[Superman]

My first try was with simple 180° arc. By that I mean sheet arc with radius 55mm divided on 10 equal segments. Roughly that should be about 18° per bend.

Possible maths error ???
... you may have issues regarding # of bends verses # of segments.... 10 segments = 11 bends, or if you want 18° bends for a 180° return, which is 10 bends or 9 segments (10th segment is the total bend result)

Eg...think about 45° bends, 4 bends/ 3 segments for 180° total bend...
All this is theoretical, each machine would need over-compensation to achieve correct size. It depends on material properties, springback, bend length, design requirements, machine capability.. it is not all easy, a lot depends on operator knowledge.