As files are hand tools, the cutting parameters, such as cutting force and tool wear, are not clear. To clarify the cutting performance of files, we developed a file performance tester based on a shaper with a link mechanism, and determined the specific cutting force, a basic cutting parameter, with reference to the multi-edge cutting process of broaching. The results showed that as the number of cutting strokes increased, the work piece removal length and cutting force decreased, with increases in specific cutting force. The flank wear length increased with increasing the number of cutting strokes, confirming that the cutting performance decreased with wear of the file cutting edge, increasing the specific cutting force.

In this study, the differences in machining characteristics of sapphire between polished and unpolished polycrystalline diamond (PCD) tools with different diamond abrasive protrusion heights were examined. An unpolished PCD tool with a cut depth of 0.2 μm and feed rate of 2 mm/min was utilized to achieve a high-quality machined surface with arithmetic mean roughness of 3.2 nmRa. Machining by brittle fracture was dominant with the polished PCD tool, and the arithmetic mean roughness of the surface after machining was 242.4 nmSa. The presence of adhesive materials that adhered strongly to the tool surface was confirmed after long-distance machining. These adhesive materials on the tool surface were eliminated using an alkaline electrolysis reconditioning method. Furthermore, reconditioning by microdrop peening using saturated water vapor also successfully removed the adhesive materials on the tool surface, and a higher quality machined surface was obtained after compared to that before treatment.

Vibration acceleration during 5-axis machining was acquired using a wireless vibration measurement holder, and the workpiece surface condition after machining and the cause of vibration were examined. In the polishing system using a cooperative robot, we studied the improvement of the polishing process using various types of data, including polishing force and position from internal information and wireless vibration measurement information. Using these data, we propose a new improvement method that links in-process data from the front-end process to machining improvement in the back-end process.