Strange printing issues with my P1S, need your help friends

Hello dears printing friends.

I’m facing a printing problem that I’ve never had before.

I work with a very well maintained P1S, and I did a calibration just before.

Attached you will see a photo of a model that I printed without problems 2-3 weeks ago. I just reopened my bambu project, I sliced it as I did before, and the result is very… different.

The model is poorly printed and there are visible streaks on the model (circled in red). However, everything is normal in bambu slicer. I also have this problem with other models (example with the blue piece) which I also printed without issues before.

My filament is dry, and I only use Bambu filament (matte PLA for the black piece ; basic PLA for the blue piece).

Do you have an idea for a solution? Because I print again and again by changing parameters… but the result is always the same and I wear out my plastic :confused:

A BIG thank you and have a nice day


My printing settings :

0.4 nozzle. Bambu slicer and P1S/AMS with latest updates on it.
Using Bambu PLA basic or Matte.

0.2mm standard printing profile, with theses differences :

First layer : 0.25mm.
Fill density : 25%
Speed of first layer : 20 mm/s

Pictures :

Well printed before:

Poorly printed now :

Everything is ok in bambu slicer :

Another example of poor print :

Everything is ok in bambu slicer :

Have you tensioned your belts?

Another tip is that you can use your print history in the Handy app to reprint the same gcode you sent when the prints were the quality you were accustomed to. That will take out any slicing factors.

Also I might mention that I see you are printing multiples of the same part. I personally found that I didn’t have the same quality when printing multiples on a sheet compared to when I was only printing one.


Maybe this changed ?


Hello friends,

Thank you all for your help.

Well… I Thought i was doing my maintenance well but… I still have a lot to learn. I never checked my belt tensionning.

Well, now that I’ve done it, this is the result :

And I’ll check the arachne walls next time if I’ve news issues ^^ Ty all


Well, to be honest and after few prints, everything is fine exept some edges. If i do multples print (like 3 items) onn the same plate, some have the issues, and some not… And if i print the item alone, it also have the issue. o_O

Any other brilliants ideas ?

Thanks and good evening

This looks like cooling problems. When printing multiple items, there is more time for the part to cool before the next layer. With a single one, this happens with the previous layer still hot. You can try reducing the speed, increasing the cooling or reducing the temperature.

1 Like

Thanks Johnie, I’ll test it tomorrow

It was that. Thanks again

Hello everyone.

Here I am again unfortunately. I really don’t understand anything anymore. Yesterday morning, I adjusted the belt tension, calibrated my machine, and installed a new spool of matte filament.

I PERFECTLY printed two plates of 6 pieces each. And this morning, here is the third plate coming out of the machine with lots of artifacts (the exact same artifacts as a few days ago).

It’s still the same new spool from yesterday morning, and I used exactly the same GCODE (from the phone application).

I really don’t understand anymore. Do you have an idea ? Many thanks, I’m afraid to start printing again.

I’m still figuring it out and doing test rn. It’s look like under extrusion or ringing, doest it ?

Any clues to figure wich one it is, and solve it ?

Thanks and have a good day

Are the screws on your belt tensioners loosening up?


Check your K factor for your filaments (especially that it’s not zero).