Nonlinear influence of effective lead angle in turning process stability

An analytical method for stability prediction incorporating the nonlinear influence of the effective lead angle in turning is proposed and validated. It is shown that as the effective lead angle changes, due to depth of cut variations on a nose radiused cutting insert, different structural modes are excited, resulting in different stability results. Experiments have been performed on a two degree-of-freedom system representative of the turning of long, slender bars. It is shown that chatter may be present at low depths of cut, typically less than the nose radius of the insert. The proposed model is also capable of predicting the chatter present at larger depths of cut that is typically reported in literature.