Dimensional accuracy and tolerances in additive manufacturing
Important quality indicators for products made by Additive Manufacturing (AM) methods include dimensional accuracy, tolerances, and surface roughness. This paper describes a novel benchmark part designed and manufactured by a Low Force Stereolithography (LFS) 3D printer and controlled on a coordinate measuring machine. The benchmark part contains basic geometric shapes used to check the deviation from the nominal dimensions and given features from the 3D CAD model. We have developed an automatic measurement strategy based on a 3D object model and a control plan based on previously defined allowable tolerances. We have measured the deviation from nominal dimensions, positions, and form, including cylindricity, flatness and parallelism. The results revealed large deviations in dimensions and acceptable deviations in the shape of a manufactured benchmark part.