4th Axis Posting going from + to - 355 in few lines posting with MC2021

[q4stix]

Hi, hoping to get a better understanding of what might be happening when I try to post an operation, whether roughing, finishing, contour, etc.

I have a simple shape as a test model that *should* just rock the A-axis back and forth to roughly +7.5 degrees, through 0 degrees, to -7.5 degrees, 0 deg, and repeat. If I simulate the operation Mastercam shows me exactly what I would expect it to do.

When I post the operations when using the default machine (Default.mcam-control) and post (MPFAN,pst) it jumps back and forth from positive to negative and if I were to run it would cause the table to rotate 2 revolutions without lifting the tool instead of a 10 degree sweep across the 0 degree mark.

Code example output:
N100 G20
N110 G94 G1 G17 G40 G49 G80 G90 F6.42
N120 T4 M6
N130 G94 G1 G90 G54 X3.3747 Y-.9971 A-355.625 S4365 M3 F99.75
N140 G43 H4 Z3.5962
N150 Z3.3962 F6.42
N160 S2139 M3
N170 Z2.7962 F15.
N180 S4365 M3
N190 X3.4154 Y-.9972 Z2.7949 A355.698 F31.3 <--------- would cause almost 2x rotations from A-355.625
N200 X3.4546 Y-.9975 Z2.7908 A355.938 F101.73
.....
N290 X3.5842 Y-1. Z2.7279 A359.545 F342.41
N300 X3.5865 Z2.7203 A359.976
N310 X3.5849 Z2.7128 A.408 F368.76 <--------- would cause almost 1x rotations from A359.976
N320 X3.5832 Y-.9999 Z2.7052 A.841 F345.76
N330 X3.5777 Y-.9998 Z2.6979 A1.259

So... I'm confused. The A-axis rotary under Machine Definition shows it can support continuous positioning, signed continuous and the max travel limits are super high, but even changing the travel limits doesn't seem to do anything.

Does anyone know if this is because the default/generic machine needs to be changed or is it a post processor issue? At this point it's *prior* to being able to run on any machine. I also tried adding a 4th axis to our existing Fadal config that was supposed to be good for 3 or 4 axis setups but that's doing it too.

Any help is much appreciated!
-Matt

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[q4stix]

Quick update on this... it appears the post processor isn't actually reading the machine definition like it should so I'm hunting that down. When I manually hardcode the post to have the machine setup I want (just setting certain parameters that aren't carrying over) then the code outputs as I would expect. I've got some more research to do but I have an idea of the root of it.