Flow as an "unfold tool"

 From:  Mik (MIKULAS)
7406.9 
Hi Pilou,

you mean probably rotation faces without drawing auxiliary circles, it means choosing edge as axis of rotation and then offset the face.

Because it's possible to calculate compensated length of radius, maybe it's more handy to rotate the face using centre of radius and then move the face in right direction by calculated distance.

Mik