Hello i have another problems with my Anet A6 printer.
1st. layers are shifted
2nd. in point where Z axis move UP is weird thing
In attachment is photo of my tested model. What can be a problem please?

Robert

How is the belt tensioner?

Belt tensioner i have only on Y axis because i have shor belt and now waiting for new belt.

In the first photo: it looks like you have experimenting some wooble in Z axis.

Try to print that (or something like this, searching ‘antiwooble’ at thingiverse): ANET A6 antiwobble by dmpush - Thingiverse

I think u have a Z wobble; your vertical threaded rods does not rotate around the vertical motor axis, not aligned. check the Z couplers.

check some unusual friction on Z mechanism (perhaps is not working smooth).

this is like a acrylic frame problem but try make this Anet A8 - X belt tensioner by Robchiks - Thingiverse maybe need little update for A6

and use anti backlash nuts