BL Motor temp question.

[BrianG]

Originally Posted by coolhandcountry

Accually what happens with a low load on a brushless is that the rpm goes up and the efficency goes down. So all the extra heat is generated by the lost of efficency. If you keep a brushless lower rpm I find you can have a lower gearing with out the problems of over heating.

I can see how overall efficiency would technically be reduced, but since there is less current being drawn, there is less heat on the motor (P=V*I), despite the inefficiency. Heating from overrevving makes sense though.

For example, I ordered a Wanderer 8XL (kv=1875) and plan to run that around 16.8v - maybe as high as ~20v in the future. According to the BK site, this motor is rated at 80,000 max rpm. So, even at 20v, that's only 37,500 RPM. I would have to run around 40v (maybe a bit less since the kv rating is the loaded value) to get close to 80k RPM. That being said, I really couldn't overheat from over-revving could I?

I'm not trying to be argumentative; I just to be sure about this stuff. :) The reason I'm going BL is so it is more worry free and plug-n-play than Nitro or brushed setup. I was hoping I wouldn't have to carry my temp sensor around with me to check temps every 5 minutes. I figured as long as the motor was not running free, I'd be fine as long as I made sure the gearing wasn't too tall.