Sherline spindle motor suggestions?

[Herbertkabi]

Originally Posted by Hans_G Hmmm, interesting. I figured there must be a difference between AC and DC motors or they wouldn't have different names. To me, AC implies sinusoidal voltage vs time, whereas DC is PWM'd when "on" and 0v when off. Again, I need to do some more research. Maybe a coil is a coil and doesn't care quite as much as an engineer does about what the input waveform looks like. So do VFD's pwm the motor phases the same way and look for back-emf on the non-powered phase? When a VFD spec's a frequency range (like 10-400Hz), what does that mean? Herbert- thanks again for the links and tips.

When BLDC, like RC motors and most of brushless motors, then controller does not "generate" - controller, sensored or sensorless - does follow rotor position - instead of brush commutator you have electronic commutator,
whereby electronic commutator gives much more possibilities to play with number of slots versus rotor poles - commonly higher number than 4 of magnet poles you do not see when brushed motor because room limits for more brushes. Simplest two pole / "three leg" armature dc brush motor is equivalent of 2 pole / three tooth brushless motor - 3phase motor
Brushless DC motor is most common brushless motor - does not matter it has what design - slotless_ironless_airgap ... axial, radial ... outer rotor, inner rotor. When it is commonly designed as 3phase dc brushless, then anyway it is DC motor, it could be maden as 2 phase, 5 phase ... what ever.
Mostly used trapezoidal waveform, sometimes sinus as well, but even when sinusoidal, its not "generated" - faster synthesized.
When AC brushless then electronic commutator commutates pure AC current. Mostly these are higher voltage motors ... hopefully you have seen "normal" brushed AC motors
Motors where controller "generates" are induction motors, variable frequency ... these are AC motors ...asynchronous like hf spindles, variable f servos what could be as synchronous as well as asynchronous ...,

cheers,
Herbert

http://www.townbiz.com/wd/clients/ex...ldc_motor.html
http://users.tinyworld.co.uk/flecc/4...otor031102.swf
http://users.tinyworld.co.uk/flecc/brushless_motor.html