Motors

[69bradley]

How many times can you get a motor turned until the comm is gone?

[SteveP]

It depends on how much material is removed each time the commutator is cut. The average commutator is .300 to .295" in diameter. If you take off .002" per cut, you can get as many as 15 cuts before the comm is used up. take off .005 per cut and it's toast in as few as 6 cuts. You shouldn't cut the comm to less than a diameter of .270".

[B3 Bomb]

You can get more cuts out of a motor if you dont wait until the brushes have cut huge grooves in the comm themselfs. Before I got a lathe the motor I was running could not be cut.