Wierd grinding noise from the Banebot transmissions

We were extremely tight on schedule when we were building the robot and didn’t get to test it till the day we shipped it. When we powered up our robot, there were loud noises comming from transmissions or wheels when we drove it. When we drove it straight forward(Note:We proped it up on boxes so there was no load on the wheels) the wheels weren’t driving properly. One was starting slower than the other. I don’t think that it was a calibration problem, but rather the gears in the 2 motor adapter was grinding against the cylinder part of the BB transmissions. What does everyone else think? And if it really is the gears grinding on the transmission, is it possible to just let it run and grind away the rest? (It takes a LONG time to take apart and we won’t have time at the competition.)

Others have had problems with the 56mm transmission with the two motor adapter, and the problem was that they inadvertently removed a large, thin, black steel plate from inside the transmission while installing the adapter. This resulted in the gears rubbing against the aluminum body of the adapter, instead of that hard steel plate, and the soft alumimum and soft brass gears were getting ground up.

I don’t know if this is your problem…but it could be…

Also there seem to be issues with adjusting the end play in the transmissions, I don’t know the specifics of the two motor adapters, but with the single motors you need to check carefully to make sure the gear and motor shaft are not extending too far into the gearbox, and also that there is not too much free play (which allows the output planet carrier to be too loose on the output shaft).

No, we didn’t remove the thin peice of metal. (The one resting on the several small gears)

Then there must be some other issue, you probably will have to take the transmission apart and see what’s going on. Check clearances and such before/during disassembly, and look for signs of wear or seizing. Also make sure the output shaft is well supported by a bearing block on the end of the shaft beyond the sprocket/wheel.