Hi Everyone,
Recently I got this odd noise which I noticed during the flow calibration and it does not sound healthy and I am rather worried and just wanted to check if I overreacting.
The grinding noise can be heard on the movement back to the left, is that normal as I don’t recall hearing it before. The printer is only 2 weeks old.
Thank you.
I think you might have some dirt in your sleeve bearings on the x-axis. Theres already visible scraping on the carbon rods. 
I would try cleaning the rods according to the instructions: https://youtu.be/0T43m4FB854?si=Myp-T9eIjMvN8m-T
Do these really look bad? I mean the printer is only 2 weeks old and always been covered, I print with top and door losed.
Pictures will not provide a definitive answer. It’s simple thing to just clean the rods. If the noise goes away you will know dirt was the cause. If not, no harm done and you can look elsewhere for problems.
I worked quite a bit with carbon fiber rods abused for mechanical movement systems…
There is some fundamental issues with their use like it is done in our printers.
These rods are NOT sealed!
Bambu failed to apply sealing coat on the surface of the rods to PREVENT wear and tear caused by the much harder roller grinding over them all the time.
This results in fine carbon particles accumulating on the rods AND rollers as there is NO measures taken to keep these rods clean - like a simple brush going around it with the moving print head.
These particles not only cause further damage to the rods, they are also a killer for all other moving parts, especially once it got into bearings.
It is next to impossible to prolong the lifespan of these rods through cleaning alone.
Yes, wiping the rods clean once a week or so DOES help.
But if a white cloth comes back with clear carbon residue you already know things are wearing out, means tolerances go down the drain and things get loose.
Nothing though can PREVENT the wear and tear on the rods.
Good care provides a MUCH longer service life though.
So what went wrong here?
Costs of course 
Sealing those rods with a hard coat would require at least some final polishing to ensure the rod is withing tolerances throughout the entire length.
Bambu probably did not go this route because once such a coating eventually fails it usually fails badly and if the rod is not replaced right away things only get much worse.
On the other hand those plain rods will gradually fail and annoy the user more and more with increased noise levels and finally visual imperfections in the prints.
Since almost ALL moving parts of our printers are deemed CONSUMABLES it is expected that those rods are replaced once they start to show signs of too much wear and tear.
Sadly replacing them and getting all back together is not for the faint of heart and requires a lot of work.
Similar story for those rollers.
Ideal would have been a braided layer that is hard coated on the outside of these rods.
A failing coat getting brittle would turn from shiny to pale and a good polish can often restore the surface.
Ideal would have been to use rollers with a soft enough PU coating on the contact surface…
Allowing for a tight tolerances, tighter than the current system, while also drastically reducing the pressure on those carbon fibers.
Such rollers however cost more.
But while it would not solve the hassles of having to take the entire thing apart: Those PU coated rollers would cost only a fraction of those carbon rods…
Like it or not: Our machines require far more tender loving care than advertised and come with a lot of parts that are designed for a limited lifespan.
A bit like with our paper printers: Provide the machine as cheap as you can justify and make up for it through the consumables.
I contacted BBL tech support for something that sounds exactly like what you described. I hadn’t been printing much PLA up to that point so my machine hadn’t really done a lot of high speed printing. Anyhow they got back to me and told me it sounded like I didn’t have arc smoothing selected. I almost argued with them because that’s a default I never de-select. But then I checked to my print settings and sure enough…it was deselected and greyed out. That was a few months ago and I only just recently figured it all out. I had that problem right after Orcaslicer introduced the scarf seam feature. Something I read about good settings suggested extrusion rate smoothing, so whenever I used the scarf seam setting, I selected that option. For whatever reason, that automatically disables arc smoothing. That becomes the noise you’re hearing when you’re printing arcs at very hight speeds - because you’re really not printing arcs, but a polygon, unless that arc smoothing setting is on.
Anyhow I think this is pretty old, but I just happened to see it and decided I should answer so anyone stumbling on this later may see it and find a solution without waiting on tech support.
Cheers,
NathanJim
I experienced something similar this week. I wiped down my carbon rods with IPA (per the maintenance instructions) and the noise went away for me.
Hi,
any updates on this?
I received my X1C yesterday and got the same noises while fast moving.
→ I checked my nearly 1 Year P1P without any maintanance, and hes not facing this noise.
I’ll give it a go. My X1C is just 4 days old and is also making these noises.
well I did the carbon rod clean and lubricated the pulleys but that didn’t seem to help
If you want to tackle the fix on your own without waiting for painfully slow support-
I would isolate the toolhead by removing the XY belts (wiki videos for this) and check smoothness of the carbon rod assembly.
If you have catches, tight spots, anything besides fluid, butter smooth motion, its a problem. If this is the case, you could then try separating the toolhead to remove the rod bushings, and try to flush/clean them/ work them on the rods to see if motion improves- but replacing the carbon rod assembly is probably the best bet.
So took me a long time but you helpfully posted a vifeo with the sound it makes and mine does exactly the same thing with exactly the same noise. I have more than 1 machine and its the machine thats only about a month or so old thats doing this. Did you manage to get to the bottom of this ?
My printer makes those same kind of noises when I printed the circular parts for the jet engine model. Hasn’t done it since. Got the printer may 17 2024, over 400 hours on it now.
Same issue here, following.
I think I had similar thing happen after a while.
Solution was to apply lubrication to pulleys/bearings.
1 One set is on Carbon Rod housing units (left right)
2 Another set is reachable from back of printer (left right).
Make sure to have printer run some movement right after to achieve good lubrication. (Maybe do 1 layer print of 200x200mm.)
I used Dry PTFE Spray for them.
Should be enough as printer is new, I assume there is no dirt on belt, but worth checking there.
Let us know if this helped.
It is 100 EUR to replace carbon rods.
I expect them to live for 4000hrs+ print time based on field results (other people than me have printers at that time without having issues there).
My printers are 1500-2000 hours print time.
I posted above regarding arc fitting and how using skarf settings automatically disables this. Without arc fitting, and when printing at higher speeds, your machine will sound as you describe. I’d bet good money that most of you are experiencing this. The solution is to either turn off the skarf seam option (and turn on arc fitting), or slow down your print. I have a pair of X1c’s, one new and one with 2k hours, and they both do the same thing at high speeds and without arc fitting. It isn’t failing hardware (necessarily).
Currently having exactly the same sound, even outside of regular prints (Like when doing bed leveling or running the calibration procedure), so arc smoothing might be treating the symptom and not the cause. I am not sure if this is unrelated, but after tensioning the belts, the sound got worse (my guess is that I over tensioned them).
Current plan is to disassemble the pulleys on the back (like one would do for replacing them), to fully remove the tension and then retension the belts again.
What I am not sure about, is if that sound was always present and how much of a problem it really is. While printing it sounds fine and the prints are still flawless.
Similar situation for me. I end up doing the belt tensioning procedure and checking their alignment, plus lubrication for pulleys. Issue resolved immediately. There are a few youtube videos of people getting similar grinding/squeaking noises due to belts and pulleys.
Experienced exactly the same noise in the same fast movement from right to left side. The printer was one week old at the time.
Fixed by cleaning rods and retightening belts. After that performed the full calibration. The issue is gone for now.
