BubbleGum

Hey Ya'll.


I am looking for a new Neu motor. I have a been flying a Neu 1510-1Y in the Sunracer ~1meter pylon plane. Now I am looking at a 4x higher power application with lower prop pitch speed but much higher thrust. The Neu motor calculator tells me everything needed to spec out a motor. Except for maximum voltage. The max voltage for each particular motor is not available.

There does not seem to be any max voltage information for Neu motors. Can anybody tell me how to interpret max V from the motor calculator?


~Bub

Dr Kiwi

Aren't Neu motors rated for 60,000rpm max... so if you divide 60,000 by the Kv, that would indicate max allowable voltage.

If you look at the Medusa tables that is how THEY do it.

DaveFlynn

Motors don't have a max voltage, just max watts, Amps and RPM. Unless you're planning on an actual high voltage, 230V, don't worry about the volts.

Dr Kiwi

But Dave.. that's basically my point - the RPM limit determines the maximum allowable voltage... so a 3000Kv NEU motor is going to be limited to 20V... otherwise your no-load RPM will >60,000.

DaveFlynn

Just because you have a high voltage on the input to the ESC doesn't mean it has to drive the motor to a high rpm. The motors on machine tools run on 300 volts which would be 12,000 rpm based on a 40 Kv, but the ESC is programmed with a max rpm of 4000. Because of the PWM output of the ESC and the inductance of the motor the peak voltage, the RMS voltage and the BEMF voltage can be three very different numbers. It all comes down to how sophisticated is the ESC. I think that as the hobby ESC's evolve they will get more of the features of industrial ESC's. Like current and rpm limit settings.

Dr Kiwi

But I don't think our ESCs run that way - put 20v to a 3000Kv motor at no-load and it will spin at somewhere just under 60,000rpm... the ESC cannot control the rpm!

wingster

My Feedback: (26)

Max voltage is given here- http://www.castlecreations.com/produ...motors/nm.html

DaveFlynn

the ESC cannot control the rpm! Not true, they're externally commutated motors. It's only a matter of software. Ever hear of governor mode used for heli's.

Dr Kiwi

Yes - in governor mode - but not on a pylon plane!

DaveFlynn

If enough people call their favorite ESC manufacturer and ask for this feature, they'll add it eventually, it's just software.

I did it by adding a little module in the wire between the Rx and ESC, it's just not that hard to do. Getting the voltage up and the amperage down has advantages. In the not to distant future I would not be surprised to see settable max RPM, Current and even a servo output to control the pitch servo of a constant speed propeller.