# Motor just stopped - any ideas?



## ta_man (Apr 10, 2005)

This past weekend, I was running 1/12th stock road course and in one heat, after taking a few laps to check in and get ready to run, my motor just stopped running. It didn't slow down beforehand. I stopped to wait for other guys to check in and then the car wouldn't go again. I thought it might have been a hung brush, so I plulled on each shunt and let the brushes snap back on the com but that didn't help.

When I took the motor out and connected it to my Turbo35 to try to run it, it only drew .1 amps and did not run by itself. I could spin it by hand and feel no resistance except for the brushes. Then when I checked it out at home, it ran fine. The com was not burnt, nor were the brushes. Com diameter was .280 - not worn out.

Anyone have any ideas what could cause this? The only think I can think of is that something got wedged under a brush, lifting it from the com.


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## Fordplay (Jan 7, 2007)

Thats what I would think. It dont take much grit.


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## TEAM_lost. (Sep 30, 2006)

oh you were runnin at dirtrunners? yea that track has lots of gunk, man there is sooo much fuzz and crap. did you notice and things on the comm when you got home?
mike


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## Matt Kav09 (Mar 14, 2002)

I have had a washer get sucked in the vents and lock a motor before.


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## Brad Sousa (Nov 19, 2005)

my first guess would have been a hung brush or a washer. but saying that it ran after i think just a thought but. did you just cut the comm on the motor i've seen people cut the comm and not clean the left over copper out from between the cracks in the com and have that happen. so that could have been it. it makes the motor short out when that happens and would cause what you said. like i said it's my thought on it but could be what happened.
Brad Sousa
Team 
Voodoo cells
Lightspeed racing motors
Finishline racing products


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## ta_man (Apr 10, 2005)

TEAM_lost. said:


> oh you were runnin at dirtrunners? yea that track has lots of gunk, man there is sooo much fuzz and crap. did you notice and things on the comm when you got home?
> mike


Actually the com, the entire motor for that matter, was pretty clean. My motors get much dirtier running on the dirt oval and the only problem I have had there was hung brushes, which gradually slow the motor until it stops.



Brad Sousa said:


> my first guess would have been a hung brush or a washer. but saying that it ran after i think just a thought but. did you just cut the comm on the motor i've seen people cut the comm and not clean the left over copper out from between the cracks in the com and have that happen. so that could have been it. it makes the motor short out when that happens and would cause what you said. like i said it's my thought on it but could be what happened.
> Brad Sousa


I was pretty lazy this past week, The com was last cut 2 weeks ago,had one practice pack and four heats on it before the one where it just stopped. There was nothing in the grooves - I am very meticulous when I cut coms.

I would think if the motor was shorted because of stuff in the com it would have drawn more than 0.1 Amp when I put it on the turbo35 at the track.

I've run motors where the brush was hung and they start to slow down before they quit entirely. This was like a light switch. Full power, stop to wait for other guys, and then no power. My first thought was that it was the ESC because I've never had a motor just shut off like that. I'm still puzzled.


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## Brad Sousa (Nov 19, 2005)

very puzzling. did the car still have steering? thats weird i guess i don't have the answer after all but dirt and crap will do that to a motor if it happens again spray it with motor spray quick and see what happens. :freak: 
Brad Sousa
Team 
Voodoo cells
Lightspeed racing motors
Finishline racing products


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## DJ1978 (Sep 26, 2001)

ta_man said:


> When I took the motor out and connected it to my Turbo35 to try to run it, it only drew .1 amps and did not run by itself. I could spin it by hand and feel no resistance except for the brushes. Then when I checked it out at home, it ran fine. The com was not burnt, nor were the brushes. Com diameter was .280 - not worn out.
> 
> Anyone have any ideas what could cause this? The only think I can think of is that something got wedged under a brush, lifting it from the com.


Now that the motor runs again, Have you put the motor back in the same car to make sure it is not an electronics issue like the ESC?


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## ta_man (Apr 10, 2005)

DJ1978 said:


> Now that the motor runs again, Have you put the motor back in the same car to make sure it is not an electronics issue like the ESC?


Electronics was actually my first thought, even before the hung brush idea. But the lights on the ESC worked so I tried the brushes. When that didn't work, I went to my pit and unplugged the ESC from the motor and plugged in another motor. The other motor ran fine so I used that for the main. I have, at home, since checked that the ESC runs the "stopped" motor, but until I dyno the motor (or race it) I will not know if it is again running to full potential.

Overall, I do not think it was electronics in the car.


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## Barooose (May 31, 2002)

Next time you have the motor apart, take the brushes and see if they move freely all the way in. Sometimes hoods get malformed or tapered and snapping the brush works but during normal operation they will get stuck. Is that clear? Or a peice of dirt got in there and you may never know for sure. Good luck.

"Big Dick Wood"


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## martian 710 (Jan 22, 2004)

I've had the same thing happen a couple of times and it was because of carpet fuzz under a brush.


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## ta_man (Apr 10, 2005)

Brushes do move easily in and out.

So far, it sounds like something got between the brush and the com and carpet fuzz is as likely as anything else.

Thanks, guys.


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