Sheet transitioning in spiral formed structures

Spiral forming devices, systems, and methods can be used to join edges of a of a stock material, in a curved configuration, along one or more joints to form tubular structures, such as conical and/or cylindrical structures (e.g., frusto-conical structures). A planar form of the stock material can be formed from a plurality planar sheets coupled to one another in an abutting relationship. By controlling relative orientation and shapes of the plurality of planar sheets forming the stock material and/or by controlling a position of a roll bender used to curve the planar form of the stock material into the curved configuration, the curved configuration of the stock material can be controlled through transitions between sheets to facilitate rolling the sheets to a desired diameter with a reduced likelihood of dimples or other errors and to facilitate fit up between adjacent sheets in the curved configuration. Page 38 of 38