gangtool setup / backtools

U[date: I caught mhaberler on IRC (he did the remap code). He looked at my code and didn't see a problem, when he tried the code himself he discovered a bug in his code. It would not take the G68 remap, G68.1 would work. He has since pushed a fix for this to master.

ALSO! Being all remaps are modalgroup 1, axis parameters are normally required. BUT !!!!! He also made a change to the remap code to accomidate this!!! Now, if its a remapped G code, axis parameters are no longer needed. This was a second fix, pushed to master.

So........... G68 and G69 can now be remapped to the approporiate G10 L2 P0 Rx code in a subroutine.

I never dreamed it was a bug in the remap code, as always, linuxcnc support was beyond outstanding !!!

I think this makes this pretty much a case-closed with the exception of me writing some info for the docs to give to John. I will wait a bit to do that so I can test a bit further and become more familiar with the whole process.

Has there been any progress made on G68/G69 since 2012? Or some other officially supported method for swapping from traditional to back cutting? This seems like a pretty common lathe operation and I'm surprised to find it so challenging to accomplish. I felt like I must be missing something but after reading through this thread it seems maybe not.

I am in the process of figuring how to set up my post processor to do back cutting. Right now it isn't putting any G68/G69 in the g-code. It looks correct when simulated in Fusion 360, but when I get it into LinuxCNC both turning and part-off tool are on the same side and turning tool goes the wrong way on arcs. Since (I think) my post processor already needs modifications, I was going to figure out what it takes to make it put G68/G69 in, but maybe that's the wrong answer. Looks like I need to figure out how to make it put in negative X-values.

I have never tried to use remap.

Thanks! I'll give it a shot.

Hi, does anyone have a update on g68 and g69. Thanks Andy for posting remapping. that's pretty nice. Does fusion 360 output g68 and g69 now or does anyone has a post processor that do that?

I'm trying to figure out how to retrofit this okuma lathe with front and back tooling. Seems like i'm going to face the same situation with front and back tooling.

forum.linuxcnc.org/38-general-linuxcnc-q...-retrofit-servo-help

I know you'll need to make an XYZ config to use G10 l2 p0 r180 if using 2.8 or master.
make the Y home in place and then always use 'all home'

After that ignore the Y axis.

The remapped g68 does not take care of the spindle direction.