Abstract
Static and dynamic characteristics of NC machine tool's feed driving system are very important because they determine servo characteristics and machining performance of machine tools. The conventional methods for measuring these characteristics require many measuring apparatus and are time consuming. Here, a simple method is introduced for measuring static and dynamic characteristics of NC feed driving system. In this method, the static characteristic is found from the relation between amount of lost-motion and armature current of servo motor. For dynamic characteristics, the slider is accelerated and stopped suddenly and the generated inertia force is used to vibrate the slider on the condition that position loop is switched off and only velocity loop is switched on. Dynamic characteristic is found from the transfer function between armature current of servo motor and vibration acceleration of driven part during the vibration. The results by this method agree well with the results by conventional methods.
