guys, i have a couple of motors that behave the same, for the 1st few time of flying with brand new motor, u can feel that its really powerful, but then about after 10times of flying, the motor starts to get slow. And this happen to not only 1 motor, about 6 of my motors behave the same.

So i was wondering if i shd do any break-in / run-in these outrunner motor like we do for nitro engine. thats the only thing i can think of that might cause it. thanks.

Outrunners are brushless, so there is nothing to run in. Id be looking at your battery packs.

Yeah, nothing to really break in on brushless motors. Unless for some odd reason you're bearings are getting tight. Are you flying in salt water?

hmm, battery wise is ok, coz i have about 6 lipos, then whenever i use a new motor, wah, i m very satisfied at the 1st few flight, but then like i said after about 10-20 flights, it become slower and slower. like for example, recently i got a motor, 1st 10 flights, i m able to climb unlimited vertical, then recently, it climb half of the height compared to when new. really strange!! bearings are all fine. well, maybe its the wind i guess. hha.. thanks guys

Does the motors have the same RPMs as when you first got them? Can you tell if the RPMs are still about the same? Do the motors run slower now, all the time?

Could it be related to plugging in the lipo while the Throttle in not all the way down? The ESC got programed by mistake that 3/4 throttle is full throttle? I don't know how to word this but it sounds like you may need to re-program you ESC to know the throttle range.

Ron

If you are pushing cheap motors really hard you may be getting them hot enough to demagnetize the magnets

John

I've been touching the bell on the outrunners to check for heating on the bench and after flights. And never felt them more than warm, never hot.

But I noticed recently that if I hand held the motor (with no prop) by the 8mm mounting stub/bearing housing and spun it up that the stub and housing quickly heated up.

It makes sense that the heat is in the stator, and maybe a tiny amount from the bearings too, and that the path for wicking it out is the mounting stub.

If you can get the magnets hot enough to lose magnetism the armature and stub must be getting very hot at that point.

Jack

If you have demagnetized the magnets, the motor will have a very high kV (if the stator didn't fry, that is). It will not lose rpm because of too much heat, unless the bearings are failing.
I cant think of a failure mode that fits the description, apart from losing the thrill of a new plane after 10 flights with it?

Any signs of vibration? Prop save, Prop balance, some of the cheaper motors some times have a pressed on Bell and it comes loose.

Just tossin thoughts

Is it always the Same ESC, maybe it is having issues.

Probably weak cheap magnets. Might be the windings breaking down.

Originally Posted by Rusty-Gunn

Does the motors have the same RPMs as when you first got them? Can you tell if the RPMs are still about the same? Do the motors run slower now, all the time?

i m not sure of those as i dun have tools for measuring the RPMs. They run slower now, all the time compared to brand new.

Originally Posted by daoldguy

Could it be related to plugging in the lipo while the Throttle in not all the way down? The ESC got programed by mistake that 3/4 throttle is full throttle? I don't know how to word this but it sounds like you may need to re-program you ESC to know the throttle range.

Ron

it can't be coz i have even tried using new ESC and reprogrammed them.

well, i also can't think of the reason for that cause. but i have tried using different ESC, reprogrammed of course. As for heat wise, i m always careful for not letting them run too hot to touch.

the reason that i can think of is maybe i shd prop it down from recommended size. maybe it gets hot in the air, and cool down after i land it, as it will throttle down and let them glide and land.

anyway, thanks guys for all the advise, hiaks.......

Bearings. Tower Pro motors? I eat bearings really fast on the 2409-12 motors on 4S. I may get 3 weeks on 3S. Now I just replace the bearings as soon as I get the new motors.

Rick