CAD CAM EDM DRO - Yahoo Group Archive

Re: Why is the push to such high step rates (Grex and Arc100)?

on 2006-12-18 08:30:26 UTC
256 microstep drive at 3,000 RPM equals a 2.56 MHz step pulse
frequency.

4,000 line encoder on a 6,000 RPM servo equals a 1.6 MHz step pulse
frequency.

Not all applications are low speed, low resolution.

Mariss





--- In CAD_CAM_EDM_DRO@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:
>
> I can't tell if this is turning into a peeing contest of specs or
if
> there is some actual merrit to these high rates. Assuming that
these
> are for machine tool motion control (yes I am well aware of other
> types of motion control) I am failing to see the point.
>
> With a possible frequency in the range of around 2 Mhz or more,
this
> works out to a pretty fantastic velocity. Assuming a resolution
> of .0001"
>
> 2000000 * .0001 = 200 Inches per second
> 200 * 60 seconds = 12,000 Inches per minute
>
> 12,000 IPM is about 3 times faster than the fastest commercial CNC
> machines on the market, and those use linear motors.
>
> We know that stepper motors have a very finite, useful RPM range.
The
> steppers I have been toying with recently have a limit of 500 RPM,
> beyond that torque drops very quickly. Assuming 200 steps per rev,
> the maximum useful frequency is
>
> 200 X 500 RPM = 100000 / 60 = 1666 Steps per second
>
> Even when factoring in microstepping of say 16 microsteps
>
> 1666 * 16 = 26,666 steps per second
>
> Servo motors certianly can run at much higher RPM ranges - many
around
> 4000 RPM. Putting that into some form of perspective relative to
> motion, assuming a .2" pitch screw and a minimum resolution
of .0001"
>
> 4000 RPM X .2" = 800 IPM (very fast for most industrial machine)
>
> 800 IPM / .0001" resolution = 8000000 steps per minute
> 8000000 / 60 seconds = 133,333 steps per second
>
> So with the potential of stepping rates into the millions....
>
> A stepper motor doesn't have enough torque at speed nor can it
handle
> that rate of stepping frequency.
>
> A servo motor, driving a relatively fine pitch ball screw at a
> resolution of .0001" doesn't need a stepping frequency in the
millions.
>
> Why is there such emphasis put on that level of performance in
> stepping rates?
>
> Chris (Confused as usual)
>

Discussion Thread

lcdpublishing 2006-12-18 07:09:10 UTC Why is the push to such high step rates (Grex and Arc100)? Mariss Freimanis 2006-12-18 08:30:26 UTC Re: Why is the push to such high step rates (Grex and Arc100)? turbulatordude 2006-12-18 09:00:14 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 09:13:32 UTC Re: Why is the push to such high step rates (Grex and Arc100)? turbulatordude 2006-12-18 10:14:19 UTC Re: Why is the push to such high step rates (Grex and Arc100)? caudlet 2006-12-18 10:31:11 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 11:06:01 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Mariss Freimanis 2006-12-18 11:20:22 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 11:45:42 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Fred Smith 2006-12-18 11:45:55 UTC Re: Why is the push to such high step rates (Grex and Arc100)? C.S. Mo 2006-12-18 12:14:34 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? atelierrobin 2006-12-18 12:22:02 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 12:32:27 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Leslie Newell 2006-12-18 12:39:43 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 12:41:58 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 12:53:38 UTC Re: Why is the push to such high step rates (Grex and Arc100)? atelierrobin 2006-12-18 12:58:12 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Mark Vaughan 2006-12-18 13:05:57 UTC RE: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 13:08:38 UTC Re: Why is the push to such high step rates (Grex and Arc100)? John Dammeyer 2006-12-18 14:20:46 UTC RE: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Tony Smith 2006-12-18 14:25:18 UTC RE: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-18 14:33:30 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Leslie Newell 2006-12-18 14:46:59 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Leslie Newell 2006-12-18 14:48:02 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Fred Smith 2006-12-18 15:01:55 UTC Re: Why is the push to such high step rates (Grex and Arc100)? John Dammeyer 2006-12-18 15:16:54 UTC RE: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Jon Elson 2006-12-18 20:47:23 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Jon Elson 2006-12-18 20:47:37 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? turbulatordude 2006-12-19 04:58:10 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-19 05:15:37 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-19 05:29:33 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Jon Elson 2006-12-19 07:59:03 UTC Re: [CAD_CAM_EDM_DRO] Re: Why is the push to such high step rates (Grex and Arc100)? Graham Stabler 2006-12-19 08:38:12 UTC Re: Why is the push to such high step rates (Grex and Arc100)? lcdpublishing 2006-12-19 08:56:42 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Graham Stabler 2006-12-19 09:46:05 UTC Re: Why is the push to such high step rates (Grex and Arc100)? optics22000 2006-12-19 10:27:16 UTC Re: Why is the push to such high step rates (Grex and Arc100)? John Dammeyer 2006-12-19 11:04:49 UTC CNCing a 7x12 minilathe Graham Stabler 2006-12-19 12:06:19 UTC Re: Why is the push to such high step rates (Grex and Arc100)? Peter Homann 2006-12-19 12:12:22 UTC Re: [CAD_CAM_EDM_DRO] CNCing a 7x12 minilathe John Dammeyer 2006-12-19 12:47:34 UTC RE: [CAD_CAM_EDM_DRO] CNCing a 7x12 minilathe David Bloomfield 2006-12-20 04:09:10 UTC Re: Why is the push to such high step rates (Grex and Arc100)?