I have a noise on my X1C that is really getting me down. It is so unbearable that I am currently only printing with the A1. I’ve already turned the printer over and in my opinion the noise is either coming from the lower bearing of one of the Z axles or, more likely, from the belts that run over the pulleys/bearings.
In any case, I had localized it down there with my smartphone and an app for measuring volume. In other forums I had read something about lubricating the backs of the belts, I had also done this minimally and it had worked immediately, but now it is even louder and to be honest I am unsure whether it is so good to grease the belts.
It’s definitely not the Z spindles themselves which are well lubricated. The bearings also look well lubricated from the inside.
Hard to judge what it can be based on the sound recorded by your phone. Definitely not right, though. I don’t think it’s belt noise, though if it is, removing the belt and turning the idlers by hand should expose the bearing that’s rough.
Three possibilities I can think of… there’s a scrap of filament jammed in to one of the Z stage screws, there’s an alignment issue with the build plate or with the position of the plastic bezels at the back of the printer resulting in interference when the Z stage moves (the back is the only place the build plate is close enough to anything for this to be a possibility but it’s a long shot), or lastly that you have a seized bearing or bad ball screw on one of the Z stage rails or screws or belt pulleys.
I think if it was a belt/pulley the sound wouldn’t change depending on where you are on the Z axis. It’d happen at the top same as it does lower down. The belt goes around many times for each CM of travel. Same logic applies to the bearings the Z axis components ride on. If it’s only happening down low, I think it’s likely a ball/screw issue.
You’re going to have to take stuff apart to figure it out I’m afraid.
I did put a large drop on the pulley with the intention of just lubricating the bearings but it went on the belt too. But it did stop the squeaking almost immediately
I reached out the Bambu to confirm what to do and this was their response:
Judging from your video, the noise could be from the friction of the Z belt and wheels. The four areas highlighted in red circles in the diagram are potential sources of friction.
We recommend applying lubricating grease at the Z belt tensioner idler wheel to address this issue and make the noise.
You can follow steps 5 and 6 in this wiki article to remove and inspect the tensioning idler assembly of the Z belt for any misalignment shown in the picture below.
I can confirm that putting the grease on the idler pulley as shown in Bambu’s video eliminated the z hop sounds I was getting for the first few layers.
Thanks for the detailed explanation. I got rid of the noise by lubricating the back (flat side) of the belts. Looking at your video, it seems to be greasing the same areas. However, I used a lot less as I was worried that a lot of dirt would collect on it. Grease magically attracts dust.
I signed up here just to say that I had exactly same sound and couldn’t identify what was wrong. And lubricating that pulley on the bottom solved it! Ugh, what a relief not to hear this sound anymore
