CIM Motor Life

My team has been testing our 3 CIM Vex Pro Ball-shifter drive train and after about a week of driving fine one of the sides started to go much slower than the other. We tested our motor controllers and electronics to make sure there was no issue with the connections but everything was all right. In addition, the software was working just fine. We ended up testing each individual CIM motor in the gearbox and it turned out we had to replace one of our CIM’s in the gearbox.

I was wondering how long is the life of most of these CIM motors. We only used it for a total of maybe 24-30 hours so that isn’t that long. These were also new 2017 CIM motors.

Sounds like you just got a dud motor. We’ve been running CIMs every year, with the oldest of them being 5-6 years old. Out of our stock of 26, we’ve only had 2 die.

PLEASE do not throw it away.

Give it to someone knowledgeable/experienced with CIM teardown inspection.

Let’s find out what happened.

The bathtub failure curve strikes again. It’s highly impractical to have products with zero “infant” failure rate, but once you get past the break-in period, the failure rate can go down dramatically and stay low until you finally start wearing the product out. Which appears to take quite a while for CIMs. But yeah, there’s always duds. Always nice to catch them in the shop and not on the field, though.

We managed to smoke a CIM last night as well, but it was our own fault. Our winch arm has a tendency to fall out on acceleration, so we have a limit switch to tell us when this happens so we can pull it back in (until we’re ready to climb). The programmers coded the “pull it back in” but not the limit switch. I’m amazed we had enough battery voltage to do the driving we did up to that point. It was our first CIM failure in six years.

As well? Did you infer from the OP’s post that they smoked that CIM? IOW, not an infant failure as Kevin suggested?

BTW, that’s why I suggested a post mortem teardown inspection