Evaluation of Dimensonal Precision in FDM 3D-Printed Parts via Computed Tomography

Abstract

This study investigates the dimensional and geometric tolerances of a 3D printed timing belt pulley for a Dacia Logan engine. Using FDM technology, six pulleys were printed—three with different materials and three with varying nozzle sizes (0.2 mm, 0.4 mm, 0.6 mm). Computed tomography (CT) was used for precise, non-destructive measurements. The printed parts were compared to the CAD model and the original metal component to assess deviations in accuracy and tolerances. The study focuses on how material properties influence shrinkage and warping, and how nozzle diameter affects surface quality and detail. Smaller nozzles offer higher precision but longer print times, while larger ones reduce time at the cost of accuracy. The goal is to evaluate the feasibility of FDM for producing functional automotive components and to identify optimal trade-offs between material choice and nozzle size for precision and efficiency.