Surface quality related to machining parameters in 3D-printed PETG components

Fused Deposition Modeling (FDM) finds extensive application across various fields due to its cost-effectiveness and user-friendly nature. However, it does come with certain limitations, including challenges in achieving high surface quality, precise dimensional tolerance, and the characteristic anisotropic mechanical properties it exhibits. The aim of this paper is to investigate the machinability of 3D-printed PETG and analyze the roughness and burr formation that occurs as a result. A Design of Experiments (DoE) was developed with three factors: rotational speed, feed rate, and depth of cut. Each factor had different levels: rotational speed at 3000, 5500, and 8000 rpm; feed rate at 400, 600, and 800 mm/min; and depth of cut at 0.2, 0.4, 0.6, and 0.8 mm. The machinability was evaluated based on two response parameters: roughness (Sa), determined on the milled surface, and burr height, measured using a profilometer on both sides of the milled surface. The findings indicate that milling parameters strongly affect roughness and burr formation. However, the optimal conditions for minimizing roughness and burr formation are not coincident. The results were also compared to the machinability of PLA machined under similar conditions.