On Tue, 6 Jan 2009, Jon Elson wrote: > Date: Tue, 06 Jan 2009 21:30:20 -0600 > From: Jon Elson <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] Steppers with Encoders > > Stuart Stevenson wrote: >> Gentlemen, >> My suggestion was to use a stepper of a type built like an >> alternator. If that concept would be useful. Just throwing out ideas. >> It may not be feasible but who knows? Definitely not me. :) >> > Even an 8-pole alternator would only have 32 full steps/rev. Since it > wasn't designed as a stepper, who knows if it would even give properly > spaced full steps, or what would happen if you tried to microstep it. > One could try it and see. Of course, it is a 3-phase motor, so it would > not work with any standard step motor driver.
48 steps maybe? > > On the other hand, using it as a brushless servo motor (except for the > field brushes, of course) has some promise. The encoder would at least > try to solve any problems with position error. One would have to add > Hal sensors or use an encoder with commutation tracks. > > Jon > You can get away without Hall or commutation tracks if you have a relatively high resolution encoder. This just requires rotor-encoder alignment at startup One thing I would worry about a little is that the field winding is on the armature, generating heat thats hard to dissipate when the rotor is static. I guess you could reduce the field current when idle but that complicates the drive circuitry > ------------------------------------------------------------------------------ > Check out the new SourceForge.net Marketplace. > It is the best place to buy or sell services for > just about anything Open Source. > http://p.sf.net/sfu/Xq1LFB > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
