How to manually set the z axis

3

Hey William,

driving Z to “1” inch is not possible since Z travel goes from 0 to −133 mm (0 to −166 mm with Z-20 “heavy” slider). I assume you mean 1 inch above the worksurface. This value is not known as it differs strongly between the machines, depending on your setup of wasteboard etc., you got to probe it.

To move to X=0 and Y=0 first, you could enter this into your manual data interface (MDI):

G20 ; Set imperial units mode
G90 ; Set absolute distance mode
G53 G0 X0 Y0 Z0; Rapidly move to the machine's home position in machine coordinates
G92 X0 Y0; Set the X,Y posistion as the new zero coordinate of the new coordinate system in effect

G92 is the most important command in a probing sequence, you could also simply probe XY instead of G92. Note that this is somewhat superfluous since X=0 Y=0 is the machine home and is already the zero coordinate in the default coordinate system. But it drives Z to its highest (zero) position.

Now you could lower Z by probing (comments including the “;” are ignored, can be pasted or omitted):

S0 ; set milling motor speed to 0
G70 ; Save all modal modes
G21 ; set metric mode
G0 Z-80 ; Lower Z to a position -80 mm
M0 (MSG, Please connect the touch plate to the controller, place the touch plate underneath the bit and attach the magnet end to the collet of your milling motor.) 
F100 ; Set feedrate to 100 mm/min for probing. (which means slow) 
G91 ; Set incremental distance mode 
G38.2 Z-90 ; Move the milling motor downwards until the bit touches the touch plate 
G92 Z15.4 ; Set this position as the new Z zero value (to reflect new tool length - including subtraction of the touch plate's height which is 15.4 mm thick) 
G0 Z30 ; Lift Z by 30 mm 
M0 (MSG, Please remove the touch plate and start the milling motor)
G72 ; Restore all modal modes that were saved previously

Now you have set the Z zero to the machine workbed.

(You could also simply press the “Z probe” button instead of entering all these commands.)

If you then want to move 1 inch above workbed, you enter:

G20 ; Set imperial units mode
G91 ; Set incremental distance mode
G0 Z1 ; move upwards 1 inch
G92 Z0 ; set this z heigt as the new zero coordinate.

See also

With your gamepad, or with the Jog Pane, or with MDI commands, you must move the bit closely over the circle in the touch plate prior to start probing.

See also

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