thats what i was gettin at is that its illegal once u cut it...you can turn the com on any motor. you may have to bend the tabs on some old non-rebuildable stockers and closed endbell motors (the silver can ones). then pull out the com. once turned clamp the tabs back down. the only downside to this is the motor would NOT be legal for racing after its rebuilt but there is nothing wrong with continuing to use it as a practice motor or basher motor.
Great idea man!Best and easiest idea:
Get some Brasso from the hardware store, and one of those grease syringes (monoject is the name I think). Suck some Brasso into the syringe, and put a small amount onto the comm by going thru the vent on the motor. Put a pinion on the motor and roll the gear back and forth. The Brasso should turn black quickly. This will remove most of the junk on the comm, and also help to seat the comm and brushes back together as much as you can without a lathe. Make sure to throughly clean the motor with motor spray to get all the Brasso out.