Re: [CAD_CAM_EDM_DRO] g02 I and J

kevinagilent wrote:

>I need to get some info on how to program a hole using g02 and g03
>how are the i and j related to x and y ?
>example (how would you code for a 2" hole using a 1/2"em. with
>centerline at x0 y0)? Can anyone give a site with a good explination
>on this subject? thanks kevin
>
>

The general scheme on most controllers is that the I and J are the
offsets from the STARTING
point to the center of the arc, and X and Y are the coordinates (in
absolute) or offsets to (in
relative) the end position. So, in your example, using absolute coords,
it would be
N10 G01 X0.75 Y0
N20 Z-.25 (plunge cutter in )
N20 G02 X-0.75 I-0.75
N30 X0.75 I0.75
N40 Z0.1 ( retract cutter)

I think this is correct. I have some programs that make nice boring
cycles, one bores out
a hole completely, orbiting out from the center, and then finishing with
a fine cut. The
other 'trepans' out larger holes, leaving a disc in the center. See
http://pico-systems.com/gcode.html
The first program is described at the top of the page, the second is
down near the bottom, and
called "make ring". Sample output is available, as well as DOS
executables and C source
code for download.

Jon