RE: [CAD_CAM_EDM_DRO] Re: breakout boards plus - hard choice

The worrying bit Graham is while one axis slows, what are the others doing.

To work they all need to be tied together, and by quite a complex set of
formulae to maintain the shape accuracy.

At present you won't loose steps, but you will still suffer an error in the
work, so it becomes debatable whether there is any major benefit.



Regs Mark



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

RSGB DRM111(Cornwall)

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Graham Stabler
Sent: 19 July 2007 10:41
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: breakout boards plus - hard choice



--- In CAD_CAM_EDM_ <mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>
DRO@yahoogroups.com, Jon Elson <elson@...> wrote:

>

I think Mariss' idea uses a step driver which has a

> master current setting, so the controller can ramp the current
> up as needed to drive the mechanical load. It might work with a
> G201 or G203 drive without the pulse multiplier (which
> complicates the phase relationship a lot). The motor would run
> hotter as it runs at full current all the time. Then again, the
> current modulation may be part of the key. I certainly have not
> done this.

I was under the impression that the "unstallable stepper drive" just
slowed the feed down to get more torque (presumably it talks to the
motion controller) and although the motor might come to a complete
stop that isn't a real stall because the driver decided to slow it
down to a stop. Obviously you are not supposed to try and push the
point.

All sounds very nice but I'm not sure what it will do to surface
finishes, I cant help but think its better to stick the correct sized
motor and use proper feeds and speeds people have done that for a long
time perfectly well.

Graham





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