ORIGINAL: patternrules
Can anyone give some info on outrunner design. I understand that the less winding you have the more RPM you get, and the less torgue. But is it winding wire size that allows the motor draw more or less amps without harm to the motor? Watts are volts X amps. So if you have 37 (10s) volts X 60 amps = 2220 watts, and 2220 watts / 29.6 (8S) = 75 amps, will they be the same in efficiency.
I'm sure some will see where I'm going with this and some won't.
Thank You
Steve Maxwell
Generally speaking, you will find that for a given power, higher voltage and lower current yields better efficiency. Low efficiency is caused by resitance in the motor, ESC and batteries, so lower current means lower voltage drop in each. So an 11s or 12s with a lower Kv motor would be more efficient. The problem is now you have heavier packs. You will also find that the current goes up pretty fast when you are trying to get another 300 rpm with a given prop. As long as we have very little margin with battery capacity and weight it becomes a tricky balancing act. We never had to worry about efficiency with glow engines, just put more fuel in the tank. However, I hear that is beginning to be a problem as the engines get bigger. Hope this helps.
Jim O