Z-Axis noise. Is this normal?  

There is no Z belt ...

The noise will come from the linear bearings that ride on the veritical rod.  If you lubricate them (pack them with grease) before you put the printer together, you won't get that noise.  The only way to fix it is to take it back apart, and lubricate the bearings and then put it back together.

RE:

Thank you for your input. You seem very certain about this. Have you encountered this exact noise? I've tried greasing the rods, although only by applying it to the rods and moving the Z-Axis up and down several times. It does not change the sounds at all. And it very distinctly seems to come from the left stepper motor.

The reason I am asking so specifically is to avoid taking my printer apart unless it is absolutely necessary. 🙂

RE: Z-Axis noise. Is this normal?

Posted by: @muldjord

I've meticulously built my Prusa i3 MK3S+ about a month ago....

If you followed this step exactly, then you did it wrong. Correct way is:
1. Use holes without thread!
2. Do NOT fully tighten those two screws!
Trapezoidal nut must have just a slight free play horizontally -you should be able to "rotate" it by applying a little force. Means, tighten the screws just enough, so there's no vertical play. Again, this can only be achieved, if holes without thread are used.
-and Z-axis noise will gone.

Is hard to believe.. Prusa is assembling that trapezoidal nut in wrong way (at least that was the case with my pre-assembled Mini).

RE: Z-Axis noise. Is this normal?

Thank you for the suggestion. Turns out my right trapezoidal nut was fastened through the threaded holes so I unscrewed it, turned it slightly to align with the non-threaded ones, and screwed it back in place. I already made sure that my trapezoidal nuts aren't too tight. They weren't before either. I even tried loosening them quite a bit. Unfortunately this made no difference to the noise at all. 🙁

I even ran the full calibration again to ensure the level of the two side stepper motors. This also made no difference.

That noise is awful - no idea what it is.

I would not run a printer that sounds like that.  It won't be long before the problem reveals itself in a most expensive way.

RE: Z-Axis noise. Is this normal?

By the way, in case it isn't clear, I am only talking about the wrrrrrrrrrrr sound in the video. The clacking sound is just me turning the knob to get the Z-Axis to move.

RE: Z-Axis noise. Is this normal?

Just did some further testing today. I moved the Z-Axis up and down and noticed that the left-most stepper motor got hot quite quickly, while the right-most stepper motor did not. I've contacted Prusa support.

RE: Z-Axis noise. Is this normal?

Did you ever find out where the noise was coming from?  I'm experiencing the same noise.

RE: Z-Axis noise. Is this normal?

No, unfortunately my MK3S+ is simply noisy in comparison with my friend's MK3S. Potentially it could mean a regression due to some changes in how they are designed around the print bed and possibly the bearings. I am in no way knowledgable enough to say anything meaningful about that.

SO! Take that with a large spoon of salt, as this is based on my personal assessment of two printers only. It might just well be because they are simply intricate machines and resonances can be caused by all sorts of weird things due to minute differences in how my friend and I put them together.

Prusa sent me a new Z-Axis stepper motor after a bit of back and forth with the support, and while it did help a bit, it didn't remove the harsh noises in a way that would make me say it's "fixed". So I've decided to simply live with it.

Luckily it prints perfectly due to me being extremely meticulous when building it. So I'm in no way disappointed with my printer. It's just that I live in an appartment complex, and after hearing my friend's MK3S it is very clear to me that my printer is simply noisy in comparison. But that's just how it is, nothing I can do about it unless I want to take it all apart and hope that the simple fact that it got taken apart and put together again, would change some resonances for the better.

A quick note: My printer is A LOT noisier when using stealth mode. So I never use it. I'm not sure if that's normal either but it suggests to me that there is something on my printer that resonates more than it should, as "stealth mode", I would assume, should be less noisy than normal mode. For me it is not. It sounds like someone stepping on a cat repeatedly when I use "stealth mode".

RE: Z-Axis noise. Is this normal?

Ich habe einen neuen neuen mk3s+ gekauft. Wenn ich von Hand bediene sind die Geräusche der Z Achsen normal. Wenn ich ein Stück drucke 

macht er beim Anfahren Schnellgang ziemlich laut. Ich bin ratlos!!??

RE: Z-Axis noise. Is this normal?

I used holes without thread but still the noise is coming up

RE: Z-Axis noise. Is this normal?

I have the exact same noise, on the right side motor, any one solved it?

RE: Z-Axis noise. Is this normal?

I have the same sound coming from somewhere on the LHS of the machine. If i press my finger against the x-axis motor holder (item on the left here https://help.prusa3d.com/guide/3-x-axis-assembly_167854), i can stop the noise completely. Im trying to figure out whats vibrating. Will update if i figure it out.

RE: Z-Axis noise. Is this normal?

Thank you for the video! I had exactly this same sound. In my case, it was because the screw going into the X-end idler bearing assembly had worked its way loose and was rubbing into the lead screw of the right hand side. https://help.prusa3d.com/guide/3-x-axis-assembly_167854#168110 (look at the second picture).