X-axis layer shift or something else?...
This is an issue that has arose in the past few weeks. I'm getting this layer shift all throughout my prints and I do not know why. Has anyone seen this before and if so what was your fix? Prusa says it's a loose belt but it's not when I try to loosen the belt (X-axis belt @209 Y-axis belt at 253) to get it within range(240 or better) the belt begins to sag by 213 and the tension screw is about to fall out. I wasn't satisfied with Prusa's short answer so I thought I should post it to a broader audience. I've included this image to demonstrate this issue. This seems the worst in prints that require support material because it shifts as well making it impossible to remove. Even so on straight square side box on two of the sides the layers aren't even attached.
I hope someone recognizes this issue and can point me in the right direction. I'm using an MK3S+ that is less than a year old with a new nozzle and it has been working flawlessly until about 3 weeks ago I really hope someone can help and of course thank you in advance. Chris 
RE: X-axis layer shift or something else?...
could you check the grub screws in the toothed wheel on the X and Y axis.
If the screws are loose, the toothed wheel can move a little and cause misaligned layers
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: X-axis layer shift or something else?...
For something extreme like this my money is on loose grub screws, as Joan suggested. As far as belt tension is concerned I don't even look at these numbers anymore. Once your printer is printing again, print yourself a copy of the Prusa belt tension gauge in printables.com. I found it to work better than chasing those numbers.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...