Optimization of CNC Turning Parameters for Surface Roughness Using the Taguchi Method

Abstract

The quality of a machined surface matters to how a part performs and howlong it lasts, and in turning, the cutting of a rotating workpiece on a lathe, the smoothness of the finished surface depends on the cutting parameters chosen, the speed, the feed, and the depth of cut, yet trying every combination to find the best is wasteful; the Taguchi method finds good settings with far fewer experiments. This study optimizes the turning parameters for surface roughness using the Taguchi method, identifying which parameter most affects the finish and what settings give the smoothest surface. Turning experiments were planned by a Taguchi design that varies the cutting speed, the feed rate, and the depth of cut together over a small, carefully chosen set of runs rather than every combination, the surface roughness was measured for each run, and the influence of each parameter was analysed. The feed rate was found to be by far the most influential parameter: the surface roughness rose steeply as the feed increased, because a coarser feed leaves deeper marks on the surface,whereas the cutting speed had a smaller effect, a higher speed giving asomewhat smoother surface, and the depth of cut had the least effect. Thesmoothest surface was therefore obtained at a low feed rate with a highcutting speed, and the Taguchi analysis identified these best settings from only a fraction of the experiments that testing all combinations would haverequired. The study shows that the Taguchi method efficiently identifies thecutting parameters that govern surface roughness and the settings thatminimise it, and it discusses how the method guides the choice of parameters in machining. KEYWORDS: CNC turning, Surface roughness, Taguchi method, Cuttingparameters, Feed rate, Design of experiments, Machining optimization,Process optimization, Manufacturing