How to save machine coordinates with tool length compensation?

Hello,

how can i save the machine coordinates (g53, not g54 - g59.3) where the touch probe is atm. ?

For example:

touch probe is at x30 then touches in x+ direction until it hits the part, then backs off and touches off again, then set zero and then go back to x30 in machine coordinates.

thanks

Hi 3d master,

G53 has no data. It has nothing. But you can save data if you want to.

I give you a short example :

axis.x.pos-cmd

If you connect this float value to your input 3D.comp file. It will do your trick. After that you must output is somewhere, but
that is up to you.

Or, what i use in my probing routines, to read out actual G53 startposition:
G28.1 returns xyz values to parameter #5161 #5162 #5163

There are several offsets you will need to take care off.

- axis position
- G5X.offset
- tool offset
- may be even a XY rotation

Norbert

okay thank you

LinuxCNC returns the results of a probe in the current WCS, which unfortunately is not consistent with most other controls. Even though LinuxCNC uses the same gcode (G38) and result parameters (#5061-5069) as Fanuc controls, Fanuc probes in machine coords, while LCNC probes in the current WCS. This has tripped me up more than once!

Several of the main devs and I discussed possible solutions, including adding parameters to LCNC for the probed pos in machine coords (seb has a branch where he started to implement this), or even changing the current behaviour to be fully compatible with Fanuc. The full discussion thread is in the dev mailing list. No additional progress has been made, and I don't expect any.

Workaround

A workaround I came up with was to make use of parameter indirection to get the offset of the currently active WCS and add the probed pos value to that to get the probed pos in ABS coords.

Calculate ABS z pos at which probe tripped:
If you need the probed post for other axes simply replace the x below with the axis number. (x = 1, y = 2, z = 3 ....)
Cheers,
Kurt

Okay using G28.1 and then G53 G90 G0 X#<x> (#<x> was defined before using #5161) worked perfectly

O500 IF [#5220 EQ 1]
#1102 = [#5063 + #5223] ; G54
O500 ELSEIF [#5220 EQ 2]
#1102 = [#5063 + #5243] ; G55
O500 ELSEIF [#5220 EQ 3]
#1102 = [#5063 + #5263] ; G56
O500 ELSEIF [#5220 EQ 4]
#1102 = [#5063 + #5283] ; G57
O500 ELSEIF [#5220 EQ 5]
#1102 = [#5063 + #5303] ; G58
O500 ELSEIF [#5220 EQ 6]
#1102 = [#5063 + #5323] ; G59
O500 ELSEIF [#5220 EQ 7]
#1102 = [#5063 + #5343] ; G59.1
O500 ELSEIF [#5220 EQ 8]
#1102 = [#5063 + #5363] ; G59.2
O500 ELSEIF [#5220 EQ 9]
#1102 = [#5063 + #5383] ; G59.3
O500 ENDIF

you can do this
#1102 will have G53 Z coordinates