Single edge cutting phenomenon and instantaneous uncut chip thickness model of micro-ball-end milling

Different from the conventional scale milling, micro-milling is significantly affected by the scale effect. The microball- end milling instantaneous uncut chip thickness cannot be accurately calculated using the instantaneous uncut chip thickness model of conventional scale ball-end milling directly, which influences the accuracy of cutting force prediction. In this paper, firstly, the single edge cutting phenomenon in the condition of steady-state cutting is discussed and modeled after analyzing the cutting edge model of micro-ball-end milling tool. Secondly, considering the influence of spindle runout, minimum cutting thickness, discontinuous chip forming and other factors in micro-ball-end milling process, the nominal uncut chip thickness model which treats single edge cutting and multiple edges cutting respectively is proposed. After further analysis of the possible pseudo single edge cutting phenomenon in the single edge cutting, the actual instantaneous uncut chip thickness model is proposed. Finally, an example of horizontal symmetrical slot milling is introduced to verify the proposed models.