Avoid z_calibration if already set

[KiwiChrist]

Is there a way to avoid setting the z_calibration before every print... like my homing or QGL settings in my print_start.cfg...

Currently my z offset lowers each time a new print is started even with "SET_GCODE_OFFSET Z=0.0" defined at the begining of my print_start.cfg.

This does not home if the printer has already been done and set (obviously z is listed so may need to remove it for z to be excluded if it's not to be reset)... {% if "xyz" not in printer.toolhead.homed_axes %} G28
{% endif %}

This does not do the QGl if the printer has already done and set.... {% if printer.quad_gantry_level.applied != True %} quad_gantry_level {% endif %}

I do not want the z offset to be reset before every print unless it has to. I would like to keep the last z offset settings starting the next print.

How do I write this up in print_start.cfg?

config-20230806-130025.zip

[TitusLabs]

There is currently no way to do this. I will add this feature...

[KiwiChrist]

Thanks Titus. Any idea why my z_offest keeps reducing height between print starts? Probe accuracy is not an issue. Currently I'm restarting the firmware between prints which is successfully eliminating the issue.

I have looked through the cfg's and cannot for the life of me find anywhere that is reduces the z_offest.

[TitusLabs]

Sorry, I was wrong! You can do like this:

{% if printer.z_calibration.last_query != True %}
  CALIBRATE_Z
{% endif %}

I will add this to the documentation..

[TitusLabs]

You calibrate everything, print and rerun calibrate_z and the resulting offset changes without rerunning homing, QGL/Z-Tilt or mesh?

Is the value even wrong? Or is the offset then still correct? The fact is that the value may well change when the printer has become warm.

[KiwiChrist]

I have G28... so I'll change it to... {% if "xyz" not in printer.toolhead.homed_axes %} G28
{% endif %}

I already have.... {% if printer.quad_gantry_level.applied != True %} quad_gantry_level {% endif %}

I will change calibrate_z to this as suggested to... {% if printer.z_calibration.last_query != True %} CALIBRATE_Z {% endif %} SET_GCODE_OFFSET Z_ADJUST={params.Z_ADJUST|default(z_offset_dflt)|float} MOVE=1

I'll let you know how I get on.

[KiwiChrist]

All working now as expected. There is no longer a z height reduction between prints... that I can tell ATM.

[TitusLabs]

Glad to hear that! But, I would recommend calibrating z before every print if the printer is closed and can heat up.