A dynamic model of a micro-stepped mill with time-dependent boundary conditions

Abstract

The trend toward higher-precision manufacturing technology requires more micro-machining, such as micro-milling. The dynamic characteristics of the micro-milling process must be studied to improve quality, produce a higher production rate, and avoid micro-mill breakage. A dynamic model of a micro-stepped mill with time-dependent cutting-boundary conditions was studied to understand the dynamic characteristic of a micro-mill in the milling process. This work presents the dynamic model and numerical analyses on vibration in micro-milling. An experiment’s result is used to validate the accuracy of the above model. A stepped pre-twisted beam was used to simulate the micro-end mill. The time-dependent boundary and cutting force were used to approximate the milling process. Consequently, a time-dependent vibration model in a micro-milling process is presented. The effects of the rotation speed, cutting depth and boundary stiffness on the dynamic characteristics were considered. Both numerical and experimental analyses indicate that the vibration amplitude was reduced as the micro-mill moved into a work piece.