Burro crane shorting out

I'm sure other more knowledgeable post war experts may have more to add to this, but the most glaring thing I would make sure of is that the insulator between the collector assembly (bracket the 2 center rail rollers are mounted to) and the frame is truly insulating.  (and is still there - you didn't accidentally "put aside" any pieces during disassembly, and then forget to put them back, right?   )

That and the wire itself that runs from the collector assembly/rollers to the motor.  Any missing insulation along that wire could easily short to the frame (especially if the wire accidentally got pinched during re-assembly)

Good luck.

-Dave

@Dave45681 posted:

I'm sure other more knowledgeable post war experts may have more to add to this, but the most glaring thing I would make sure of is that the insulator between the collector assembly (bracket the 2 center rail rollers are mounted to) and the frame is truly insulating.  (and is still there - you didn't accidentally "put aside" any pieces during disassembly, and then forget to put them back, right?   )

That and the wire itself that runs from the collector assembly/rollers to the motor.  Any missing insulation along that wire could easily short to the frame (especially if the wire accidentally got pinched during re-assembly)

Good luck.

-Dave

Thank you for the reply. The plastic insulator is in place, and I have verified that it is working by placing just the chassis and collector rollers on the track, applying power, and not getting a short circuit. The wires also look ok. The only time there is an issue is when the motor is in contact with the top of the chassis. It seems like the motor is supposed to be insulated from the chassis, but there's a screw that anchors the motor directly to the chassis, so there must be something else going on.

Looks like the problem was the armature windings contacting the exterior of the motor. I'm not sure what caused this, but my guess is that I did not anchor the motor completely, causing it to sit too high while the armature was pulled down by the gears. I reassembled the unit and it no longer shorts out. It also looks like the gear issue resolved itself, as the unit runs well in both directions. I'm glad I didn't bring it back to the service station!

Glad you were able to fix it.  Makes sense.  Since the whole frame definitely is connected to the outer rails, I was wondering if some odd thing had happened with the motor itself.

-Dave