Enhancing Dimensional Accuracy of Circular End Milling on CNC Machines Using Integrated Experimental Design Methods

The present work examines methods for enhancing dimensional accuracy and circularity in CNC circular end milling processes. While conventional optimization often focuses solely on mechanical cutting parameters, this research integrates the Taguchi method, Response Surface Methodology (RSM), and Analysis of Variance (ANOVA) to explicitly quantify the impact of thermal equilibrium alongside cutting mechanics. The results reveal a novel finding: warm-up time is the dominant factor, contributing 41.01% to dimensional accuracy and 49.97% to circularity variation, significantly outweighing spindle speed and feed rate. The optimized parameter combination—comprising a specific warm-up protocol, depth of cut, and feed per tooth—improved dimensional accuracy by approximately 38% and circularity by 33%. This study provides a critical operational guideline for precision manufacturing: implementing a thermal stability protocol is a prerequisite for realizing the benefits of mechanical parameter optimization.