whatever wrote:this is a bit off topic but.... if a hubmotor is getting hot and needs to be cooled, is it not better to rewind it to suit the power level being used? Would save alot of wasted energy
Miles wrote:Not sure what you mean? For a given torque output, copper losses will be the same, no matter how you wind it (assuming equal fill factor).
whatever wrote:Miles a hub motor is going to get hot if its overvolted, run within specs should be negligible heat.
Instead of cooling rewind for the amp/volts that are intended for it. Number of turns and thickness of wire are the main two variables, effect on torque I have no idea, but there should be some formulas out there to find out.
I think this is all completely true for motors that are being run within specs. If a motor is getting hot within specs, either the specs are wrong, or something else is wrong. And rewinding it would probably improve the specs, preventing the motor from getting hot.
However, feeding a HS motor >1kW can be considered out of specs. I think that there is a limit to the amount of rewinding that can be done due to the physical spatial limitations to fill the stator with more copper, regardless of amount of turns or size of copper wires. Therefore, cooling starts to become most important when you try to tease out the highest performance with a given stator and a given winding, where the variables are more "soft", e.g., battery voltage, battery current and phase current.