AndyMark CIMple Box Stripped Out

[BobbyVanNess]

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?

[JB987]

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

[BobbyVanNess]

Originally Posted by JB987

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

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

[MrForbes]

They do need periodic lubrication....

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

[Richard Wallace]

Originally Posted by squirrel

They do need periodic lubrication....

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

[Madison]

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

[Adrian Clark]

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.

[BobbyVanNess]

Originally Posted by Richard

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?

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.

[JVN]

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

[Garret]

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.

[BobbyVanNess]

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.

[sanddrag]

Originally Posted by bobby5150

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.

Oiled or greased?

[BobbyVanNess]

Originally Posted by sanddrag

Oiled or greased?

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

[PhantomPhyxer]

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

[pmangels17]

The little tubes of grease that come with the CIMple boxes work great. We have a stash of them since we usually build transmissions and don't open the cimple boxes, but if you have some, those are great. We actually had the same issue this year at SBPLI, but we greased it a lot and it spun like a pro.