FIRST Cim problem

[Avihu]

Hey we just ran our *new* chariot and we FAILED..
the chariot ran very nicely for almost a day when we decided to test who much weight can it carry.. the answer: Not that much...
than when we tried to run it without the weight one side of the chariot (one cim) got jamed or something and then it started to run OK again and then jamed again and it just repeat it self and we don't know what to do.. we might have broke a Cim already..?
and if not.. what to do??

[nathan_hui]

How is the CIM geared to the wheels? Did you grease the gearboxes? What control inputs are you giving it when you see the failure? What does the motor controller think you're telling it to do?

[Avihu]

toughbox, yes and i didn't undeestand the last one..

[nathan_hui]

Is software telling the motor to go 100% forward, 100% backwards, or what? And what does the motor controller status light say it's getting? (Basically, is the motor controller and control system working?)

To add on to my initial questions, when the robot is off and unplugged, can you turn the problematic drivetrain by hand? How many turns, and how hard is it to turn?

[Ankit S.]

We had a slight problem with the gearbox jamming. When we inserted the bearings, a freshman was somehow able to bow the mounting plate a little. As a result, the gearbox would jam when tightened.

We flipped the plate around, and haven't been troubled so far.

[Bill_B]

Sounds more like low battery power is having controllers cut out. If you have a battery with one sick cell, the charger may tell you it has finished charging, but the battery is incapable of delivering what the control system needs for your heavy load testing.

[nathan_hui]

@Ankit: Not the OP's problem - he's got occasional jamming, not continuous.

[Avihu]

the problematic rail is kind of hard to roll by hand and when rolling one way it makes a really *not good* sound that the other does not make..

[EricH]

Have you opened up the gearbox and looked inside? Something might have gotten loose in there and be jamming gears as it jostles around.

[nathan_hui]

I would definitely look at the gearbox. If you can, simply replace it. Otherwise, do what Eric says. If you can't figure out what the problem is, try replacing all of the grease. Make sure that there aren't any dings on the gears. Make sure the bearings are good. Since your problem was (according to your description) intermittent, I doubt it's the plates, but now that it apparently isn't intermittent anymore, Ankit's problem may have a lot more commonality to your problem than I initially thought.

As you are replacing the gearbox, run the CIM motor separate from the gearbox. It should spin up pretty nicely. If it doesn't, the CIM's shot. Doesn't mean the gearbox isn't shot too, so keep checking both.