Calibrate the Z probe trigger height

Karim

@Phaedrux Hey I am not following you, are you saying add G30 at then end of home.g after G32.

How do I get G30 to go at the center of the bed. Like this.

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v3.3.14 on Sat Oct 29 2022 11:20:15 GMT-0400 (Eastern Daylight Time)
G91                     ; relative positioning
G1 H2 Z5 F6000          ; lift Z relative to current position
G1 H1 X355 Y355 F6000 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X355             ; home X axis
G1 H1 Y355             ; home Y axis
G1 X-5 Y-5 F6000          ; go back a few mm
G1 H1 X355 F360        ; move slowly to X axis endstop once more (second pass)
G1 H1 Y355             ; then move slowly to Y axis endstop
G90                     ; absolute positioning
G1 X140 Y150 F6000     ; go Center of bed
G30                     ; home Z by probing the bed
G32
G30 P4 X140 Y150 Z-99999

Phaedrux

G90; absolute positioning
G1 X140 Y150 F6000 ; go Center of bed
G30 ; home Z by probing the bed

Add that to your bed.g right above the last line.

Karim

@Phaedrux Thank, I can get a good first layer now.
Here is another question. How do I get the probe to go three times around the bed.

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2 on Mon Dec 10 2018 01:47:39 GMT+0000 (GMT)
M561 ; clear any bed transform
;G28 Z ; home Z
M671 S20
G1 F20000 X0 Y0 Z10
G30 P0 X0 Y0 Z-99999
G1 F20000 X0 Y275 Z10
G30 P1 X0 Y275 Z-99999
G1 F20000 X282 Y275 Z10
G30 P2 X282 Y275 Z-99999
G1 F20000 X282 Y0 Z10
G30 P3 X282 Y0 Z-99999 S4
G90                                              ; absolute positioning
G1 X140 Y150 F6000                 ; go Center of bed
G30                                               ; home Z by probing the bed
G1 F9000 X140 Y150 Z150

A Former User

@Karim

You want to probe each point multiple times? Check out the M558 "A" and "N" parameters... A is maximum number of probes per point and N is the tolerance

https://docs.duet3d.com/en/User_manual/Reference/Gcodes

change this line in you config

M558 P5 C"^zprobe.in" H5 F300 T6000            ; set Z probe type to switch and the dive height + speeds

to

M558 P5 C"^zprobe.in" H5 F300 T6000  A3 S0.02          ; set Z probe type to switch and the dive height + speeds

This change will probe each point up to three times or only twice if the deviation between the two probings is less than 0.02

Phaedrux

If you mean doing 3 iterations of the leveling process, the easiest way is to simply duplicate the commands the number of times you want it to do.

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2 on Mon Dec 10 2018 01:47:39 GMT+0000 (GMT)
M561 ; clear any bed transform
;G28 Z ; home Z
M671 S20
G1 F20000 X0 Y0 Z10

;first
G30 P0 X0 Y0 Z-99999
G1 F20000 X0 Y275 Z10
G30 P1 X0 Y275 Z-99999
G1 F20000 X282 Y275 Z10
G30 P2 X282 Y275 Z-99999
G1 F20000 X282 Y0 Z10
G30 P3 X282 Y0 Z-99999 S4
G90                                              ; absolute positioning
G1 X140 Y150 F6000                 ; go Center of bed
G30                                               ; home Z by probing the bed

;second
G1 F20000 X0 Y0 Z10
G30 P0 X0 Y0 Z-99999
G1 F20000 X0 Y275 Z10
G30 P1 X0 Y275 Z-99999
G1 F20000 X282 Y275 Z10
G30 P2 X282 Y275 Z-99999
G1 F20000 X282 Y0 Z10
G30 P3 X282 Y0 Z-99999 S4
G90                                              ; absolute positioning
G1 X140 Y150 F6000                 ; go Center of bed
G30                                               ; home Z by probing the bed

;third
G1 F20000 X0 Y0 Z10
G30 P0 X0 Y0 Z-99999
G1 F20000 X0 Y275 Z10
G30 P1 X0 Y275 Z-99999
G1 F20000 X282 Y275 Z10
G30 P2 X282 Y275 Z-99999
G1 F20000 X282 Y0 Z10
G30 P3 X282 Y0 Z-99999 S4
G90                                              ; absolute positioning
G1 X140 Y150 F6000                 ; go Center of bed
G30                                               ; home Z by probing the bed

G1 F9000 X140 Y150 Z150

Karim

@Phaedrux ok, Also how do you slow the z probing in each of the three passes.

I saw someone has this.

; Probe the bed at 4 points, x3 for more precision
M558 K0 H10 F1200 ; increase the depth range, gets the gantry mostly level immediately
M98 P"/sys/bed.g"
M558 K0 H4 F240   ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed.g"
M558 K0 H1 F60    ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed.g"

Phaedrux

That could work too, or just add the M558 commands to your bed.g between the iterations.

Karim

@Phaedrux Hey how about this. Do I have to add M671 S20 to bed.g

;bed_probe_points
G30 K0 P0 X0 Y0 Z-99999            ; probe point 0 near a leadscrew
G30 K0 P1 X0 Y275 Z-99999          ; probe point 1 near a leadscrew
G30 K0 P2 X282 Y275 Z-99999        ; probe point 2 near a leadscrew
G30 K0 P3 X282 Y0 Z-99999 S4       ;probe point 3 near a leadscrew and calibrate 4 motors

; bed.g
; Called to align the gantry to the bed plane via G32

M561                    ; Clear any bed transform
M84 E3                  ; Turn off noisy Extruder motor
G28                     ; Home all axes

; Probe the bed at 4 points, x3 for more precision
M558 K0 H10 F1200                ; increase the depth range, gets the gantry mostly level immediately
M98 P"/sys/bed_probe_points.g"
M558 K0 H4 F240                  ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed_probe_points.g"
M558 K0 H1 F60                   ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed_probe_points.g"


G90                     ; absolute positioning
G1 X140 Y150 F6000      ; go Center of bed
G30                     ; home Z by probing the bed

Phaedrux

@Karim said in Calibrate the Z probe trigger height:

Do I have to add M671 S20 to bed.g

No that should probably stay in config.g. Only call it if you intend to change it.

Karim

@Phaedrux ok what do this means.

The K parameter is applicable to all G30 commands. It is the Z probe number, default 0. It is not remembered between G30 commands, it always defaults to 0.

For example I use it here.
M558 K0 H4 F240

Phaedrux

Do you actually have multiple probes? If not, just remove the K0 entirely from all commands.

Karim

@Phaedrux like this.

;bed_probe_points
G30 P0 X0 Y0 Z-99999            ; probe point 0 near a leadscrew
G30 P1 X0 Y275 Z-99999          ; probe point 1 near a leadscrew
G30 P2 X282 Y275 Z-99999        ; probe point 2 near a leadscrew
G30 P3 X282 Y0 Z-99999 S4       ;probe point 3 near a leadscrew and calibrate 4 motors

also the K0 in here too.

; bed.g
; Called to align the gantry to the bed plane via G32

M561                    ; Clear any bed transform
M84 E3                  ; Turn off noisy Extruder motor
G28                     ; Home all axes

; Probe the bed at 4 points, x3 for more precision
M558 K0 H10 F1200                ; increase the depth range, gets the gantry mostly level immediately
M98 P"/sys/bed_probe_points.g"
M558 K0 H4 F240                  ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed_probe_points.g"
M558 K0 H1 F60                   ; reduce depth range, probe slower for better repeatability
M98 P"/sys/bed_probe_points.g"


G90                     ; absolute positioning
G1 X140 Y150 F6000      ; go Center of bed
G30                     ; home Z by probing the bed

Phaedrux

Yes but how many probe devices do you actually have?

Karim

@Phaedrux one z probe, no z end stop switch

Phaedrux

Then you don't need K0 anywhere.

Karim

@Phaedrux Got it working, Thank You.