Bed temperature mode uses first project filament instead of plate-used filament

[doppleganger53]

Is there an existing issue for this problem?

• I have searched the existing issues

CrealityPrint Version

7.2.0.5225

Operating System (OS)

Windows

OS Version

Windows 11 Pro 10.0.26200, 64-bit

Additional system information

No response

Printer

Creality K1

How to reproduce

1. Create or open a multi-material / multi-plate project with several filament slots loaded globally.
2. Put a high-bed-temperature material in the first global filament slot, for example PCTG/PETG with High Temp Plate first-layer bed temperature 80C.
3. On a plate/object that only uses a different filament slot, assign a lower-bed-temperature material, for example LW-PLA with High Temp Plate first-layer bed temperature 45C.
4. Set Bed temperature mode to Use first material (bed_temperature_mode = use_first_material) and select High Temp Plate.
5. Slice/export the plate.

Actual results

The generated G-code uses the first filament in the global/project filament list for bed temperature, even when that filament is not the material used by the sliced plate/object.

Example emitted G-code/metadata from a K1 export:

; generated by Creality_Print V7.2.0.5225
START_PRINT EXTRUDER_TEMP=248 BED_TEMP=80
T2
...
; bed_temperature_mode = use_first_material
; curr_bed_type = High Temp Plate
; filament_settings_id = "3DFuel PCTG @Creality K1 0.4 nozzle";"Polymaker PA6-CF-0.6mm @Creality K1 0.4 nozzle";"SainsmartL-W PLA @Creality 255-v2";"Hyper PLA @Creality K1 0.4 nozzle";"Hyper ABS-detail @Creality K1 0.4 nozzle";"Hyper PLA-cleaning"
; hot_plate_temp_initial_layer = 80,50,45,50,80,60
; first_layer_bed_temperature = 80

In this case the actual print starts with T2, which is the LW-PLA slot with High Temp Plate first-layer bed temperature 45C, but START_PRINT receives BED_TEMP=80 from the first global filament slot.

Expected results

For multi-plate / multi-material projects, bed temperature selection should be scoped to the material(s) actually used on the sliced plate/object.

Expected behavior would be one of the following:

• Use first material uses the first material actually used by the current plate/object, not the first material loaded globally in the project.
• Use max of all materials uses the max bed temperature among materials actually used by the current plate/object, not unused global filament slots.
• Or Creality Print warns that unused global filament slots will affect the emitted BED_TEMP.

The current behavior is surprising and can start prints with unsafe/incorrect bed temperatures. For example, an LW-PLA plate configured for 45C can start at 80C simply because an unused PCTG/PETG filament slot is first in the project.

Project file & Debug log uploads

Not attached in this issue. The relevant generated G-code metadata is included above. I can provide a minimal sanitized reproduction project if needed.

Checklist of files to include

• Log file
• Project file

Anything else?

Current workaround is to reorder or remove unused filament slots before slicing/exporting each plate, so the material used by that plate is first in the project filament list. This workaround is fragile for multi-plate workflows where each plate may use a different subset of materials.

[pjJedi]

Mine is doing exactly the same.

[eknkc]

Same here. Just finished a print of PLA on 80 degrees bed due to this apparently.

[duka10]

Same thing. Noticed just now with a failed print with ABS at 50 C bed. In CFS had ABS and PLA.