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Unread 20-02-2011, 23:57
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Re: Banebots RS-775 Case Short

I found the short. The first winding on the motor was touching the amature core, at this corner. I found it by connecting my trusty 77 DMM to one end of the wire and to the shaft, and it beeped until I got this part of the winding loose. It was very difficult to remove the wire here. As soon as I pulled it loose, the beeping stopped.

My take on it: I did not find any "debris" in this motor, but it also had a complete short of winding to armature core. If you have a completely shorted motor (less than 5 ohms resistance from either terminal to case), then I'd suggest you do not use that motor. If the resistance is considerably higher, then you might possibly have a "debris" problem, and if you "fix" it by blowing it with high current from case to winding, the motor might be fine.

btw the white stuff is glue that is used to hold the plastic fan in place.

I hope this little forensic exercise was helpful!
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