EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: Mjolinor on November 03, 2019, 01:46:02 pm
-
I bought a couple of these because the size is right for what I need:
https://www.ebay.co.uk/itm/NIDEC-25H-12V-24V-20V-11300RPM-High-Speed-Brushless-DC-Motor-PWM-BLDC-18W-Holzer/254370691431 (https://www.ebay.co.uk/itm/NIDEC-25H-12V-24V-20V-11300RPM-High-Speed-Brushless-DC-Motor-PWM-BLDC-18W-Holzer/254370691431)
At 1000 RPM the open circuit voltage is about 2 volts and the short circuit current is about 1.5 amps. This is probably enough power for what I need (2 amps for 9 ms per rev).
However at 2 volts it is too low to easily use so I thought I would rewind it with more turns, get the voltage more usable at lower currents.
Once in bits I notice that the rotor is 2.5mm smaller than the stator which to me seems massive. The stator has rare earth magnets embedded in there but the outside is non conductive.
I wondered if putting a 1 mm thick sleeve over the rotor effectively reducing the rotor / stator gap would be worth the work involved. I have no feelings whatsoever about the sort of increase I could expect from doing that. Could the sleeve just be steel or would I need to make it from strips with insulators between the steel bits?
Any thoughts?