Bambu PETG Basic – Small Letters Suddenly Printing Badly

Bambu Lab X Series Bambu Lab X2D
1

Hi everyone,

I need some help with a problem I recently started having with Bambu PETG Basic.

I have printed many of these keychains successfully before. The model, printer and nozzle are the same, and the prints were previously coming out very clean.

Recently, however, the small raised letters started printing badly.

As you can see in the photos:

Photo 1 – Previous successful print:
The large white and red areas are clean and the small details were much better.

Photo 2 – Recent print:
The large surfaces still look very good, but the small raised letters have become rough and poorly defined.

Photo 3 – Close-up:
The main problem is especially visible on the small text “ΜΕΝΕΛΑΟΣ”.

Printer & print settings

  • Bambu Lab X2D
  • 0.4 mm nozzle
  • Textured PEI plate
  • Layer height: 0.08 mm
  • Initial layer: 0.20 mm

White filament – Bambu PETG Basic / PETG FORGE

  • Nozzle: 240°C
  • Bed: 70°C
  • Flow Ratio: 0.948
  • Flow Dynamics K: 0.050
  • Max volumetric speed: 15 mm³/s

I calibrated both Flow Rate and Flow Dynamics for this filament.

Red filament – eSUN PETG

The red part is printed with eSUN PETG.

My previous successful settings for this filament were approximately:

  • Nozzle: 240°C
  • Bed: 80°C
  • Flow Ratio: 0.8294
  • Flow Dynamics K: 0.036

The red filament has worked very well for me in these keychains.

What I have already tried

I have tried slowing down the print and also changed some of the settings to match an older profile that previously produced very good keychains.

The large top surfaces are still very good. The problem seems to be specifically with the small raised letters/details.

This is why I am wondering if the problem could be related to:

  • Nozzle temperature
  • Filament moisture
  • Flow
  • Flow Dynamics
  • Small perimeter speed
  • A recent Bambu Studio/firmware change
  • Something else I am missing

Could someone experienced with Bambu PETG Basic and small 0.4 mm nozzle details take a look at the photos and suggest what I should test first?

I especially want to know what nozzle temperature you are using for Bambu PETG Basic when printing very small raised text.

I have already printed many of these keychains successfully, so I would really like to understand what changed before continuing to print full keychains for every test.

Thank you!

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2

A few things. You seem to be discussing issues with white PETG Basic but the before and after photos appear to just show a thin layer of white before the red - if I’m even seeing that right. I don’t see any real difference in the before and after photos. Maybe if you called out with arrows or circles what we are supposed to notice different between the two?

And the third photo where you specifically call out the white text has no “before” to compare with and still doesn’t look bad. No idea the scaling on that one either to say how big or small the issues are

Humble bragging? I looked carefully at the excavator badges and they look nearly identical. I’m not spotting any real issues. Maybe underextrusion on the black on the second excavator image but it’s on the first maybe to lesser extent but hard to tell by the lighting and focus.

3

I was having a problem printing text and someone here in the forums (& I’m afraid my old brain has forgotten his handle/name) sent me the settings shown and that has taken care of the problems I was having. Might want to give these setting a go and see if they solve your problem.

Settings for printing text
Settings for printing text472×538 44.8 KB

4

When I am printing smaller items, I will switch to a 0.2mm nozzle to get finer details. 0.4mm works for many of the prints I make, but changing downward gives me much finer detail.

5

Honestly I can not see the problem in the pictures, but there is a similar topic in the forum, that may be helpful.