A REVIEW OF NUMERICALLY CONTROLLED METHODS FOR FINISH-SCULPTURED-SURFACE MACHINING

This paper presents a mathematical review of methods and algorithms us ed to compute milling cutter placement for multi-axis finished-surface machining. In general, these methods and algorithms compute tool path points based on tangent-plane contact between the milling cutter and the surface while maintaining a fixed tool orientation. This tangent-p lane method of tool positioning and orientation is examined by discuss ing its strengths and weaknesses. Errors resulting from the tangent-pl ane approach are typically determined using a posteriori cutter path c hecking and graphic visualization techniques. Although these checking techniques have proved useful in identifying the tool path errors befo re actual machining, the problem of generating an error-free tool path remains. In this paper, we discuss the analysis of tool path position and orientation data as they are generated. This a priori analysis me thod is used to show error locations along the lateral face of the too l. The conclusion is reached that additional research is needed in the area of simultaneous multi-axis tool path planning, if errors are to be eliminated and the efficiency of the milling machine is to be impro ved. The reader is referred to research efforts that extend beyond the traditional or computer-aided design (CAD, vendor supplied) tool path planning methods. Some of these efforts show great promise in elimina ting gouging and improves machine tool efficiency.