CAD CAM EDM DRO - Yahoo Group Archive

Re: stepper vs. servo

Posted by ballendo
on 2004-02-12 09:03:44 UTC
Ray,

A bit more:

A stepper is just a syncronous motor run using square waves (At the
fullstep resolution). In other words, the square waves are as close
as you can get to a sine wave using only on and off.

When you go to 1/2 step, you add another level of current control,
and the input waveform gets another step, and is a little closer to
the sine wave ideal. As you go up in microsteps, you keep refining
the input waveforms by adding steps/levels towards ideal sine waves.

At some point, you're back running a synchronous motor with sine
waves...

Ballendo

P.S. Our typical steppers will run just fine at 72 rpms, using a
capacitor on one coil, and fed by 60 cycle ac. (infinite
microsteps<G>)

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Raymond Heckert" <jnr@a...>
wrote:
> Has anybody ever designed a micro-stepping driver that outputs
> approximations of sine/cos to two adjacent coils. I understand
that you
> develop max torque at any rpm, up to the max (which is higher than
the
> square-wave input). Is this true? How much would it take to
develop,
> assuming no one already has? BTW does anybody know anything about
Don
> Lancaster's (tenaja.com) Magic Sine Waves, and if they can be
applied to
> this application.
>
> RayHex
>
> ----------
> > From: Jon Elson <elson@p...>
> >
> > Given the Gecko 320 as the driver for the servos, I think there
are a
> > couple of significant advantages over steppers. First, the
servos are
> > usually capable of a greater speed range, while steppers rapidly
lose
> > torque at higher speeds. With servos, you rarely have to worry
about
> > resonance issues. You don't say whether you will use belts, rack
and
> pinion
> > or leadscrews to drive this machine, but the servo will likely
provide
> > smoother motion, and be less perturbed by some backlash in the
mechanics.
> > Steppers can go wild when rack and pinion drive is used, and
rattle the
> > gears
> > something awful. Finally, if you lose a step with a stepper
drive, you
> > won't know it until you measure the finished part. With the
gecko 320,
> > it won't allow small errors to build up, and will fault if the
drive
> binds
> > up or crashes. This can be sensed by the computer and cause it
to stop
> > all axes.
> >
> > Jon

Discussion Thread

plastiguy 2004-02-09 18:41:27 UTC stepper vs. servo bull2003winkle 2004-02-09 19:49:34 UTC Re: stepper vs. servo Jon Elson 2004-02-09 21:24:17 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo ballendo 2004-02-09 21:59:06 UTC Re: stepper vs. servo Albee Tang 2004-02-09 21:59:07 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Roy J. Tellason 2004-02-09 22:35:39 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Les Newell 2004-02-10 00:55:07 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo John Johnson 2004-02-10 05:22:09 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo Peter Renolds 2004-02-10 06:01:12 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo - H Bridge question Jon Elson 2004-02-10 07:47:46 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Stan Aarhus 2004-02-10 07:49:36 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo ballendo 2004-02-10 07:50:14 UTC DIY servo drive? was Re: stepper vs. servo Jon Elson 2004-02-10 08:02:47 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo bank haam 2004-02-10 09:47:15 UTC Re: [CAD_CAM_EDM_DRO] DIY servo drive? was Re: stepper vs. servo Mariss Freimanis 2004-02-10 11:36:49 UTC DIY servo drive? was Re: stepper vs. servo dchristal2 2004-02-10 13:32:47 UTC Re: stepper vs. servo ballendo 2004-02-10 16:59:46 UTC Re: stepper vs. servo ballendo 2004-02-10 17:02:13 UTC Re: stepper vs. servo ballendo 2004-02-10 17:03:03 UTC Re: stepper vs. servo Roy J. Tellason 2004-02-10 17:51:24 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Jon Elson 2004-02-10 21:23:22 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Roy J. Tellason 2004-02-10 21:42:58 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Tony Jeffree 2004-02-11 02:17:12 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Les Newell 2004-02-11 02:31:50 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Les Newell 2004-02-11 02:43:21 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Raymond Heckert 2004-02-11 19:23:21 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo Robert Campbell 2004-02-11 19:40:12 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo bull2003winkle 2004-02-11 20:35:58 UTC Re: stepper vs. servo Jon Elson 2004-02-11 20:51:18 UTC Re: [CAD_CAM_EDM_DRO] stepper vs. servo Jon Elson 2004-02-11 21:02:29 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo ballendo 2004-02-12 09:03:44 UTC Re: stepper vs. servo ballendo 2004-02-12 09:04:03 UTC microstepping was Re: stepper vs. servo Harvey White 2004-02-12 11:44:40 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Chris Cain 2004-02-12 16:44:15 UTC RE: [CAD_CAM_EDM_DRO] microstepping was Re: stepper vs. servo JanRwl@A... 2004-02-12 20:42:04 UTC Re: [CAD_CAM_EDM_DRO] microstepping was Re: stepper vs. servo ballendo 2004-02-13 06:36:22 UTC Re: stepper vs. servo turbulatordude 2004-02-13 07:26:28 UTC Re: stepper vs. servo ballendo 2004-02-13 07:51:51 UTC microstepping was Re: stepper vs. servo Harvey White 2004-02-13 08:34:30 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Mariss Freimanis 2004-02-13 10:11:40 UTC Re: stepper vs. servo Jon Elson 2004-02-13 10:15:17 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Mariss Freimanis 2004-02-13 10:59:38 UTC Re: stepper vs. servo Jon Elson 2004-02-13 18:46:24 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo ballendo 2004-02-14 07:46:52 UTC Re: stepper vs. servo ballendo 2004-02-14 07:46:53 UTC Re: stepper vs. servo Harvey White 2004-02-14 08:43:17 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo Mariss Freimanis 2004-02-14 12:31:32 UTC Re: stepper vs. servo ballendo 2004-02-15 11:45:06 UTC Chopper methodology was Re: stepper vs. servo ballendo 2004-02-15 11:45:07 UTC Stepper Mid band resonance Help! please... jeffalanp 2004-02-15 12:22:14 UTC Re: Stepper Mid band resonance Help! please... Mariss Freimanis 2004-02-15 13:02:29 UTC Chopper methodology was Re: stepper vs. servo Mariss Freimanis 2004-02-15 13:22:53 UTC Re: Stepper Mid band resonance Help! please... zephyrus@r... 2004-02-15 16:33:25 UTC Re: Chopper methodology was Re: stepper vs. servo Mariss Freimanis 2004-02-15 17:05:54 UTC Chopper methodology was Re: stepper vs. servo turbulatordude 2004-02-15 22:20:30 UTC Re: stepper vs. servo - hundreds of microsteps turbulatordude 2004-02-15 22:40:08 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... Jon Elson 2004-02-16 09:39:54 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo - hundreds of microsteps Mariss Freimanis 2004-02-16 10:48:05 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... ballendo 2004-02-16 10:52:22 UTC Chopper methodology was Re: stepper vs. servo jmkasunich 2004-02-16 14:07:51 UTC Re: Stepper Mid band resonance Help! please... Mariss Freimanis 2004-02-16 14:22:28 UTC Re: Stepper Mid band resonance Help! please... jmkasunich 2004-02-16 14:38:26 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... jmkasunich 2004-02-16 14:41:11 UTC Re: Stepper Mid band resonance Help! please... ballendo 2004-02-16 15:25:25 UTC Re: Stepper Mid band resonance Help! please... Jon Elson 2004-02-16 22:01:46 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo - Allegro and ignoring the edges.... Mariss Freimanis 2004-02-17 07:14:02 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... turbulatordude 2004-02-17 08:09:24 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... Mariss Freimanis 2004-02-17 09:27:33 UTC Re: stepper vs. servo - Allegro and ignoring the edges.... Jon Elson 2004-02-17 19:28:16 UTC Re: [CAD_CAM_EDM_DRO] Re: stepper vs. servo - Allegro and ignoring the edges....