Really bad Corners and top Layer

Bambu Lab P1 Series Troubleshooting
1

I have a brand new P1S and the Corner and top layer quality is really bad. I’m using the standard Bambu Studio settings.

  • 0.4mm nozzle
  • 0.2mm Standard BBL X1C Profile
  • Bambu Lab Basic PLA
  • my printer stands on a stone plate and foam
  • I dried the filament after unpacking

I printed a 30mm x 30mm x 10mm cube.

I have no idea what the problem is…

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2

Tried calibrating the filament ?

3

Just the K factor (0.02), but i printed a calibration cube and the cube looks fine i think.
The corners are a little bit sharper.

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4

If in doubt don’t think, just do :wink:
If it is not the filament or hardware it is the calibration and it is also the easiest starting point.
I suspect your flow ratio is a bit off, resulting in over extrusion, most prominent after several solid infill layers where the top layer has nowhere to go.
Could also be moisture but then the surface would look more rough.

Confirm the flow ration calibration is ok.
If it is you could try to increase or decrease the nozzle temp slightly to see whether or not it improves things.

5

i did a flow test and printed the cube again, but i don´t see any mayor different.
just the top layer looks a bit better.

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6

Can’t really see without a magnifying glass but I assume your K-factor is quite high after this calibration?
Somewhere above 0.03 maybe?

Anyway, the top infill is a tad weak, it is the line ends though that seem to cause the main issue now.
Reduce the overlap of infill and walls, I usually go in the range of 5 to 10% depending on the filament.
Ideally there should only be enough overlap to bond while no extra extrusion goes over the wall.
Can’t be fully prevented by I think a slight reduction of overlap will clean out those saw teeth.
If not then double check this green print with a magnifying glass.
You are not using the same calibration for all filaments ? :wink:

7

If you are confident that your filament is of good quality and properly stored, I would recommend the following calibration steps in this order:

  1. Bed Temperature Calibration:
    Ensure that your bed temperature is correctly set for your filament type. Inconsistent bed temperatures can affect first-layer adhesion and overall print quality. Start with the filament manufacturer’s recommended temperature and adjust if necessary after test prints.
  2. Nozzle Temperature Calibration:
    Calibrate your nozzle temperature to find the optimal range for your filament. Use a temperature tower test to determine the best temperature for layer adhesion and surface finish.
  3. Flow Calibration (Static Flow):
    Perform a flow calibration to ensure the correct amount of filament is being extruded. This is done by printing a single-wall cube and measuring the wall thickness. Adjust your flow rate in the slicer until the measured wall thickness matches the expected value.
  4. Dynamic Flow Calibration (Pressure Advance):
    After setting your static flow, calibrate pressure advance to account for the dynamic flow changes during acceleration and deceleration. This will help reduce issues like corner bulging and ensure consistent extrusion during rapid movements.

Assuming you are not using ironing here, as incorrect ironing settings can also create visible patterns instead of smoothing out the lines.

8

Just keep in mind that too low an infill overlap can cause the infill to lose adhesion to the walls, which can weaken the overall structure. While it may not be critical for this specific model, it will definitely matter when printing something functional or load-bearing.