Cylindrical mapping

Cylindrical mapping in linuxcnc: you program a part with X Y and Z in a lathe and it is mapped in a rotary axis (using spindle a C axis)
Better explained here


Best regards!

Cylindrical mapping in linuxcnc: you program a part with X Y and Z in a lathe and it is mapped in a rotary axis (using spindle a C axis)

Looks interesting.
So are you saying you have implemented this in linuxcnc and if yes are you going to show us how you did it?

Exactly, i did implement it, i dont know why the video is not embbeded. This is my second attempt

youtube.com/shorts/X_OvO9vH9e8?si=9NnEw1TGMq_6w-eU



Attached the kinematics file, you will find two kinematics ,it works out with kinematics switch.
Basically is a custom lathe i built that is has X, X', Z axis with motorized tool where X and X' works together to form a Y axis, this would be kinematics 0.
Kinematics 1 is this cilindical mapping, where it must work in combination of:
  -First reference de spindle
  -C axis is always present but not used until kinematics 1 is activated (but spindle encoder is always linked to joint.xx.motor-pos-feedback pins in hal
  -Remapped Gcode G7.1:
      G7.1 Rxxxx for activating the transformation on specified diameter
      G7.1 without R to deactivating the transformation


Any questions are welcome

 

Nice.

Couple questions...

• Do you have an example of g-code which runs this kinematic switch? i.e. simple part code snippet to see what the cylindrical mapping looks like.
• Have you done this for polar interpolation? (i.e. an axial tool on a C-axis lathe)
  • Reason I ask is that another forum member cooked (and shared) up a polar interpolation kinematics component, but after trying to digest it, I noticed he had hard-coded the tool offset on which the interpolation was based.
    • My guess is that due to the hardware he built (only a single live tool along the turret rotational axis) this offset was never going to change so he didn't write the component to be universal
  • My (slightly stalled) live-tool lathe project would be much more useful if polar interpolation was available.  As would LCNC in general, I think.

Thanks for sharing.  Still looking forward to the THKHMI and other changes you've made backstage in LCNC.

Hi Spumco!
So yes, at the end of the video link I shared you can see how it looks like, but basically you write the code as if you write it in a plane where the Y axis is mapped to the C axis to a particular diameter (specified with R parameter when calling G7.1)
Example
G0 z0 y0
Y100
Z100
Z0
Y0

That would map the Y axis on the C axis, easy thing (tomorrow I need to machine some parts and I will post the gcode and the finished part)

PD: attached a picture of the new panel working (still missing the label strips)

I took a picture of the first kinematics on the file, Y axis is interpolation of X an X’
When second kind is active (Y axis is mapped to C and physical Y is not moved)