Context:
2 months ago I bought my first p1s and now I have 4. They are working very good, except one of them (the first I bought) that last week started failing.
It got stuck a few times, like between 5 and 10 times I had to remove the extruder and unstuck the filament inside it. I don’t know if that’s normal in this printers but the other printer never got filament stucked in the extruder and I never had to remove the extruder.
Problem 1:
In all printers I’m printing the same 2.000 keychains and it printed awesome, but the issue is that 5 days ago the printer started to get stuck everytime the AMS changes the color of the filament. It prints the base with black perfectly, but when it changes to white the filament doesn’t go out (and the printer continues in the air), or starts printing with a little bit of white, like underextruding, and it doesn’t stick to the base.
I tried changing the filament thinking that maybe the plastic is bad but nothing changed. I tried changing the order of the filament in the AMS, removing the extruder and assamble it again, factory reset the printer, re-calibrate it, formating the SD, and creating a new file for the keychains. Nothing changed, 3 printers works perfectly, the other one doesn’t.
Problem 2:
Now in the “bad” printer I’m printing another keychains to see what happen and it printed perfectly, but when I try to print it again the same file it makes all perfect, except when it changes the filament and stars underextruding again. Is like the first time it prints a new file does it great, but when I try it again it doesnt work well.
Sometimes I get an error saying that the filament is stuck, or that the filament couldn’t reach the extruder, but I press “continue” and it works well. It is like the printer stops without reason and I have to manually continue the print.
I have something similar, the printer is relative new, 3 month, and a few days ago I started to have problems:
When printing multi-color objects using the AMS, after a color/tool change, the first few lines do not extrude any filament. After a few moves, extrusion starts normally, and the rest of the layer looks fine.It happens regardless of the model or filament used.
What I’ve Tried (No Success):
Printed the same 3MF file on a friend’s P1S — prints perfectly.
Swapped nozzle (even tried 0.2mm).
Factory reset the printer and reinstalled software.
Cleaned and lubricated rods, cleaned extruder gears, AMS internals, PTFE tubes.
Verified correct loading and filament tension.
Tried with different filaments, including Bambu brand.
I also contacted Bambu support and said:
“The issue appears to be insufficient extrusion flow and a short inner wall path. When filament isn’t extruded immediately, it’s likely due to retraction and delayed recovery. Try increasing flow and reducing speed.”
However, the exact same file works flawlessly on another printer without any changes.
this might work for the first layer however if you want to print a text on 2-nd layer with a different color the problem still exists. Did you experience this issue? I have to mention that you need to print without prime tower - with prime tower the problem is visible while purging in the tower that for the first 2-3 lines there is no extrusion.
I have posted the issue with pictures on an H2S thread:
Other than the brim, or purge tower, none. I have send video files, logs, STL to bambulab support, I got better answers from ChatGPT rather than the official support.
This is why I am writing here. I hope there is someone here who knows how to fix this. I can’t believe just the 2 of us had this issue- if there are 2 there are many- let’s hope one of these threads will get some attention from the comunity.
Yes, is strange, mayne other people didn’t use the printers like this, ot didn’t notice the problem. Because I changed the printing head, filament type, filament brand, firmware, mabu studio versions, reinstall the app, factory reset the printer, even fully dissasembled the printing head, clean, lube everything, and put back, the problem is the same. Tried the same STL file on friends printer, no issue.
just talked on discord with someone - it is the pressure in the nozzle after the material change - solution is to use the prime tower, this way you build pressure in the nozzle
Hi everyone, sorry for the late response. I didn’t know that a few of you wrote a reply on this thread.
These last of months the “bad” printer continued with the same issue, and a few weeks back another p1s started doing the same thing so I came here to read your comments.
I will try what @MaickR said and let you know. It’s very frustrating to go and see how the printing goes and realize that it stopped a few hours back because it doesn’t extrude anymore. I have to unstuck it (15-20 minutes) a few times a day and it’s very time consuming.
My next question is: why does it happen to 2 of my printers but the other 2 doesn’t have this issue?
I will start using the prime tower now on and let you know
When you print by object the slicer will not create any prime tower- so this is an issue because when you change colors the pressure in the nozzle is reduced and, without a prime line or tower the first few seconds of printing there will be no material flow. I read somewhere that some people are inserting a cube to the object group that has the color change- this way the printer will print first the cube and then the objects- the cube will become a prime tower. Another way is to add a bigger brim - increase brim size and add a gap if you don’t want it in the model-it worked for me (maybe a skirt will also work as a prime line). But yes it it’s frustrating when you have very small objects.
