Design and analysis of a desktop multi-axis hybrid milling-filament extrusion CNC machine tool for non-metallic materials

Abstract Additive Manufacturing has unlocked the ability to introduce new concepts for parts of very high complexity to the industrial landscape, which could not be manufactured with traditional manufacturing processes in a single or in a small number of steps. However, surface quality of 3D printed parts and process repeatability are low to medium, at least in an industrial context. This study proposes a new design of a fully automated multi-axis hybrid Additive and Subtractive Computerized Numerical Control machine tool for non-metallic parts, which can overcome the drawbacks of both Additive and Subtractive Numerical Manufacturing. It combines the operation a 5-axis CNC machining center with a 5-axis extrusion 3D printer with automated tool head change, which is able to make parts made of polymer and special 3D printing materials (eg. carbon fiber reinforced filaments) of high complexity which require minimal post-processing to produce the final product in the shortest possible time. The design process also includes static, dynamic and harmonic response analysis with the Finite Elements Method, so as to improve design features of the machine tool structure. Results are presented and commented on in terms of machine efficiency to cope with applied loads during operation.