Vertical artifacts (VFA) on both x and y axis
Hello, my printer kit purchased 6 months ago has had a problem with slight vertical lines on all prints (at least on Y axis) since it was built.
Since it seems to have gotten a little worse in the last 2-3 months to the point that it started to spoil the otherwise relatively good print quality, I decided to try to solve it.
Symptoms:
- Vertical lines on the X and Y axes, 2mm apart, regardless of the filament (pla, petg, abs) and brand. Worse on the Y axis. Almost always purely vertical, only sometimes their distribution changes a little around a sharp corner (Mostly on X axis, it seems to be a mix of ringing/ghosting and VFAs there)
- The Y axis vibrates noticeably when I try to move it by hand slowly. The X axis is similar, but less pronounced. I feel the vibrations similarly often even when I tried to rotate only the stepper motors themselves (with the belts disconnected from them).
- The printer movements are louder on Y axis too compared to the X axis
- Speed doesn't really matter - I put 20mm on the perimeters and I still saw them. In fact, it outright seems to resonate at those lower speeds. I thought input shaper is supposed to prevent that?
What I've already tried:
- I tried contacting support via LiveChat - I only got general instructions to re-grease the axes and tune the belts, which I did, but to no avail
- I oiled all the axis rods.
- I tried changing the belt tension countless times using the Prusa Belt Tuner
- I completely disassembled the Y axis, lubricated the bearings, made sure the belt was straight all the way in its mount and not crooked
- I tried printing a different X motor mount - https://www.printables.com/model/814369-mk4-y-axis-overhaul-reduce-vertical-artifacts-on-y - and Y-idler mount: https://www.printables.com/model/758324-mk4-improved-y-axis-idler-mount-helps-reduce-verti This helped with centering the belt on the motor side in the middle of the toothed pulley, but the artifacts changed minimally, if at all. On the opposite side, on the idler - smooth pulley, the belt is still on the left and does not stay centered (it behaved this way even before I printed the replacement holder) - the picture with the red text and line shows the belt's original position
- I tried contacting email support, which told me pretty much the same stuff as live support before stopping replying to my emails.
So I would like to ask for advice if there are any other methods to solve this problem. I have certainly expected less artifacty prints from a 1000 dollar printer.
Pictures:
RE: Vertical artifacts (VFA) on both x and y axis
Hard to say from the pictures. But make sure that the set screws are aligned with the flat sections of the motors.
From the picture below it looks to me that the set screw is not tightened normal to the flat section of the motor.
If its not it can slip and cause shifts in layer lines. 
RE: Vertical artifacts (VFA) on both x and y axis
It indeed isn't and i'm going to fix it. However i've never got a layer shift so i guess it does hold. The issue seems to be, that something resonates, not that the pulley slips.
Also it looks like the VFAs actually somewhat reduce at higher speeeds (using SPEED rather than STRUCTURAL profile)