Re: [CAD_CAM_EDM_DRO] G code Examples

Jon,

Lots of useful information! I am interested in:

G92 - Programming of absolute zero point (from NIST)

As I understand it, G92 "sets" the controller's coordinates to that
specified? And something is saved to a file, for the next time the
machine is run? I'm not clear on what gets remembered. MaxNC remembers
the last coordinates the machine was at (when restarted), is that part
of G92's function?

I was looking for a "Gcode" instruction to set the current location for
MY program! Thanks!

Alan KM6VV

Jon Elson wrote:

>
> John Murphy wrote:
> <snip>
>
> I generally use an edge finder, position until it deflects when approaching
> the left side with the X axis, and go to MDI and enter G92 X-.1, because
> the .2" diameter of the edge finder has the spindle located .1" to the left
> of the actual edge of the part. Then I go back to manual, and approach
> the bottom of the part with the Y axis, and enter G92 Y-.1 when I get to
> the point where the tip deflects. My usual method of Z origin for one-offs
> is to touch the tip of the tool to the part, often with a piece of paper between
> the tool and the part, and then enter G92 Z.005 to compensate for the
> thickness of the paper. So, the top of the part becomes Z=0, and the
> rest of the part is in Z- coordinates. Some people find this ghastly, and
> insist you need to make Z=0 the BOTTOM of the part, by doing the
> same 'touch-off' on the fixture holding the part. Then, the part is entirely
> in Z+ coordinates. Sometimes I do this
> when actually using a fixture, but often I'm holding the part directly in
> the vise. I had some round parts that had a fixture with a bored hole or
> boss at the center, and used a dial test indicator to bring that circular feature
> under the spindle and set X=0 Y=0 with a G92 X0 Y0.
> <snip>
>
> Jon