Kinematics for XYZAB mill

Actually, the A axis and the spindle do  coordinated TCP moves but the movement is not coordinated on the B axis (it just uses identity)
Eg, on A xis rotations, the behaivour is correct and thats the one I modified.
Maybe something is not connected correctly. I'll have  a look at the pins later..

You jumped the gun a bit there Rod, presenting that.
Finally found the mistake that was staring me in the eye. 
Here is a presentable solution that actually works for both A and B axes. So you might want to halcompile that and shoot that video again

 

Anyway, the other think I had was that Dy is not needed because the axes of our A and B DO actually intersect.
 

Sorry to keep posting but the problem with the B axis was there before I made my changes.
If you go back to the screen dumps of vismach on this post, the tool paths are displayed there on a purely  b axis rotation.
forum.linuxcnc.org/10-advanced-configura...mill?start=40#258349
It seems really odd to have made a mistake on just one rotating axis..
Sorry I just don't know enough on this branch of maths to help..

We don't want the public to laugh me off the streets, do we?

Just kidding Rod, I forgot the smiley when I wrote that you jumped the gun

Doesn't take much to screw up a kinematic, a 'CB' instead of a 'CA' will do.

Anyway I'll redo the pdf with the math and I'll need to have a look at the kinematics comp because I'm having issues setting the rotation point in the ini file.

[Edit]
Just to be clear, the error was in the comp I posted earlier. Nothing to do with your changes.

[edit2]
Also tool length offset is not implemented yet.

Aciera wrote:

You jumped the gun a bit there Rod, presenting that.
Finally found the mistake that was staring me in the eye. 
Here is a presentable solution that actually works for both A and B axes. So you might want to halcompile that and shoot that video again

 

File Attachment:

File Name: xyzab_trt.comp
File Size:8.71 KB

Anyway, the other think I had was that Dy is not needed because the axes of our A and B DO actually intersect.

 

Well the translations work but in TCP mode, I'm not sure if the axes are right. Eg to lift the spindle by 50mm while turning A & B I need to do
g0 b360 a -90 y 50
IS that expected behaviour? We might have the simple axes connected to the wrong joints.
I'll look later and redo that video.

Maybe compare with the xyzac-trt and xyzbc-trt simulation configs.