Tilted Working Plane

I don't think that is supported in trivial l(XYZ) kinematics.
It is possible to rotate the XY around Z using G10 L2
linuxcnc.org/docs/stable/html/gcode/g-code.html#gcode:g10-l2
But the only available work planes are XY, ZX, YZ, UV, WU, VW:
linuxcnc.org/docs/stable/html/gcode/g-code.html#gcode:g17-g19.1

What is the use-case for tilted planes? Is this for canned-cycles such as drilling and boring at angles?

It is possible to achieve this with non-trivial kinematics.

But it requires a specific machine configuration.

Or is it intended for hand-coded G-code to machine a surface? (There seems little point if using CAM, and I doubt that CAM knows how to use the codes anyway?)

I have created a sim config with a rotary/nutating head and I'm working on a G68.2 'tilted-work-plane' remap. I'm using this fanuc document as a guide:

nanopdf.com/download/fanuc-5-axis-programming-codes_pdf

While defining the work plane can be done on any kinematic moving the tool to the requested orientation will depend on the specific machine kinematic at hand.
If anybody has hands on experience using M68.2 and it's affiliated gcodes I'd like to pick their brains.

 

I wonder how they define the work plane if they allow a +-5deg error in the defining vectors?
Would you take the z-vector as passed in the parameters and orthogonalize the x-vector?

 
 

Another question: Am I correct in assuming that for G68.3 with alpha=0 (default) the target x-axis is in the machine xy-plane (ie horizontal)?
 

I have created a simulation config with an implementation of Tilted Work Plane for Spindle CA and Spindle CB kinematics. Both the kinematic and the twp remap support nutation of the secondary rotary joints (ie A or B ) form 0 to 90°. Hence this also works for the 'usual' orthogonal spindle rotary-tilt type machines:

Implemented:
G68.2 : defines twp using euler-angles, pitch-roll-yaw, 2-vectors, 3 points, optionally with offset in XYZ and rotation in XY
G68.3 : defines twp from current tool orientation, optionally with offset in XYZ and rotation in XY
G68.4 : same as G68.2 but as an incremental definition from an active TWP plane
G69 : cancels the current twp (resets all parameters, moves to G54 and sets Identity kinematics)
G53.1 (P) : spindle orientation without tcp, switches to G59 and activates tool kinematics
G53.3 (P XYZ) : same as G53.1 but with simultaneous move the the XYZ coords on the twp plane
G53.6 (P) : same as G53.1 but spindle orientation with tcp

- Spindle is C primary, A secondary or B secondary as defined in the [TWP] section of the ini file
- All G53.x commands will respect axis limits as set in the ini file for the respective primary and secondary spindle joints.
- The P word sets the orientation strategy: 0(default)=shortest distance, 1=positive rotation only, 2= negative rotation only (this applies to the primary rotary, the secondary move the shortest distance)

For more:
www.forum.linuxcnc.org/show-your-stuff/4...nutating-head#271334