Extruder makes clicking and clattering sounds / print scrappy

Hello it all. After a few succesful prints, my Bambu A1 mini makes strange noises and I am not sure if this is normal. I’ve recorded a video to show you what it does.

I’m using a new spool of Bambu PLA Basic filament, and after two successful prints, the problem started. Here’s what I’ve tried so far:

  • Unscrewed and cleaned the nozzle
  • Performed a cold pull to clean the filament path
  • Tightened all screws as recommended in related troubleshooting guides
  • Ran a complete calibration

Unfortunately, none of these steps have resolved the issue. I’m running out of ideas, so any suggestions or advice would be greatly appreciated!

Thanks in advance!

you can see the extruder gears skipping, it might be time to replace the extruder or at least the extruder gears · Shop Spare Parts Extruders Parts A1 Series at Bambu Lab EU

by the way, and quite the coincidence, but the same thing is currently happening with my X1C, have already ordered the replacement and waiting for it to arrive :slight_smile:

Have you looked into this:

The printer is 3 and a half weeks old. I wonder if it is really time to replace parts of it. o.O

Thank you, lion7718, I will look in to it.

Edit: Yes, I already did this. The screws were already tight, but I even tightend them a bit further. It did not solve the problem.

Are you using the default filament settings or did you change things…??
What nozzle are you using…??

I did have an experience with my X1C in the past where a partial nozzle clog led to extruder skipping. Only a Hex key cold pull was able to clean the nozzle. But then abraded filament from the extruder was fed back inot the nozzle.

I resolved that by using the hex key cold pull and cleaning out the extruder and removing the last 50cm of the troublesome filaments from the spools.

ah ok, yeah that is weird then, but depends if you used some rough filaments in there or not, to my knowledge the a1 doesn’t come with hardened steel (but not 100% sure on that), but yeah it’s strange as it’s so new, on my X1C i’ve had it for a year and a half and have ~2400 hours of print time, so that extruder served me well and i have no complaints on having to replace it now :slight_smile:

The printer is the way it came out of the box. So I’m using Bambu PLA Basic Filament and the nozzle is the 0,4 nozzle.

given that the printer is basically brand new I’d open a support ticket with bambu (right now there are slow response times due to the holidays, but they should get back to you)

Did you tighten the 3 bed screws after you unboxed…??

Meanwhile I’ve been following various troubleshooting steps for my Bambu Lab A1 Mini, but I’m still struggling with the extruder skipping issue. Here’s what I’ve done so far:

  • Removed the nozzle multiple times and performed several cold pulls (though a hex key cold pull isn’t very effective with this printer, as the thin key doesn’t go deep enough into the nozzle).
  • Interestingly, when I manually extrude filament through the touchscreen, there’s no skipping at all. Loading and unloading filament also works without any issues, which leads me to believe that the motor itself is functioning properly.

The A1 Mini came with a tiny needle stored in a clear plastic tube. I’ve used this needle to poke through the nozzle from both ends. While it’s hard to get through when the nozzle is cold, it works when the nozzle is heated. However, when poking inside, I can feel a soft, waxy resistance near the nozzle’s tip. I suspect this might be the cause of the skipping issue, as the motor might need extra force to push through the blockage during printing, something that’s not required in other routines like filament loading or manual extrusion.

After cleaning with the needle, I noticed that the next print attempt went better: the extruder skipped less, and the clicking noise was reduced. But unfortunately, the skipping still occurs, and the print quality drops after a few layers.

So, my main questions are:

  • How can I fully clear out this material inside the nozzle? Cold pulls don’t seem to be effective.
  • Am I right in thinking that a partially clogged nozzle could be causing the extruder to skip?
  • Any other suggestions on how to approach this issue?

Thanks in advance for any advice you can offer!

And yes, I did tighten the 3 bed screws.

The nozzle isn’t the issue.
I gave my thoughts, you said you did them …so I’m done.
I’ll continue to follow to find out the results.

The nozzle isn’t the issue.

However, it seems like in EnTheThracian’s case it was the nozzle. He recommended the hex key cold pull, which is not working with an A1 mini, but since it works a lot better after I picked around in the nozzle with the needle, this strongly indicates it is the nozzle.

Not having an A1 myself, take my advice with a good pinch of salt.

Nevertheless, since the needle resulted in a temporary improvement, I tend to agree about a partial clog.

There are a few tricks to make the hex key method more effective but there’s a risk of injury and printer damage. So your best bet seems to be a nozzle replacement.

Just keep the old one. Some time in the future you may want to block intentionally (so the heat sink is loaded with filament), give the hex key a really good wallop of heat to push it in real deep (with the inserted filament ensuring a good grip), letting it cool and then pulling. If you can’t pull it out, you have done everything right. Heat the nozzle slowly until you can pull it out with all your might.
But that is on an X1C with full awareness of the risks on injury (burn, cut, squeeze) and printer damage (if using the heat cartridge to heat, rather than placing the nozzle in an oven or on a hot plate). Try at your own risk only.

Thought I mentioned a partial clog here.
This is in 3 threads…

Hi everyone,

Good news—I’ve finally resolved the extruder skipping issue! I’m not entirely sure which step fixed it, but I suspect the clogged nozzle was the main culprit. Here’s everything I did:

  • Performed several cold pulls, including two hex key cold pulls with the help of a lighter (initially, I was hesitant to push the hex key far enough in).
  • After multiple cold pulls, I noticed that the waxy resistance inside the nozzle was gone when using the needle.
  • Switched PLA filament, though only the color (went from black to brown, and back to black again—Bambu Basic PLA).
  • Did a full recalibration of the printer.
  • Adjusted the “z hop when retract” setting to 0.6mm.

Result: The printer is now working perfectly, and the extruder skipping is completely gone!

Hopefully, this helps anyone else facing similar issues!

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For those with a similar problem: I also experienced this and it was obvious that the extruder gears could not push the filament through the nozzle i.e. a clogged nozzle. Tried all the above without success. Eventually put it down to a contamination particle stuck at the end of the nozzle. Replaced the nozzle and that fixed it. Where did a particle come from? Adhered to the PLA while feeding in? PLA contaminated? No idea. I did not have 0.4mm rigid wire to push with which might also have fixed it. I now also keep spare nozzles and a 0.4mm drill.

I have a Bambu Lab A1 and experienced much the same problem. There was no issue extruding filament before starting a print, and it had nothing to do with temperature or bad filament. I cleaned everything thoroughly and even installed a new nozzle, but the issue persisted. I also dried the filament just to eliminate that variable—no change, as expected.

When I pushed on the nozzle, I noticed some movement where there shouldn’t be any, which made me suspect loose screws. Behind the nozzle, there is a plate that holds the nozzle mount in place. I removed the three screws at the front (behind the nozzle), and when I took the plate off, one screw fell out and the other three were loose (four screw mounted behind the plate).

After tightening all of them properly, the problem was completely fixed.

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Hello! I suggest you tighten the extruder belt tensioner located on the left side of the extruder. Try loosening or tightening the screw to try and see if it clicks anymore. You will not need to take anything apart, not even the front extruder cover.