Re: [CAD_CAM_EDM_DRO] G code Examples (Was RE: Cutviewer program - file renaming

I've found similar problems using cutview, but I figured it was because
I'm a G code newbie and didn't know everything I was doing. It seemed
to ignore cutter compensation commands.

Along those lines, I'm working on generating some G code for my newly
finished mill running EMC. I'm trying to first understand how
the different codes are working (before I let a tool do
everything) and trying to understand what operational methods people
typically employ (locating origins, incremental versus absolute
positions, etc.)

I have a tool called cam expert which I can configure to produce G code,
and
I can configure how it produces G code by modifying the directives, but
in order
to do this effectivly I need to understand G code better. I'm working
from
some tutorials I've found on the net, but I'd like to see some examples
that employ cutter compensation (as found in EMC), tool changes (manual
changes
with a message/key prompt as is often done in EMC, and multiple
operations with
rapids, tool changes, etc in the programs.

Which boils down to the following questions:

1) Does anybody have G code examples they would consider sharing with me
(I can accept attachments directly, or from the files section, to
prevent
clogging the list).

2) With respect to origins, and absolute mode, etc. How are these set,
and used
both in the drawing package and the machine tool/G code.

My mill is configured to "home" at the center of the X and Y Axis, with
Z almost
all the way up, and Z-10 around 1 1/2" from the table. I would think I
might
use some type of relative coordinate system (ignoring the positions EMC
reports after homing) to allow me to locate the tool and touch off where
I want the operation to start, then have the cut proceed from there.

Another part I'd like to make involves a large half circle flat plate,
which I would cut a contour to create the perimiter of the half circle.
If my origin was
the center of the circle, and the radius was almost the limit of a
direction of
travel, then I might have to start my operation near the -limit of the
travel, i.e.:

+y
| ********
| * *
| * *
| * *
| * *
-x------*----------------*------ +x
| * *
| * *
| * *
| **********@*********
|
-y

My machine is configured so the head moves similar to most CAD
coordinate
systems, where moving the tool up and right with respect to the part
is increasing both Y and X. My current part drawing has the origin of
the
drawing at the "@" sign. In order to cut this part, my initial start
position
would need to be close to -y. How is this properly set up, with respect
to
configuring my origin in my cad software, and configuring G code to
cut this (absolute versus incremental coordines in my moves, and
relative/absolute values in EMC)

I suspect that this has very little to do with EMC and much more with
understanding how the G codes work.

I apologize for this long winded attempt to convey this question. I've
been fooling with the G code generation seriously for a few days, and
am dying to try making some of my own parts.

Thanks,
John Murphy

Smoke wrote:

>
> Well, I've been playing with the Cutviewer program for a while.
> Turns out it doesn't work so well after all......unless your program uses
> nothing but simple XYZ moves.
> I've tried for over an hour to get it to "machine" a simple island program
> using cutter compensation.
> No matter what I tried, the program will not cut the island ON THE PART. It
> will start where I put the tool origin just fine. After that, It doesn't
> make much difference what you use for I or J (either positive or negative
> numbers too). The damn thing still cuts a circle that runs off the part.
>
> I did find that you can (one you learn how) save some time by setting up
> your tools and stock size in advance right in your text program. you have
> to precede them with a semi-colon and (in my case if I want to run the