Tool tip trajectories investigation and its influences in micromilling operation

In the micromilling operation, due to the special geometric features of the micromill, its tip trajectories at high speed rotation are obviously different from the common sense. In this work, a new method is proposed to measure the tool radial error motion and to calculate the tool tip vibration caused by the unbalances. After acquiring these data, a tool tip trajectories model is developed for a two-flute micromill. The model calculates the trajectories of the tool tip center and each flute exactly. Based on the model, the cutting force, chip thickness, and slot width (machining error) can be predicted. Meanwhile, the influences of the flute angle and the feed angle, which are very important input parameters to the model, are analyzed in detail. The analysis shows that one flute cutting condition often occurs in the micromilling. Through the experimental case studies, their results show the good agreement with the model´s work.