Originally Posted by John Stranahan
John-the two problems were not heat related but caused by the comm tabs or larger segment of the comm contacting the angled brush hood tips (and brushes). Enough debris was created to pepper the armature windings with damage as well as damaging the brush hood tips. I'll aggree that if you never bump the side of the car on a high speed layout that this damage may not occur, but thats what we race on.
If I understood correctly, the comm moved up and down so much that it actually reached and hit the copper tubed brush hoods?
If this is the case, I find it very strange! The o-rings that secure the endbell bearing would defenetly not allow so much movement if any.
This is the first time I hear of this problem.
Could it be that while rebuilding them the endbell bearing was not proberly positioned?
I can't think of any other reason.
One of the things that I like in V2 motors is that there is no need to aling the brush hoods, as to my experience they do not move.
There is one thing I can think off. While soldering the wires on the motor, if in order to check whether the wires were properly secured they shaked the soldered wires left-right while the whole endbell was hot (and the epoxy that holds the copper brush tubes on the aluminum endbell was soft) then the tube might have turned just a bit reducing the distance from the comm.