Re: Reviving my mill (EMC)

Hey Murph

Sounds like you did a lot of work on your machine and the EMC setup. The
problem that you are having with locking up when motion starts has to do
with the size of a buffer or two. We found this problem soon after the
first BDI was released at NAMES. I don't remember where the specific fix
had to go but I believe that it was in one of the emcmot related files.

Most of the circular interp problems had to do with the level of accuracy
required by the interpreter. This can be set before a compile in the
"interpreter".h file At the time that you did your work, there was also
a problem with full circle blocks causing some circles to be skipped.
Both these problems have been fixed in recent releases.

For the first three years of my work with the EMC I built from scratch
the way you have. I've found that the BDI is so much easier that I
haven't patched or compiled a kernel for quite a while now. The BDI 2.18
series uses RTLinux 3.0. There are some problems noted recently with the
3.1 and EMC. The BDI-TNG series uses RTAI. Most of those issues have
been resolved and RTAI's development is progressing much faster than RTL.
There are a few obscure issues still cropping up now and then.

I'm with you in wanting a "wristwatch" version. The kernel, even with
the real time extensions runs to less than a meg. If we left off the
x-windows and windows managers, expanded the EMC's text mode interfaces
with key bindings, and used multitasking terminals for viewing and
working with the parts of a running system we should be able to build a
compressed, run time binary that would fit on that 4 meg flash. I once
made a compressed single personality version of the EMC code that fit on
and ran from a floppy.

I worked a bit with a SBC supplier who thought that we should be able to
push it all into a 32 Meg flash and that included x-windows a window
manager, tickle, and the EMC.

I'd be interested in getting your extensions for the 24 pin card into the
code base. Did this configure the 8255 to act like a parport? Were you
able to pick up and use the extra pins?

Ray

>    From: "John Murphy" <john@...>
> Subject: Reviving my mill (EMC)
>
> I've been away from the CAD_CAM_DRO world for a couple
> of years and dusted off my mill (a grizzly mini mill
> I converted with EMC...).  I've got some dust or gremlins
> in it because my system is hanging any time I try a
> move...  I'll need to work those things out.
>
> I wrote my own parallel interface to use a 24 bit digital
> IO card for I/O and added a few other things in there
> like controlling spindle on/off over the RS232 port.
> Now I'm thinking I need to upgrade and get things
> a little more current, so I either need to re-wire
> or port my changes up.
>
> I'm using linux 2.2.14 with rtl 2.2, (I'm still
> trying to figure out which version of EMC I'm running,
> but it's about 2 years old).  My system has problems with
> circular interpolation (I,J type G02/3 moves)...
>
> Right before I got too busy for the mill, the BDI had come out.
> (although I was not terribly interested it as I had gotten
> EMC working the slow way)..
>
> Anyway, I was hoping that some of the EMC guys around here
> might contact me off list (unless you think that it's
> valuable to the group) and bring me up to speed on the tips
> and tricks to the newer EMC and what platforms (distro and
> RTL, etc) are best for building it up again.
>
> One thing I'm considering is building my next EMC system up
> under peewee linux, since then the system runs out of RAM
> or read-only mounted hard-disk, and hence no fscking of file
> systems or waiting to power stuff off.  (I'm using this, running
> linux off of 4MB flash cards for other projects).
>
> Thanks, and sorry for bothering the list.
>
> Thanks,
> murph
>
> Erie, CO