Bed temperature set to PETG even when only PLA touch the bed

Bambu Lab H2 Series Bambu Lab H2D
1

If I print a model in PLA and use PETG only for supports, the bed temperature is automatically set to 70 °C, even when the entire first layer on the build plate is PLA.

I understand that I can manually override the bed temperature for PETG in the material settings, but logically the bed temperature should only match the hottest material that actually touches the bed.

If the PETG support never contacts the bed, the bed shouldn’t heat up to 70 °C. This looks like a slicing logic issue.

This image is a simple test. Red is PLA, Green is PETG. Bed heat to 70 °C. So the PLA is melting on the bed…

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1 Like
2

In the printer settings you can define the “Bed temperature type”. Set it to “By first filament”.

EDIT:
In the plate settings you can define the order of the filaments for the first and other layers.

3

Thank you for the suggestion.

Could you please tell me exactly where this option is located? I searched with the magnifying glass tool but I could not find it in Printer Settings, Plate Settings, Filament Settings, or in the Print Settings.

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I can’t screenshot the other search bar since they are drop-down list.

Thank you :slight_smile:

4

It’s in the machine settings I think.

5

You can find the plate settings under the gear on your plate:

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Then the window you show appears.

6

I recommend carefully reading the Bambu Wiki article about this. I also struggled with it quite a bit. It specifically mentions exactly what you’re describing. In your case, you need to set the bed temperature in the PETG profile settings to the same as for PLA. I really recommend checking it out.

7

I mainly use that option too, and save the PETG profile specifically for PLA support with a lower bed temperature.

But this alternative works fine also.