Design of a milling cutter with large length–diameter ratio based on embedded passive damper

Abstract

A milling cutter with large length–diameter ratio has been essential in machining structural parts with deep cavity and deep hole features. However, chatter vibration is apt to occur with the increase of tool overhang. A damped milling cutter is developed by employing a single-degree-of-freedom passive damper located inside the arbor. The stiffness and damping design of the embedded damper are carried out by following the equal peaks criterion. A novel design is fulfilled to avoid the disequilibrium of the cutter during high-speed rotation, and an accurate experimental tuning of the design parameters is required to achieve the optimum vibration suppression due to a low mass ratio of 2.5%. Modal analysis demonstrates that the damped cutter with an approximate length–diameter ratio of 8 can reach 75% magnitude reduction at all orientations, which is benefical to resist milling force excitation varying with the rotation angle. Chatter stability simulation demonstrates that the damped cutter is able to increase the stability limits based on the evaluation of undamped and Sandvik cutters. Three configurations of machining tests are carried out and the design of the damped cutter is validated by the machining audio signals and machined surface roughness in the end.