Re: 5-axis machine controller

[Jon Elson <jmelson-at-artsci.wustl.edu>]

"D.F.S." wrote:

>
> I was almost to the point of deciding EMC was not worth the trouble.
> Keep in mind I'm a Unix Geek and love linux so the "Trouble" would have
> come from all the issues I've seen with people actually getting EMC
> and the hardware working.
> Maybe that was based on a bit of mis-interpretation.

I think you'll find it easier than some other people, then.  Getting the RT
patch installed and rebuilding the kernel is the biggest hump most folks
run into.

> Anyway, the internal controller is a bit braindead and I need to
> replace it. I have plenty of old computers and power supplies and
> simply planned to Bit-bang some MOS-FETs directly driving the steppers
> from the parallel port.

Well, this will work, but you would do well to use a "chopper" type drive.
There are commercial chips that do this real well.

> What presumptions does the Stepper control module make and it is more
> of the "Step & Direction" output or the "Energize Coil #1,#1&#2,#2..."
> variety?

It now does both.

> Keeping in mind I am a unix geek and live in that env. is getting EMC
> up and running on such a setup, a day or two project?

It might be doable in that time.  Do you have a machine already running
Linux?  Do you have the hardware that is fully supported on their hardware
compatibility list?  The video card is the big stumbling block - many of the
no-name brand video cards may not be fully supported by the Xwindows
system.  Make sure it is a REAL Intel Pentum CPU.

Jon