Force-controlled metal spinning machine using linear motors

Metal spinning is a plastic forming process that forms a metal sheet by forcing the metal onto a rotating mandrel using a roller tool. A novel metal spinning machine was designed in which the roller is directly driven by linear motors. We aim to form non-axisymmetric products by controlling the pushing force of the roller so that the roller can quickly track the changing radius of the mandrel. Our experimental results show that the linear motors substantially improve response of the force control and non-axisymmetric products can be rapidly formed. Open-loop force control without a force sensor was also studied. It exhibited a comparable performance to closed-loop control with regard to the forming time.