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Unread 21-02-2011, 01:58
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Re: Banebots RS-775 Case Short

You're welcome.

The motor uses oilite type bushings, it looks like they're plenty large enough to conduct a lot of current without damage. I'd be more concerned about the brushes and commutator than the bushings. But I would be even more concerned that "fixing" a shorted winding will melt the wire and open it, so the motor will only be running on 80% of it's windings.

I looked closer at the armature, and I think the issue is that the wire was making contact at a corner of the winding, where it wraps around the core. The green insulating paint is deformed where some of the windings contact it at the corner, and in one spot metal was showing. I think that either the paint was not fully dry, or the wire was pulled too tightly as it was wound on the core.

I've enjoyed taking stuff apart ever since I was a little kid. I think it's part of the engineer mentality.