Developing a tapping and drilling measurement system for a performance test using a laser diode, position-sensing detector, and laser interferometer

Tapping and drilling are frequently used in mechanical working. Previous research on tapping and drilling has mainly focused on cutting force variations, drill and tap wearing, and drill and tap design: machine tool performance has seldom been dealt with. A novel performance test system of tapping and drilling for a computer numerical control (CNC) machine tool is established in the current paper. This system includes a two-dimensional position sensing detector, a laser source, and a laser interferometer. The laser source was fixed on the spindle of the machine tool by the cutter, and the position sensing detector was mounted on the machine tool table. The reflecting mirror of the interferometer was fixed on the z axis of the machine tool, and the laser source of the laser interferometer was mounted on the machine tool table. Therefore, the spindle errors and the z axis position of the machine tool could be recorded by the position-sensing detector and laser interferometer respectively. Consequently the spindle error and z axis motion of the machine tool in the tapping/drilling test could be measured simultaneously. The accuracy of this system in the x-, y-, and z-directions was about 1 mu m in each case. The present paper describes the experiments of the position-sensing detector calibration, stability test, tapping test, and drilling test. The findings are discussed below.