Dimensional and Surface Roughness Analysis of 3D Printed Impeller Pattern for Investment Casting

Impellers are critical components in industrial applications, requiring smooth surfaces and precise di-mensions. Traditional investment casting methods are often time-consuming and costly. Fused Deposition Modeling (FDM), an additive manufacturing (AM) technology, offers a faster, more cost-effective alter-native. FDM produces 3D-printed sacrificial patterns directly from a CAD file, making it ideal for low-volume and complex patterns. Unlike wax patterns, which can shrink or distort, 3D-printed patterns offer precise tolerances and allow for thin-walled geometries. FDM also eliminates the need for tooling, reducing capital investment. However, achieving the desired surface finish and accuracy remains a challenge. In this study, a semi-open impeller for a centrifugal pump was printed using FDM with Acrylonitrile Butadiene Styrene (ABS) material. The Taguchi Design of Experiment (DoE) method was used to evaluate the impact of printing parameters layer thickness, extrusion temperature, and infill density on dimensional accuracy and surface roughness. Dimensional accuracy was assessed for features like inner and outer diameters, blade thickness, and height. Surface quality was evaluated across geometries like thin sections, curvatures, and surfaces (parallel to the XY/XZ, and YZ planes). Descriptive statistical analysis was performed to provide a comprehensive overview of the results, aiding further decision-making in the research.