Influence of Process Parameters on Dimensional Accuracy of Fused Deposition Modeling Built Parts

Additive manufacturing is the process of making objects from 3D CAD model data by joining materials layer by layer. Fused Deposition Modeling (FDM) also known as 3D printing is an additive manufacturing technology used for prototyping, modeling and manufacturing applications. Various process parameters such as layer thickness, extrusion speed, extrusion temperature, part orientation angle, etc., effect the dimensional accuracy of the FDM built parts. In the present work the effect of layer thickness, extrusion speed and extrusion temperature were studied. The factors layer thickness, extrusion speed and extrusion temperature were selected at 2 levels each and thus a full factorial design with 8 experiments and without replications was used. Percentage error in their responses i.e., height, internal hole diameter and outer diameter of the part were determined and ranking was given according to least error in dimension. It was found that different best values or ranking was found according to different responses. Therefore two Multiple Criteria Decision Making methods i.e., Weighted Average Method and Analytic Hierarchy Process were used to find the best values of parameters. From these two methods it was found that experiment 2 with lower layer thickness i.e., 0.1mm, lower extrusion speed i.e., 40mm/s and higher extrusion temperature i.e., 230℃ are preferable. The least preferred is experiment 7 with high layer thickness 0.2, high extrusion speed 60mm/s and lower extrusion temperature 220℃ with regard to effect on dimensional accuracy.