Jakeer Hussain Shaik^1,, J. Srinivas¹

Chatter is a issue of uncertainty in the metal reducing procedure. The trend is characterized by aggressive oscillations, noisy sound and low quality of surface finish. Chatter causes a reduction of the life of the device and affects the efficiency by disrupting the regular functioning of the machining procedure. This paper presents a coupled model of high-speed end-mill spindle system by considering the dynamics of angular contact ball bearings and cutting forces. Initially, the spindle device is examined by considering the gyroscopic and centrifugal terms using Timoshenko beam theory. Hertz bearing contact forces considered at front and rear side ends of the spindle. Frequency response functions at the tool-tip are obtained from the dynamic spindle model. In the second phase, solid model of the system is developed and its dynamic response is obtained from three dimensional finite element analysis. After, verification of the outcomes with beam theory concept, the stability lobes are plotted from the tool-tip frequency response (FRF). Later parametric analysis are conducted for different tool-overhang measures, bearing span values and helix angle of the cutting tool conditions to effectively plot the stability lobes for the spindle system.

spindle dynamics, stability, bearing contact forces, timoshenko beam element, solid modeling, parametric analysis