RE: Kulago/Mauch DRO ISA quadrature feedback kit

["Tim Goldstein" <tgoldste-at-mlh-services.com>]

> Dan has since emailed that confirmation.   Looks like the way to go.
> The  LS7266R1  has  24 bit counters, so using a 0.1 um scale  I'm assuming
> you'd  get (2**24 == 16777216  * .1e-6 = 1.67m)  ~ 66 inch travel.

I haven't studied EMC code that reads the DRO card, but there is no reason
it has to be limited to the size of a 24 bit counter. The code could easily
detect the overflow and compensate accordingly. Again, I don't know if that
is how it works. You would have to look over the code or ask Fred.

> Another question:
> The stepper controller brick posted here a few days ago by
>  http://www.geckodrive.com  has a 200 KHz maximum step rate.
>
> What maximum typical step rate can EMC produce on a
> 200 MHz (or 500Mz) Pentium?

First to answer your question, I am running on an AMD K6-500 and can get
speeds up to 90 ipm is everything is set just right. I have 5 tpi screws and
a 2 to 1 belt drive run with a 200 step per revolution motor in half step
mode, so that works out to 6000 steps per second.

I will admit that I always seem to get messed up on this stuff, but here
goes anyway. If the controller you reference is good to 200 KHz am I correct
in figuring that on my setup it would have a pulse train that is good to
3,000 ipm? If so, I have to ask what is the point? The stepper motors could
not actually be driven that fast and if you have ever seen a machine heading
for a crash at 90 ipm it will soil your pants. I can't imagine what it is
like to have a servo machine run away at 2 or 3 times the rate.

Tim
[Denver, CO]