PETG-HF Problems

Bambu Filament and Accesories Filament
1

P1S
0.4 Nozzle

When I use PETG-HF I run into the problems shown in the pictures.
I tried two different colors. Results are the same.

There are no problems using PLA Basic, PLA Matte, ABS and ASA.
Printed this part over 20 times with no issues, just PETG-HF causes Problems.

Filament is dry.

IMG_6351
IMG_63511920×2560 825 KB

IMG_6353
IMG_63531920×2560 258 KB

2

Seems to me like pressure advance / flow dynamics is set completely wrong.

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3

Default Settings for PETG-HF, haven´t changed anything.

4

Default or not, your pressure advance is incorrect. Calibrate the filament.

5

I have zero PETG HF that could run stock without issues so full calibration flow ratio and PA.

6

Even if default profile is not perfect, it shouldn’t be so far off that it produces such results. something really seems to be fishy. I think there is a generic petg hf profile. Maybe you can test that too?

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7

@L0rdS474n

Do you have a suggested calibration routine that you use for tuning filament? I’ve been struggling with PETG HF since installing a .6 nozzle and I’d love some directions.

  1. flow dynamics

  2. pressure advance

  3. temp?

8

OP, you ever solve??? I ONLY use PETG HS and may be able to give you some thoughts for remediating.

9

Just to be sure BBL PETG High Speed? what plate?

10

Not strictly recommended, but it depends on what you’re trying to achieve.

  1. I use a single-wall hollow cube to determine the exact line width, or the number of walls that will be used in the actual print. For a one-wall measurement, divide the expected value by the measured value and multiply by the current line width setting. Keep adjustments reasonable — you may end up slightly over or under the target.
  2. I use a one-layer sheet test and visually inspect how the lines behave at the start and end of each pass. Depending on your print profile, you might want to add up to three layers for comparison. The key is to make small, incremental adjustments.
  3. I usually print at the higher end of the temperature range that still produces a clean model, so running a temperature tower can be useful for fine-tuning.
11

A common problem that leads to the issues found if the first post is related to an incorrect K factor set on the P1 series. If there was an attempted calibration done, and instead of a value of 0.025 you have used 0.25, the issue you shared would occur.

The easiest way to return to normal is a factory reset of the printer which will use the default values of around 0.02.

A detailed calibration guide is available on this wiki: Flow Dynamics Calibration | Bambu Lab Wiki

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