TCP 5-axis kinematics

Hi andypugh
Thank you for your reply and sorry for the delay, I have dedicated some time to solving the problem.
I state that I have an EtherCAT controller, the EpoCAT FR1000, and the problem was that the C axis followed the other axes and did not move simultaneously, so the machining was deformed, I set the PID appropriately and the axis C moves simultaneously and now it works!
I insert the link of the video I made.
thanks to plopes 9000


hello everyone from Italy and thanks for the precious support

plopes9000 wrote:

Here's my update regarding the 5 axis.

Just before I went on vacation and since I arrived back, I have been working on a complete workflow for 5 axis.

With TCP but without an easy to use 3+2 setup its still a pain to rough out before the TCP operation.

Enter Dynamic Work Offsets - see Haas DWO G254 - link .

 

I've configured my rotary table with XYZAC-TRT switchkins.  I'm able to switch to the TCP mode and it seems to work as advertised.  Very cool!
I'm also playing with the DWO configuration that plopes9000  did (back on page 16 of this monster thread).  I have it working, mostly.  If I jog the A axis and do the G55.4 command, the next move is exactly where I would expect it.  But if I jog the C axis, the next move is clearly wrong.  I suspect that the math in dwo_on.ngc is being calculated with reversed direction of rotation. 
Can anyone else confirm this?  Is there an updated dwo_on.ngc that I missed? 

In which file of the kinematics directory is the calculation done for TCP when using xyzac-trt-kins ? Is it "trtfuncs.c" with its functions "xyzacKinematicsForward" and "xyzacKinematicsInverse"?

Edit: yes, it is.

I managed to adapt the trtfuncs.c file to my needs. With that, the kinematics module compensates for the offset dy and still works in trivial kinematics. I wanted to share that and maybe it will be useful for someone else in the future.

Thanks for everyone´s help again!

Hello ,
I need your help ☺
I just changed the orientation of my AC rotary table . The A axis was parallel to the X axis and now it is parallel to the Y axis.
Of course my kinematics does not work anymore .
I had a xyzac-trt configuration that worked very well when A was rotating around X.
I don't understand well the documentation. Should I take a xyzab-trt configuration so that the configuration ( A turns around Y ) for my configuration to work .

Thanks for your help

 

We just put this together in the last few days. You can try it  XYZAB-trt config
forum.linuxcnc.org/10-advanced-configura...tics-for-xyzab-mill\

Give it a try, it would be good for it to be tested on real hardware. Pleas ask questions on the other thread.

I just changed the orientation of my AC rotary table . The A axis was parallel to the X axis and now it is parallel to the Y axis.

That would turn your machine from a XYZAC-trt to a XYZBC-trt there is already such a kinematic in LinuxCNC have a look at 
configs/sim/axis/vismach/5axis/table-rotary-tilting/xyzbc-trt.ini
that uses
xyzbc-trt-kins

Hello,
I have indeed configured the xyzbc-trt kinematics, made my pivot point and everything works correctly.
Now I don't have an A axis but a B axis, this is a problem for me for post processor which gives me G programs with an A axis.

Can I change the designation of the B axis to A axis in Lcnc 2.9 while keeping my xyzbc-trt configuration?

Thanks for your help

There is not really any easy solution. If you've changed your machine's kinematics, you need to be generating gcode from your cam that suits your machine.

The axes need to correspond to the kinematic. Can't you swap the X and Y axes and move back to xyzac-trt kinematics?

The only other solution I can think of is an 'filter script' that replaces the 'A' letters in the gcode with a 'B'. I haven't used an input filter myself but I think you could write a script (eg python, bash) and have it do it's magic to the gcode file as you load it into linuxcnc.

linuxcnc.org/docs/devel/html/gui/filter-programs.html

[edit]
Or of course you could modify the actual kinematic file written in C and recompile linuxcnc