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Ultra-precision machining of sinusoidal surfaces using the cylindrical coordinate method

Micro- and ultra-precision machining is an effective approach to achieving a nanometric surface finish, which is important for the sinusoidal surface as the calibrator of multi-axis precision machines. A cylindrical coordinate micromachining method is studied for the ultra-precision cutting of sinusoidal surfaces in this paper. The three-axis (X, Z, C) turning machine is used, whose NC path is generated in a spiral curve considering the workpiece surface and tool geometry. The avoiding interference technique is proposed, including the optimal selection of tool geometry and simulation of the cutting process. The tool geometry is optimized by using a sectional curve method. The cutting simulation is implemented using a constrained B-spline path fitting and a pipe model of the cutting face. With the method developed, sinusoidal surfaces with a nanometric finish of 5.54 nm in Ra are achieved effectively.