Having a bit of a perplexing time with a Bambu A1 with ~800 hours on it. Been great until I switched to a .2 nozzle. After doing so, it printed great and was quite impressive until a print seemed to have an issue after the first 2 layers (see picture). The print was still running, but the filament was not being pulled in from the AMS, even though the extruder seemed to be working correctly. When I stopped it, the filament was ‘stuck’ in the extruder, and the auto procedure to unload the Bambu filament would not complete. I had to gently help it unload during the unload procedure by manually flowing the filament through the extruder via the front panel to get it out of the extruder. Once free, the filament that was in the extruder seemed stretched, but I am not sure from what.
Took the nozzle out, cleaned the extruder as best as possible, ran filament manually through via controls on front panel without issue. Filament flowed steadily and no issues. Verified locking clasp is closing and locking correctly, and screws are tight on the back of the heating element. Calibrated throughout all the tests below and cleaned the build plate each time.
- Tried different Bambu filament with the same file.
- The same event occurred at a different point in the print but early in the layers (<layer 4). Same process to unstick the filament, same stretched filament, although it was easier to get out.
- Took the nozzle out, cleaned the extruder as best as possible, ran filament manually through via controls on front panel without issue. Filament flowed steadily, and no issues.
- Attempted print again with the same second Bambu filament and it printed without issue - success.
- Printed a different file with original filament - and it printed without issue - success.
- Attempted original file again with the original filament, and it printed without issue - success.
- Then tried a different file with the original filament, and the same failure event occurred. Cleaned up and removed filament like above.
- Printed a different file with original filament - and it printed without issue - success.
- Attempted the same new file, failure event occurred again in the same way. Same process to unstick the filament, same stretched filament, although it was easier to get out.
- Then, I completed a filament flow calibration, which worked perfectly, and adjusted the flow rate as explained in the wiki.
- Tried another file with the same Bambu filament. The same thing occurred - stuck, but print kept running as normal, just no filament flow. Harder to get the filament out, but eventually succeeded.
Any guidance here? The issue happens with different Bambu filaments and different files, but also succeeds intermittently with the same files. When it fails, the machine has no idea, even though it’s not pulling any filament, and it fails very early on. I have three A1s and PS1, and this is the first time I have run into this.
Hey there!
Some common mistakes might be;
-
That you haven’t done the calibration, though I the A1 does a automatic calibration, sometimes when changing a nozzle like in your situation where you changed to a .2 nozzle sometimes you need to do a full flow dynamics calibration. As it sometimes pushes less filament and has a lesser flow rate.
-
The .2 nozzle sometimes is a bit more easier to be clogged compared to the .4, which might be your issue in this case, especially on A1s (from my experience) where the filament may be very moist, or it being dusty.
-
I had a quick read, but I presume you have the pre-sets in Bambu Studio for the .2 nozzle, as if you got it off MakerWorld or another 3D Designing Website majority of fitted for the .4 Nozzle.
-
Maybe your speed might be a bit too high? I’ve just been looking around and some similar people had an issue with a problem like this and it was because their speed was too fast.
I was look around and found some kinda common but uncommon issues relating to something like this..
- You may have some loose wiring, specifically your thermoister wiring which can cause an unstable nozzle temp.
Please let me know if these were some of the issues, if not I’ll have a bit of a deeper look into this for you,
Cheers,
Thanks for the feedback!
I did the calibration as you mentioned and the flow calibration (Noted above).
I dried all the filament at the start. Not sure why it would work and then not if this was related.
Only using presets from Bambu.
Haven’t messed with speeds, but again, sometimes it works and then it doesn’t.
The loose wiring may be related, I can’t find any when I cleaned everything I checked. Odd thing is the intermittency, but that issue works both ways. 
No worries,
Let me know how you go next print to see how it goes so I can look deeper for you, if you want I can list some resources below for if you want to compare your wires and/or if you want another forum listing that is somewhat similar to yours.
Fingers crossed! 
Same thing happened a few minutes after the original post. New file same printer. Hoping for ideas as this makes no sense.
Okie dokes, this is what I found for you.
-
The 0.2 mm nozzle may be partially clogged or damaged, which can interrupt the filament flow.
-
Filament quality or moisture could cause inconsistent extrusion, especially with a very small nozzle.
-
The extruder gears might slip occasionally, meaning the filament does not feed properly.
-
Cooling or heat-creep issues in the hotend could soften filament too early and cause temporary blockages.
I did a second search for you, sometimes it could be the hotend screws, but they are rarely the actual problem. If you want you can have a read of where I got it off of, if this doesn’t help and nobody else can fix this issue on the forums, I’d suggest log a ticket with Bambu Lab.
I’ll attach the link below and I’ll also ping @MalcTheOracle because he may know how to fix this since I am clueless now.
Cheers,
Is the filament on the spool snagging?
This could be a spool that has the filament snagged or too tight.
This could explain the hit and miss as it would normally affect one section of the width of the spool.
Unspool a couple of metres, noting if there are any issues. Either way, put it back and perform a print that you know has failed.
Does the initial portion of the print function?
Thanks for the ideas.
Thought of the spool sticking first time it happened. Checked and no issues. Even still I had tried exactly what you said after the fail and it didn’t change. When I used different filament on different AMS position it still happened so don’t think this was the issue.
Like was mentioned, the failed print didn’t work, then did on new filament and eventually on the same filament. Very inconsistent.
Felt this could be the feeder gears failing but when the flow calibration worked flawlessly I figured that cant be it. Seems odd that it fails like this always in the initial few layers.
Thanks! Yeah, that fb link has all the things i thought of and/or found too, doublechecked the clip even. I did the manual flow test today (the pic I showed) and still had a file fail in same way after that.
You are in quite an interesting situation.. I’ve thought through everything that’s happened with my A1 and how I fixed it. By chance, is it Matte PLA? As I’ve had issues with it in the past, and I’ve found that .2 nozzles and Matte PLA don’t go well, and what I’ve seen on the forums and across the internet.
You may have something. I’ve not heard if this issue and in all tests I was using different reels if bambu matte. What information is out there?
I will try non matte this morning, as a test.
Nope. The issue is not Matte vs normal PLA. Couldn’t make it past first layer.
In my experience, Matte PLA + .2 Nozzle = a recipe for disaster.
Which is why I brought that up. At this point, I recommend submitting a ticket to Bambu Lab. I suggest you include this, as they’ll probably be the same things that Malc or I said.
Before you do, these are the last things that could be your issue;
Uno: The extruder gear could be slipping, hence the under-extrusion and random failures.
Dos: The Hotend Assembly could be slightly loose, causing the under-extrusion, or just becoming inconsistent.
Tres: Small defects in the .2 nozzle, such as slightly wet filament, tiny debris, or small calibration errors, which can lead to your issues.
Hope your issue can finally be resolved.
Cheers,
1 Like
Thanks!
FWIW, I did one more test before I was going to tear down the extruder on the machine. I took the same .2 nozzle and matte filament, but both into one of my other A1s, and it printed one of the failing files perfectly. I tried it a few times, and every time was perfect.
Certainly leans toward it being in the extruder/assembly. Not sure which is easier, just replacing the entire extruder or the extruder gear, but it seems to be where the issue is at this stage.
No worries,
Now you’ve tested the nozzle on your other A1s, it’s our favourite time!! Logging tickets!!
But in all seriousness, that is really weird. As I said, please add a link to this forum so customer support won’t say the things Malc and I said.
I’ve attached the Support Ticket Request below. I hope this gets resolved.
Cheers,
https://bambulab.com/en/my/support/tickets
Hey @UnhappyDan,
Just checking to see how you are going with the issue,
Cheers,
Wow this is the exact issue I am experiencing from reading through the thread.
Had an A1 printing .4 nozzle prints just fine. Changed it to a .2 for a 2 color print 2 days ago. Noticed that the first layer went on weird, but just chalked it up to “a faulty nozzle” as that’s what research into it suggested. Wasn’t that big of a deal as it got through the print. When I went back to try again with a different .2 nozzle today, the failure to extract errors began.
I took apart the extruder, tested that there were no clogs, cleaned gears, checked the sensor, did everything mentioned above. I can with 100% certainty say that it is not a clog, and is not a sensor issue. The AMS was able to feed the filament to the hotend, but then it would “get stuck” and would not be able to extrude. I was able to manually help it (apply pressure to filament pushing it into ptfe tube) and then it would be able to load and extrude. Without this pressure applied manually, the filament would not extrude properly.
OP, did the issue persist when you put your .4 nozzle back on? My issue seemed to persist regardless of the nozzle type after the initial .2 issue.
I have since put my AMS Lite on to another A1 unit I have. Installed my .2 nozzle (correctly) and was able to load/unload the filament without issue. Tried the same print and got an error “flow rate is abnormal, print quality may be effected” or something to that degree. I cancelled the print and did one more google search which brought me here. I read the potential Matte filament issue, so I changed them to basic filaments and now it APPEARS to be working as expected.
I am still going to fill out a ticket regarding the original unit as this is beyond bizarre. I have printed matte filament on the effected unit with a .2 nozzle many times before, so it just started.
Latest firmware (1.07.02.00)
This continues. Support has given a number of options that I have tried with no success. I was out of town for the last 5 days so they resolved my ticket. Looks like they want me to try looking at cleaning the nozzle. They seemed to have missed the point that I tried 2 nozzles, one brand new. They also mention a pressing block that may be an issue for me to “watch”. Haven’t watched the pressing block but no clear direction as of yet.
That’s quite disappointing, fingers crossed to get the issue resolved so you can start printing again.
Good Luck,
Cheers,
