Re: [CAD_CAM_EDM_DRO] Still losing steps in M5 or Mach1

In a message dated 15-Aug-02 09:17:51 Central Daylight Time,
j.guenther@... writes:

> but my 266 MHz shop computer runs EMC, DeskNC and TurboCNC just fine. I
> have other things in the shop that I can spend $$$ on before I purchase a
> shop computer that is faster than my general use PC.

John! Faster than 266 MHz? Your imagined "Need for Speed" is likely the
problem! What stepper needs MEGAHURTS?

Just now, I have been noticing "audible glitching" and "strange extra- and
lost-steps" with the first-ever Gecko-drive stepper device I have ever done.
And THIS one, I did not install monostables (for "widening" the input-pulses)
between the printer-port buffer and the drives, as I had on the other "home
brew" CNC stuff I have done. DUMB! So, I am fixing it in software
(delay-loop). I did some "bench testing", and sure enough, the Gecko
G210's call for a "MIN ON-TIME" of 4 µS, and I was supplying only 3+ µS! I
fiddled with my machine-code patch to increase the ON time (but DEcrease the
OFF time by same amount, so F is not changed), and this FIXES the problem!

So, suggest you either "tweak" your software so that it outputs 5-10 µS
pulses, or, install 74HCT4538 Dual Monostables between your parallel-port and
machine-inputs! (If that does no good, TELL us, so save someone else the
hassle/expense!)

Jan Rowland, Old Troll


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