9920 too hot

[Scott711]

Well after having nothing but good luck it would apear bad luck has found me. My 9920 is getting hot (150+) after just a couple of minutes of running. Previously I've never had it above 125 even after hard speed runs and 20 minutes. I've check everything imaginable, wiring, driveline, gear mesh, etc. The motor and batts are still very cool 110F and 75F respectfully, which is where they always ran. I'm at a loss to what could have happened but I noticed one capacitor is deffinetly hotter than the other. If I'm missing something let me know other wise I'll be e-mailing Mike to see what I should do. The esc only has about 6 runs on it so it's dissapointing to have this happen so soon.

[coolhandcountry]

have you changed body or something? Maybe move the esc to another spot. What gearing and motor cell count to?

[crazyjr]

Have you had a change in outside temp over the last few days

[Scott711]

I've changed nothing, gearing 14/51 with 5s lipos with an 8XL. Outdoor temps around 50. I can't figure it out maybe I'll shoot Mike an e-mail and see what he says. I think tomorrow I'll peel all the shrink wrap off and see what the PCB looks like. I've had all I can take for one day...... This is suppose to be fun.:frown:

[BrianG]

Is it possible the 8XL is pulling too much current for the 9920 to handle consistently and damaged one or more components forcing others to work harder?

[Scott711]

I suppose that is possible but I find it hard to believe that would be the case since most people on the forum here said this setup would work fine and should not be a problem for the 9920. When I get to it tomorrow I'll take a closer look at the esc and see if there any discoloration on the pcb or components.

[BrianG]

Are you by chance using the built-in BEC? If a servo or something is drawing more current for whatever reason, it will heat the regulator pretty quick on that small heatsink.

[offtopic]: Wow, I didn't know there was a Des Moines in WA. And now that I checked, there is one in NM, and CA as well. I learned something new today. :)

[coolhandcountry]

The 9920 on that gearing should run a 7xl. I don't see a problem yet in the setup. Unless you was running some big huge massive tires like jumbo kongs or something.

[Sylvester]

Maybe there was a short? or not... your problem could be the motor pulling a bit too much amps.

[Scott711]

Well I got back after it this morning and see nothing wrong with the esc. The pcb and all its components look clean and undamaged. So I hooked up the batts and took it for another spin to see if the magic elf fixed it over night. No luck, after a couple of spins up and down the street she was glitching again and getting hot. The thing is it is hot at the spot where the negative lead terminates to the pcb and that capacitor is also heating up pretty fast. The heat sink and rest of the esc are in the 60's on the heat gun.

I've got another problem that has come to light. The motor is making a sound like gears striping. When I put my foot in front of the truck and hit the gas I get no power to the wheels just an awful gear striping sound and it definitely is not in the tranny or drive-line. I get my ear down there and it's coming from the motor. At first I thought the pinion was striped or something but the shaft showed no signs of that. So I've taken the motor off and give the shaft a good spin and it spins real clean feeling no weired grinding feeling or anything. I don't see anyway to get a look at the inside of the motor so I'm not sure what to try next. Is it possible there is a short inside the motor?

Btw, I'm using a UBEC and standard size tires nothing monster anything like that.

DesMoines, WA is a small suburb 10 miles south of Seattle.

[coolhandcountry]

You can pop the rear endbell off the 8xl pretty easy. Take the pinion off and tap the motor on the shaft on some wood or so.it won't take much. It may be your magnet has come loose on the shaft.

[Sylvester]

Hmm.... that sounds very weird... somthing in the controller may be doing it no good.

To look inside the motor you have to pop off the rear endbell. I dont think there is a short IN the motor, it could be 2 of the 3 wires touching though.

[Scott711]

I may have found the culprit. It appears one of the motor leads has cracked or peeled away the casing and exposed wires and possibly grounding to the can. What do you think. Can it be fixed? Do you think this is the problem?

[Sylvester]

That could be the problem, it can be fixed, you can use electrical tape to cover that up.

[Sneeck]

I'd go for heatshrink over electrical tape.