CIM Motors reusable?

[Chris_Ely]

Originally Posted by yash101

They were shooter motors running at free speed for maybe 10-20sec, with sudden loads (frisbees being shot)! We used two BAGs. I think some of them got shorted and others had their bearings broken. I think this was all because of poor design because 14000 RPM seems like it would cause arcing in a brushed motor!

Do you have any evidence to back up your arcing claim? Many brushed DC motors achieve speeds much greater that this, including FRC motors. See the 2013 Motor Performance Data sheet.
If you had you shooter wheels directly attached to the output of the gearbox, I could see the side loads from the discs being shot effecting the motor.

[yash101]

Originally Posted by luckof13

Do you have any evidence to back up your arcing claim? Many brushed DC motors achieve speeds much greater that this, including FRC motors. See the 2013 Motor Performance Data sheet.
If you had you shooter wheels directly attached to the output of the gearbox, I could see the side loads from the discs being shot effecting the motor.

I have a feeling that that may actually be the problem, though it seems unlikely. When a frisbee is being shot, it will put a force on the wheel, causing the motor to be sideloaded. That was partially our design, because the compression in the disks helps push them get accelerated better!

Anyways, I (and many others) are done with talking about THIS bag motor failure!

[Al Skierkiewicz]

CIM motors do last a long time if they are not abused. However, the brushes do wear and produce varying resistance to case. Do not be surprised to measure a 2K to case. I have taken some apart and cleaned the dust around the brush assembly. While apart we also added some oil to the bearings.
Do not believe that simply mounting a motor to a gear box will eliminate loading problems. I have seen more than one motor damaged by improper mounting to a transmission. Also, depending on design, a severe side load on a transmission can translate to the motor shaft.
The good news, a CIM smells really bad when it has been abused. Take a good whiff at each end of the motor. If it smells burnt, don' trust it. A CIM motor that has been abused and shorted some windings will have less power output and lower free speed. There are several other failures that occur if you follow the links above.