Re: rapid G210 'overdrive' rates using logic on header blocks

Hi,

I responded off-list Doug on this but perhaps I should mention it
here as well.

What I am looking at is to have 2 STEP inputs. One would be a full
step one (using the G210) while the other one would be a 10 microstep
one. Both could be used simultaneously.

The second input would never need more than 9 step pulses. These
could be sent all at once or parceled out evenly over the duration of
a move.

This still in the "pencil and paper" phase. I would like to do it
with just the STEP and DIRECTION inputs, perhaps by "stepping" the
direction input for the residual microsteps. If not, 3 inputs would
be used.

The advantage would be not having to precisely time velocities,
distances and rates of acceleration "on the fly". You would simply
add the fractional part of a full step in the form of 1 to 9
microstep pulses.

The trick would be to place this on the multiplier board and still
have it backwards compatible with accepted STEP and DIRECTION
protocols.

Mariss

--- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi Doug, Tim and the List,
>
> Adding a "gear box" to the G210 (G201&G901) sounds like a neat idea!
> Although it seems it would throw the acceleration tables and rate
tables
> off! I still haven't figured out how to accommodate different uStep
> (1X, 2X, 4X, 5X, 10X) values. It's obvious that the 'X' counts
> calculate into the resolution of the stepper, and the rate table,
but
> what to do about the acceleration? If the table is non-linear, you
> can't just "slide up the curve", can you?
>
> Alan KM6VV (in way over his head!)
>
>
> Doug Fortune wrote:
> >
> > Tim Goldstein wrote:
> >
> > > Got to see the Series II Bridgeport I purchased on E-Bay back
in September
> > > today. It got to the rigging company last Thursday and today is
the first
> > > chance I had to drive out and take a look. You are right, those
finned
> > > steppers really are ugly.
> >
> > Should keep them cool though! Who cares what they look like.
Might
> > even get to appreciate their Batman/Gothic look !
> >
> > > Still not quite sure what I am going to do for drives.
> > > Don't know if I would be happy with the rapid rates
> > > I would get with G2XX drives.
> >
> > I had asked Mariss before, if a guy could have a 'low drive' ie
1/10 step
> > and then shift to 'overdrive' ie 1/1 or 1/2 step by putting logic
to his 210
> > headers (instead of jumper blocks), but didn't hear back. The
software
> > guys seem amenable to such a thing (taking just one output pin
for 'overdrive').
> >
> > It seems such an obvious answer to a continual nagging problem
> > (of resolution vs rapids).
> >
> > Doug Fortune
> > http://www.cncKITS.com