Hi Graham,
I have been giving this problem some further thought.
I recently had a similar problem when I tried to use a G68 to rotate the toolpath so a job could fit in my vice jaw limits. Long story short, but I rewrote the code with the dxf file rotated and, did not use any G68 rotation commands. The result is shown in the successful toolpath in the previous post.
So I thought, "What if i get rid of subroutines?"
The result was a successful toolpath as shown in the image attached. The program is useless for my purpose but proves the point.
So it appears that Mach3 does not like the combination of G41 Offsets with Subroutines or G68 rotational commands.
Fot the job in hand, I guess I have no choice but to abandon my attempts to use G41 offsets and go back to my old proven, long winded, methods of using toolpaths generated with Bobcad. So a few more hours rewriting 4 new programs doing battle with Bobcad.
Regards
Chrisjh