Process Force and Stability Prediction of End Mills with Unequal Helix Angles

The stability of cutting processes in end rnilling can be increased by an optimization of the tool geornetry. In this paper the influence of unequal Helix angles is investigated. Unequal helix angles lead to varying tooth pitches. Thus, the cutting condition of each tooth is different. A mechani stic model is presented 10 determine incremental process forces along the tool axis. Based on the proposed model, stability charts for 100ls with unequal heli x angles are computed and cornpared with experimental in vestigations from literature. The presented res ults show that tools with an optimized geometry can increase the stability significantly .