Discovered that I had fat-fingered the safe start line, putting in G17 instead of G18. That fixed the arc being missing, but revealed that the postprocessor is using G3 when it should use G2 and vice versa.

I *think* I have that fixed, but I'm going to have to design a part with a bunch of different profiles and make sure all the arcs are in the right direction to be sure. The part of the post that controls this bit is crazy complex.

Great work thank you for trying to fix the post . Sure would like to use I & K instead of R .Only been using because I ,k gave me code that the ars were all messed up .?

Discovered that I had fat-fingered the safe start line, putting in G17 instead of G18. That fixed the arc being missing, but revealed that the postprocessor is using G3 when it should use G2 and vice versa.

I *think* I have that fixed, but I'm going to have to design a part with a bunch of different profiles and make sure all the arcs are in the right direction to be sure. The part of the post that controls this bit is crazy complex.

See "Newfangled Lathe Turret Standard.pdf" for an explanation tool post position affecting G02/G03 direction.  Depending on your lathe configuration, you may have to define your tool as being secondary direction.

Steve