Abstract: In this paper‚by the motion analysis of four-axis wire-Electric Discharge Machining （WEDM） machine tools‚it is concluded that‚during the machining of intricate ruled surfaces only with linear boundary curves‚the maximum inclining angle of the wire and the maximum displacements of the machining table and the wire guiding head occur on the vertices of the boundary lines．Based on the conclusion‚an algorithm to calculate the maximum angle and displacement is proposed and then applied to the NC verification of WEDM to avoid the motion collision and profile interference．A verification example shows that the proposed method can effectively ensure the machining accuracy．

Key words: wire-EDM, NC verification, maximum inclining angle, maximum displacement, motion collision