Tool compensation switching plane

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.

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.

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.

I tried to set my system up to do this a couple of days ago, for this job
However I don't think that the Touchy GUI can cope with non-trivial kinematics. I got a lot of error messages I didn't recognise and decided to just use a G1 X[40 * COS[21]] Z[40 * SIN[21]] F20 instead to get the job done.

The HAL changes are very minor indeed, replacewithand addIn your case this dummy-axis also needs to operate the head tilt, but I would suggest still leaving the feedback short-circuited like this, and operate the head tilt actuator with simple HAL.

INI changes are a bit more complicated. You probably need AXES = 9 and COORDINATES = XYZBW.
You probably also need an [AXIS_N] section for all 9 axes. though these can be very basic, with just limits, a home-sequence and home-velocities set to zero to activate immediate homing.

REEEN wrote:

I thought that kinematics are independant from the gui...

It ought to be, but the GUI needs to be able to switch from Joint Mode to World Mode.

An easy test would be to take a sim config (sim-axis-vismach-5axis for example) and change the GUI in the INI file and see what happens.

In practice your mill has two identity-type kinematics. So it is possible that you can use a switchable trivial kinematics.

The very worst case is running two separate configs and two separate G-code files for each head position. And that probably isn't too much trouble in practice.

Is there a tool-changer?