RE: [CAD_CAM_EDM_DRO] Skipping steps, avoiding resonance

Hi, Randy:

A couple of questions -

Have you ever tried your system at 'insanely low' speeds to see if it has a
chance at working at all? I'm guessing that you're trying to run too fast.
It's best to start slow and then increase speed on each axis a little at a
time until you start dropping steps. Then back off a little.

In my glossary, jog means that you take a few steps at a time to move the
controlled point a few thousanths of an inch or so. With moves that small,
you'll never get to the 60 ipm you claim.

I've also used DR-DOS, so that isn't a problem. But, what drivers have you
loaded? if you've got EMM386.EXE and maybe HIMEM.SYS running, they may be
causing enough overhead with the 18.2 millisecond clock interrupt that you
can't get a robust pulse stream.

Before I updated to an obsolete old pentium, I was running a Sherline mill
at step rates between 2600 and 4000 steps per second using a Zenith
486DX2-50 notebook, DR-DOS, and TurboCNC as the GCode interpreter. My speed
was limited to the mechanical system, not the computer or the OS or
software.

-- Jerry

|I finally got the thing running this weekend, and it is not running
|reliably. I have the drivers in half-step mode, which with the 4mm-pitch
|leadscrews gives 2540 steps per inch. I can jog the X and Y axes at
|insanely fast speeds (200 ipm,) but I have fast jog set at 60 ipm. I'm
|using CNCPro running under DR-DOS 7.03.