Unlimited rotary axis

Hello

I have been now running some 5 axis work.
Mostly impellers, but some parts that are cut with helix motion around part.
This leads to running several turns like 60-200 turn around part.
When operation is finished I need to run back(rewinds) 200 turns to get back to C 0.0.
now rewind is mandatory cause I can not change kinematic mode to TCP:off, unless C0.0.
This frustrates me.

Is there any option to run in 360 modulo format, so that sign determines rotation direction or it uses closest path?
Axis would be limited to 0-360. degrees.

One option would be a reference command to run axis home.
some controllers use G28 U0. to command axis home and find reference.
This would be useful for unlimited rotary axis, it would find nearest home point and zero it self to that.

Any other ideas how to get rid of rotary rewind?

Hi,

I know your problem. At the end of your proces, you can do a homing for your rotary axis to home switch and reset your value.
Then you are ready for the next round...

So this is not possible at the moment?
Can i make PID loop zero at index pulse?
I have servos that i can program to give index pulse once per table rotation.

I know that many other suffers from this problem as well.
So let's try to solve this.

If not next best thing would be G-command to home single axis.
how much work this would need?

Method using g92,g10l20,g92.1 (for the c coordinate):

Ref:
www.linuxcnc.org/docs/html/gcode/g-code.html#gcode:g92
www.linuxcnc.org/docs/html/gcode/g-code.html#gcode:g92.1-g92.2
www.linuxcnc.org/docs/html/gcode/g-code.html#gcode:g10-l20

Ok I need to investigate how this works with 5-axis kinematics.

This could work, but not best possible solution.
quick and dirty, I would say.

G10 L20 P#5220 A[#5423 MOD 360]

Will eliminate all the multiples of 360 degrees. You then just have to "unwind" the remaining part of the rotation. I haven't run a complete project with this but it seems to work in my tests. Voodoo.

Yes.
This offsets zero point that is in use.
if you run another job with different zero point, lets say that you are finishing part in fixture, then this zero point has not this offset.
And your post tells to run C0. for this operation.

Or you close the machine and start next day, home your machine and and comman C0. in your next job.
Rotary will rewind to Cxxxxxxxx.xx ....

Like i said, quick and dirty.

Need better one.

First thing i tried.
I did not notice any change in behavior.
My axis value still goes from 0 .... xxxxxxxxxxx.xxx
and f I type C0. it will rewind it back home.

0, 360, 720 are not same position as they should be.