Investigation of Chip Thickness and Force Modelling of Trochoidal Milling

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel approach to modelling the chip thickness of the process for low to medium range cutting speeds. It has been found that the tool path cannot be described as a purely circular path, instead requiring the model of a true trochoid, which is presented in this work. Utilizing efficient, numerical method, the instantaneous chip thickness is solved for and validated experimentally with cutting force measurement, using a semi-mechanistic force model, where the experimental cutting forces find good agreement with the simulated results.