Auto Z-Offset Calibration for the QIDI Q1 Pro

This is a plugin for Klipper that makes use of the QIDI Q1 Pro's bed sensors to automatically set the toolheads Z-Offset.

Install

cd ~
git clone https://github.com/frap129/qidi_auto_z_offset
ln -s ~/qidi_auto_z_offset/auto_z_offset.py ~/klipper/klippy/extras/auto_z_offset.py

Command Reference

AUTO_Z_PROBE: Probe Z-height at current XY position using the bed sensors

AUTO_Z_HOME_Z: Home Z using the bed sensors as an endstop

AUTO_Z_MEASURE_OFFSET Z-Offset measured by the inductive probe after AUTO_Z_HOME_Z

AUTO_Z_CALIBRATE: Set the Z-Offset by averaging multiple runs of AUTO_Z_MEASURE_OFFSET

AUTO_Z_LOAD_OFFSET: Apply the calibrated_z_offset saved in the config file

AUTO_Z_SAVE_GCODE_OFFSET: Save the current gcode offset for z as the new calibrated_z_offset

Basic Usage

auto_z_offset helps calibrate the z_offset of the inductive probe on the Q1 using the piezo electric sensors under the bed. It allows for finetuning, saving, and loading the calibrated offset.

⚠️ NOTE ⚠️ AUTO_Z_CALIBRATE should not be used in a PRINT_START macro! On rare occasion, the bed sensors can fail to trigger or trigger too late. If this happens when a print is started, you can end up grinding the nozzle into the bed. Instead, you should calibrate it prior to your first print, and load the offset in PRINT_START.

First, calibrate the z_offset:

Heat the extruder to a reasonable temperature that wont ooze (160+)
Home all axes
Run AUTO_Z_CALIBRATE
Move Z to 0
Verify that you can slide a piece of paper under the nozzle
Run SAVE_CONFIG to save the measured offset.
- Note, this does not modify the z_offset of the inductive probe in your config. This value is only used by auto_z_offset

Add AUTO_Z_LOAD_OFFSET to your PRINT_START macro to load the value every time you start a print. If you make adujstments to the offset by micro-stepping durring a print, you can save that with AUTO_Z_SAVE_GCODE_OFFSET and SAVE_CONFIG

Config Reference

[auto_z_offset]
pin:
#   Pin connected to the Auto Z Offset output pin. This parameter is required.
z_offset:
#   The offset between measured 0 and when the bed sensors trigger.
#   default is -0.1
prepare_gcode:
#   gcode script to run before probing with auto_z_offset. This is required, and an
#   example script is provided below.
#probe_accel:
#   If set, limits the acceleration of the probing moves (in mm/sec^2).
#   A sudden large acceleration at the beginning of the probing move may
#   cause spurious probe triggering, especially if the hotend is heavy.
#   To prevent that, it may be necessary to reduce the acceleration of
#   the probing moves via this parameter.
#probe_hop:
#   The amount to hop between probing with bed sensors and probing with probe.
#   default is 5.0, min is 4.0 to avoid triggering the probe early
#offset_samples:
#   The number of times to probe with bed sensors and inductive probe when running
#   AUTO_Z_CALIBRATE. Note this is not the same as `samples`. 
#   default is 3
#speed:
#samples:
#sample_retract_dist:
#samples_result:
#samples_tolerance:
#samples_tolerance_retries:
#activate_gcode:
#deactivate_gcode:
#deactivate_on_each_sample:
#   See the "probe" section for more information on the parameters above.

Example Configuration from OpenQ1

This example config also includes the control pin for the bed sensors and the config for the inductive probe. Use them as shown for the best compatiblity.

[output_pin bed_sensor]
pin: !U_1:PA14
value:0

[probe]
pin: !gpio21
x_offset: 17.6
y_offset: 4.4
z_offset: 0.0
speed:10
samples: 3
samples_result: average
sample_retract_dist: 4.0
samples_tolerance: 0.05
samples_tolerance_retries: 5

[auto_z_offset]
pin: U_1:PC1
z_offset: -0.1
speed: 10
probe_accel: 50
samples: 5
samples_result: average
samples_tolerance: 0.05
samples_tolerance_retries: 5
prepare_gcode:
    SET_PIN PIN=bed_sensor VALUE=0
    G91
    {% set i = 4 %}
    {% for iteration in range(i|int) %}
        G1 Z1 F900
        G1 Z-1 F900
    {% endfor %}
    G90
    SET_PIN PIN=bed_sensor VALUE=1

frap129 / qidi_auto_z_offset