Hi Felix, I'm not really sure if I'm following the rotation problem - there are quite a bunch of objects in that last file you posted and I'm not entirely sure which ones were used to make that particular result that had the improper rotation.

One thing that I did notice though is that in your original object, the seam of the circular part is at a different rotation than the nearest point of the star, like this:



Did something happen like you got a 90 degree rotation in the result of the Flow because the surfaces happened to have a different UV axis direction placement, and then you rotated the base object a bit to compensate? If you wanted the seam of the outside circle tube part to align with the star, that would need to be aligned in the base model.

Maybe I'm just not understanding what the rotation problem is though...

- Michael