CAD/CAM

["Arne Chr.Jorgensen" <instel-at-online.no>]

Hi,

I did mention Varkon and MRSEV, some time ago.

And here is a short story:

For several years ago, I made a machine design, a model of a
manufacture system.
To make things easy, I reduced it to 5 axis and used stepper
motors.  I wrote all the control software for it.
I hacked a Acad10 cad system, made some external control system
that used TSR to invoke things in lisp, and
modified the internal Acad structures.  Short it worked like this:

You did draw a simple centerline, and "planes" in Acad. The
external system would take this, and fill out the model as
a wire mesh, and return it into Acad.  You could then edit parts
of it, or what ever.  The external programs would then
convert this or add  tool information to it, and you could run a
simulated machining in Autocad, or dump it to the machine,
and do the mechanical stuff.  Because I wrote it all, - I just
skipped the Gcodes, and used a simpler format with pre calculated
feed rates etc.  I spent several years on this, and all my work
was destroyed due to virus, and disk crashes. :(

( I did not want to even look at a computer for a very long time
:)

But the thing is, - a lot of it resembles the MRSEV things, - I
just did not know about such things at that time.  The Acad hack,
was very difficult. The main thing I did learn, was that there
were a lot of difficulties because it did not have enough
information to work with in the internal representation, and my
math and programming skills was/is not any good at all.  So it is
strange I got this working at all :)  To read things like MRSEV,
I realize that.

So here is the reason that I asked if someone with some knowledge
had something to add on the subject, because there is so much you
could do, if you just have the right fundamental functions in a
CAD system.

TCL:

To write something in Tcl, - and the general impression I get from
your inputs, - is a limited and simple system. I don't have any
objections to that.  I just wanted to make it clear that - here is
a huge gap.

The tclVogel, is something I think could be a bit better, - and I
did mention this in the context of a "simple" system.

And here is a short description of it:

- it is just a some more graphical functions than in plain X, and
it is a binding to Tcl. You could take any tcl/tk program,
and by just using these added graphical commands, - would get a
very different result. It would be more like a "cad" system, but
still stay simple in respect to the tcl code.  The TDCAD program,
would just need to be changed in the command calls. Instead of
calling Xlib, it would call Vogle. Commands would more or less be
the same thing, just an added letter, to the command calls for
drawing.

The benefit would be that you would have resolved a lot of the
problems with code to remap positions from what a DXF file use,
into the canvas.  You could skip all that, and you would get 3d as
an added bonus.

The tclVogle, is written for sparcstations, and a few "SIGXX" (
signals to os has to be changed - should be simple) Then
the system is built in this way:

It has a file with the names of the Vogle lib cmds, and  tcl (
Xlib ) as inputs, plus the tcl/tk source . Then it adds these
Vogle commands into tcl/tk and makes you a new tcl/tk and wish
interpreter.  So it is in fact based on a program, that generates
a new tcl/tk - based on the input from the source files.

If I had the time,  I guess I should be able to figure it out in
the end. But with programmers and experts out in this forum,
- I would not be surprised if they just after a short glance at
it, would know what to upgrade, in less time than I could make
even read it !  I am new to unix systems, and don't have much
knowledge about  programming ( but with a lot of time, I once in a
while get something working :)

So this was the thoughts I had around this.

There might be a lot of other libraries, like Mesa etc. But Vogle
is small and simple. I just have no knowledge about the other
libraries - but I have found some of them to be complicated and
big, and I don't know of any that has a binding  so you can write
simple tcl programs.

//ARNE

Well, it is just a few ideas :)