Torque master pro not spinning

[Tyler-brown]

Hey guys! so here's the story
I have 2 holmes hobbies torque master pro motors on a moa rig, with a 10 amp castle bec, 11.1v 3400mah lipo battery, axial ae-2 esc, and a Spektrum DX3E receiver. Works great, never really had an issue, untill today. I was out crawling some rocks and the rear motor stopped spinning,(forward or reverse) I could get it back spinning if i helped spin the tires in the direction i wanted to. It wouldnt take much, just the front tires pulling ( or pushing in reverse) my rig across the ground would be enough to "jump start" the motor. So i figured brushes and replaced those even though the originals didnt look bad, and same thing! I pulled the motor all apart and cleaned it with compressed air, and realised the com was abit worn so i gently sanded with 600grit sandpaper untill nice and smooth, and blew it all out with compressed air again, and reassembled. And... same thing, the motor needs just a bit of help to get it spinning in either direction. i have about 10 runs on these motors, and the front works perfect. So to test to see if it was motor or wiring, i put the rear motor (one giving me troubles) in place of the front motor (one working perfect) and same thing.. needed "jump starting" which leads me to believe it is motor and not wiring.. I wont rule that out though. It has seemed like i`ve had "clod stall" on the rear motor as well. Any ideas would be greatly appreaciated! Thanks guys!

Tyler

[benoj]

Usually when a motor needs a bump to start spinning it means either the armature has a short in it or the brushes need replaced. Since u said you changed the brushes I think the arm is the problem and the only fix is a new one. And by the way it's not a good idea to use sand paper on a comm as it may look better it's not uniformly smooth which will cause the brushes to wear the comm out even faster


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[EddieO]

Since the problem moved with the motor, that pretty much eliminates it from being anything other than the motor.

So, its one of two things

1. Its a hung brush....while you started at well in replacing the brushes, you finished terribly by sanding the comm. The only way to fix a hung brush is to cut the comm with a lathe, in fact the sandpaper probably made it worse. I am starting to think John and I should have stickers made that say "please don't use sandpaper on me".

2. It's a shorted (often called a stalled armature). This will mimick the symptoms of a hung brush usually. This pretty much happens from a nasty bind that caused an internal short on the arm. There is no fix for it other than replacing the armature.

Later EddieO

[Tyler-brown]

well now i know not to do that again! figured i couldnt make it worse since there was a groove in it before and i smoothed it off and rounded it nicely, but. now i know not to do that again. Is there any way in looking at the armature to know if its hooped? Or just order a new one and do process of elimination? thanks for the fast answer guys!

[EddieO]

If you cut the comm and replace the brushes, but it still remains, its shorted....

Later EddieO

[Charlie-III]

Originally Posted by EddieO

If you cut the comm and replace the brushes, but it still remains, its shorted....

Later EddieO

+1.

I've tried to "find" a stalled/shorted arm, usually never find anything I can see or measure other than the motor works wonky.

[JohnRobHolmes]

Put an ohm meter or continuity meter on the brush leads and slowly spin the motor, or take the armature out and test each segment to the next. You should have low resistance and continuity at all times.


I have gone through many of the "stalled" arms in the past month and found that every single one had a broken wire that wasn't visible with inspection. Push on the wire just a bit and the culprit shows itself! If you don't have hanging brushes, you probably have a broken wire.