[FTC]: TETRIX DC Motor failure analysis

[PhilBot]

We just came back from the MD regional, and while doing some Autonomous programming, I noticed that YET ANOTHER DC Motor was acting up.

A quick observation indicated that it was a gearbox failure (We have yet to actually smoke a motor).

When I got home, I added it to my growing collection:
Three from last year, and two from this year.

I decided to pull them all appart to see if there was a common fault.

I'm mention here that all of these motors were used to drive mechanisims OTHER than the drive system. Last year it was the Puck Bucket (used to collect and score) and this year it's the Ball Chute Trigger arm.

Here's the final analysis:

3 x Second to last gear in drive chain shattered.
1 x Final Drive Shaft main brass bushing come loose
1 x Final Drive Shaft small secondary brass bushing broken

I've attached a pic of the drive gear that failed three times. Clearly this gear cannot deal with the force/shock of a mechanism hitting something. It looks like a sintered gear (not brass or steel).

I guess if there was a published spec for MAX load on this gearbox I could make sure we don't exceed it, but there isn't one that I can find. I guess I can add some padding for impact, but that won't help if we get stuck on something.

I'd really like to find a replacement for this gear, becasue it's an expensive motor to throw away. Luckilly I was able to canibalize the two gearboxes with the busted bushings and make two good motors out of the 5 bad ones.

Phil