Motor issue! Can someone please help?!

[JDeezie82]

I'm currently running an Integy 45t lathe motor in my SCX10 with a 23/87 gear setup. My problem is that now the motor will not turn under any kind of load. If I hold the truck up in the air the motor will turn the drivetrain but once I set it down it will not move. The motor makes a whirring sound like it's spinning inside the can but the shaft will not move. Does anyone know what might be going on? I just bought this motor less than a month ago.

[Mudsy]

Check for loose soldering joints at endbell, hung bushes and dirty comm. These are a few basic things to check out.

[Ghost]

might want to check the setscrew on the pinion also

[JDeezie82]

Checked all the basics. Took the motor apart and it looks to me like the brushes are rubbing the magnets in the can. Oiled the brushes, put the motor back together, and hooked up a fresh battery. The motor spun but was throwing sparks out of the end bell and got very hot quickly. Took it back apart, checked everything again, put it back together and now it doesn't move at all. Guess I'm out $18. Not sure what else to do.

[Badmuthatrucker]

You oiled the brushes?

That's screwed it.

They should have dry contact to the commutator and in their hoods. A hung brush is caused by either crud or brush dust jamming the brushes in their hoods and not letting them keep a good pressure on the commutator. It's normally fixed by just grabbing the little shunts out the back of the brush, pulling them out of their hoods a little and letting them snap back in.

You did put the endbell back on in the exact same position, not twisted around by 30 degrees or something?

Another thing than can cause bad things is if you left the phenolic washer out of the motor... Its a little washer, normally brown in colour that insulates the end of the commutator from the endbell bearing. Leave that out and you have heat and spark-o-rama unitl your ESC melts.

[JDeezie82]

Yeah I oiled everything. Still kinda new to motor maintenance. I did put the orange washer back in. Not sure if I put it in the right place though. Does it go inside of the bearing on the inside of the end bell or on the top before the shaft goes through the last bearing on the end bell? Also I didn't water break this on in. Not sure if that would have anything to do with it or not.

[Badmuthatrucker]

Break in is not essential (although it can have slight benifits) with such a slow motor. Anything racy, like a 16 or 9 turn, def.

The phenolic washer normally buts up against the commutator, the little shims go between it and the bearing in the endbell.

Shims are important, if there is too much endfloat in a motor, the tabs the windings pass through on the com plates can hit the brushes and get all munted up. Too many, and the motor has no end float, you burn stuff up.

Now, back to your oil... Brushes are a sintered bronze, and soak up oil and are ruined pretty god and proper by it. You could use a motor spray and clean the oil off the commutator and the brush hoods and get yourself some new brushes. You need stand up brushes, not lay downs.

[JDeezie82]

Well I know the brushes weren't hung cause as soon as I pulled the shaft assembly through the brushes closed on each other. I did put the orange washer in as described as well as the one shim that was on top of it. The only other thing I can think of that could be the problem is the shaft assembly rubbing against the magnets in the can. It had a lot of black on two opposite ends when I pulled it out.

[EddieO]

If the magnets are rubbing, thats bad news. Its possible they shifted. ...

Break in is VERY essential.....should never be skipped. By not breaking in your brushes.....you decrease brush life, comm life and cost yourself power.....just because its a crawler motor, doesn't mean much. Stock motors were 27t, not far off the 35t most crawlers run.....and break in was extremely critical on them. Brushes will rarely seat themselves correctly, especially at the speeds crawler operate at....the benefits are fairly significant, not slight.

Oil on the brushes, depending on the brush is bad....not all are made of sintered bronze, so oil has worked for comm drops before.......I don't advise it though. More than likely, your brushes are toast and the comm probably needs to be cut to get a clean face.

Sounds like a host of things could be wrong at this point....and some of the stuff you have done, may of made it worst....possibly toasted the motor.

Possibly post some pics of the arm....inside of the can, etc...

No motor needs a phenolic either.....urban legend.....Checkpoints and Orion V2s did not even come with them....I've never seen a motor short from it.....while I am sure it could happen, you would have to be running no washers on the top for contact to happen, even then the comm has a slight raised portion in the center to prevent it....the inner part of a comm is all plastic, just the outside plates are copper....

Later EddieO

[JDeezie82]

I'm not sure at this point either. Like I mentioned the motor is only a month old and has only been ran outside twice. It was working fine and then it just started acting up and then got worse. I've been noticing a good amount of glitching since I've been using my new body but I figure that's just the radio not getting a good signal now. It's the cheap axial 2ch. I can only get the truck about 10ft from me now before it bugs out and starts hopping and has issues going into reverse. I don't think it would be the esc cause it worked fine before the body switch.

[flizz]

Ya oiling the brushes is bad news the glitching sounds like an antenna problem on the RX if it's a crystal type transmitter

[JDeezie82]

Got home this morning and took the motor back apart and discovered that the shim on the shaft side was missing. I also cleaned off the commutator and filed down the brushes. Put it all back together and after a quick dip in some water, and a little oil to the end bell, it's better now than it was when I first got it. Thanks for all the help everyone!