Re: Drive Assembly Sprockets are Custom Bored
 

did anybody else have the problem with the lockwashers grinding in the transmissions? we had this horrible noise and saw they cut a groove into our gears...the manual says it was really rare...but it happened to us. And the washers were on there exactly as they had told us...they just seemed too big. We worked it out, but it was quite a scare to hear grinding in the gearbox.

Re: Drive Assembly Sprockets are Custom Bored
 

The lockwashers on the end of the CIM motors came in 0.010" too large on the diameter. The prototype boxes did not have this problem. The lockwashers will be replaced by something else next year (if FIRST wants to use them next year. I really do not know that for sure, but I am pretty positive we will see them again). We are using the set screws in our transmissions and they are holding up fine. Remember, you must use loctite on the threads of the set screw and make sure the set screw is clean and dry before applying the Loctite.

Re: Drive Assembly Sprockets are Custom Bored
 

If I remember correctly there were two sizes of the plastic washers and each size had a particlar place it needed to be. That could be what caused the grinding noise... :confused:

Re: Drive Assembly Sprockets are Custom Bored
 

What we are talking about is the metal locking ring that looks like a washer. It is round on the outside and has little fingers on the inside. You press it on the CIM motor shaft to lock in all the components on the shaft.

Re: Drive Assembly Sprockets are Custom Bored
 

It happened to us, too. We eventually just popped them off and relied on the setscrews. So far, so good, but our tournament starts tomorrow...

Amusing anecdote: we first tried to reduce the diameter of the washers by holding a file up to them as they spun. Ha. Ha ha. Ha ha ha. Want to buy a file with a nice groove carved into it by a spinning washer? Those washers are made of hard steel...

Re: Drive Assembly Sprockets are Custom Bored
 

I just ground the OD down on a bench grinder--no problem at all, and took about 2 minutes each.