Surface improvement of fused deposition modeling parts by barrel finishing

Fused Deposition Modeling (FDM) processes have limitation in term of accuracy and surface finishing. Hence post processing operations are needed. The aim of this work is to study the integration between this technology and barrel finishing (BF) operation in order to improve part surface quality. A theoretical and experimental investigations have been carried out. A geometrical model of the profile under the action of machining is proposed. The model takes into account FDM formulation and allows to predict the surface morphology achievable by BF. The MR needed in the model is obtained by a particular profilometer methodology, based on the alignment of Abbot Firestone curves. The experimental performed on a suitable geometry validated geometrical model. Profilometer and dimensional measurements have been used to assess the output of the coupled technologies in terms of surface roughness and accuracy. The coupling of FDM and BF has been assessed and characterized in terms of obtained part surfaces and dimension evolution. Deposition angle strongly affects the BF removal speed and alter nominal dimensions of part. The geometric profile model gave interesting information about profile morphology and machining mechanism; moreover the height prevision allows to estimate BF working time in order to accomplish part requirements. The prediction of the geometric profile as a function of FDM fabrication parameters is a powerful tool which permits to investigate surface properties such as mechanical coupling or tribological aspect. The coupling of BF and FDM has been assessed and now optimization of this process can be performed just evaluating effects of parameters. This research has been focused to an industrial application and results can be used in a Computer Aided Manufacturing. The prevision of surface obtainable by this integration is a tool to choice the part optimum orientation in order to accomplish the drawing requirements. Both the experimental findings and the model can guide operator towards a proper process improvement thus reducing or eliminating expensive trial and error phase in the post processing operation of FDM prototypes. In this paper a novel model has been presented. It allow to know in advance profile morphology achievable by a specific surface of a FDM part after a determined BF working time. A particular application of FA curves gives the MR values.