Bed noise at some speed
I have a Prusa MK4 kit and it started to make a noise in bed movement but just at some speed.
Video showing the problem: https://youtube.com/shorts/YE7dDXmHj0k
At the first 2 seconds it makes the noise but in the last 2 it doesn't because it's a different speed.
What can it be?
RE: Bed noise at some speed
I tightened the Y belt and the noise it's almost gone. By the app to "tune" the belt tension it's in the upper limit and the noise it's still a little bit present, can it be another thing?
RE: Bed noise at some speed
check if something is loose, for example the psu or the cover fromvthe controller box. check all screws.
RE: Bed noise at some speed
I have the exact same thing. Haven't found a solution for it yet. It doesn't seem to have any negative impact on the print quality so I'll leave it for now.
RE: Bed noise at some speed
Mine is exactly the same, I've tried new bearings, re-seating everything, double checking tension etc with no luck.
You can feel the smooth rods vibrate on Y when it happens but nothing even remotely similar on X.
Following to see if a solution appears
RE: Bed noise at some speed
The problem is usually in smoothed bars. Prusa has them too in minus tolerances against the bearings and the bearings are loose. For me, it manifested itself on the Y axis, when there was play when grasping the pad and moving in a perpendicular direction to the axis of the bar. I had to throw the rods away and buy new rods and bearings from a local dealer. From that moment on, the problem is solved.
RE: Bed noise at some speed
The noise in your vid clip seems to be common on some with the MK4s. There are numerus threads discussing this concern, unfortunately, in my option there has been too much focus on the linear bearings and rails as the source of noise. This noise is not generated by ball bearings rolling, grinding, or rattling inside the bearing guides, but is an amplified rotation vibration, which I believe is being generated by the y-axis stepper motor at discreet motor speeds and is related to how the 400 step motors are being controlled.
Since Prusa doesn't seem to have any advice on correcting this, our actions are limited to reducing the transmission and amplification of the vibration.
what @miroslav-h4 suggest could also be contributing, but the motor itself is the source, my opinion. @miroslav-h4 may have the answer, but the noise just doesn't sound like linear bearing noise to me.
As @cloud1983 recommends, seek out any part connected to the motor, be it bracket, belt, heat bed and yes linear bearings, bearing clamps, and smooth rods, to ensure the transmitted vibration is dampened to the maximum extent possible.
As @skyhawky says, I don't think this noise is affecting print quality, but it sure is annoying.
Try this. start a print that you know will cause the noise and when the bed is moving in a manner to reproduce the noise grasp the back frame bracket and apply a strong twist to it when the noise is occurring. Also when the noise is present press down hard on the belt. For me, both of these actions almost completely damped the noise. I could not find any loose or identifiably vibrating components, but increasing belt tension higher than I would like has reduced the noise level from 80db down to more comfortable 65db. I fear that leaving the belt as tight as it is will ultimately wear out the motor bearing, but its that or lose of my hearing.