Cutting force and surface roughness depend on the tool path used in side milling: an experimental investigation

This paper proposes a method, based on the driven and self-propelled rotary tool cutting processes, using tool path strategies on side milling with a solid end mill to change the process kinematics. The main objective of this work is to evaluate the path’s influence on the cutting forces and surface roughness, and simultaneously the impact of milling parameters (cutting speed—vc, feed—f, and path period—T). A randomized experiment and a Taguchi Method were applied, and as a result of the experiments, the sinusoidal and triangular paths imply lower net forces (45–70%) and can improve surface quality with similar cutting times to the linear path method, as demonstrated by simulations. Mainly, the triangular and sinusoidal paths could increase the effective feed in the perpendicular direction of the programed feed; however, the maximum material thickness removed remains constant. Thus, this increase in feed causes a specific cutting force reduction, and consequently, forces become smaller than those on the linear path. It is possible to improve the surface roughness in comparison to the linear path, a 20–30% reduction, using the alternative paths (sinusoidal and triangular). Minimal cutting forces and surface roughness can be achieved with triangular path (also easier to program), path period T = 60 mm, cutting speed vc = 120 m/min, and feed f = 0.1 mm/rev.