pic: Ex-bearing

Diagnosing a “clicking noise” on our test bed revealed this today. Removing the outer race from the drive rail proved to be quite a pain; one good reason not to press-fit bearings into drive rails.

What caused it? Was it an old bearing?

Too tight of a press fit can cause premature bearing failure.

New bearing; likely caused by students being a bit too careless when lowering the testbed back onto its wheels (we prop it up on its side to allow the wheels to spin freely for debugging). The test bed is weighted to 135lbs; allowing it to “drop” probably shattered the bearing.

It wasn’t actually an interference fit when the thing was put together (more of a tight slip-fit - it could still be taken out by hand with some force); it seems to have deformed, probably at the same time that it failed.

We had a similar thing last season at worlds that we didn’t know about until we revamped the bot for IRI. It was the main bearing that the drive axle was in as well.