Originally Posted by shadow102
why would they not work that well running sensorless
BTW doing some more playing with the whole system but will a sidewinder even work on 4cells?
It has to do with how a sensorless speed control determines rotor position. It is harder for a sensoreless control to determine the position of higher wind motors then lower wind ones.
Since there is no rotor position sensor, the speed control has to 'guess' what position the rotor is in, and try to start the rotor spinning that way. If it guesses wrong, the motor may spin the wrong way. Making matters worse, since it is so hard to determine the position of the rotor of high wind motors (especially at low speeds), the speed control may not even be able to tell it has 'guessed' wrong for a second or more. Once the motor is up to speed it becomes easier for the speed control to determine rotor position so hesitation should go away.
My Tekin RS has some real difficulty with a 17.5 running in full sensorless mode. It gets even worse with a 21.5. I have to use sensors to get it to start acceptably.
As for your other question, the Sidewinder should have no problems with four cells, but I would still recommend picking up a sensored control.