Process planning and contour-based error compensation for precision grinding of miniature scalpels

Miniature scalpels are mainly used in microsurgeries such as ophthalmic and cardiovascular surgeries. The size of a miniature scalpel is only a few millimeters, and the precision of the blade shape is high, which makes production of miniature scalpels extremely difficult. This study proposes a new sharpening process for grinding miniature scalpels on a four-axis machine tool. A post-processing algorithm for a four-axis grinding machine based on a kinematics model is established. We then propose a corresponding parameter calibration method for the parameters used in the kinematics model. Because of possible errors in the parameter calibration, a contour-based error compensation method is proposed for accurate adjustments to the edge shape following grinding. This can solve the problem of large deviations between the actual edge shape after grinding and the ideal edge shape. The effectiveness of the proposed process planning and error compensation method is verified experimentally, and the grinding process parameters of the miniature scalpel are optimized to improve its surface processing quality. The sharpness of the optimized miniature scalpel is less than 0.75 N, and the blade shape is symmetrical, which meets the technical requirements of miniature scalpels.