Tool compensation switching plane

Hello Community,

my current project is the conversion of a big milling machine.

This machine has a hydraulic swivel head to switch from vertical to horizontal machining eg. g17 to g18.

My problem is that the tool compensation is along the z axis, which is right in g17 but when activatiing g18 my tool compensation should be along the y axis.

How can I achieve this without specifying a new tool offset ?

The offset should somehow be applied to the right axis according to the active plane.

Thank you!

Greets Rene

REEEN wrote: How can I achieve this without specifying a new tool offset ?

I am pretty sure that you can't.

I see a few possible options.

1) Create a new tool table entry for each tool with an offset in Y and do a tool-change when you tilt the head.

2) If you don't tilt the head during a job then you can use an alternative INI in the same config directory that will share parameters and tool table data, but will re-assign the axes. This is what I do with my horizontal/vertical mill. But I need a hoist and tools to switch orientations.

3) configure the machine as a 4-axis and use tool-length compensation in W. This will introduce the complications of non-trivial kinematics.

Okay, thats what I ecpected.

Two configs is a very bad solution for an automatic tilt head.

I think the best option is using a fake a axis to rotate the tool from vertikal to horizontal.

Now I need a special kinematic.

What do you mean with tool conpensation in w? Never heard that before.

Thanks
Greets REEEN

REEEN wrote: What do you mean with tool conpensation in w? Never heard that before.

Have a look at the 5-axis sim config. (sim->axis->Vismach->5-axis)

Tool-length is stored in the W column of the tool table, and the config has a "virtual" W axis. if you jog in W then movement is along the tool axis. Which allows drilling angled holes. XYZ jogs still happen in cartesian space.

Thanks Andy !

Okay, but using a fake w axis means I have to use w axis instaed of z for every operation ?

I figured out two ways to manage the problem:

1.( Iam not sure about this )
If I use a fake A axes to turn the tool in vertikal and horizontal direction, and use a special kinematic for this, wil I achieve tool center point compensation ? Such that the tool length offset ( z offset ) will be along the tool vector ?
Or isn't this possible in linuxcnc ?

2. I use a remap script to remap any free gcode as a replacement for g43 which checks the position of the head and switches tool offset from z to y axes in the tool table. Very messed up I think, and I don't like that the preview tool will point in the wrong direction which is very confusing ....


Thanks Rene

REEEN wrote: Okay, but using a fake w axis means I have to use w axis instaed of z for every operation ?

No, you can still command moves in the XYZ directions. [/quote]

If I use a fake A axes to turn the tool in vertikal and horizontal direction, and use a special kinematic for this, wil I achieve tool center point compensation ? Such that the tool length offset ( z offset ) will be along the tool vector ?
Or isn't this possible in linuxcnc ?

Yes, that should be what you get. Have a play with the Vismach simulator I mentioned earlier and you will see how it works.

2. I use a remap script to remap any free gcode as a replacement for g43 which checks the position of the head and switches tool offset from z to y axes in the tool table. Very messed up I think, and I don't like that the preview tool will point in the wrong direction which is very confusing

This ought to work too.

I prefer the kinematics solution. In fact I have frequently considered doing exactly the same with my milling machine, which has a manually tiltable head.