Erik Christiansen wrote: > On Sun, Jan 23, 2011 at 08:00:22AM -0500, gene heskett wrote: > >> I don't think this is the link you intended? This is to a pdf brochure >> describing only the encoder. >> > > Whoops! Here's the recycled alternator BLDC example that I had in mind: > http://www.youtube.com/watch?v=Tu-ia7GylO0 > > OK, this video seems to be about using an alternator with a sensorless drive chip. I think that would perform horribly as an axis positioning motor. Unless the motor is run at at least several hundred RPM, the chip loses track of rotor position and needs to wiggle the motor to figure out where the poles are. It may also give no way to reverse the motor. Now, if this whole discussion is about spindle motors, that would probably be fine. If it is for axis motors, I think it will be a problem.
Also, a good brushless servo motor has minimal torque or velocity ripple, even down to extremely slow speeds. Certainly, a car alternator is not optimized for smoothness at low speeds. The Keling motors are so cheap they may cost less than a used alternator at the junkyard. Jon ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
