Optimal Detuning of a Parallel Turning System—Theory and Experiments

Parallel turning is an excellent candidate for keeping up with current trends set by manufacturing industry, namely, to increase accuracy and productivity simultaneously. In the field of manufacturing of cylindrical parts, these cutting processes offer huge potential in increasing productivity, since they ensure high material removal rates and appropriate accuracy at the same time. The above benefits can yet only be harvested if the process is free of chatter vibration, which affects the workpiece surface quality. In this study, it is shown that by means of tuning the dynamical properties of cutting tools, it is possible to expand the stable machining parameter regions in order to eliminate adverse chatter. A parallel turning system is investigated, where tuning of the system is realized by varying the overhang of one of the tools, that is, by modulating the frequency ratio of the cutters. Measurements have been carried out for the validation of the theoretical predictions of robustly stable chip width limits, below which the turning operation is stable for all spindle speed values.