lost some power, time for a motor rebuild?

[haligen]

So I just put my new crawlmaster pro 20T in about a week ago and failed to do a break-in, my bad. Took it out and ran a few packs through it, everything seemed fine. Redid some things on my rig (put the sway bar on and vented my wheels) and went back out the next day to play some. Everything was going great, and I was playing around trying to see how slow I could crawl. Then the truck started acting like the pack was dying so I went to change the pack and It had a slight electrical smell. I put my finger on the motor and it was good and warm, could do a 3 count before the finger had to come off it. Stupid me left the temp gun at the house. I let it cool for a bit, changed the pack and went back out. I'm not sure if its mental but the truck seemed to have lost a step. Like it had dropped a cylinder or something, still running but just not what it was. I pulled the brushes when I got home and they dont look to bad to my untrained eye. Could it maybe be the esc acting up? I'm running a 10T pinion on the stock spur and 2s. Sorry for the crud pics, it was late when I finally got to take a look.




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[JohnRobHolmes]

brushes look good on the face, just a little pitting on one edge. the wire shunt may have been catching on the hoods. It normally gets bent over during shipping, and after a little use the brush wears and starts getting bad contact. get a photo of the comm too, look for any groups of wires that are discolored from the rest, and inspect that none of the wires are broken where it meets the comm.

[haligen]

Pulled the motor apart and I'll be damn if I see anything obviously broken. Maybe its the esc.




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[Steve-O]

I would bet that you just had a "hung brush". What happens is the brush can sometimes get stuck in the hood of the endbell. Just lightly pull on the braided wire out of the back of the brush and let it "snap" back against the comm. Those brushes and the comm look completely fine. Like John stated earlier if the braided wire is hung up it can keep the brush from being pushed against the comm as well.

[allanon1965]

I do seem to recall Holmes motors are already broken in when you get them, I know I have never broken in any motor I bought from Holmes Hobbies and never had any issues with longevity

[powder4breakfast]

Well I learned something new here. I didn't know we were supposed to break in motors. I guess I have some research to do.

[haligen]

Well I went out and ran it again this afternoon. Everything seemed to run fine except it liked to get really warm. If I did a few back to back crawls the motor would get up close to 200 degrees. If I pushed it for another run the temp would keep climbing. The max I let it get to was 215. So I guess the motors not fried, not yet anyway, now to fine why its running so dang hot.

[jeepgod]

I would check for binding, what gearing are you running? And check to make sure there are no wires touching that shouldn't be.

[haligen]

Everything seems to spin freely, and I'm running a 10t pinion on the stock 64t spur. I used the leads off the factory motor, I wonder if there to small for the amp draw.


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[JohnRobHolmes]

Did you ensure that timing isn't retarded? Above 160f on the can isn't normal.

[haligen]

Originally Posted by JohnRobHolmes

Did you ensure that timing isn't retarded? Above 160f on the can isn't normal.

I think its timed right? I am running in reverse direction, would that effect it?