I'm running an ancient version of FeatureCam that came with my late lamented Bridgeport Interact - it's V13 from 2007

I have a Heidenhain TNC355 controlling my Beaver Partsmaster in my home workshop, and I've added a 4th axis using servo cards etc from the poor old Interact, and at long last have got round to trying to sort out a suitable post processor for engraving text on a cylinder.

Starting with INMTCI4X.CNC which ships with this vintage it is intended for the TNC155 which is virtually identical to the TNC355 that I have. I've edited all references to 'B' axis as my 4th axis is 'A', and changed all the tool change bit's to account for my having a tool changer, and it basically works BUT gets it's maths wrong !

There is a variable <ROT1-MATH> that is supposed to represent the absolute angular position of the A axis, but if it goes through zero it gets it calculations wrong - <ROT1-MATH> needing to be subtracted from 360 in most (but not all !!! ) cases.

As a work around I'm using the variable <@ROT1-WIND> which is the incremental value of the A axis position, and am using incremental positioning and now it works as it should. But I'm curious if anyone has a known working post that drives a 4th axis on a TNC150 TNC151 TNC155 or TNC355 - and what variable it uses

This is entirely a hobby so there is no real pressure, but I'd like to know !!!!!!!!