Independant heater control during G29 probing



  • Hello,

    I use mesh grid compensation at the start of each print by calling G29 in my start Gcode in Cura. Currently my bed and nozzle heat up, the printer homes, G30 single probe, followed by G29 5x5 grid.

    My nozzle oozes during probing, particularly with PETG. I understand that adding B0 to my M558 command turns off heaters during probing, but:

    • this turns off my bed heater, which I do not want.

    • my nozzle temperature falls considerably (fine) but is not allowed to heat back up to printing temperature before the print starts after probing.

    Is there a way to do my bed probing before the nozzle heats up, but with the bed at the set temperature, and then pause until the nozzle heats up?


  • Moderator

    @nbGU said in Independant heater control during G29 probing:

    Is there a way to do my bed probing before the nozzle heats up, but with the bed at the set temperature, and then pause until the nozzle heats up?

    Yes, but you have to take manual control of the heating process in your cura start gcode. You can use place holder text labels for the temperatures that cura will then replace with the temperatures you set for the material.

    https://github.com/Ultimaker/Cura/issues/1131#issuecomment-378851858

    For example:

    {print_bed_temperature}: Bed temperature.
    {print_temperature}: Nozzle 0 temperature.
    

    M140 S{print_temperature} would then change to M140 S200 after slicing.

    Then you can adjust your script to heat the bed, do the probing, and then heat the nozzle.

    Alternatively, if you use more than one slicer and don't want to have to modify the scripting for all of them, you could use the start.g macro file that gets run before any of the slicer gcode. In there you could do all your preheating and probing without heating the nozzle and then it would pass off to the slicer to get the final temps and start the print.



  • @Phaedrux

    I'll try with the start.g file so that I am less tied to one Slicer.

    Your help is much appreciated as always



  • Problem solved by making a start.g file which heats the bed and does the probing prior to heating the nozzle.


  • administrators

    @nbGU said in Independant heater control during G29 probing:

    my nozzle temperature falls considerably (fine) but is not allowed to heat back up to printing temperature before the print starts after probing.

    You can use the M116 command after running G29 to wait until temperatures have been reached.


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