Re: Tool Comp G41,G42

The G41/42 in EMC is great.

But I remeber getting burnt once, edited the tool table, ran the
part and it didn't recognize the new tool. The finish cut was
supposed to be offset for a 3/4" EM, but it took the old data
for a 1/2" EM.

I am now super cautious about editing the tool table while it's live,
I'm more likely to load a couple of slots with similar tools so I
can swap to any one of five 1/2" EMs, all predefined.

-Damon

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> stcnc2000 wrote:
>
> >Hi to all, If you have to draw you part. It seems to me i would
> >rather use the offset function that is built into Cad programs,
like
> >Intellicad or Autocad. If you want an example go to:
> >http://STcnc.tripod.com/tutorial
> >It shows you how easy it is to allow for cutter compensation.
> >
> >
> But then, if an off-size cutter or tool deflection causes the part
> to come out a bit out of tolerance, you have to go back to the CAD
> and redraw the offset line, and redo the generate G-code function.
>
> With cutter radius compensation, you edit the tool table to change
the
> apparent cutter diameter, and rerun the SAME program! A trick I use
> for tricky, one-off parts, is to just generate the final (finish
cut)
> toolpath
> using cutter radius comp and the toolpath eauals the part outline.
>
> I put a spring-loaded ballpoint pen in the quill, and a sheet of
paper on
> a "platen" in the vise. I run the program with the tool table set
to a
> diameter of zero, and verify that the drawing looks like the part I
want.
> Then, I tell it the tool is, say, .020" larger than it really is.
I run
> the program
> and it makes a rough cut over the part, leaving it oversize. Then,
I change
> the tool table again, setting the actual measured tool diameter, or
> compensating
> slightly for tool deflection, give it a number .002" smaller than
the tool
> measures. Run the sam program again, and you get the finished part.
> By twiddling the size given in the tool table, you can adjust for
tool
> wear to keep the parts coming out within tolerance.
>
> Jon