Re: [CAD_CAM_EDM_DRO] Minimum hardware for EMC

John Murphy wrote:

>
> Before I waste time trying, I wanted to get some peoples experience
> on using EMC.
>
> I've run linux on everything from piddly 386-16/4b on up, and have
> a nice rackmount 486-33 8/mb system already set up with linux and the
> RT
> extensions. X runs, although I don't use it much. Will this setup
> reasonably run a three stepper CNC mill? I'm not looking for high
> speed feed rates; I'll be quite content to take small bites and many
> slow
> passes if it makes the part. So, to the EMC'ers who are in the know:
>
> 1) Will EMC run OK on this system?

Maybe - it is awfully close to the bone.

> 2) Will the slower system affect feed rates, etc.

Yes, because you won't be able to run the freqmod task anywhere near the

16 uS intervals that people seem to have the best results with.

> 3) Obviously, with 8mb of RAM, I've got lots of swap. Will swap
> use inhibit EMC performance?

No, the RT task does not swap, or wait for swaps to finish.

> 4) For a mini mill setup, driving steppers over the parallel port,
> which task should I use (steppermod, freqmod, minimill, bridgport,
>
> etc.)

freqmod will give the best stepper performance, but may use vast CPU
resources
on a 486. Noone has ever run it on that CPU, as far as I know.
Minimill and Bridgeport
are auxilliary I/O routines (spindle start/stop, coolant on/off, etc.)

> I'd like to use this system since I could mount my drives, the
> computer,
> etc in a
> nice 19" rack.

maybe you can get a 100 MHz Pentium motherboard and put it in the nice
rackmount system. I can usually find a 100 MHz Pentium classic, heat
sink,
fan, motherboard and 32 MB memory for somewhere around $25 on eBay
if I'm willing to wait a week or so.

Jon