I have put over 350 hours of print time on my P1S since I first got it. The other day however, I began to notice issues in ringing/banding/ghosting/VFAs (I know it has a lot of names). I’ve been messing around with different things because as far as I’m aware there’s not a whole lot I can do hardware wise. I’ve already re-tightened the belts at least 10 times and I used some IPA wipes to clean off the carbon rods, then re-ran calibrations after that and every other time I tightened the belts.
I contacted Bambu support. As of now, it’s a bit early to say much, but they provided me a test print to do with one of their profiles. It revealed that ringing on the Y-Axis was almost non-prevalent; instead, the ringing/VFAs were most noticeable on the X-Axis. This is nice to know but also not, because I really don’t know what to do from here.
Most other threads on Reddit/this forum that I’ve seen about this issue all have various answers, with some suggesting it’s impossible to fix, others suggesting it’s a speed issue, and others suggesting it can be fixed by changing the idlers to teethed idler
So, what should I do? Attached are images. Any help would be nice.
I must admit, this is quite a puzzling situation. Let me explain why.
The movement of each belt/stepper motor combination actually only moves the print head in a 45 degree direction. To prove this to yourself, power off the printer so that you don’t damage the machine when you do the next part. Move the head with your hand in a 45 degree direction and witness which belt moves. What you will see is that only one belt moves.
So this would suggest that the problem is not likely mechanical in nature but somehow related to the firmware or control logic of the board.
I’m sorry that’s not an answer or remedy but what you might try is to experiment with orienting the cube 45 degrees and seeing what change occurs. Then feedback that data to Bambu lab and ask them to comment.
There is one very, very longshot thing you can try. Go into handy and change the firmware revision to anything else other than what you are running now. So if you’re at the latest revision, downgrade to the lowest. What you’re looking for is to repeat the test and note if there is any difference whatsoever. Then again, report that back to Bambu.
In the same vain, try another slicer like Orca at a very different revision. So currently Orca is at 2.2. Try downloading Orca at 1.9 and see if it has any influence on your test.
I tried the last part of your response about downgrading both slider and printer firmware, and unfortunately yielded no differences in results. I will try rotating the object and post the results here. But I’m a bit concerned thus far.
I would be concerned too. I must confess, I do enjoy a good problem to solve, especially when I can remain objective. Although it sucks for the individual experiencing the problem, I derive new knowledge when a problem is solved, whether by me or the community here. But this one is truly baffling. Based on everything I know about how the machine’s mechanics and logic function, I can’t think of any way this could occur. The truth is, without that photo, if this were just a text post, I’d be questioning the poster. But there we have it: your indisputable photographic evidence.
With the revision levels ruled out, I am looking forward to seeing how the problem can manifest itself with the 45 degree print. Will it show on both side or just one?
Two questions:
What does the opposite side look on the X side? Does it have the same ringing?
Have you attempted this with a simple cube primitive? I ask because although you said it does show ringing, it would be interested to see how pronounced that ringing is on a smooth surface. It shouldn’t make a difference but is it as obvious on a smooth surface as one with a feature?
Keep in mind, in the images attached to this reply, the cube on the left was printed at a 45 degree angle, and the cube on the right was printed normally. The only exception is the primitive cube.
Interestingly, printing at 45 degrees seems to add a tiny bit of ringing to the Y-Axis that wasn’t there previously.
The primitive shape seems to match what I’m seeing in the calibration cube, with larger amounts of ringing in the X-Axis than the Y-Axis.
Can you upload a screengrab of the sliced file along with the strength tab. These are the parameters that are most interesting as well as a cross section of the slice.
You could also manually manipulate the infill angle to an odd angle like 17°. Anything that is not along a 30°, 60° or 90°. What we are looking for is changes in the ringing.
The theory I’m trying to test out, however unlikely, is this even ringing at all but perhaps rather an influence by internal structures.
Unfortunately, this didn’t work for me. Sure enough, my infill did look exactly like yours. I changed/messed around with the infill angle, percentage, and type (I tried gyroid and lightning as well). Unfortunately, nothing I tried made a change or any positive impact on the outcome of the model.
I won’t share any additional images because they came out pretty much the exact same as previous set of cube images I shared.
I now have a large collection of cubes that all look the same or very similar to with ringing on one axis only LOLL
Any other ideas? Bambu support is telling me it’s normal.
That is NOT normal no matter what Bambu is telling you. The fact that it’s happening in one axis and not the other is telling and baffling at the same time. The only other remedy I can think of is increase the wall thickness and slow down the print speed for the outer wall. Outside of that, I’m out of ideas. Did you say this does this with all filaments?
Yep. Happens with all filaments. I tried with Bambu PLA too, specifically, Bambu Gray PLA. The color of the PLA makes it harder to see any imperfections such as ringing, but if you look carefully you can notice it still.
I also tried with Bambu PETG-HF, and sure enough, there’s definitely VERY noticeable ringing there. Although I’ve heard PETG is a material prone to showing any and all inconsistencies, so I’m not sure if that’s normal or not.
Adding on to this- here is what Bambu has told me.
Thank you for the help. I already watched that video unfortunately (and countless others). I’ve also been scouring Google for more potential fixes, but unfortunately, nothing has really made a significant change.
I have now had this exact same issue on two P1S printers in a row. It happened with the first one so I went through support and then returned it, got my new printer out of the box last night and printed the same file, same result. I have tried re-tensioning the belts, cleaning the rods etc but nothing helps.
So now I am not sure what to do, third time is the charm and go through another multiweek return process for another printer, or is this just something that the P1S does or a software bug which could be fixed moving forward.
I have yet to find a cause or solution for this issue, but I have continued to use my P1S normally. I am thinking it is a software related issue, although I’m still unsure if it’s a firmware issue or slicer issue. In the past weeks I’ve continued using my printer normally, I’ve noticed some parts print 100% fine with no ringing, some parts print with minimal ringing, and some parts print with horrible ringing. It seems to have some correlation with speed though.
And the 3mf with the profile that you used to print - would help debugging.
I’m having some issues myself, but the lines are different. I have two friends that’ are getting their P1S in the next days, so i can’t wait to test with them too. All machines have, indeed, a sweet spot where the resonance from vibrations is more pronounced, and so you need to avoid those speeds. In general, slowing outer walls to 50 or speeding over 200 should do the trick. Check your layer time/speed in the slicer too. Also, to rule out the slicer (which i doubt it can be), you can try a different slicer and test.
Also, please note, some models are just not high quality, so it very much depends on the models you are testing with. I suggest something simple and battle tested, like the Orca cube or Bambu cube.
I have attached some photos, although this kind of thing can be quite difficult to capture.
I have also attached the file I am using, which is a pre-sliced Bambu Cube from Bambu Labs support which we used to try and diagnose this issue with them. As such I haven’t really tried varying the speeds as it is a pre-sliced file but I was going to try some of that this evening. P1S_TexturedPEI_GenericPLA_DoorOpen.gcode_1731077661208_leh9r.3mf (623.6 KB)
Yep, same thing here. I really hope the new responses to this post will bring some new potential answers, because I’m still not sure what the issue could be, and it’s getting progressively worse. All I can do is try retightening the belts and cleaning the rods again.
UPDATE!!
This might turn out to be a failure later, and not actually work. But I think I’ve made progress.
Essentially, the issue might have to do with belt “tracking”. I realized that this issue only started to get really bad once I re-tightened the belts for the first time, which means in that process besides the belt tension something else must have changed which resulted in my issue.
I looked at the back of my machine and noticed the belts were riding on the very top/bottom of the idler pulleys, which I believe was causing excessive friction that could have resulted in the VFAs/ringing artifacts that I have been seeing. This is an issue I’ve heard some call “belt tracking” or “belt alignment”.
So, this morning before I left, I re-tightened the belts, this time also compensating for alignment issues and fixing them. The belts aren’t perfectly centered, but they also aren’t riding on the very top or bottom of the idlers anymore. After doing this a few times, I noticed that moving the XY gantry was now much easier and had a noticeable amount of reduced friction. So I re-ran calibration and I’m going to run some test prints as well. I’m praying this could be the solution.
I came home to find the model I was printing still had the VFAs/ringing. I was extremely disappointed and losing hope, but I decided to check the belts to make sure they were still centered after the print.
Turns out in my first attempt of centering the belts, it wasn’t good enough and both belts were still riding on the very top/bottom of the idler pulleys most of the time. So, I decided to re-do it one last time. This time, I was able to get the belts much more centered. Then, I hit print again.
The print is still going. So this is a bit early, but I’m just so excited and happy I can’t wait to share this news.
One of the smaller parts of the print is done. I took it off while the other parts were still printing, and compared it to a version of that part I had printed yesterday. And to my utmost surprise and happiness, there is nearly no ringing in the part anymore.
There are the tiniest of VFAs still visible- but they’re so tiny I don’t care. The part is relatively tiny, probably like half an inch in width. But despite that, you can certainly tell a big, big difference. And I’m super happy right now.
I hope I won’t regret making this reply, only to come back later and say the bigger parts still printed bad. But again, I’m just so happy and excited I can’t wait to share the news.
In the below image, the part on the left is before, the part on the right is after. Huge difference!!
