Design and Assessment of Rotating Tool for Incremental Sheet Forming

Incremental sheet forming (ISF) is an emerging manufacturing technique in which sheet metal is formed through application of localized force using a moving tool. ISF has many potential uses for manufacture of small batches and product prototypes in industries such as aerospace and automotive (where pressed sheets components are common). The advantages of the process for small batches are its low cost, good surface finish and small lead times. However despite its flexibility there are limitations such as its low production rate and an incomplete understanding of the process"s mechanics. One gap in ISF process knowledge is the impact of different types of tools on the quality of the final component. As part of an ongoing program to understand this aspect of the process, this paper reports the evaluation of five different conceptual designs of rotating tool and the experimental assessment of the most promising one. The selected concept attempts to decrease friction during the ISF process by incorporating a rolling element bearing to allow rotation between tool and work piece. Prototype tool was used to form Aluminum sheets using a CNC machine and a flexible fixture. The thickness, shape, surface roughness and strain of the formed components were then measured.