). Billfred is spot on about the two most common failures:

Originally Posted by Billfred

1) Set screw hub maladies. [...]
2) [...] shock loads [...]

We've tried a lot of solutions to the D-shaft/set screw issue, a lot of which had slipping issues we couldn't solve. The most effective solution we found that still used the NeverRest gearheads was mounting these to the D-Shafts, then drilling through hex adaptor and the D-shaft and tapping to 4-40. About 90-95% of the D-shafts were hardened steel and required a carbide drill bit, 5-10% were mild steel. Before we settled on this solution, we lost ~5 motors in one season because a set screw would round out part of the D-shaft.

We didn't try the nubs because the above was more effective at converting D to 0.5" Hex in our opinion.


Shock load causing the individual gears to shear teeth is the most common problem (in my experience) with 20s, 40s, and 60s. The gearheads share the same design as the 2011 tetrix gearheads with spiraling pairs of spur gears held together by hopes and optimism. We lost ~15 motors in one season due to shock load, mostly in drive train applications.

Originally Posted by Billfred

FIRST hasn't announced whether switching (or removing) the gearhead will be an approved modification for the 2017 FIRST Robotics Competition. So that may be a moot point.

I can't imagine it would be illegal as swapping the gearhead isn't an electrical modification. I sincerely hope this is legal because the two most common failures are gearhead failures, not motor failures.


My recommendation to any team using these motors in FRC (or FTC) is to remove the gearhead/buy the version without the gearhead. As others have said, these motors integrate very well into VersaPlanetary gearboxes. We put 2 of our 8 NeverRest motors into VP gearheads last season and experienced zero failures with them. This season we have put every single motor on the robot into a VP and have had zero failures so far.

TL;DR: The motors are pretty good but replace the gearhead for serious use.