Tapered structure construction

A method for forming a frusto-conical structure from planar metallic stock, the frusto-conical structure having a virtual peak located at a point where the taper of the frusto-conical structure would decrease to zero if the structure were not truncated, the method comprising:nfeeding the stock used to form the frusto-conical structure into a curving device such that:na portion of the stock that has not yet been deformed by the curving device undergoes a substantially rotational motion in the plane of the portion of the stock about the peak of the frusto-conical structure such that each point on the portion of the stock that has not yet been deformed maintains a constant distance throughout feeding from the peak; andthe stock meets a predecessor portion of the stock along one or more adjacent edges; andtranslating the portion of the stock in a direction different from a feed direction of the stock and adjusting an in-feed angle of the portion of stock according to the substantially rotational motion.

A method comprising:nfeeding stock used to form a frusto-conical structure into a curving device such that:na peak of the frusto-conical structure translates with respect to the ground at a direction and speed;a portion of the stock that has not yet been deformed by the curving device rotates in a substantially rotational motion about a center of rotation, wherein the center of rotation translates with respect to the ground in the same direction and with the same speed as a location of the peak;an in-feed angle of the portion of stock varies at the curving device according to the substantially rotational motion, andthe stock meets a predecessor portion of stock along one or more adjacent edges,wherein the peak is a virtual peak, and wherein the location of the peak is a point at which a taper of the frusto-conical structure would eventually decrease to zero if the structure were not truncated.