A methodology to choose the best building direction for Fused Deposition Modeling end-use parts

Building end-use functional parts with additive manufacturing technologies (AM) is a challenging task. Several factors influence the surface finish, dimensional accuracy, mechanical properties and cost. In many AM processes building direction and slice thickness take most of the attention. When using Fused Deposition Modeling (FDM) to build such parts, additional important factors must be considered Mechanical behavior and cost of a part are directly influenced by the pattern that the extruded filaments follow to fill the space among contours in each layer. This study pretends to find the best building direction to build and end-use part with FDM to improve mechanical behavior, dimensional accuracy and surface roughness combined with the lowest cost of a given part. Some knowledge about the influence of FDM building parameters on surface finish, dimensional accuracy and cost has been reported. However, less knowledge is reported about mechanical behavior of final parts under functional requirements loading. A methodology is proposed describing how to rank all the possible combinations of building parameters for each property (surface roughness, mechanical behavior and cost). Any user can use the methodology with an FDM machine in order to find the most suitable orientation to build a part for a given use or specifications. The algorithm can be also used in other AM technologies because the building orientation is a common important parameter. Finite element analysis (FEM) is proposed to calculate the stresses generated by the loads and restrictions acting on the part. A characterization of the FDM materials is needed to feed the commercial FEM software materials database. FDM material must be considered anisotropic since its mechanical properties are different along each axis.