AndyMark CIMple Box Stripped Out
 

So earlier today we were demoing our robot when it started making a nasty grind, and suddenly our CIMple box on our right side drivetrain locked up. This seems totally bizarre seeing as how both the CIM gear and the output gear are made of steel. Has anyone ever had a problem like this with a CIMple box? We're a little unsure whether it's going to wind up being a stripped cim or output gear, which basically will determine what we need to disassemble and replace. Has anyone had any similar experiences?

Re: AndyMark CIMple Box Stripped Out
 

Obvious (?) question...was the gearbox properly lubricated?

Re: AndyMark CIMple Box Stripped Out
 

When it was installed during build season, I'm fairly sure we did lubricate it.

Re: AndyMark CIMple Box Stripped Out
 

They do need periodic lubrication....

Other possible problems are loose screws, or the key falling out

Re: AndyMark CIMple Box Stripped Out
 

The sudden failure described suggests that squirrel is on the right track there.

Did you disassemble and inspect yet, and if so what did you find?

Re: AndyMark CIMple Box Stripped Out
 

If it locked up, it's unlikely that the teeth are stripped away.

Re: AndyMark CIMple Box Stripped Out
 

If you stripped a gearset you would be having the exact opposite of the problem you described. If it's locked up it's probably because a set screw or keyway has come loose inside the gearbox, as mentioned before.

Have you disassembled the gearbox yet? You'll get much more information from the gearbox itself than you will from a bunch of CD'ers trying diagnose your problem based off of one symptom.

Edit: In hindsight it was probably the external self-locking retaining ring popping off the CIM shaft and getting jammed between the gears. But if there was a grinding sound beforehand then you might have larger problems.

Re: AndyMark CIMple Box Stripped Out
 

We havent disassembled it yet, we've scheduled to fix it later this week back at the school. I'll post what it was once we confirm the problem.

Re: AndyMark CIMple Box Stripped Out
 

So your gearbox failed, and your first course of action was to post about it CD?

This is an interesting failure recovery plan. :)
Opening it up is probably a good next step.

-John

Re: AndyMark CIMple Box Stripped Out
 

We had this same thing happen to us just after the fall classic in 2011 with our back left drive gear box. Ended up that the teeth on the large gear had worn away and one of them had failed. Pretty sure the issue was the we didn't grease it enough during the season and we drove that robot pretty hard.

Re: AndyMark CIMple Box Stripped Out
 

For anyone still interested, the cause of the drivetrain malfunction was two completely stripped 12 tooth CIM motor gears. According to our lead pit mentor, we oiled it routinely throughout competition, but we must have let it slip this summer. Proper lubrication is certainly important to avoid things like this happening, we're just lucky it happened at the end of a demo, not at an offseason competition.

Re: AndyMark CIMple Box Stripped Out
 

Oiled or greased?

Re: AndyMark CIMple Box Stripped Out
 

I think many of us would like an explanation as to how exactly a stripped gear made your gearbox lock up.

Re: AndyMark CIMple Box Stripped Out
 

I'm not entirely sure, I wasn't in charge of that.

Re: AndyMark CIMple Box Stripped Out
 

Is oli the right lubricant? I would suggest a gear grease developed for high gear pressure.