Is voltage limit with travel volume safe.

[clytle374]

hi everyone. I have a question. I have a problem with burning up motors, in about 5 minuits. The motors are rated for 10.8 volts, and i'm useing 3 li-polys at 12.6 volts max. I used the travel limit on my radio to limit the motor voltage to 10 volts with a full charge.

I'm not the only person with GWS EDF motor problems, so i figured it was the motors. But i just talked to a guy at the hobbies shop and he said that it was because of the battery voltage.

I can't find i reason to believe him since he didn't understand OHM's law, but i thought i would ask here and hope someone would tell me if I'm wrong and why.

how could it hurt the motor if ESC is limiting the current to a point that the voltage is with in specs.

Thanks for any help.
cory

[DaveSawers]

The ESC for a brushed motor does not regulate the voltage to the motor, it turns the full battery voltage on and then turns it off again. The frequency of the switching determines the average voltage seen by the motor and hence its rpm.

Havig said that though I can't see any reason why a mere 12.6V should ruin a 10.8V motor. We regularly run 6V Speed 400 motors on 10V or more without doing much damage to them.

[Ollie]

My guess is that you are using too much prop and the load of the prop is causing excess current and excess heat at the voltage you are using. If you use a slightly smaller prop, turning at higher RPM, it may solve the problem of burning up the motor. Try cutting the prop diameter 1/4 inch at a time till motor life becomes acceptable.

[Mr.RC-CAM]

I tend to believe you are a bit over-prop'd too. Measure the motor current and then draw your conclusions from there.

RC-CAM

[clytle374]

It is for a ducted fan, and the fan is the standard. My current draw is with in specs. 60% of the rated current at 10.8 volts, with travel volume limited, still failed.

I do realize that the ESC is pulsed, but on the same line of thought the heat is what would destroy the motor so i would think a motor would take twice the rated current for %50 for the time. Since the pulses are quick enough as to not allow heat to build during the ON time.

Is there any reason that voltage alone, with in reason, would hurt the motor. As long as it was not arcing?

I think GWS doesn't want to admit that they have some bad motors or that they over rated them. I'm not the only one.

Thanks for the help
cory