Hi Stephan! Today I managed to do some real tests with your macro and thread helper! In plastic yet...

But the 3/4 16 TPI thread I tested (not the fine one, the other one) worked perfectly and fit my bolt in the first attempt. I’ll test in brass over the weekend.

A doubt: I chose Z = 0 as the start and Z= 6 (-6) as the end of an external thread.

It begins the thread at 5.17 (or something like it) and stops before the -6. I had to make it to -7.5 to actually get to -6 in Z

The clearence in Z is 0.2mm

My settings are metric, Z-, 0.2 in clearence in x and z, parallel port for now...

It should have the -6 at the very end of the pullout. I did that to prevent collisions if you have a tiered bolt (and it was so originally). So if you have 360 degrees pullout, you have to add a full pitch to get the length of full thread you want.

The 5 - something is around three pitches run-up to stabilize the sync between spindle and Z-axis. The parallel port takes longer to stabilize than the Smoothstepper, so i made that an option (smoothstepper is one pitch plus clearance).