Hi,
I am using Ultimaker 2 Extended. It is a new printer and is used just for a couple of test prints yet. And I am having this problem you can see in the attached image.
The problem is that, the print quality is bad (kind of loose) at some layers. They can happen at any height -sometimes closer to the bed, sometimes more high up. The distortion is always horizontal.
I used PLA for this test print. I tried different settings for print temperature but the problem remains the same.
Any idea on how to solve it? Thanks in advance for any help.