Drop Z quickly before homing?

0nn0

I have a cartesian printer with an inductive Z-probe set up as the Z-limit switch. Currently the feed rate for G30 is 120mm/s, which quite low and it will time out if the printhead is at the top of the Z-axis range.

Is there a way to quickly drop the Z-axis before doing a G30? I´d like to preserve the accuracy of the lower feed rate for the actual

I tried the script quoted below, but it gives an error: Error: Probe already triggered at start of probing move

This is my homez.g

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v3.3.16 on Fri Jul 07 2023 17:37:13 GMT+0200 (Central European Summer Time)
G90
G1 X106 Y97 F6000 ; go to probe point
G91             ; relative positioning
G1 H1 Z-245 F6000  ; drop Z relative to current position, use endstop as safeguard
G90             ; absolute positioning
G30             ; home Z by probing the bed
G1 Z30 F6000  ; lift Z relative to current position

droftarts

@0nn0 in M558, which sets up the probe, you can have two feedrates; a fast one for the initial probe, then a slow one. See the F parameter of M558 here: https://docs.duet3d.com/User_manual/Reference/Gcodes#m558-set-z-probe-type

Ian

0nn0

@droftarts I had not considered the possibility that this was a machine parameter. I had only checked out the parameters for the G30 command. Thanks for pointing this out!