A new method for determining the instantaneous uncut chip thickness in micro-milling

The calculation accuracy of instantaneous uncut chip thickness (IUCT) plays a very important role in the modeling of milling processes. Tool runout is an obstacle to the accurate calculation of IUCT in micro-milling. This paper focuses on the calculation of IUCT and proposes a new method for determining the IUCT in micro-milling. Firstly, the effects of tool runout and single-edge cutting on nominal uncut chip thickness were analyzed. Then, the calculation methods of nominal uncut chip thickness and actual uncut chip thickness in micro-milling were proposed respectively, which took into account the impact of tool runout, single-edge cutting, intermittent chip formation, and the minimum chip thickness. The pseudo-single-edge cutting which may occur in single-edge cutting was discussed. Finally, nominal uncut chip thickness and actual uncut chip thickness in micro-milling were analyzed respectively. The calculated results showed higher accuracy compared to conventional method.