I am dealing with an 89-pole Axys Brushed DC Motor and experiencing what I hypothesize as dead-shorting of the circuit. I belive the dead-shorting theory because I took the motor apart when it was not functioning properly and saw that one of the brush's "caps" (excuse me for not knowing the correct term - but the component that connects the brush to its spring) was completely removed from the brush itself. I do not belive this could occur by simple overheating.

So, does anybody have any clue what could cause this short to occur? The motor is in a system with an inductosyn mounted very close (6 millimeters) to the face of the motor, and I have also noticed little balls of solder material on the motor face surface. Speaking w/ the motor manufacturers, they think these solder balls could have extruded up from the inside of the motor (from the windings and through the slots, etc.), but I think they may be occuring from these solder flakes "morphing" into balls and then hardening on the surface.

Does anyone have any experience with this? This is the second time these types of motors have seen this issue and I would so much appreciate any insight to what might be causing this to occur, whether it be extreme overheating or a dead-short within the motor circuit.
I have pictures of the above stated phenomenon, and will gladly share if there is a response to this thread. Thanks so much!

 

Generally, if any motor has "thrown its solder", you may consider it a paperweight. Something happened internally to short the armature, heating it enough to cause the solder to liquify and get spun out.

Do you have another motor you can check this one against?