Hey all, I flew my E-flite mini Edge today just doing laps in the sky and when I brought her in, the motor was hot, couldn't keep my finger on it for more than 2 1/2 seconds. setup is 1500mah Lipoly, E-flite 40 amp esc, himaxx 2025 5300 motor, stock gearbox, stock gears and stock 12x6 prop. I'm a bit puzzled as to how the other fliers with the same setup handle this issue. I'd ask them but I haven't seen them at the field last couple of times I went... anyway thanks for the help

I'm fairly new to electrics too, but make sure your motor is not turning too many r.p.m's. I'm not sure what your gear box ratio is. Also, make sure your esc is programmed for your setup.and have adequate air over and around your motor. Hope this helps!

I am interested in your comment about the motor not turning too many rpms. I don't recall seeing that caution in relation to electric motors before. The only way I can imagine you would over RPM a motor would be to over voltage it. Is this what you are saying?

Also not sure what you mean by being sure your ESC is programmed for your set-up. Can you be more specific so he can make the correct settings?

"but make sure your motor is not turning too many r.p.m's."

This does not cause heat. AMPS cause heat. Lower your amps by reducing the prop. By the way the GWS 12 X 6 pulls more amps then the APC slow flyer 12 X 6 and that pulls more amps than the APC electric 12 X 6.

I optimize my thrust per Amp by measuring the static thrust for a whole bunch of propellers, to see whitch one generates more thrust at an Amp rating it can handle. When you overprop, the Amps go way up, and you actually loose thrust as well.

I don't have that motor, so I can not tell you exactly the right prop to use.

Larry

My hacker manual warns not to exceed 20,000 r.p.m. Which would probably only happen with a gearbox and too small of a prop, or no prop at all. About the e.s.c., be sure it's programmed for three cells not two (if thats what your using). Like I said, I'm fairly new to electrics myself, others could probably be more helpful. Sorry!

A hot motor is normally caused by too too many amps, or a mechanical problem like a bent shaft or an unbalanced propeller.

If we assume the shaft isn't bent, the bearings and the gearbox aren't damaged and the prop is close to being properly balanced, too many ampes is caused by one of two things:

too much prop for the motor/gearbox/battery combo

or

too much voltage driving too many amps into the motor.




Since I have a Himax motor, I know that Himax includes documentation with their motors that recommend prop and battery sizes and amperage limits for their motors.

You did not say how many cells in the lipoly. This is extremely important. You may have too high a voltage going into that motor. Too much voltage would be like putting too big a supercharger on your engine. Eventually it will break the engine.

By stock gearbox, are you saying the gearbox that came with the plane or with the motor?

What prop does the Himax documentation recommend for that motor/gearbox combo?

Can you confirm that you are conforming to these recommendations?

Is your ESC programmable? Have you made adjustments to the timing in the ESC?

We need more info if we are going to help you.

RTFM - Read the friendly manual and available documentation
2025-5300 3mm 6.6 25A 80g 175
Integrated GWS Motor Mount and Himax Motors
-Direct upgrade for GWS 300/350 & GWS400 gear motors,
-Himax HA2015 or HA025 BL motor installed –optimum power and performance,
-use 2015 to replace 280 & 370 type motors,
-use 2025 to replace 370, 400, & 480 type motors,
-Aluminum gear housing – no more broken gear housing,
-Built-in cooling fins – no more overheated motors,
-10mm x 10mm mounting box – fits most planes designed with GWS gearboxes,
-6.6:1 gears installed, 5.3:1 & 4.3:1 gears included – flexible power manage

Based on this I would expect that the motor can take up to 11.1V. I would guess that a 12X6 prop is either too large or too deep, but I would consult the documentation that came with the motor. You are probably pushing over 16 amps/175 wattts, and that is probably too much.