Weird Top Layer grid-like extrusion

artickraft · December 19, 2024, 1:22pm

Hello everyone,

I’ve been experiencing a persistent issue with the top surface on one of my P1P printers, and unfortunately, support hasn’t been very helpful so far.

Here’s what I’ve tried so far without success:

Replacing the hotend
Performing fine flow calibration
Running the printer’s calibration process
Changing the filament
Cleaning the carbon rods and lead screws

Despite all this, the problem persists. Everything else seems to print fine, but the top layers consistently show a grid-like pattern, as you can see in the attached picture:

Has anyone encountered a similar issue? If so, I’d greatly appreciate any advice or solutions you might have.

Thanks for taking the time to read and help!

John_Nick · December 19, 2024, 1:39pm

That is strange.

What orientation is the part being printed?

it looks like bad under extrusion but on the rest of the part it is not a problem.
When you say performing fine flow calibration what do you mean? can you explain?

Is the problem also on other models?

artickraft · December 19, 2024, 2:04pm

The print is horizontal to the buildplate, maybe the pic was not the best, as it is a finished model assebled from multiple parts, here´s another picture that also answers the flow calibration question.
It is the calibration that BambuSlicer allows in the ¨calibration > flow rate¨ menu.
And yes, it happens on any model I print.

John_Nick · December 19, 2024, 2:35pm

silly question but have you run a bed leveling recently

artickraft · December 19, 2024, 2:37pm

Yes, I run bed leveling on every print

John_Nick · December 19, 2024, 2:46pm

In orca slicer there is a option to fine tune the results.
can you run this calibration as well

artickraft · December 19, 2024, 7:49pm

Unfortunately all test have the bumpy surface

magickarle · December 19, 2024, 8:14pm

are the sub-layers in the same area where it looks bad the same (try to put a pause on some layers to check them out)

John_Nick · December 20, 2024, 8:42am

Can you share a screen shot of the filament settings you have right now?
What is the presure advance
what is the flowrate

It just comes to mind.
Maybe the nozzle diameter is not set correctly?!

ZeroCtrl · December 22, 2024, 9:41pm

I have the same problem, maybe it’s some kind of bug with the new update?

BTR · December 29, 2024, 12:54pm

Have you maybe solved this? Got the same now, top layer and also some in between show more of a gridlike pattern than before.

artickraft · December 29, 2024, 4:41pm

Unfortunately not yet, it happens on the inside a bit too, sometimes it stops happening and then it happens again later with no apparent reason

artickraft · December 29, 2024, 4:42pm

I just use the default Bambu PLA settings, everything automatic, nozzle correctly selected at 0.4, none of my other P1P’s have this problem with the same settings and filament

simon14 · December 29, 2024, 5:58pm

Maybe -7 is the best for the first.

While the second is overextrusion, by 10-20% for all of them

I just say what I see. We don’t have any more data to play detective with so that’s that.

Super_Space · January 5, 2025, 9:25pm

I notice on one of my machine, it starting showing these grid patterns and it no longer print straight. For example, if I print a circle, it will come out as an oval and if I print a square, it will out rectangular. Is the belt just bad?

MalcTheOracle · January 5, 2025, 9:33pm

Just a thought in case it is related.

Selecting Stainless Steel nozzle when you have a hardened nozzle can sometimes cause issues depending on the filament.

n.boltshauser · January 24, 2025, 10:56am

Hello everyone.

I’ve had this problem for a while now and just can’t find the solution.
My last layer is like torn. it is a Generic PLA filament in the slicer is smoothing in it.
It is calibrated.
I have now read through almost the entire forum and have not found this problem anywhere.
I’m slowly running out of ideas. Can anyone help me further?

Many thanks for your help