A1 mini stops extruding mid print and will air print

Bambu Lab A1 Series Troubleshooting
1

I have an A1 mini that will stop extruding mid print and continue to air print.

To troubleshoot this issue I printed the same file with my other mini and it printed without an issue. I am using all the same settings on both printers. I have used both the filament and nozzle from the second to see if that was the issue but did not fix it. If I remove everything from the plate and start a new print it will start extruding again with no issue but again will stop midway. If push the filament in slightly after it stop extruding it will start again, almost like its being cut. I have placed a camera to watch the process and can confirm that it is not being cut by the printer.

I have replaced the follow;

  • Extruder Gear
  • Nozzle
  • Toolehead board
  • USB-C
  • New SD card that I formatted thru the printer

I am not printing with an AMS Lite. Any help would be greatly appreciated.

2

Is your feeder tube getting in a bind/not inserted thoroughly at a certain height causing an issue?

3

Nope, I have confirmed it was seated correctly. I also read it could possibly be due to worn out feeder tube but replaced that with a new one I had.

4

Hi,
When it continues printing in the air, do you see the extruder moving, or does the small wheel behind the cover not turn?
If it’s turning and nothing is coming out, it’s probably the filament.
Try manually pushing the filament a bit.

I had a spool of Bambu PLA Matte Scarlet Red that caused nothing but problems.
However, I am using an AMS Lite.

5

Yeah the extruder will continue to move. If I push the filament in while its air printing it will start extruding the filament again.

I have tried different filaments and run into the same issue. I even went as far as using the filament that stopped extruding in the A1 with the issue and placed it in my other one, which printed with no issue.

6

Hi. I had the same problem and it got solved after disassembling and cleaning the extruder.

7

Then it might be the nozzle.
Try swapping the nozzles between the two printers and see what happens.

8

Yup tried that to. Swapped the nozzles between both printer and my other printer will print that nozzle without an issue

9

Im gunna try this tonight. Will disassemble the whole extruded again and see if im missing something

10

The problem came back, and got fixed by cleaning the extruder wheels again. I finally think it’s the filament, for some reason that filament fill the extruder wheels with dirt and when there is much the filamment slides and can’t be pushed into the hot end. After cleaning, and using other filaments, the printer works fine. With that filament, after some printing work it starts failing again. It’s sunlu white basic pla

2 Likes
11

Unfortunately, I don’t have any experience with Sunlu’s PLA, but I’ve already printed several kilos of PLA+ and some Meta.
I haven’t had any problems with it so far.
But good to know. Thanks for the tip.

12

PLA is great, but I had less issues moving across to PLA+, some say its identical, but for me… it stopped issues I was having with standard PLA.

13

I do think you can notice a difference between PLA and PLA+, especially with certain colors.
But white gives me the least problems.

14

I also run sunlu pla along with polyterra. I have tested the issue with multiple different filaments both sunlu and polyterra in different colors. But also tested that theory with my other print which will print fine with same filament roll.

Last night I took apart the extruder and didn’t see anything that raised a red flag. But did decide to swapped out extruder gear again cause I felt that was the only thing that made sense. I was able to complete print without an issue. I have since done 10hrs of printing all completed with no issue. So I’m thinking the replacement part was defective and that’s why the issue continued. I’ll follow up in a couple days and let you know if it comes back

1 Like
15

Yeah, there are many things that can go wrong, and many things you can try.
Just like back in the days with Windows 2000, lol.
I’m curious to see if that was the issue.

16

I have 5 A1s running most the time. Had good success printing about 150 spools of TPU then a rash of your problem. Turned out to be a rash of inconsistent filament size.

Now upon a failure I measure with a caliper and if less than 1.60 or greater than 1.9 mm I swap out the spool with plans to send back filament (not Bambu product). I’m up to 30 or so I need to send back and seeing less of a problem now.

17

it could be just tolerances. Maybe the Extruder having issues has just a little bit less pressure on the filament or the filament clearance in it’s closed state is slightly larger than on your other extruder.

combine that with filament being a little small in diameter and the gears can start to grind away on the filament and stopp moving it.

18

UPDATE: I have replaced the extruder gear again and this has solved the problem. I have put about 30hrs of prints thru it and have not had an issue since.