Gap between perimeters on certain angles

Hi folks,

I have printed quite a lot of things already but just now noticed a weird artifact. Whenever I print somewhat straight thin walls at a certain angle, the perimeter walls do not meet.

The attached image is a test print with .8mm thick walls at different angles. As you can see, the "60° NW-SE" wall, is not solid. A 50x50mm square I printed today came out to be 49.87x49.75mm, thus I don't think this error comes from misconfigured steppers. Measuring the thickness of the walls, you can clearly see how the malformed wall sticks out. The precision is as I would expect. To me, this also rules out underextrusion, since most walls are already wider than they should be.

I have attached the stl-file of the print so someone else may check whether its due to the slicer acting up. Any help would be greatly appreciated.

Best Regards,
Cyclonit

Would be interesting to see a preview of your slicer.
Can you repeat the result, when you rotate the part a few degrees?

The preview does not show this defect. I'll provide a screenshot later on once I am home.
When I rotate the part, the defect stays in approximately the same location, somewhere between 45 and 70° NW. It also happens in slightly curved parts in that orientation, only less pronounced.

As promised: [i.imgur.com]

I don't see the gap in there.

Is your printer a Delta? To me it seems it's a mechanical problem, like the rods of a Delta aren't exactly same length or the distance between the rods isn't equal.
These imperfections lead to tension in the effector system, that might release/snap at a certain position/angle.

No, its a prusa clone.