Walls not touching only on one axis

[jasko]

Hello,

I am making one large 3D printer as you can see on images that I have attached. Everything works fine except I have some weird effect on Y axis ( dual Y). Using Duet 3 board with latest firmware. config.g
Extruder is e3d titan aero with supervulcano hotend.

When printing rectangle parallel to axes, as you can see on photos attached, walls are not touching on Y axis but on X axis everything is fine.

When printing some radius then walls come out some pattern in which one is shifted left and the next one is shifted right.

Things I have tried up till now:

1. Tightening belts, equal force on Y and X axis
2. Reinforcing Z axis

Does you have some ideas, is this software or hardware issue?

[dc42]

The pattern here indicates to me that it is printing alternate layers in alternate directions and that you have backlash in at least one of the axes and/or belt mechanisms, the one going front left to back right in this image.