Need advice: Electric motor occasionally just stops working after front-on crash...
 

Hey all,

I've got this one motor that will just plain stop running maybe 10% of the time after a fairly hard front-on crash at my local off-road track.

Sometimes, if i don't have enough speed, i'll fall short of the landing ramp and smack nose-first into the front side of the ramp. Three times lately the car has just stopped running.

The first time i picked it up, gave it a good shake, and it was good to go.

The next time I took it over to the bench, swapped out a different speed controller, and the motor still wouldn't turn. I then turned the motor axel (to make sure it wasn't frozen in the bushings) and it was fine, then i pushed a bit on the brushes and it had no effect... finally I just tapped a bit on the can of the motor a few times (in controlled frustration) and it began working again...

Any ideas on why this might be happening? Or how I can fix it? The motor *seems* to run fine other than this problem, and it got pretty new brushes on it...

I had a similar problem with my fantom monster stock. I realized later that the one of the magnets had come unglued and was catching on the armature. Try rotating the whole motor 180?. if that doesnt work than you might have to re-epoxy the magnets or just get a new motor.

sounds like a hung up brush to me

When's the last time you changed the brushes or cut the comm? Did it happen all of a sudden or progressively has gotten worse? Are you using connectors or hard wiring? Is your steering affected? More info needed to diagnos.

brushes were new-ish... (5 runs?)

com was cut recently

seems to have happened suddenly

using deans ultra plugs

steering unaffected.

I now think it was brush hanging... but it's subtle... the brushes still appeared to move freely in the hoods :confused:

Look at the brushes, are they discolored or a lot shorter than the original state. With modified electric motors, one run with a slight overgear for the track you running can ruin the brushes. Make sure the hoods aren't bent or damaged on the end bell.

Check for carbon build up on the comm. If its red or dark, it needs cutting. Same with brushes, also make sure the brushes move freely in and out witth the tension only coming from the springs.

Deans are good.
If steering is unaffected, then its not radio or radio related. If you got steering, it also means you're getting power, no issues with batteries especially with it happening suddenly.
Could be ESC, but doubt it. Sounds like something with motor. Especially if you knock it and it works.

Batts dead in remote, brushess worn down, or turing colors, or chipped the brush.

tell you what.. run a direct lead to your motor.. no connectors between it and your esc... pull your motor apart.. clean thouroughly.. get a trinity hood and can aligner.. align the hood and bearings.. or bushings.. make sure the brushes move free.. can actually fall into the hood without pushing it through.. lightly lube the bushing or bearings with proper lube.. shim the arm in the center of the magnetism of the can.. use teflon shims for the outer shims... make sure there is 1-2mm of play and that's all.. do not make it tight.. turn the comm properly... install new brushes and springs according to manufacturers specs or to your racing desire.. time the motor at stock setting... you should be good to go... a clean well managed motor will amaze you..

this is vague I know.. but, maybe it will help

Cool guys, thanks for your help. I'll break the motor down and check the hoods thoroughly.

HeY!!!

warpig i don't think you have to get new springs for the motor, only if they're old and bent, or lost color.....

yes you do... to be certain.. I replace mine often to keep the correct tension... springs don't last forever at the same rate