Abstract:This paper presented a method to compute toolpaths for machining the transitional surface, which can gradually change from the boundary of the machined surface to the boundary of the fillet corner. The toolpaths generated by our method can precisely overlap the boundary of the region that has been machined. This method analyzed the toolpaths, which had been used, to find a group of points. These points were employed to represent the machined surface. Then a boundary extraction algorithm was employed to reconstruct a NURBS curve to represent the boundary of the point set. A group of curves were generated between the boundary of machined surface and the boundary of the fillet corner. Then those curves were applied to reconstruct the blade root transitional surface. And the surface was employed to generate relevant toolpaths. This method was applied to machining the blade root transitional surface of a blisk. The machining result indicated that the blade root transitional surface smoothly connected the upper region of the blade and the corresponding fillet corner after machining.