Abstract
Several methods for evaluating the motion accuracy of the rotary axes of five-axis controlled machining centers have been proposed up to now. Since it is known that particular motion errors exist around motion direction changing points, it is important to evaluate the behavior of the rotary axes around these points. In this study, the characteristic of axial displacement around the motion direction changing point of the rotary axis in a five-axis controlled machining center and the influence of this characteristic onto the machined surface are investigated. The dynamic behavior around the motion direction changing point of the rotary axis was measured by the eddy current type displacement sensor. And the axial displacement of the rotary axis was investigated from the measured results. A machining test to evaluate the influence of the axial displacement of the rotary axis on machining surface is also proposed. It is confirmed from the results that the axial displacement of the rotary axis exists caused by the rotational direction change and it has an influence to the machining surface. In addition, it is confirmed that the influence of the axial displacement of the rotary axis can be compensated by translational displacement of linear axis.
