Chatters of a workpiece arising in lathes

In this paper the authors researched primary and regenerative chatters, especially their transient behavior. To this end, the authors measured the following quantities by use of a computer-aided measuring system : the horizontal and vertical deflections of a workpiece ; the horizontal and vertical cutting forces ; the depth of cut. Further, the behavior of a generated chip was observed by use of a high-speed camera. Then, the authors found out the relation between a workpiece deflection and cutting forces and compared cutting forces through initial chip generation. These investigations showed the following transient properties of chatter. A small disturbance which is able to occur under any cutting conditions causes a built-up of chatter under a certain cutting condition. The roundness of the cutting edge, a rake angle of tool and the depth of cut have a significant effect on primary chatter. As a result of this investigation, physical causes of the primary chatter and properties of the dynamic cutting force are revealed.