Calibrate Probe Z Offset
This section explains how to calibrate the probe z_offset
which is critical to obtaining high quality prints. The z_offset is the distance between the nozzle and bed when the probe triggers. The Klipper PROBE_CALIBRATE
tool can be used to obtain this value - it will run an automatic probe to measure the probe's Z trigger position and then start a manual probe to obtain the nozzle Z height. The probe z_offset will then be calculated from these measurements.
From the MainsailOS web interface;
Click the
Home All
button in theControls
section;This should move the print head to the
safe_z_home
position;

Move the print head to a position near the centre of the bed;
Send a
G1 X125 Y125 F3000
command in theConsole
;

Send a
PROBE_CALIBRATE
command in theConsole
;This will return a Z position to start
the paper test
from;

Using a standard weight copy paper, place the piece of paper on the
Heater Bed
under theExtruder
;

You want to avoid having the nozzle crash into the bed and risk breaking the strain gauge on the printer. It is best to take your time, just use common sense, and be cautious when entering the distance a Z=-1 and Z=-.1 is a big difference!
Send a
TESTZ Z=-.1
command in theConsole
;After the nozzle stops moving, push the paper back and forth to check if the nozzle is in contact with the paper;
Continue sending
TESTZ
commands until you feel a small amount of friction when moving the paper back and forth;You only need a small amount of friction, you should still be able to move the paper back and forth feeling a slight contact with the nozzle without making the paper buckle;
If too much friction is found then send a
TESTZ Z=.1
command in theConsole
to raise the nozzle and test the paper friction again;If you raised the nozzle too high, adjust the negative
TESTZ
command by splitting the last distance in half;For this example you just went up Z=.1, try Z=-.05 or even Z=-.025 until you find the the sweet spot.
Once you have the little bit of friction between the paper and the nozzle;
Send an
ACCEPT
command in theConsole
;Record the
probe: z_offset: ###
setting as displayed in theConsole
, we will verify this setting matches what is saved in theprinter.cfg
file in one of the steps below;
Send a
SAVE_CONFIG
command in theConsole
;This will update the
printer.cfg
file with the newprobe: z_offset
settings and restart Klipper;
Remove the paper from the print bed.

Checking the
printer.cfg
file to ensure the newprobe: z_offset
settings are updated:From the MainsailOS web interface, click
Machine
, then click onprinter.cfg
;

The
printer.cfg
file should load into an editor window;Scroll down until you see the
[probe]
section, the default z_offset setting should be commented out and will not be used;

Continue scrolling down to the very bottom of the
printer.cfg
file until you reach the;#*# <---------------------- SAVE_CONFIG ---------------------->
section;A new
[probe]
section should be present, along with the new z_offset setting;This should match what you recorded from the
Console
in a previous step;

Once you have confirmed these settings;
Close the
printer.cfg
file by clicking theX
near the top right of editor;
Repeatability Check:
After calibrating the probe Z offset it is a good idea to verify that the probe provides repeatable results. You will use the
PROBE_ACCURACY
command for this test;From the MainsailOS web interface;
Click the
Home All
button in theControls
section;

Move the print head to a position near the centre of the bed (same position you used to calibrate the probe z offset);
Send a
G1 X125 Y125 F3000
command in theConsole
;

Send a
PROBE_ACCURACY
command in theConsole
;The command will run the probe ten times and produce output similar to the following;

Once you have confirmed these settings;
Close the
printer.cfg
file by clicking theX
near the top right of editor;
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