Question Re: Work Offsets

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Tom Benedict <benedict@h...>
wrote:

> Ok, let me put this question another way:
>
> I am generating absolute coordinate G-code (i.e. if I do a "G0X1.0"
> followed by a "G0X0.0", I expect to be at x=0).

>
> What steps do I need to perform so that when I reach a line in my

program

> that says "G0 X0.000 Y0.000 Z0.000", the tool moves to the

workpiece

> (0,0,0) point?
>

Tom, as the EMC is taken from Allen Bradley framework, here is what
I would do on my Allen Bradley controller:

After positioning to X & Y zero location with your edge finder, Jog
your tool tip to 1.0 inches above the work piece

MDI:
G92 X0.0 Y0.0 Z1.0

All coordinate readouts should now be in part reference.

Work offsets and tool offsets will be screwy after this, but for
that one tool it should be usable. Don't put any tool offsets in
your G-code program or it will mess up the Z locations. If you want
to use multiple tools or multiple parts, use the tool offsets and
work offsets instead of this simplified, single tool method. The AB
is "REALLY" strange about this command which may explain why so many
have trouble with EMC and G92.

On my machine G99 cancels the G92 reference and returns to Absolute
Machine reference, which should be where you set your coordinates
when you home it at startup. G92.2 should have the same effect on
the EMC.

Does that work for you?

Fred Smith - IMService