Vibration Characteristics While Machining Various Materials Using a Four-Axis Milling Machine

In this study, the authors developed a four-axis milling machine and determined the vibration characteristics of the machine while cutting various materials. The four axes of the milling machine consist of three translation axes—X, Y, and Z—and one rotation axis, A. The amplitude of the vibration was calculated by solving the Lagrange II equations of the machine model. The dimensional parameters, the moments of inertia, and the stiffness of the model were determined from the three-dimensional (3D) model of the milling machine by using analysis tools and computer-aided engineering (CAE) simulations in the Siemens NX and Siemens Simcenter 3D software programs. The experiment of cutting various materials, such as aluminum 6061 and CuZn40Pb1 brass alloy, was conducted to measure their cutting forces. Based on these forces, the translation displacement of the tool tip was calculated for various directions (i.e. X, Y, and Z). The calculation results show that the maximum total translation displacement values of the tool tip in the Oyz plane when cutting the aluminum 6061 and CuZn40Pb1 brass alloy materials were about 26 μm and 45 μm, respectively. The maximum total translation displacement of the tool tip depends mainly on the toughness of the milling machine, the toughness of the cutting tool, and the cutting conditions. The calculated results are useful for proposing suitable cutting conditions to achieve high-accuracy and high-productivity machining and for increasing the lifetime of these tools.