Abstract
The measurement of cutting force is important to monitor the status of the process during micro drilling. It is used the cutting dynamometer, the shape of the workpiece is restricted and must be set to the center. These problems can be resolved by adoption of the spindle with built-in sensor. The purpose of this study is the development of the sensor built-in spindle for micro drilling that the thrust and the torque can be measured simultaneously. The structure of the spindle uses a static pressure bearing and a capacitance sensor to realize high accuracy measurement. As a result of study, this spindle was able to measure very weak thrust and torque to occur by micro drilling of 0.05mm in diameter. These results of research can be constructed the advanced processing system which prevents the breakage of the drill by monitoring the cutting force.
