Z offset ignoring me!

[brainkrud]

I've had this printer for a year. I have everything working great EXCEPT for the z-offset calibration. I have to update the z offset manually in the config file.

My last go was to try the "auto_z" calibrate plugin. Seemed to work great with my klicky- found the z-endstop switch, found the klicky base on the endstop switch, then the bed.

Next when I do a G90 - then a G0 Z1 the nozzle is pushing into the bed. This same thing happens when I do a standard z- endstop calibration. It is off by about 1.3 millimeters every time.

Is something overriding this?

Here are the values I got from the auto_z: Nozzle on z-endstop : Z=10.80775, Klicky base on z-endstop: Z=6.417750, Klicky on bed: z=1.312750.

Why won't it remove that 1.3????
Thanks for any help. This printer is almost junk if the first layer needs to be set by hand!!!

brainkrud.

 

[OmarGherd]

Share your config

 

[brainkrud]

Share your config

Config attached. Thanks for any suggestions- I tried again a regular "Z_ENDSTOP_CALIBRATE" and the nozzle was within range for a print after repeating the z_endstop_calibration procedure 3 times. (then I printed 4 items). Once I shutdown- the endstop was incorrect again after restarting. Arrrgh!!!

 

[MichaelOToole]

From your config file you set it to -0.400?

Do it manually, add this to printer.cfg

[probe]
z_offset: -0.400

Or what ever you set it to...

 

[OmarGherd]

I think it is down to missing 'zero_reference_position:' in the bed_mesh segment which you do not have.

I had the same issue but mine was always printing above the bed & the only way to make a change was to manually edit the config at the very bottom under the DO NOT EDIT THIS BLOCK OR BELOW.

What I woould do is add the bed_mesh config but amend for your machine, then the start macro (section it out with comments so it's easy to remove. restart, run a bed mesh then start a print, it should be pretty close if your switch offset is good. If it's looking better then you can look to refine the start macro & bed mesh to suit what you need.


Here is my bedmesh config:
note my v2 is a 350 so mesh_max would need reducing to fit within the bounds of your 300

[bed_mesh]
speed: 500
horizontal_move_z: 10
mesh_min: 10,22 #25, 30
mesh_max: 345, 310 #325, 300
fade_start: 0.6
fade_end: 10.0
probe_count: 20, 20
#relative_reference_index: 12
zero_reference_position: 175, 175
mesh_pps: 2, 2
algorithm: bicubic
bicubic_tension: 0.2

Here is my start macro.
I would remove the CLEAN_NOZZLE macro

[gcode_macro PRINT_START]
# Use PRINT_START for the slicer starting script - please customise for your slicer of choice
gcode:
M109 S180
BED_MESH_CLEAR
G32 ; Quad Gantry Level
G90 ; absolute positioning
#G1 Z20 F3000 ; move nozzle away from bed
{% set bedtemp = params.BED|int %}
{% set hotendtemp = params.HOTEND|int %}
BED_MESH_PROFILE LOAD=default
CLEAN_NOZZLE
CALIBRATE_Z
G0 X3 Y10 Z20 F8000
SET_FAN_SPEED FAN=exhaust_fan SPEED=1
M190 S{bedtemp}
M109 S{hotendtemp}
PRIME_LINE
STATUS_PRINTING

 

[MichaelOToole]

@Omar, that's for a 350mm?​

Heres mine, I don't have G90 in start code, should I?

[gcode_macro PRINT_START]          #   Use PRINT_START for the slicer starting script - please customise for your slicer of choice
gcode:
    {% set target_extruder = params.EXTRUDER|int %}
    {% set target_bed = params.BED|int %}

    G32                            ; home all axes
    G1 Z20 F3000                   ; move nozzle away from bed
    BED_MESH_CALIBRATE
    # set nozzle temp ?
    M109 S{target_extruder}
    M190 S{target_bed}
    LINE_PURGE

[gcode_macro PRINT_END]            #   Use PRINT_END for the slicer ending script - please customise for your slicer of choice
gcode:
    M400                           ; wait for buffer to clear
    G92 E0                         ; zero the extruder
    G1 E-10.0 F3600                ; retract filament
    G91                            ; relative positioning
    G0 Z1.00 X20.0 Y20.0 F20000    ; move nozzle to remove stringing
    TURN_OFF_HEATERS
    M107                           ; turn off fan
    G1 Z2 F3000                    ; move nozzle up 2mm
    G90                            ; absolute positioning
    G0  X125 Y250 F3600            ; park nozzle at rear
    BED_MESH_CLEAR

 

[OmarGherd]

Its been a long time since I did anything with the my start macro (I probably should clean it up). From what I understand I don't need it but you may, from my limited understanding & searching is its used before issuing a G1 command, which on mine is commented out & yours is not. I would wait for someone with a better understanding on G-code commenting before putting any weight to it.