Dimensional accuracy analysis of additively manufactured parts

Additive Manufacturing (AM) techniques, that allow for the fabrication of parts and shapes impossible to manufacture with traditional processes while reducing material waste, development time and weight, are becoming more and more exploited by aerospace designer. In order to select the right technology for the part to produce or to foresee any eventual inaccuracy of the final product caused by the specific AM tool, it is advisable to be familiar with the limits of each of the manufacturing device. Despite the fact that most manufacturers provide data on the accuracy of their prototyping machine, in non-laboratory conditions, these values are difficult to achieve. The aim of this research was the analysis of the dimensional and shape accuracy of parts manufactured using Fused Deposition Modeling and PolyJet techniques. The geometries were realized in ABS Plus p430 and VeroWhitePlus (RGD 835) materials, using, respectively, an FDM Fortus 250mc and a PolyJet Objet30 V5 Prime. The models were measured with both a laser and a piezoelectric scanner to compare the actual printed parts with the nominal CAD models and the accuracy specifications given by the manufacturing device provider.