Kinematics for XYZAB mill

Let me put a bit more mud in the water...

I think A and B are right.

The thing is that we are used to have X axis left and right but in this case it is front and back (see legend). The A axis then definitively wrap around the X axis.

Then if you put the B axis at 9 o'clock (horizontal) instead of about 7 o'clock like tit is on the picture you will clearly see that it is in fact rotating around the Y axis.

Note: NO, you cannot put the A axis vertical and then use the B axis as a C axis simply because rodw mentioned that it rotate between 6 and 12 o'clock. (Is that muddy enough?)

What do I win ?

JPL wrote:

The thing is that we are used to have X axis left and right but in this case it is front and back (see legend). The A axis then definitively wrap around the X axis.
Then if you put the B axis at 9 o'clock (horizontal) instead of about 7 o'clock like tit is on the picture you will clearly see that it is in fact rotating around the Y axis.

Yes and yes.

JPL wrote:

Note: NO, you cannot put the A axis vertical and then use the B axis as a C axis simply because rodw mentioned that it rotate between 6 and 12

It can not go to 12, it will hit the spindle.
It seems something like 4-10 or 5-10 max. Notice the probe position on the right side.

JPL wrote:

What do I win ?

You both win coffee, any time you drop by, all you can eat/drink is on me.

@rodw:

This may be a crazy idea but if you modify the machine in such a way that the arm connected to the A axis rotate from 3 to 9 o'clock  you will then have a XYZAC machine since the B axis will then act as a C axis (visualize with the arm at 6 o'clock). (There's also a bracket on the right of the legend that is interfering with such a motion)
 

That is exactly what i saw at first!

JPL wrote:

@rodw:

This may be a crazy idea but if you modify the machine in such a way that the arm connected to the A axis rotate from 3 to 9 o'clock  you will then have a XYZAC machine since the B axis will then act as a C axis (visualize with the arm at 6 o'clock). (There's also a bracket on the right of the legend that is interfering with such a motion)

 

Of course that would be nice but when the machine manufacturer in question has been around 20 years and already has their own cad/cam software, it really needs to respect XYZAB kinematics to transition to Linuxcnc.

I suspect there is a fair bit of turning done on the machine with the spindle treated as a live tool which would explain their choice of kinematics.

Can anyone help me bring them on board with Linuxcnc?

PS @Tommy, thats what I saw first too.

Shouldn't be more complicated than the kinematics for the existing XYZBC- or XYZAC-trt kinematics. Maybe this helps:
forum.linuxcnc.org/media/kunena/attachme...5-axis-machines2.pdf

Don't let the matrix syntax scare you off, behind the scenes it's just a lot of trigonometry (sine/cosine). It's not as bad as it looks but it's tedious work to do by hand.

This is all very much on the outskirts of what LinuxCNC can do. Given that feedback from users running full 5 axis setups with LinuxCNC is very rarely seen here you might be in for a very lonely ride. My approach would be to create a simple vismac model of the machine and try to create a kinematic for XYZAB-trt and test it on a simulation config.