[sanddrag]

So, today we had our first BaneBots failure. It's a 256:1 P60. It slightly spun the ring gear and really seized the whole thing, before we even made it to the field. It sees only about 10 or 12 lb-ft average load, not accounting for acceleration of the arm or shock loading. The shaft is well supported. It has probably only 50 cycles of our arm on it. We took it apart, and found the DD hole in the final carrier plate and the DD shape on the output shaft to be significantly yielding/deforming. We had that welded up at the regional. Also, in place of the roll pins on the end block, we had them put in a couple weld beads, and file it flat, to match the flats on the gear. It seems to be okay now, we'll see how long it lasts.

Also, one interesting thing we discovered is that the optional Steel ring gear has slightly different dimensions than the Aluminum one. It shouldn't be different, but it is. The distance across the flats is different.