Toolpath design in spinning is an open ended problem, with a large number of solutions, and remains an art acquired by practice. To be able to specify a toolpath without the need for experimental trials, further understanding of the process mechanics Is required. At the moment, the mechanics of the process Is not completely understood, due to the complex deformation and because long solution times required for accurate numerical modelling of the process Inhibit detailed study. This paper proposes and applies a new approach to modelling the process and aims to contribute to the understanding of process mechanics, In particular with respect to the mechanisms of failure and and to apply this understanding for toolpath design In spinning. A new approach to numerical modelling Is proposed and applied to Investigate the process. The findings suggest that there are two different causes and two different modes of wrinkling In spinning, depending on the stage In the process and direction of roller movement. A simple test Is performed to estimate the limits of wrinkling and provide a guideline for toolpath design In a typical spinning process. The results show that the required toolpath geometry in the early stages of the process is different from that In later stages. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA. Weinheim.