Diagnosis of two-axis cylindrical grinder machining error

Abstract

This paper attempts to develop a machining error diagnosis method for classifying the error sources on the external/internal contour surfaces which are fabricated using a two-axis cylindrical grinding machine. A derivation of the contour profile to grinding wheel motion trajectory and also the grinding wheel motion trajectory to the contour profile equations has been performed. Due to the contours having a sinusoidal polynomial polar curve instead of a rose curve, the grinding wheel motion trajectory equation is then used to generate the NC code for the machining. The grinding wheel motion trajectory equation is needed for the synthesis of the profile error caused by the motion error as well as the variation of the grinding wheel diameter. The two-axis motion equation is obtained by transforming the non-circular contour equation through the coordinates of the grinding wheel and workpiece. The influence of different machining parameters such as grinding wheel outer diameter error, grinding wheel feed rate, and workpiece rotation speed on the external/internal contour profile is being studied and analyzed. The diagnosis method is based on the least square method to assemble the components of the profile error due to each individual error sources. The actual machining with probe system is used to verify the diagnosis result.