Recently, the role of skilled operators in manufacturing systems is recognized again and the utilization of the mentality and flexibility of human operators to them is focused on with fresh interest. In order to apply the manual operation to a manufacturing system effectively, it is important to investigate the skill learning characteristics of the operators and derive a reasonable skill training method for them. The virtual reality techniques appear to be very useful to carry out this investigation, though the actual manufacturing system is not necessarily suitable for it. In the present paper, the objective manual operation is small-diameter deep-hole machining of an aluminum workpiece with a bench-mounted drilling machine, which is known as a difficult operation requiring operator's sensitivity highly. Firstly, a simple simulator of the drilling machine or a virtual machine has been developed taking into consideration the dynamic characteristics of a real machine. Secondly, its effectiveness to the skill training has been studied through experimental operations by inexperienced testees. A new index for assessing operating performance was also discussed. As the results, it is found that the developed simulator is significantly effective in skill training for the actual drilling machine operation and the operating efficiency continues to improve during early 15 time operations with the simulator.
