C-axis rotation

[ThisGuy]

Hello People

To start with, my apologies if I don't properly describe the problem, English is not my native language and I don't write posts myself. So if not a solution any information would be very welcome, I'm learning here.

I post here cause.. well, you never know how a cow caches a hare.

So we've ruin into an issue writing a post for a DMG DMU 80P with Heidenhain 530 control. It has a nutating head that rotates the B-axis at a 45-degree angle and a rotating table C-axis, picture attached.

The issue we're struggling with is that when the C-axis needs to make multiple rotations it goes to 359 and then back in the opposite direction to get what would be -1 or 361. Now it is able to do 36000 degree but no matter what we try it makes one rotation and then just rotates back... did anyone run into a similar problem and solved it?

M126 Shortest-path traverse of rotary axes didn't seem to have the wanted effect.

Another issue we run into, which is already solved as far as I understand but I'd still like to learn more. When indexing, the machine uses an M-code to calculate where the head and table must be, since a 45-degree angle on a surface on the workpiece is not at 45-degree angle for the B and C-axis in reality. But when doing the same when trying to use 5 axis at the same time this M-code didn't seem to work. I think the programmer writing the post solved this by inserting a formula and writing out the exact coordinates for both B and C axis. As far as I understand this is related to a transformation matrix.

I've been searching for more information on the subject but its bits and pieces so far.