1515 1.5y very hot
 

so i have a 1515 1.5y in my lsp and my truck stand for about 4 days in my garage.....today i removed all my electronic for cleaning my truck and my esc/motor(oiled bearing,clean the dusty fan of the esc)after that i decided to test my set-up(motor esc)and in 6 second of spinning onloaded a huge smoke come out of my motor and it come really hot fast!!!!(189f)...dont really understand what happen....4 days ago all running flawlesly and now i have a dead motor...:bad:


i checked everything(wire,plug)all its ok....could it be the rust...who causing this kind of issue??

my set-up is

ezrun 150amps
6cell lipo
1515 1.5y

Running without load is the cause... Expensive lesson...

Never run a motor without a load on it- sounds like you just killed your rotor and possibly windings by doing that. Remove the rear endbell to inspect the damage, but I expect you'll be giving Neu a phone call and a big fat cheque for repair- they wont warrenty that kind of damage.

seriously...impossible :surprised:well i think this is not about 10 second onloaded that caused this issue....a lot of time ive doing this and i never broke or melt any motor(even a feigaoor a kd)

I don't get the no load thing either unless max bearings rpm exceeded. What voltage were you running.

I test my motors without a load and have never smoked one. While I agree its not a good idea to do that I dont see how a 10 second test could have let the smoke out like that. I think those rules only apply to the sensored motors that novak puts out as they have different loaded and unloaded rpm numbers, but the sensorless stuff should have the same RPM loaded or unloaded. No load running amps are also really low, in the 5 amp or less range when I test them.

without a load the motor will spin up much faster and exceed ratings for the bearings and magnet. Bearings fail and magnets can explode!

I think the advice that you should NEVER run the motor without load is sensible. However in real life things dont always happen as they should. Manufactuers and everybody else will blame running a motor without load as its cause for failure. Now if life was that simple then we can assume that no motor should ever fail under load. Of course not - motors will fail for any reason. I challenge anybody to say that if you apply 7.2 V to a 1Y motor it will spin beyond its capability to cause self destruction. It is not going to spin at 50, 000rpm simply because there is no load.

So what is a load? A pinion mounted to the shaft?

However if you apply 25V without load then it is a different matter to this motor as clearly it has potential to over rev. The number of times I have been racing flat out when suddenly the pinion comes flying off - ie motor is not under load at full throttle - I should have dozens of burnt motors / busted magnets etc..

Unless someone can do a detailed analysis and also do a detailed forensic type investigation into the setup that led to the motors destruction I think this type of failure is going to a guess on what went wrong.

I have seen brushed motors being tested by slipping a fan blade on the shaft, just something to put a load on the motor. A pinion offers virtually no resistance to a motor on it's own. A nitro motor should also never be run without a load as it will over rev and that could be very dangerous. A snowmobile motor is the same, don't run it without a belt on the clutches, I've blown apart belts and let off the throttle. The motor doesn't come back to idle, it will free rev even with no throttle.

Well, I don't know where 7.2v came from, but running a brushless motor with no load is a dumb thing to do in any circumstances. I'm not even sure why anyone would do that, especially for 10 seconds.

In this context, a load would be something like a full driveline IMO and even then I would be very reticent about running WOT.

The OP's setup in his signature infers 6S, that's a lot of voltage !

A lesson - Yes. Expensive - quite possibly

Everybody has offered sensible advice - do not over rev a motor with no load. We are making an assumption that the OP held the throttle to the max - ie full 6S voltage. If you hold the throttle lightly clearly a ESC will only apply a small proportional voltage. It would be a very foolish thing to do to hold max throttle for full 6 seconds on 6S to see what would happen ot to test how fast the motor runs. On the other hand when I setup my brushless motors for my own safety I always take pinion off the shaft after the motor is mounted to the gearbox to check if the motor spins the right way etc.. I never plug the esc and batteries on a new setup with the pinion on in case the whole damn thing flies off due to a incorrectly setup esc. I blip the throttle to ensure that the motor is turning in the correct direction and to see if the radio needs the servos reversing etc..

Without knowing how much voltage was applied to the motor I really think we cannot be 100% certain that this was the main reason the motor blew. Did the OP hold full throttle or even 80% throttle? Were the Lipos fully charged? Is the ESC faulty? It is possible that for example the windings on motor may have been damaged already and the oil may have had some contribution.

I don't think simply running without a load would do that unless you were switching the throttle from off to WOT to full brake repeatedly. The over-revving theory seems a bit fishy too; 6s on a 1500kv motor is ~33k rpm, well within specs.

I've run motors without a load plenty of times during testing with no ill harm. I also go very gradual on the throttle too.

I'm not saying it's ok to run a motor without a load, but it seems odd that it blew the motor in 6 seconds. I would suspect something else personally.

That's what I didn't get about the no load argument. As long as rpm's are kept in check (within specs) I don't see how it can be more harmful to a motor including piston engines. It seems to me that for the same rpm a loaded motor will have more tendency to break due to the higher physical/electrical load on it's parts.

For the motor to smoke running with or without a load just simply means something failed within the motor. The only part of the motor that would cause it to smoke is the copper winding. Now the heat issue only came because you held the throttle for too long. It doesn't matter if you applied half a throttle. When a wind shorts out, you get heat. The good thing I hope is that your ESC came out ok as some times it will fail too. Most motors will never reach a high enough AMP unloaded to cause anything to fail like this. So one of the phase failed and the cause could be that it was due to fail or the ESC made a mistake switching the wrong phase.

right lutach...but my esc still running great...(i only test my set-up about 30sec) and my motor come realy hot fast...no damage on the esc



i think thi is the rust who suround the metal part inside the motor and now the electrical magnetic force couldnt make is job....so this is causing my issue,,,like ive said 4 day ago all running very well,,,,i opened my motor and a lot of rust are sticked on the stator(visible place)...