Rotation Axis on Ramps 1.4 with Marlin Firmware

Hi there! You guys helped me out a lot in the past and I hope you cann provide another idea to solve my problem.

I worked on an experimental printer with a rotating printhead (Yes I need it, otherwise I wouldn't ask). I "solved" the issue in the past by using the second extruder (E1) port on the RAMPS board and controlled it by moddifing the g-Code semi-manually.
Now I am trying to implement the rotation-axis (R) into marlin firmware so it can be controlled via G1 command.

Does any one of you have an idea on how to realize this?
I would be greatful for any advise

Isn´t it useful to implement this function in a slicer?

I know Cura can do a lot of magic things when you add another extruder to it.
I was able to do some nice "skin pattern print" with manipulating the "T0 /T1 " specific g-codes.

Do you have to switch axis orientation?
-Olaf

I wrote a small simple "slicer" for that purpose. The Problem with changing extruders mit T-Command is, that the controller messes up the extrusion length, so I had to set it to 0 every time the motors are switched.
It's kind of a dirty hack, which provides a lot of trouble. That is the reason why I'm trying to establish an autonomously working axis.

The orientation of the axis has to work in both directions and a homing function to set it to 0 drgrees (via hall effect sensor or opto endstop) would also be pretty good.

Marlin provides the "dual x-carriage" feature in Configuration_adv.h. I thought about tweeking that, although I'm not sure how the g-Code has to look in that case.

What's your opinion on that?