Optimization of Polygonal Shaft Machining Parameters for Surface Roughness, Dimensional Error, and Cycle Time Using Response Surface Methodology

Abstract

In the power transmission process, the shaft is a crucial component. In its development, the cross-sectional features of the shaft are created by referring to specific geometric shapes, such as polygonal profiles, which require precision machining processes. This study examines the impact of machining parameters on surface roughness, dimensional accuracy, and machining time during the manufacture of polygonal shaft models using AISI 304 and AISI 1020 materials. An experimental design, analysis, and optimization were employed using response surface methodology (RSM). Input parameter variables include cutting depth and cutting speed, while response parameter variables include surface roughness, dimensional error and cycle time. Additionally, analysis of variance is used to determine the significance of input variables on response variables. The experiment began with a machining simulation using Esprit CAM software, followed by the machining process on a CNC Turn-mill machine. The workpiece was inspected using a surface roughness tester and a Coordinate Measuring Machine (CMM). The shortest machining time with the best machining quality per polygonal shaft standard was selected. Analysis of variance revealed that the input variables had a significant impact on surface roughness and cycle time, with a p-value of less than 0.0001; however, they did not significantly affect dimensional error. The most influential parameter on the response of both materials was the depth of cut. AISI 304 material yields the best surface roughness value of 0.3637µm at a cutting speed of 48 SPM and a depth of cut of 0.6 mm, while 1020 material yields 0.4045 µm at a cutting speed and depth of cut of 48 SPM and 0.6 mm. In contrast, 3.96 minutes and 5 minutes are the ideal machining times found for each material.