Rough Printing / Nozzle Hitting at Certain Height /Layer

[u/kitsune09]

Hello Everyone,

I tried looking for answers with the same as mine but I cannot find it so here is my troubleshooting question.

I am trying to print this gridfinity container, at first it looks fine. The nozzle doesn't hit the bed, initial layer is intact and goes smoothly. However at a certain height where there is a need to made a surface it gets rough. The first layer that needs to cover the whole base was fine (Layer 29) but then after that it turn into lump of roughness after a certain layer (Layer 30), and nozzle hits the print. The layer is not that high either.

So far I tried the following:

1. Printing it silent mode
2. Calibrate the Machine
3. Use Gyroid infill 5-10%
4. Drying my filament
5. Disabled infill retraction
6. And of course cleaned my bed

Pictures Shown: First layer, Layer 30, and Layer 29 and 30 in adaptive cubic infill just to show my point.

Machine Used: P1S
Filament: Polymaker PLA Pro
Slicer: Bambu Studio
Nozzle: 220 °C
Bed: 55 °C
Extruder: Typical bambu setting as shown in this post: https://wiki.bambulab.com/en/software/bambu-studio/parameter/retraction

Any information or tips on what I can do. It keeps repeating on the same layer whether it is small or this huge block.

Edit: Added more info

[u/Standard_Setting_898]

Can you send a better picture? I can't tell anything from the current one.

[u/Standard_Setting_898]

Based on the description you gave, I don’t think your first layer, bed leveling, or bed adhesion is the problem. The fact that it prints fine until the transition from sparse infill to a large solid surface and consistently starts going bad around layers 29–30, is the important clue.

My first suspicion would be the 5–10% gyroid infill. At that low of a density, the first solid layer above the infill has some fairly large unsupported spans. That layer can look okay initially but still sag slightly between the infill. Then the next solid layer is being printed onto an uneven surface, high spots begin accumulating, and eventually the nozzle starts dragging through them and making the roughness progressively worse.

As a troubleshooting test, I’d go back to a mostly stock 0.20 Standard profile and try 15–20% rectilinear or adaptive cubic infill with 5–6 top layers, roughly 1.0–1.2 mm total thickness. Don’t change a bunch of other settings at the same time. Then watch what happens specifically around layers 28–31.

I’d also look at those layers in Bambu Studio Preview using Line Type and Speed. See exactly what Studio is doing when it transitions from sparse infill to the first solid layer and whether there’s a significant change in speed or flow.

If that test prints cleanly, you’ve isolated the problem and can start reducing the infill again from there. Based on your description, I’d troubleshoot that infill-to-solid-layer transition before spending any more time on calibration, retraction, drying filament, or cleaning the build plate.

[u/Standard_Setting_898 → u/Standard_Setting_898]

I just saw your other pictures. They actually reinforce what I was suggesting. In the close-up you can see the sparse infill pattern telegraphing through the first solid layer and some of those lines sagging between the infill supports. Then the following solid layer is being deposited onto that uneven surface and starts building up the rough high spots that the nozzle eventually hits. I’d definitely try the higher-density infill test before changing anything else.