Chatter suppression analysis for variable pitch cutter in milling

Milling cutter with variable pitches can effectively suppress chatter. In order to quickly and accurately calculate stability boundaries in the milling process with variable pitches, a novel method is constructed to calculate the stability boundary of delay differential equations (DDEs) involving inconsistent delay terms. Firstly, the stability analysis is derived separately involving the variable pitch cutter (VPC) for low and high radial immersions. Two dynamic models are different depending on how many teeth participate in cutting simultaneously. Secondly, the stability boundary is constructed based on the supposed method for the two typical cases, which has nearly 10 times increase in computational efficiency. The validity of stability boundary is verified by the time-domain simulation, in which various chatter types are also explained in detail. Finally, a milling experiment was conducted to demonstrate the effectiveness of the proposed method by machined surface morphology. This study provides a theoretical framework for the rapid and high-precision stability analysis of dynamic models with variable pitches.