Voron 2.4 Klicky Mesh Leveling and Z Offset

[Phaedrux]

@Chaos3d said in Voron 2.4 Klicky Mesh Leveling and Z Offset:

Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.4.6-rc.1 (2023-07-13)
Duet WiFi Server Version: 1.27
Duet Web Control 3.4.5

First stop would be to update to the 3.4.6 final release.

https://github.com/Duet3D/RepRapFirmware/releases/download/3.4.6/Duet2and3Firmware-3.4.6.zip

Upload this zip file as is.

@Chaos3d said in Voron 2.4 Klicky Mesh Leveling and Z Offset:

I have read that the compensation is applied to the offset but no matter what I do the head is always about 3mm off the printing surface when it starts to print.

How exactly are you setting Z0? Share your homing files as well.

[Chaos3d]

My Homing for Z is done via homezm.g which is just this:

M98 P"/macros/homing/scripts/zhop_up.g"
M98 P"/macros/homing/scripts/probe_zm.g"
;M98 P"/macros/moveto/center_xyz.g"

the zhop just lifts the head up by 5mm and the probe_zm.g looks like this:

code_t; For homing Z, perform a double-tap using the mechanical switch.

;M98 P"/macros/moveto/mswitch_xy.g"

;M98 P"/macros/drive/z_downcurrent.g"

;M98 P"/macros/zprobe/use_mfast.g"     ; activate endstop switch as z-probe for fast probing
;G30                                   ; z-probe as configured

;M98 P"/macros/drive/z_fullcurrent.g"

;M98 P"/macros/zprobe/use_mslow.g"     ; activate endstop switch as z-probe for slow probing
;G30                                   ; z-probe as configured

;M98 P"/macros/zprobe/use_ifast.g"     ; restore default probe (inductive probe) settings

;; For homing Z, perform a double-tap to locate the endstop.
;; First move fast to save time, then move slow for precision.
;;
;; *ADJUST* based on your Z size as indicated below

G91                                    	; relative positioning
M98 P"/macros/drive/z_downcurrent.g"
G1 H1 Z430 F6000                       	; +Z probe move, fast. (*ADJUST* to 10mm larger than your Z size)
M98 P"/macros/drive/z_fullcurrent.g"
G1 H2 Z-2 F6000                      	; back off from the endstop
G1 H1 Z3 F60                           	; +Z probe move, slow
G1 H2 Z-5 F6000                        	; back off from the endstop

I have also uploaded the full version of the firmware

[Phaedrux]

I'd need to see the content of the macros to determine what you're actually doing.

[Chaos3d]

The two macros used are z_downcurrent.g

code_;; In order to consolidate motor current and physics settings,
;; and to enable switching between full- and low-current profiles,
;; these motor settings live in this related set of macros.
;;
;; The "downcurrent" files specify slower, gentler values
;; used for some parts of homing.
;; This can help to reduce damage in the case of a crash
;; due to misalignment, misconfiguration,
;; or sensors otherwise not triggering.
;;
;; Note that if current is too low or acceleration/jerk is too high,
;; steps can be dropped when doing a z-home, which can cause the gantry to come out of level.
;; On the other hand, if max speed is too high or acceleration is too low,
;; the gantry can fail to stop in time before crashing into the plate.
;;
;; *ADJUST* all values, or disable as descibed


;; To disable downcurrent Z moves, uncomment these lines.
;M98 P"/macros/drive/z_fullcurrent.g"
;M99     ; exit macro without changing anything else


;; Choose either an M913 percentage or an M906 absolute current value.
;M913 Z50        ; set operating current percentage
M906 Z600       ; set absolute motor drive current

;; Set reduced physics parameters to help prevent missed steps.
M203 Z3000      ; maximum speed (mm/min)
M201 Z400       ; maximum acceleration (mm/min/s)
M566 Z0         ; instantaneous speed change (mm/min)
text

And z_fullcurrent.g

;; In order to consolidate motor current and physics settings,
;; and to enable switching between full- and low-current profiles,
;; these motor settings live in this related set of macros.
;;
;; The "fullcurrent" files specify normal operating values.
;;
;; *ADJUST* all values

M913 Z100       ; restore motor current percentage to 100%
M906 Z900       ; motor drive current
M203 Z8000      ; maximum speed (mm/min)
M201 Z500       ; maximum acceleration (mm^2/s)
M566 Z120       ; instantaneous speed change (mm/min)

[dc42]

@Chaos3d after the M558 command in config.g you should have a G31 command to specify the trigger height and the probe XY offsets if any.

[Chaos3d]

@dc42 thanks for that - I have a g31 command in the bed mesh file

G31 P1000 X0 Y25 Z0

Could I ask a stupid question here - the trigger height is the height at which the probe triggers above the bed yes? i get the trigger height when the probe does its initial probe and reports it is this what i should be setting it to (normally its something like 1.4) i have a g30 command in the bed mesh set to 3

Or have I got the wrong end of the stick?

Once I have that set where would i set the diffrence between the klicky probe trigger height and the actual print head position in the z axis?

Cheers

[dc42]

@Chaos3d yes, trigger height is the height at which the probe triggers. For nozzle-contact probes it is usually negative, because the nozzle has to descend below the usual Z=0 point in order to trigger the probe. To find the offset, lower the nozzle until it just touches the bed, send G92 Z0, then step the nozzle down in tiny Z steps until DWC shows that the probe has triggered. The Z reading should then be the trigger height.

[Chaos3d]

@dc42 OK so the probe is considerably lower than the nozzle (with klicky attached) so when it triggers lets say at 1.4 mm above the bed, I set z to 0 using g92 - at that point it puts the klicky away on its deployment arm, and that leaves the nozzle roughly 2mm above the bed (which is the new zero)

so how do I handle that offset? - sorry for being thick im just confused as to how i can tell the print head it needs to be lower and use the compensation from the bed mesh

[dc42]

@Chaos3d said in Voron 2.4 Klicky Mesh Leveling and Z Offset:

Chaos3d
@dc42
9 Apr 2024, 17:44

@dc42 OK so the probe is considerably lower than the nozzle (with klicky attached) so when it triggers lets say at 1.4 mm above the bed

If you mean that the klicky triggers when the nozzle is 1.4mm above the bed, then set the trigger height to 1.4 using G31. The G31 command must be later in your config.g fie than the M558 command that creates the Z probe.

[Chaos3d]

Hi All, apologies for the late response with this, but I discovered several issues with the klicky setup and in the end I ditched the whole configuration and went with a BLTouch sensor, everything you guys posted on this thread helped me sort it out and I have now got a fully functioning Voron XL!! - I want to do some additional tweaks around load and unload and some panels to enclose the whole unit but it prints beautifully now and the bed compensation is spot on.

So many thanks everyone I would not of got it sorted without your input on this issues and the other control related posts

Rich