axis double joints detach and atach

hello all,
My question is about two joint for one axis. We are controlling these joints like another axis as XYZU which need double X axis like XYZX. For G1 codes it is not problem but we can not use G2 codes with this application. We need to pull back joints according to the material's length and first joint should stay and second should move then vice versa. Have you any recommendation to solve this problem? Any help will be appreciated.

thank you

From version 2.8 onwards LinuxCNC can have many joints for the same axis, so you can have any combination of joints/axis.
What version are you using?

We are using 2.7 and we do not have problem with multiple joints in one axis. They are moving together at the same time. But sometimes we want to detach these joints and moving them individually. For example, joint x1 and joint x2 gone 500 together, then I want to move x1 -300 and then x2 -300 respectively. Is it possible or any way to over with this problem?

We need to pull back joints according to the material's length and first joint should stay and second should move then vice versa.

Maybe the new 'switchable kinematics' feature in the 'master' version could be helpful to you.
linuxcnc.org/docs/devel/html/motion/switchkins.html

The initial motivation for this feature was to be able to switch between trivial and non-trivial kinematics. But you could also use it to switch, as an example, between x1yz and x2yz kinematic. You could even add a third more complex kinematic like (x1+x2)yz. The switching between kinematics can then be done inside a GCode program.

I've done something similar to this using only some complex hal trickery.
I have a couple of machines with two parallel Z axis, set up as Z and W. I wanted the ability to temporarily slave them together so I could run the machine as XYZZ (mostly because the new trajectory planner didn't work for W.) But I wanted to retain the ability to move each Z and W separately for homing and touching off and setting tool depth. So I set up the tools and set the Z and W offsets. Then start the milling file the Z and W move independently to a coordinated starting point above the material. A custom M-code is issued that slaves the W head to the Z axis and the file is ran using only XYZ commands. At the end of the file, another custom M-code unslaves the W axis and each head moves independently again back to their park positions at the top of their axis travels.

Here is a link to where I posted some example configurations for both step/dir and analog servos.
forum.linuxcnc.org/forum/38-general-linu...e-questions?start=20

Thank you sir. I will try your advice