Kinematics for XYZAB mill

Which also makes me think that it might be a good idea to ask the owners of the machine for a couple gcode files to run on the simulation.

[Edit]
No problem, it's certainly a valid question. I have never worked on a 5 axis machine but I gather that it is only as good as the CAM behind it.
Thanks for the video

Just cleaned up the sim folder a bit and changed the name to 'xyzab-drt'.  DRT as Double Rotary Table.

 

Tool length is not included in the kinematics yet. 

[edit]
To install the kinematic comp:
$ halcompile --install halcompile --install <yourpathhere>/xyzab_drt.comp

I also whipped up a vismach model called 'xyzab-drt-gui.py' which you might need to set as executable.

[edit2]
Here is the revised write up on the math behind xyzab_drt.comp:
 
 

Just a few things to keep in mind with custom kinematics:
The motion planner of LinuxCNC is totally ignorant of any custom kinematics so it will happily assume that XYZ moves take place in a static (ie unrotated) coordinate system and apply the axis limits as defined in the hal file. With our custom kinematics we rotate the coordinate system freely inside the bounding box of where the machine can physically move (ie the joint limits) the lengths of the axes of that coordinate system get extended to and clipped by those physical limits and thus change with the rotation.
This means that when loading a Gcode file axis limit violations cannot be properly checked and axis limit settings might have to be increased in the ini file to avoid false limit errors.
Note that it is possible to automatically adjust the axis limit settings in the ini file when switching between different kinematics (ie M428 or M429).
See the 'millturn' simulation config /home/user/linuxcnc-dev/configs/sim/axis/vismach/millturn and specifically the 'mcodes' there.
Also note that the lookahead cannot 'see' beyond' a kinematic switch in a GCode file (ie M428 or M429)

I guess what I'm trying to say is that limit violations should be checked for in the CAM as LinuxCNC cannot be relied upon doing it correctly when loading a file that is to be run with custom kinematics.