Effectiveness and feasibility of Spindle Speed Variation in turning

Spindle Speed Variation is a well-known technique to suppress regenerative machine tool vibrations especially for low spindle speeds. Despite a lot of research effort was done over the years the technique is not widespread in real turning applications. In this paper the reasons that can limit the diffusion of the Spindle Speed Variation were investigated. Therefore, the analysis of Spindle Speed Strategy was not only focused on its chatter suppression properties but also on some more general technological aspects, including the surface quality of the machined components, the cutting edge-spindle bearings load and the thermal overload the electrical spindle motor is subjected to when the speed modulation is used. A time-domain numerical model of the turning process was developed and used to support the analysis. A lot of cutting tests were also performed both to validate the numerical model and to evaluate the effect of Variable Spindle Speed on surface quality. Moreover some real industrial applications were analyzed focusing on thermal overload of the spindle motor.