This is the blade of a small Vertical Axis Wind Turbine. It is designed to be stacked in sets of 2+. It is a helical Darrieus constant torque design. It is not self starting. The airfoil is a NACA 0015 with zero angle of attack. Still needs a stand and end cap.There is a high and low polygon model if you are in to that sort of thing. Print as many as you dare and snap/glue them together.