Сhange the starting g-code for all system filament profiles

Bambu Lab X Series
1

Change the starting g-code for all system filament profiles of the same type (v1.5.0.60)

The system profile settings path (the first launch of the studio after installation is required):

c:\Users\<WINDOWS USER NAME>\AppData\Roaming\BambuStudio\system\BBL\filament\

To change the starting g-code for all default profiles of the same type (for example, to print as profile Bambu PLA XXXXX with speed of the chamber cooler of 50%), do the following:

  • look for and edit the file fdm_filament_pla.json
  • at the end of the file there will be a basic g-code in which we change the fan speed to the one we need
  • for generic profile, change in Generic PLA @base.json
  • after change restart bambu studio if it was runnig
    "filament_start_gcode": [
            "; filament start gcode\n{if  (bed_temperature[current_extruder] >45)||(bed_temperature_initial_layer
            [current_extruder] >45)}M106 P3 S125\n{elsif(bed_temperature[current_extruder] >35)||
            (bed_temperature_initial_layer[current_extruder] >35)}M106 P3 S125\n{endif}"
        ]

M106 P3 S125 - in this case S125 is 50% of the speed (value range S0 - S255). Subjectively, I see no reason to spin the chamber fan above 50% at all, since it does not greatly affect the temperature in the chamber. From user experience, it is worth turning it on even when printing ABS, harmful fumes are reduced, as a vacuum is created inside the chamber and air leaves it, mainly through a carbon filter.

Note 1: before updating the version, save these files just in case, bambu studio may overwrite them to default

Note 2: The end g-code is in fdm_filament_common.json, applies to all system profiles of all types of filament

Note 3: for example, Generic PLA and Generic PLA Silk are different types and each needs to change the g-code in the respective files

List of files where the chamber fan speed is set in the starting g-code:

For BBL X1C:

fdm_filament_pet.json
fdm_filament_pla.json
fdm_filament_pva.json
fdm_filament_tpu.json
Generic PETG @base.json
Generic PLA @0.2 nozzle.json
Generic PLA @base.json
Generic PLA Silk @base.json
Generic PLA-CF @base.json
Generic TPU.json
PolyLite PLA @BBL X1C.json
PolyTerra PLA @BBL X1C.json

For BBL P1P:

Generic PLA @BBL P1P 0.2 nozzle.json
Generic TPU @BBL P1P.json

Note: it’s not clear why this parameter is set for P1P

Hope this helps someone

2

Inrteresting idea, but won’t this get overwritten on the next Studio upgrade? Also, the changes won’t be synched to the cloud. I just keep my own filament profiles with the changes I want (I’ve also adjusted volumetric max).

3

Yes, you are right, but custom profile is not convenient because it is not in the list of AMS profiles and you have to additionally select a profile in the slicer itself before printing

4

I used this method only to reduce the speed of the chamber fan
For other changes in the print profile, it is better to make custom