Development of a toolholder with high dynamic stiffness for mitigating chatter and improving efficiency in face milling

The toolholder featuring large ratio of length to diameter and variable corss-sections is required to achieve some special machining tasks in face milling operation, whereas the chatter phenomenon can easily occur attributing to the weak dynamic characteristic of the toolholder. This paper developed a novel toolholder which possessed high dynamic performance and was able to mitigate the chatter and improve material removing rate (MRR) simultaneously. The relationship between dynamic property of cutter with its modal characteristics was theoretically investigated from the built dynamic model of face milling operation. Based on the above findings, a novel toolholder was designed to increase the dynamic stiffness of the cutter, whose geometrical parameters and corresponding materials were optimized and selected. After manufacturing and detecting, the stability and machining conditions of the new toolholder were validated and amended with the aid of transfer function, milling forces and acceleration signal responses obtained from the tool point dynamics test and milling experiments respectively. As demonstrated in the experimental results, comparing with the conventional toolholder, the dynamic stiffness of the developed toolholder was increased by about 3.75 times, expanding significantly the stability frontier. The corresponding MRR with 2.81 times was achieved without increasing the machining response amplitudes.