Black dust/residue on main gear

[aaronbru]

As the subject says, I've got some black stuff on the top of my main gear. Not on the teeth, but on the body of the gear.

Is this common? Or am I getting wear that is out of the ordinary. I've probably flown 20-30 packs through it by now.

[TZZDC1241]

I'm curious myself honestly. Could it be the gear rubbing against the body? Tail belt a little too tight? Black gear that leads from the bottom gear to the tail?

Thats all I can really think of in terms of the black stuff.

[buddha2490]

Pull your motor, I'll bet you find black dust on the bottom of it and possibly a groove ground into the motor shaft.

[FuntanaS]

It could be oil/grease from the OWB. Wipe it off and see if it comes back.

[DJtoad]

Originally Posted by buddha2490

Pull your motor, I'll bet you find black dust on the bottom of it and possibly a groove ground into the motor shaft.

Yep, what he said. If you find black dust underneath the motor is probably time for a new one. The motor shaft has a tendency to rotate in the bearing and that will wear a groove in it over time. If you search this forum you can find a few temporary fixes but in the end, you're better off just buying a new motor. Unfortunately, you can't simply buy a replacement shaft.

[aaronbru]

If I do find that to be the issue, should I step up to the 440 motor?

[buddha2490]

Originally Posted by aaronbru

If I do find that to be the issue, should I step up to the 440 motor?

If you want to... or you could go with a different brand.

[buddha2490]

Originally Posted by jdFin

I think the easiest way to detect a bad motor bearing early on is to just check the motor temperature after each flight. Once the bearing starts going, it will start getting pretty hot. I just grab the motor after unplugging the battery to see if it's hot. What is "too hot"? Grab your dust-ejecting motor after your next flight and I bet it is "too hot".

IIRC, the stock motor when new was only slightly warm after six minutes of circuits in 70 F weather. I have a scorpion now, and that's how it is, as is the 440 in my 450-X (after five minutes). Just warm, no one would call it "hot".

On my third e-flight motor, I noticed it getting hot ("ouch!") that way, pulled it, blew away all the black dust and bits of circlip/bearing, and avoided another unplanned auto. If your motor is running "hot" and you don't want to change it out, stay away from the babies & puppies because you could be coming down at any instant.

Bigger helis or harder flying might result in a hotter motor, but I can't speak to that.

That's funny you should mention that, because now that you pointed it out, that's exactly my experience. I remember my eflite motor getting very hot towards the end of its life and thinking that it was a recent phenomenon, but didn't link it to it failing. But you're right, my scorpion always comes down barely warm.

Neat!

[TDMModels]

The 440h motor in the 450x does the exact same thing. Take the motor apart and put blue lock tite in the bearing race where the shaft goes. Let lock tite cure before putting the motor back in the heli. The fix is good for maybe 50+ flights. If the shaft is worn you can build it up with Ca and then sand down smooth before doing the lock tite thing.

[aaronbru]

I have blue loctite and motor bearing lube on the way.

I've been putting off these one time costs for a while but it's about time I get that stuff.