Sloping Off - June 2005
Electric Motor Design Breakthrough
by Mike Roach
So having read about the brushless Mega 22, do you fancy a PU01 electric motor (the sort that flies my 58 gram Sopwith Racer, gives 40 grams of thrust and weighs about 10 grams) that has the power to fly a speed 400 model? Or a speed 400 that flies a quarter scale Extra? With no magnets, no metal parts at all, no heavy wiring and no expensive gearbox?
An article in The Engineer” magazine, forwarded by Clive Spencer, suggests that this fantasy may not be far away. A UK company called IMP has developed a “stepper” motor which delivers maximum torque at all RPM, can be scaled to any size, does not generate heat and, when the current is switched off, continues to free-wheel.
“The motor works by transmitting electric pulses across up to seven rotors all in different phases” says MD John Bryant. It is direct drive, microprocessor controlled and can be linked in synchronous operation with other similar motors. The first application is likely to be a 4WD vehicle with a motor at each wheel station “able to outstrip a Ferrari” according to the article. Unless the Ferrari had a similar power system, of course!
So dream on for a year or ten, and then wave goodbye to all IC engines. We’ll see!
