RE: [CAD_CAM_EDM_DRO] Re: Interface. Gauging interest.

1) That's what I thought.
2) Hear! Hear! This is what freaks me out about using the parallel port; I would
not want my Domain Server backing up my CNC machines to wreck my machine.
3) Hexapod? Answer is; you wouldn't. The Hexapod would appear as a 3 axis
device, or more depending on what end effecter you attach.

To follow up on the G-Code part of the third point; there needs to be another
language created for Modern CNC. Professionally I am a Windows programmer; I've
played around with a CNC program that is driven via scripts. The scripts can be
in any language the Windows scripting host supports. Currently VBScript,
JavaScript, Python, PerlScript, RubyScript, TclScript, and ForthScript are but a
few of the supported languages. Of course you'd have to reduce this to the
lowest common denominator for *nix.
Right now my stuff doesn't understand G-Code, I just program the part in and run
the script.
Example: CNC.Home(0,-1); // means home X axis rapid (G0)
CNC.Home(1,-1); // means home Y axis rapid (G0)
CNC.Home(2,-1); // means home Z axis rapid (G0)
CNC.WaitForOperator("Ready to start making chips");
CNC.Spindle(0,1000,0); // Main Spindle (0) spin up 1000 rpm, CW
CNC.FeedRate(2,2.0); // Z Axis feedrate 2 IPM
{
// Create a 3D fractal
// write your favorite Mandelbrot or Julia set here.
// Or if your not into 3D than a simple Koch Curve.
// http://www.jracademy.com/~jtucek/math/dimen.html
// Show me this in G-Code.
}
// See where I'm going?

Think of this new language like HTML and CSS, you just define a new keyword, or
similar to embedding scripts in a web page. You give them names and call them.
I am not proposing getting rid of G-Code just be allowed to augment it in a
standard way without having to modify the interpreter.

I have seen one case on a diamond turning machine where the finish pass on an
beryllium mirror takes over 40 hours (non stop) to complete. I can't imagine
G-Code could ever handle such a numerically complex task (paraboloids of all
types, or interlaced paraboloids). Nor would I trust it. However, the machine is
not as versatile as it could be because everything must be described in software
to machine a surface where nanometers make the difference (floating point
rounding errors taking off a few extra atoms on that radii or less on the next,
looks like phonograph record when done, and not acceptable).



-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com [mailto:CAD_CAM_EDM_DRO@yahoogroups.com]
On Behalf Of Mariss Freimanis
Sent: Monday, May 15, 2006 8:09 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Interface. Gauging interest.

Couple of additional points:

1) I wish the G-Rex was a pizza you cut into 6 slices and take as
many as you need, 1 slice or all 6.:-)

It doesn't work that way; a single axis still needs the Rabbit
RCM3720, the Xilinx FPGA, the FT245BM USB controller, the regulators,
connector blocks, xtal oscillators, pcb, enclosure, LEDs, etc, etc.
All you would save for a "single slice" would be a few 74HCT 10-penny
parts.

2) Step pulse generation is donkey-work a PC shouldn't have to do. It
is singularly ill-equipped for that task. This properly belongs in
dedicated hardware like an FPGA; it was born to do that.

Off-loading this onerous task from the PC relieves its burden. Art of
Mach fame reported he could watch a DVD and surf the web while Mach4
was running a complex contouring program. This on a slow PC without a
burp.

PCs are meant to compute, not to do bean-counter accounting parsing
out microsecond step pulse timing and counting. It is the latter task
that makes PCs difficult to run easily no matter the OS.

3) G-code is at best a 2-1/2 axis control code. It is unimaginably
unweildly for higher axis counts. How would you efficiently write
application code for 6-axis of coordinated motion like a hexapod
using g-code?

Mariss