[LongRat]

Not seen this problem reported in any searches. Basically I can trip out the motor overcurrent circuit on my X2 by lightly gripping the spindle while it is rotating - or speeding up too quickly. Certainly, there isn't enough torque available to do any cutting. This happened after I had a trip event while cutting heavily with heavily worn motor brushes. The heavy cutting pushed the motor over the edge and there was a lot of arcing followed by the motor tripping out. I took out the brushes to find them almost non-existent and the springs were brittle and cracked up from the heat.

I replaced the brushes with new ones but now I have this easy tripping problem. There's nothing binding up the transmission, and I can't see any debris around the commutator when I opened it up. The comm was worn quite a bit and I cleaned the surface of it a bit to improve the contact with the brushes, no effect though. Maybe there's a component in the speed controller that could be damaged causing this fault? Help would be much appreciated! I need to cut parts pretty soon.

[rwestbr]

It could be the plastic that holds the upper shaft bearing has melted and deformed causing the armature to ground out due to play. Thats what happened to my motor.(flame2)

Robert

[LongRat]

For anyone who stumbles on this thread in the future I thought I would post the solution to my problem.
One of the 2 power resistors in the motor controller had snapped a leg, these resistors are used to sense the current being drawn by the motor and engage the trip when the limit is reached. I re-soldered the broken leg and everything is fixed. My thanks go to Hoss for supplying a link to a very useful PDF (http://www.modelbrasscannon.com/ServiceManual.pdf), and to John Gerling for writing the PDF. A useful document to have even if your motor controller is currently working I would suggest...

[port_huon]

Thanks for the info. I hope I never need to use it.