Originally posted by mr_wood
Surely if I used a CD-ROM motor ( after re-wind) and hooked up the Hall sensors to a PIC and then wrote a prog to check the sensors and work out which FET to send signal to to turn on a coil - this would work ?? Obviously I'd need to use a conventional speed controller to power this circuit.
Yes, it will work. Considering the PWM voltage from the conventional controller, you have to take care of the gate-source inverse voltage problem.
The motor together the above mentioned circuit is very similar to a brushed motor, but with "electronic brushes", free of the usual brush problems.
Next step: there is everything in your controller to handle speed too, just write some additional code, read the pulses from the receiver, and feed your fet bridge with sw emulated pwm signal.
Next step: some more coplex code and no need for that sensors any more...