Re: emc really needs a copyleft cad/cam package

[Ray <rehenry-at-up.net>]

Hi

Some comments also mixed in to Terry's post below.  (BTW As an accidental
vector dealer, <grin>, I'm conflicted here - but a little xanax should
help me live with the tension)

I'm going to put out some numbered, almost random thoughts that come from
my long-term memory of reading most of the emc list's posts and a few
conversations here and there.  

1 - This CAD/CAM problem's been talked about by several.  Arne, Ian, Dave,
Paul, Dan, and others have poked around in several open source cad and
graphic packages.

2 - Roland Freistad showed me some of his stuff that ran out of autocad
and passed commands directly to his "old" controller, I think that it
would be really neat to do this with the EMC.  I know that NIST has been
working on some "feature based" stuff that studies a drawing and drives a
machine using many parts of the EMC.  I also know that they have given
some thought to using xml as a link in the machine tool language chain.

3 - Someone has been talking with Fred Smith at Imserv toward the direction
of getting vector ported to linux/rtlinux as the low cost cad/cam package
for those wanting a linux only environment. (vector does not run correctly
under wine but I understand Rhino does)   There was not much encouragement
here.

4 - There are several "free" cad packages and many more inexpensive but
very capable drafting packages.  What I have not found available is
anything "open source" that can take cad output and make cam of it.   This
is a significant challenge that requires a good deal of development all by
itself.

I'd like to see those interested folk working on a bi-directional
dxf and RS274NGC converter that runs under Linux.  I suppose that It could
also be ported to other OS's  If we had such an animal, even in it's
infancy, we could build an EMC gui that would tie together; 

a - conventional g-code, 
b - g-code writers like genedit scripts and Jon Elson's c routines,
c - the CPLD stuff that Ron, Phil, and Dave have talked about 
          (where you work from stock visual routines),  
d - CAD images,
e - perhaps drawings 
e - plotting and backplotting

If we used a Linux cad package the operator could even draw and
edit drawings at the machine control.  

I'd like to see us make the whole thing modular with each module
containing it's own hmi values and display needs as well as standard
communication protocols and data structures that it passes to the program
that it is called from - ala wac2000hmi.pdf  

http://www.isd.mel.nist.gov/documents/michaloski/wac2000hmi.pdf
http://www.isd.mel.nist.gov/documents/michaloski/wac2000hmi.ps

If this is done, then these modules could work as easily for tkemc, xemc,
xmemc, and stkemc, touchemc, etc.

On Fri, 17 Nov 2000, Terry wrote:
> hello;
> 
> this is being sent to multiple lists because
> of the nature of the posting, so please bear
> with me.
> 
> after spend several hours tonight/early morning
> searching for an opensource cad/cam package for
> linux it has become clear that there is not one.
> 
> the purpose of this e-mail is basically two-fold.
> 1. begin an open discussion as to what features
>    should an opensource cad/cam package/program
>    have. the goal being to draft a design specification
>    that most everyone could live with for the first
>    cut.

see above daydreaming.

> 2. should this discussion take place on the two
>    mailing lists, emc & cad_cam_edm_dro, or be
>    moved to a new separate mailing list. if it
>    is decided to have a new separate list i would
>    host it off of one of my computers here.

My preference is to make it a third module (emc, rcslib, ???) under the
current sourceforge repository.  We might have to write a tutorial on how
to work with sourceforge cvs but that way we only need to learn one cvs
system and a developer can choose to download and work on any part of
it..  

As for list.  It could be a new one or the emc developer list. 

> just so everyone understands, by opensource, i mean
> released under the gnu general public license.

Right!  And as we have already discussed, we can roll these gnu files in
with public domain files without serious problems.

http://www.linuxcnc.org/handbook/faq/faqcpwrite.html

Because of the length of this post it is being sent only to the EMC
list.  

Thanks

Ray