BLX Motor

[crtakashi]

Busted open the second motor my Senton burned through. Full of black powder. That's gotta be the plastic right? I'm gonna take all the precautions to seal up my power module, but it seems like the spur gear rubbing against the case was the primary menace to the motor bearings and probably wouldn't have failed nearly as rapidly just from regular dust/dirt finding its way in.

This is about 1/3 of what ultimately shook out...

 

[Harriot10]

Busted open the second motor my Senton burned through. Full of black powder. That's gotta be the plastic right? I'm gonna take all the precautions to seal up my power module, but it seems like the spur gear rubbing against the case was the primary menace to the motor bearings and probably wouldn't have failed nearly as rapidly just from regular dust/dirt finding its way in.

View attachment 102880 View attachment 102881


This is about 1/3 of what ultimately shook out...
View attachment 102882

Definitely looks like the dust that's coming from the inside of the power module. I keep repeating myself on this thread, but shim the slipper to keep it off of the inside. I haven't had this issue since I shimmed mine.

 

[Jason537]

Whats the side of the slipper housing look like? If this has happened twice, that thing should be worn to hell by now,.. I'm almost inclined to say you are running your motor too hot and its internals that you are seeing.

 

[crtakashi]

Whats the side of the slipper housing look like? If this has happened twice, that thing should be worn to hell by now,.. I'm almost inclined to say you are running your motor too hot and its internals that you are seeing.

Here's the scoring on the case. New to all this so learning as I go. When the first motor blew out (after 4 packs) I was worried about my driving, but motor temps never exceeded 120s F. I figured I must've just got a bad bearing. Ran a second motor through about 10 packs before it blew. (Two motors in less than two weeks.) That's when I found this thread and became privy to the source of the black dust.

Got shims arriving today, so hopefully this issue is solved. I'll also be implementing the o-ring trick to help seal up the motor and taping the bottom of the power module...but I'm starting to think that a couple of shims from the get go and I'd still be running that stock motor. This is my first hobby-grade RC and while frustrating, I'm learning a lot. Hopefully this issue doesn't plague/discourage too many new owners.

 

[Jason537]

View attachment 102894

Here's the scoring on the case. New to all this so learning as I go. When the first motor blew out (after 4 packs) I was worried about my driving, but motor temps never exceeded 120s F. I figured I must've just got a bad bearing. Ran a second motor through about 10 packs before it blew. (Two motors in less than two weeks.) That's when I found this thread and became privy to the source of the black dust.

Got shims arriving today, so hopefully this issue is solved. I'll also be implementing the o-ring trick to help seal up the motor and taping the bottom of the power module...but I'm starting to think that a couple of shims from the get go and I'd still be running that stock motor. This is my first hobby-grade RC and while frustrating, I'm learning a lot. Hopefully this issue doesn't plague/discourage too many new owners.

Mine is worse than that and I've run 18 packs through according to my xbc100. Motor bearings still good, I did shim after 12 packs, regardless hard to see material getting in when the front on the motor is sealed.

 

[Jason537]

K I just did back to back 2S and 3S runs and after done my motor temp was 195F and slipper housing about 175F,.. You say 120F, you must not be running that thing hard...

 

[crtakashi]

@Yas @Harriot10 @GRC Thanks everyone for the advice. Shimmed the spur, o-ringed the motor shaft, put ceramic bearings in the motor, and taped the power module. Took it out for three packs yesterday. Turned out there was a lot more moisture under the top layer than I thought and thrashed the tray with wet, gritty dirt. Blew out a servo, but the inside of the power module was pristine with NO BLACK DUST!! We'll see how it goes, but fingers crossed for a long, active life for my motor.

 

[Jay R]

Excellent. All you need now is a hair net to stop the crud getting into the chassis.

 

[crtakashi]

Excellent. All you need now is a hair net to stop the crud getting into the chassis.

View attachment 103171

Ha nice! I tried using pantyhose for a minute, but they got torn to shreds and were kinda finicky. Hairnet looks a lot cleaner, but I already caved and got a Dusty Motors cover on the way.

 

[Nenolanjones]

Ok, I second time that I blew my motor bearing, and it was the front one (pinion side) again. Now I'm going for ceramic, but how can I take the front bearing off, since it has blown into pieces, and only the outer ring is in the motor, and stuck? Bread wont work, since the end cap has a hole, and the bearing is busted, so I cannot punch it with anything from the outside.

 

[SrC]

Buy a new motor dude. Get ceramics while you are there. Put new ceramics or even any new bearings from the beginning. Make sure to lube the NEW bearings also. Take nothing for granted. The stock bearings are crap and usually not lubed well enough so the arm. gets bricked. Need a new motor always. And you wont brick that armature for a while with better new bearings out the gate.. Bearings need to be cleaned and relubed regularly or its too late for the armature.

 

[jondilly1974]

Ok, I second time that I blew my motor bearing, and it was the front one (pinion side) again. Now I'm going for ceramic, but how can I take the front bearing off, since it has blown into pieces, and only the outer ring is in the motor, and stuck? Bread wont work, since the end cap has a hole, and the bearing is busted, so I cannot punch it with anything from the outside.

That’s a very tough one to dig out. Like Steve said, buy a new motor.

 

[3d-rc.myshopify.com]

If you have a carbide tip dremel you can cut it out. Also ceramic motor bearings are a waste of money unless you plan on taking them back out every few packs and cleaning them up good and making sure they roll good. Ceramic balls don't due well with grease so oil is what they like. Problem with that is oil wears off very fast and there for need constant maintenance. Unless you went with boca orange seals. They have thier own special blend that work good. Still have to clean and lube them frequently.

 

[SrC]

^^^ Ceramics aren't the be all end all saving grace. Any upgrade BB, that's confirmed lubed well enough will be best. On an inexpensive motor, Ceramics may be a $waste$. They still have to be cleaned regularly. And the races still wear out just like regular ones do. Those that don't clean/lube always end up here trying to figure out why their motors get bricked soon..?‍

Sometimes throwing $money$ at something doesn't solve the issue.

 

[Surchaufeur]

Put the motor in the freezer not for too long than try hitting the back of the motor against wood(be careful of course and with the end cap on) It should fall out
But i doubt The coils are fine. You should test the motor before using it again at your hobbyshop

 

[Nenolanjones]

I think in this case, it doesn't matter what bearing I had in there, it would have been seized. The debris and dust issue with the 3S power module will kill all bearings, good that I learned it now.

And yes, I know maintenance will keep these running, but wasn't aware that you can't get 10 packs with this truck (others have survived though).

I will definitely do the shim mod to the spur gear to reduce the dust, and the o-ring in the motor shaft as well.

edit. I just tossed the motor into the freezer, I'll see if I can get the front bearing off. It's a bit hard to cut it with a dremel.

 

[Yas]

You could also try unscrewing the pinion side end cap for easier access... I didn't even know this could be done until mine actually loosened up on it's own ?

you could try putting the can in a vice - not too tight - and twisting the entire motor mount plate as per the picture (with mine, the rotor came out with it because I didn't take my pinion off). You may even need to heat up the end cap to soften the thread lock holding it on, but I would try without doing so first

 

[Jay R]

This is easy, fast, and works well...

I drilled two 1mm holes either side of the hole in the end cap. You can then knock out the outer bearing shell with a steel pin. When you put the new bearing in it will cover the holes from the inside. Just make sure to drill through just the aluminium, not the steel bearing itself. If you are lucky, just drilling the holes may push out the bearing.

Like this .o. only with the small holes level with the middle.

 

[rex6638]

I just heat mine with a soldering iron for a few minutes then they just fall right out.

 

[Jay R]

I just heat mine with a soldering iron for a few minutes then they just fall right out.

Not sure that's a solution to his problem. It's just the outer shell of the bearing stuck inside the far end of the case. Are you saying to heat the entire case at the front? Possibly that may damage the insulation on the windings inside. Apparently he didn't know you can unscrew the case at the front (neither did I, wish I'd known that before). Now I know it unscrew I'd suggest putting some bolts in the mounting holes and using them as leverage to unscrew the front after warming it enough to relax the threadlock but not enough to damage the windings. Once he gets the front off it should be easy to lever out the outer bearing shell.
He'll have to make sure he puts a bunch of threadlock back on and does it up really tight after replacing the bearing.