An optimizing tool orientation method for positional 5-axis machining

Positional 5-axis machining is widely applied in high speed machining the surfaces of automobile panel dies. Its key factor is to set up an appropriate tool orientation. The relationship between tool orientation and tool-axial inclination was analyzed, and the optimization method based on planar fitting was proposed. It consists of three steps: Firstly, the machining surfaces are scattered to points and fitted a plane, and the tool-axis is tilted a angle α that is recommended as the initial tool-axial inclination, in the plane which is defined by the feed direction and the normal direction of the fitted plane; Secondly, the heel angle of each point on machining surfaces are calculated, and the numeral scales of machining points whose inclinations are in a certain range to all are also counted; Finally, it is drawn that if the tool-axial orientation is optimal based on the counted result, otherwise, it is needed to re select a new or to re-divide the machining areas until a satisfactory result is gotten. In addition, a software tool was developed to optimize tool orientation for positional 5-axis machining, and an application case was introduced to prove the validity of the method.