Design of Motion Accuracy Measurement Device for NC Machine Tools with Three Displacement Sensors

To measure motion accuracy, including that of the rotary axis of five-axis machining center that have been widely introduced into production sites recently, a device with three displacement sensors combined to measure the center position of the master ball was invented and will be added to the International Standard. Such measurement devices are not difficult to produce in principle, but the commercially available products are expensive. This study discusses a threedimensional (3D) coordinate measurement device with multiple displacement sensors, discussing it in terms of the test standards of the machines to which the device has been applied and in relation to devices which have been studied, developed, and released. Our measurement device is then designed and produced, and its measurement accuracy is confirmed.