drx

Are all commutators of the same dimensions (diameter and length).

If he same, what are those dimensions.

Of that diameter, how much material can be removed in truing before the armature is considered useless?

thanx

</DrX>

DOMOisCOOL

I believe you can go down to .270 on stock motors and .260 on mod motors.

They both come from factory at around .290-.288. They are .300 when fresh from production.

rccartips

iTrader: (3)

Not only the diameter but the length also varies from one manufacturer to another, and from one motor model to another.

I have tried putting armatures from one company (e.g. Trinity) to another company motor can(e.g. Associated) and it was not a good fit (the magnetic field was not balanced to the different armature.

Best to stick with an armature designed for a specific motor can.

Java1970

Very true, but a mod armature in a stock can makes an interesting run goofing with your friends!!

Here's a neat trick I discovered recently: Take the armature out of the can, place it in the business end of a Dremel, put the Dremel in a bench vice, take some super fine sand paper and while the Dremel is turning the armature, hold the sandpaper to the com and it will polish like magic!!! A poor man's com lathe. I don't recommend it for EVERY time, but it works in a pinch when you have a race and the hobby shop is out of com cleaners!!!

fatdoggy

Ahh yes I used to do the old sand paper deal. If you've done it a few times you WILL be amazed at how much you'll have to cut off when you do end up cutting the comm. Not idea. But works ok as long as you've shimmed the motor properly and don't change the shimming.