Klipper bed mesh on print area only macro install guide

readme.md

READ THIS FIRST

Adaptive bed mesh is merged into klipper master branch. You can use this feature without this custom macro. Official klipper adaptive bed mesh

Klipper mesh on print area only install guide

What this macro do

• This macro will dynamically changing the bed mesh area based on the size of the parts will be printed. The fw will only probe on the area that the part will be printed (plus mesh_area_offset value)

Setup guide

• (1) Add the following macro to your printer config, this will replace the default BED_MESH_CALIBRATE command.

[gcode_macro BED_MESH_CALIBRATE]
rename_existing: BED_MESH_CALIBRATE_BASE
; gcode parameters
variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0
; the clearance between print area and probe area 
variable_mesh_area_offset : 5.0
; number of sample per probe point
variable_probe_samples : 2
; minimum probe count
variable_min_probe_count : 4
; scale up the probe count, should be 1.0 ~ < variable_max_probe_count/variable_min_probe_count
variable_probe_count_scale_factor : 1.0
; enable preference index
variable_enable_reference_index : False
gcode:
    {% if params.AREA_START and params.AREA_END %}
        {% set bedMeshConfig = printer["configfile"].config["bed_mesh"] %}
        {% set safe_min_x = bedMeshConfig.mesh_min.split(",")[0]|float %}
        {% set safe_min_y = bedMeshConfig.mesh_min.split(",")[1]|float %}
        {% set safe_max_x = bedMeshConfig.mesh_max.split(",")[0]|float %}
        {% set safe_max_y = bedMeshConfig.mesh_max.split(",")[1]|float %}

        {% set area_min_x = params.AREA_START.split(",")[0]|float %}
	{% set area_min_y = params.AREA_START.split(",")[1]|float %}
	{% set area_max_x = params.AREA_END.split(",")[0]|float %}
	{% set area_max_y = params.AREA_END.split(",")[1]|float %}

	{% if bedMeshConfig.probe_count.split(",")|length == 2 %}
            {% set meshPointX = bedMeshConfig.probe_count.split(",")[0]|int %}
            {% set meshPointY = bedMeshConfig.probe_count.split(",")[1]|int %}
        {% else %}
            {% set meshPointX = bedMeshConfig.probe_count.split(",")[0]|int %}
            {% set meshPointY = bedMeshConfig.probe_count.split(",")[0]|int %}
        {% endif %}

	{% set meshMaxPointX = meshPointX %}
	{% set meshMaxPointY = meshPointY %}


        {% if (area_min_x < area_max_x) and (area_min_y < area_max_y) %}
            {% if area_min_x - mesh_area_offset >=  safe_min_x %}
                {% set area_min_x = area_min_x - mesh_area_offset %}
            {% else %}
                {% set area_min_x = safe_min_x %}
            {% endif %}

            {% if area_min_y - mesh_area_offset >=  safe_min_y %}
                {% set area_min_y = area_min_y - mesh_area_offset %}
            {% else %}
                {% set area_min_y = safe_min_y %}
            {% endif %}

            {% if area_max_x + mesh_area_offset <=  safe_max_x %}
                {% set area_max_x = area_max_x + mesh_area_offset %}
            {% else %}
                {% set area_max_x = safe_max_x %}
            {% endif %}

            {% if area_max_y + mesh_area_offset <=  safe_max_y %}
                {% set area_max_y = area_max_y + mesh_area_offset %}
            {% else %}
                {% set area_max_y = safe_max_y %}
            {% endif %}

            {% set meshPointX = (meshPointX * (area_max_x - area_min_x) / (safe_max_x - safe_min_x) * probe_count_scale_factor)|round(0)|int %}
            {% if meshPointX < min_probe_count %}
                {% set meshPointX = min_probe_count %}
            {% endif %}
	    {% if meshPointX > meshMaxPointX %}
                {% set meshPointX = meshMaxPointX %}
            {% endif %}

            {% set meshPointY = (meshPointY * (area_max_y -area_min_y ) / (safe_max_y - safe_min_y) * probe_count_scale_factor )|round(0)|int %}
            {% if meshPointY < min_probe_count %}
                {% set meshPointY = min_probe_count %}
            {% endif %}
	    {% if meshPointY > meshMaxPointY %}
                {% set meshPointY = meshMaxPointY %}
            {% endif %}

            {% set algorithm = "bicubic" %}
	    {% if "algorithm" in bedMeshConfig %}
	        {% set algorithm = bedMeshConfig.algorithm %}
            {% endif %}
            {% if meshPointX >=7 or meshPointY >=7 %}
                {% set algorithm = "bicubic" %}
            {% endif %}

            {% if enable_reference_index %}
                {% set referenceIndex = (meshPointX * meshPointY / 2 - 1 )|round(0)|int %}
                BED_MESH_CALIBRATE_BASE mesh_min={area_min_x},{area_min_y} mesh_max={area_max_x},{area_max_y} probe_count={meshPointX},{meshPointY} samples={probe_samples|int} algorithm={algorithm} relative_reference_index={referenceIndex}
            {% else %}
                BED_MESH_CALIBRATE_BASE mesh_min={area_min_x},{area_min_y} mesh_max={area_max_x},{area_max_y} probe_count={meshPointX},{meshPointY} samples={probe_samples|int} algorithm={algorithm}
            {% endif %}
        {% else %}
            BED_MESH_CALIBRATE_BASE
        {% endif %}
    {% else %}
        BED_MESH_CALIBRATE_BASE
    {% endif %}

• (2) Go to slicer setting and replace the old bed mesh gcode the following command.

Prusa Slicer
BED_MESH_CALIBRATE AREA_START={first_layer_print_min[0]},{first_layer_print_min[1]} AREA_END={first_layer_print_max[0]},{first_layer_print_max[1]}

Ideal maker
BED_MESH_CALIBRATE AREA_START={print_pos_min_x},{print_pos_min_y} AREA_END={print_pos_max_x},{print_pos_max_y}

Cura slicer
BED_MESH_CALIBRATE AREA_START=%MINX%,%MINY% AREA_END=%MAXX%,%MAXY%

*(Cura slicer plugin) To make the macro to work in Cura slicer, you need to install the post process plugin click here to download (based on frankbags's script)
- In cura menu Help -> Show configuration folder.
- Copy the python script from the above link in to scripts folder.
- Restart Cura
- In cura menu Extensions -> Post processing -> Modify G-Code and select Klipper print area mesh

For user using single command START_PRINT

• (*) If you use single command start gcode like START_PRINT BED_TEMP={material_bed_temperature_layer_0} EXTRUDER_TEMP={material_print_temperature_layer_0} .You might need to add parameter parsing to BED_MESH_CALIBRATE inside START_PRINT. This is an example, also check my macro sample

[gcode_macro START_PRINT]
variable_parameter_EXTRUDER_TEMP: 190
variable_parameter_BED_TEMP: 60
; gcode parameters for area bed mesh
variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0
gcode:
    # preheat, homing, etc
    BED_MESH_CALIBRATE AREA_START={params.AREA_START|default("0,0")} AREA_END={params.AREA_END|default("0,0")}
    # the rest of your start macro here

And you will need to change Slicer start gcode to this

• Cura: START_PRINT EXTRUDER_TEMP={material_print_temperature_layer_0} BED_TEMP={material_bed_temperature_layer_0} AREA_START=%MINX%,%MINY% AREA_END=%MAXX%,%MAXY%
• Prusa slicer: START_PRINT EXTRUDER_TEMP=[first_layer_temperature] BED_TEMP=[first_layer_bed_temperature] AREA_START={first_layer_print_min[0]},{first_layer_print_min[1]} AREA_END={first_layer_print_max[0]},{first_layer_print_max[1]}

change logs

• 2022/07/21
  • Added force lagrange algorithm for mesh with lower than 3 points
  • Added enable_reference_index config flag

The code does not work?

• I will try to help if possible, you will have to post ALL of your configs, your slicer start gcode and your sliced gcode.
• If I'm cannot or too slow to respose, our discord members might help you. Check our discord here

Hi,
Because you have reference_index, try to change the variable_enable_reference_index : False to variable_enable_reference_index : True

Thank you for your quick help. It works perfectly now!

@rstudner I have this code on start g-code on superslicer:

START_PRINT AREA_START_X={first_layer_print_min[0]} AREA_START_Y={first_layer_print_min[1]} AREA_END_X={first_layer_print_max[0]} AREA_END_Y={first_layer_print_max[1]}

Thanks!

I ended up with this m'self:

START_PRINT BED_TEMP=[first_layer_bed_temperature] EXTRUDER_TEMP=[first_layer_temperature]
AREA_START={first_layer_print_min[0]},{first_layer_print_min[1]} AREA_START={first_layer_print_max[0]},{first_layer_print_max[1]}

please help, I sometimes get an error and I haven't figured out the reason why? the frustrating thing is that it only happens sometimes. although I do understand what the error is saying I don't understand why is happening.


``[gcode_macro BED_MESH_CALIBRATE]
rename_existing: BED_MESH_CALIBRATE_BASE
; gcode parameters
variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0
; the clearance between print area and probe area
variable_mesh_area_offset : 2.0
; number of sample per probe point
variable_probe_samples : 1
; minimum probe count
variable_min_probe_count : 3
; scale up the probe count, should be 1.0 ~ < variable_max_probe_count/variable_min_probe_count
variable_probe_count_scale_factor : 1.0
; enable preference index
variable_enable_reference_index : False
gcode:
{% if params.AREA_START and params.AREA_END %}
{% set bedMeshConfig = printer["configfile"].config["bed_mesh"] %}
{% set safe_min_x = bedMeshConfig.mesh_min.split(",")[0]|float %}
{% set safe_min_y = bedMeshConfig.mesh_min.split(",")[1]|float %}
{% set safe_max_x = bedMeshConfig.mesh_max.split(",")[0]|float %}
{% set safe_max_y = bedMeshConfig.mesh_max.split(",")[1]|float %}

    {% set area_min_x = params.AREA_START.split(",")[0]|float %}
{% set area_min_y = params.AREA_START.split(",")[1]|float %}
{% set area_max_x = params.AREA_END.split(",")[0]|float %}
{% set area_max_y = params.AREA_END.split(",")[1]|float %}

{% if bedMeshConfig.probe_count.split(",")|length == 2 %}
        {% set meshPointX = bedMeshConfig.probe_count.split(",")[0]|int %}
        {% set meshPointY = bedMeshConfig.probe_count.split(",")[1]|int %}
    {% else %}
        {% set meshPointX = bedMeshConfig.probe_count.split(",")[0]|int %}
        {% set meshPointY = bedMeshConfig.probe_count.split(",")[0]|int %}
    {% endif %}

{% set meshMaxPointX = meshPointX %}
{% set meshMaxPointY = meshPointY %}


    {% if (area_min_x < area_max_x) and (area_min_y < area_max_y) %}
        {% if area_min_x - mesh_area_offset >=  safe_min_x %}
            {% set area_min_x = area_min_x - mesh_area_offset %}
        {% else %}
            {% set area_min_x = safe_min_x %}
        {% endif %}

        {% if area_min_y - mesh_area_offset >=  safe_min_y %}
            {% set area_min_y = area_min_y - mesh_area_offset %}
        {% else %}
            {% set area_min_y = safe_min_y %}
        {% endif %}

        {% if area_max_x + mesh_area_offset <=  safe_max_x %}
            {% set area_max_x = area_max_x + mesh_area_offset %}
        {% else %}
            {% set area_max_x = safe_max_x %}
        {% endif %}

        {% if area_max_y + mesh_area_offset <=  safe_max_y %}
            {% set area_max_y = area_max_y + mesh_area_offset %}
        {% else %}
            {% set area_max_y = safe_max_y %}
        {% endif %}

        {% set meshPointX = (meshPointX * (area_max_x - area_min_x) / (safe_max_x - safe_min_x) * probe_count_scale_factor)|round(0)|int %}
        {% if meshPointX < min_probe_count %}
            {% set meshPointX = min_probe_count %}
        {% endif %}
    {% if meshPointX > meshMaxPointX %}
            {% set meshPointX = meshMaxPointX %}
        {% endif %}

        {% set meshPointY = (meshPointY * (area_max_y -area_min_y ) / (safe_max_y - safe_min_y) * probe_count_scale_factor )|round(0)|int %}
        {% if meshPointY < min_probe_count %}
            {% set meshPointY = min_probe_count %}
        {% endif %}
    {% if meshPointY > meshMaxPointY %}
            {% set meshPointY = meshMaxPointY %}
        {% endif %}

        {% set algorithm = "lagrange" %}
        {% if "algorithm" in bedMeshConfig and meshPointX >=4 and meshPointY >=4 %}
            {% set algorithm = bedMeshConfig.algorithm %}
        {% endif %}

        {% if enable_reference_index %}
            {% set referenceIndex = (meshPointX * meshPointY / 2 - 1 )|round(0)|int %}
            BED_MESH_CALIBRATE_BASE mesh_min={area_min_x},{area_min_y} mesh_max={area_max_x},{area_max_y} probe_count={meshPointX},{meshPointY} samples={probe_samples|int} algorithm={algorithm} relative_reference_index={referenceIndex}
        {% else %}
            BED_MESH_CALIBRATE_BASE mesh_min={area_min_x},{area_min_y} mesh_max={area_max_x},{area_max_y} probe_count={meshPointX},{meshPointY} samples={probe_samples|int} algorithm={algorithm}
        {% endif %}
    {% else %}
        BED_MESH_CALIBRATE_BASE
    {% endif %}
{% else %}
    BED_MESH_CALIBRATE_BASE
{% endif %}

``[gcode_macro START_PRINT]
variable_parameter_EXTRUDER_TEMP: 235
variable_parameter_BED_TEMP: 50
; gcode parameters for area bed mesh
variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0
gcode:
{% set BED_TEMP = params.BED_TEMP|default(50)|float %}
{% set EXTRUDER_TEMP = params.EXTRUDER_TEMP|default(235)|float %}
M104 S{EXTRUDER_TEMP} T0
M140 S{BED_TEMP}
G28
# preheat, homing, etc
BED_MESH_CALIBRATE AREA_START={params.AREA_START|default("0,0")} AREA_END={params.AREA_END|default("0,0")}
# the rest of your start macro here
M117 Waiting for temperature
# Start bed heating and continue
#M140 S{BED_TEMP}
{% if printer.heater_bed.temperature < params.BED_TEMP|float0.95 %}
M190 S{params.BED_TEMP|float0.95} # wait till 0.85 of bed temp is reached, then continue
{% endif %}
#M140 S{EXTRUDER_TEMP}
#M190 S{BED_TEMP}
#M109 S{EXTRUDER_TEMP}
M190 S{BED_TEMP}
M109 S{EXTRUDER_TEMP} T0
PRIME_LINE
M117 Printing...

[gcode_macro END_PRINT]
gcode:
M117 Done printing :)
# move z down
G91
G1 Z10 F3000
G1 E-5
G28 X Y
#disable hotend and heated bed
M104 S0
M140 S0
# disable steppers
M84
BED_MESH_CLEAR

@Lekkz the mesh is completed so your macro setting is good.
Here is the problem: Unlike full size bed mesh witch the last probe position always in the bed corner, bed mesh area more likely end at center of the bed where the printed part are. You have to modify your PRIME_LINE, move the toolhead to the prime line start position before calling the extrude gcodes.

@ChipCE thanks for the response, this is what I have for my PRIME_LINE [gcode_macro PRIME_LINE] gcode: M117 Prime Line G92 E0 ;Reset Extruder # move z axis G1 Z2.0 F3000 ;Move Z Axis up # move to prime position G1 X10 Y30 Z0.28 F5000.0 ;Move to start position G1 X10 Y200.0 Z0.28 F1500.0 E15 ;Draw the first line G1 X15 Y200.0 Z0.28 F5000.0 ;Move to side a little G1 X15 Y50 Z0.28 F1500.0 E30 ;Draw the second line G92 E0 ;Reset Extruder G1 Z2.0 F3000 ;Move Z Axis up

@Lekkz I think add G90 command at the start of your prime line will fix that

Can someone please explain what this section does:

{% set algorithm = "lagrange" %}
{% if "algorithm" in bedMeshConfig and meshPointX >=4 and meshPointY >=4 %}
{% set algorithm = bedMeshConfig.algorithm %}
{% endif %}

Is it setting the algorithm to lagrange if the mesh points are 4 or greater? Or.. Is it setting the algorithm to whatever is set in printer.cfg if the points are >=4?

If I wanted to increase the number of probe points calculated for any given print area, would I just increase the scale factor (ie 1.25, 1.5, 1.75)?

Thanks!

@sgoph It's not that well writen, but similar to this.

{% set algorithm = bedMeshConfig.algorithm %} {% if meshPointX <4 and meshPointY <4 %} {% set algorithm = "lagrange" %} {% endif %} Bicubic need 4 points or more so we will need to force change to lagrange if the meshPoints are under 4.

Yes. Increase the scale factor will do it.

I'm working on a macro which enables per-object meshes if:

1. 'Label Objects' is turned on in the slicer
2. moonraker is set up with:

   [file_manager]
   enable_object_processing: True
   

3. klipper is configured with [exclude_object]

This will make a single small mesh for every item on the bed and load it dynamically when the object starts printing:

https://github.com/whi-tw/klipper-adaptive-mesh/releases/tag/v0.0.2 (adaptive_bed_mesh.cfg in the Assets section)

This has the benefit of the meshes being very detailed, as they are only made on the area of each object - no wasted space.

If anyone wants to give it a go, please leave feedback on the repo with any issues.

Minor help request from y'all experts... for some reason I can't seem to get this right.

My Ender bed isn't very flat (hah!)

So if I have it calculate a mesh for a smaller object in the center of the bed, when it moves fromt he post-purge line to the center, it'll scratch/drag my nozzle on the way over.

Trying to get it to move up 1mm, navigate to 'skirt/brim/whatever' start ,then lower back down 1mm

@rstudner This macro cannot be changed to fix your problem. But modify your start gcode can fix that. Post your start gcode here and i will try to look at it.

@ChipCE Hi, I have a fairly large distance between the nozzle and the sensor (57mm). With large print I get errors like this
!! Move out of range: -27.016 86.484 5.000 [0.000]
How to compensate it?

Edit:
[SOLVED] I have changed x min in config:
[bed_mesh]
...
mesh_min: 57, 10
...

22:13
Internal error on command:"PRINT_START"
22:13
Internal error on command:"BED_MESH_CALIBRATE"
22:13
Internal error on command:"BED_MESH_CALIBRATE_BASE"

Getting this error after my voron does QGL and homes.

Here is my print start macro:
[gcode_macro PRINT_START]
variable_parameter_EXTRUDER_TEMP: 190
variable_parameter_BED_TEMP: 30

gcode parameters for area bed mesh

variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0
gcode:
G32 ; home all axes
G90 ; absolute positioning
G1 Z20 F3000 ; move nozzle away from bed
BED_MESH_CALIBRATE AREA_START={params.AREA_START|default("0,0")} AREA_END={params.AREA_END|default("0,0")}

Where exactly did you get %MINX% etc. from in Cura slicer? in my Cura that does not pass anything but the %MINX% and similar.

I am already using the "START_PRINT BED_TEMP=110 EXTRUDER_TEMP=255" part but the definition of area does not seem to work

Sorry. I didnt see the part where the plugin is mentioned...got it working now.

But will you not need a "BED_MESH_PROFILE Load=default" in your printer.cfg to actually load the saved mesh? With normal BED_MESH_CALIBRATE you need to.

The script works great, mostly. I have one issue (more of a minor inconvenience) where the Klipper gives a "Must home axis first: 0.000 0.000 5.000 [0.000]" on 3 consecutive lines. I just have to manually home the printer and then it works great, it's still just an inconvenience. My though is just that a G28 (I have a G28 macro) needs to be thrown in somewhere, I'm just not sure where exactly...
Thanks in advance for any help!

@1yrik I think you need to edit your start gcode. This override macro is the same as the original BED_MESH_CALIBRATE, it can be called without homed axis.

@ChipCE I know I have to add in a "G28" somewhere, I'm just not sure where. I'll take another look and see if anything obvious needs changing.

When I boot up my printer after doing said changes I get this error. How can I fix this?

@Matei-alt seem like you dont have [bed_mesh] enabled in your config.

@ChipCE Oh, I tought "this will replace the default BED_MESH_CALIBRATE command." meant to just replace that whole thing. Sorry for bothering you.

I have a question when probing begins the probe almost drags across the bed, like it does not go up it stays on the bed moves to the left then goes up a little and back down, is that correct?

That's normal behavior if you have the option under [bltouch] stow_on_each_sample: false

https://www.klipper3d.org/BLTouch.html#multi-probing-without-stowing

if you have no clearance issues then it shouldn't be a problem, it does save a lot of time when building a mesh

Ya the probe was actually touching the bed as it moved to the next point which was causing false readings. I have to add a line in mesh section like horizontal_Z_probe: 8. This wasn't the exact line but something similar

Anyone using Bambu Studio or Orcaslicer ? I cant seem to get this to work using either of those slicers.. using the prusaslicer settings ... "START_PRINT EXTRUDER_TEMP=[first_layer_temperature] BED_TEMP=[first_layer_bed_temperature] AREA_START={first_layer_print_min[0]},{first_layer_print_min[1]} AREA_END={first_layer_print_max[0]},{first_layer_print_max[1]}"

M190 S[bed_temperature_initial_layer_single]
M109 S[nozzle_temperature_initial_layer]
M117
PRINT_START EXTRUDER=[nozzle_temperature_initial_layer] BED=[bed_temperature_initial_layer_single] PRINT_MIN={first_layer_print_min[0]},{first_layer_print_min[1]} PRINT_MAX={first_layer_print_max[0]},{first_layer_print_max[1]}

Unknown command:"AREA_START=158.387,158.396"

it does the full bed then. Any ideas? i´m using klicky probe

Superslicer:
PRINT_START BED=[first_layer_bed_temperature] EXTRUDER={first_layer_temperature[initial_extruder]+extruder_temperature_offset[initial_extruder]} CHAMBER=[chamber_temperature]
AREA_START={first_layer_print_min[0]},{first_layer_print_min[1]} AREA_END={first_layer_print_max[0]},{first_layer_print_max[1]}

[gcode_macro PRINT_START]
variable_parameter_AREA_START : 0,0
variable_parameter_AREA_END : 0,0

gcode:
{% set FILAMENT = params.FILAMENT|default('Default')|string %}
{% set MIN_TEMP = params.EXTRUDER|int * 0.9 %}
{% set BED_TEMP = params.BED|default(0)|int %}
{% set EXTRUDER_TEMP = params.EXTRUDER|default(0)|float %}
{% set chamber = params.CHAMBER|default(0)|int %}

SET_GCODE_VARIABLE MACRO=PRINT_START VARIABLE=chambertemp VALUE={chamber}

{% if params.FILAMENT == 'ABS' %}
	{% set nevermore_fan_speed = 0.70 %}
  
{% elif params.FILAMENT == 'ASA' %}
    {% set nevermore_fan_speed = 0.70 %}

{% elif params.FILAMENT == 'PETG' %}
	{% set nevermore_fan_speed = 0.40 %}
	
{% elif params.FILAMENT == 'PLA' %}
	{% set nevermore_fan_speed = 0 %}

{% elif params.FILAMENT == 'WOOD' %}
	{% set nevermore_fan_speed = 0 %}
	
{% else %} 
	{% set nevermore_fan_speed = 0 %}
{% endif %}

SET_FAN_SPEED FAN=Nevermore SPEED={nevermore_fan_speed}
#SET_FILAMENT_SENSOR SENSOR=filament_sensor ENABLE=1
M107
M117 {params.FILAMENT}
M190 S{BED_TEMP} #M140
G28
G90
 {% if printer["temperature_sensor chamber"].temperature < chamber %}              
    HEATSOAK T={BED_TEMP} MOVE=1                                                         
    M190 S{BED_TEMP}                                                                    
    TEMPERATURE_WAIT SENSOR="temperature_sensor chamber" MINIMUM={chamber}          
{% else %}                                                                         
    {% if printer.heater_bed.temperature < (BED_TEMP-2) %}                               
        HEATSOAK T={BED_TEMP} MOVE=1                                                     
        M190 S{BED_TEMP}                                                                 
    {% else %}                                                                      
        HEATSOAK T={BED_TEMP} MOVE=0                                                   
    {% endif %}
{% endif %} 
M106 S0                                                                              
LEDWHITE 
ATTACH_PROBE_LOCK                                                              
QUAD_GANTRY_LEVEL                                                                  
G28 Z                                                                           
G90                                                                               
G0 Z20                                                                              
G0 X{printer.toolhead.axis_maximum.x/2} Y{printer.toolhead.axis_maximum.y/2} F19500 
BED_MESH_CALIBRATE AREA_START={params.AREA_START|default("0,0")} AREA_END={params.AREA_END|default("0,0")}
DOCK_PROBE_UNLOCK                                                                   
M109 S{EXTRUDER_TEMP}
SETACTUAL_ETMP
G1 E-1 F300
CALIBRATE_Z                                                                       
G92 E0                                                                             
PRIME_NOZZLE

@DaKlassiker your Prusa start gcode is splitted into 2 lines. They must be in the same line.