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Prusa MK3S making weird sounds  

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Prusa MK3S making weird sounds
I built the MK3S from a kit a few weeks ago.  I initially started printing with Prusament PLA. Then I got some Fillamentum PLA. I noticed this annoying squeaking sound coming from the extruder. It sounds like rubbing Styrofoam together. I noticed the grub screw was loose on the bondtech gears and tightened it. However I still notice the sounds. I tried Prusament PLA again and did not hear the noise. I tried loosening the door where the gear is, but that did not help.  What gives?  How can I fix this?  I also noticed a little notch that seems to be digging above where the gear is.
First link has video.  Second shows the notch.
I also noticed the bed making a weird shaking/ knocking noise when the print head is moving quickly on the infill. Is this normal?  It can be heard in this video:
This topic was modified 2 years ago 2 times by jmeadows2012
Posted : 24/07/2020 1:34 am
Trusted Member
RE: Prusa MK3S making weird sounds


I wouldn't necessarily consider the noises really unusual in the first video until I looked at the second photo. I suspect that the strange noise you are hearing is caused by the rubbing of the filament at that wear groove. Something is causing the one filament to rub. If your prints are turning out fine, I might just trim things back a bit to prevent further rubbing. But that's just me - YMMV.

The last video is pretty common on many machines that are computer controlled. You are effectively bring those moving elements from what ever rapid speed they were moving at to zero and then trying to accelerate as quickly as possible in another direction. The continued inertia has to show up some where. And since 3d printers are pretty lightweight and flexible, (everything is a limp noodle in the universe), you will see some "bounce" that can be quite pronounced. This is why CNC machining centers are made from 1000's of pounds of cast iron and steel to try and dampen such issues, (and even then such moves can still create problems if done fast enough). If it bothers you and causes print issues, slow down your rapid feed rate speeds.

If you spend a lot of time operating different machines, (even of the same type), you will notice they all have their own voice when running. What might sound wrong maybe be normal for one machine and the next machine will be shooting flames to the ceiling if it sounds the same. It is good you are listening to your machine talk to you when it runs.

Posted : 24/07/2020 5:29 pm
David Kennis
Active Member
RE: Prusa MK3S making weird sounds

I have exactly the same sound as you have in the first video.

I have the MK3s now for a week and get this sound. i got this since the last print.

With other prints i did not had this sound. Also the filement is the same.


did you solve the problem?

Posted : 31/08/2020 1:34 pm