Abstract: For the purpose of multi-axis flank machining of impellers, a new method for 5-axis flank machining sculptured surfaces with a drum-taper type cutter based on the signed Dupin indicatrix is presented. As to the cutter with the strictly convex cutting surface, the necessary and sufficient condition for gouge-free 5-axis surface flank machining is proposed, which is that the signed Dupin indicatrix of the cutter is contained in the indicatrix of the part surface at the cutting contact point. Moreover, the implementation of gouging detection and correc-tion using the drum-taper type cutter is detailed in the context. For a given scallop height, the paper also provides an approach to calculate the machining strip width. Hereby, the tool path generation procedure with the iso-scallop method is discussed for 5-axis flank milling sculptured surfaces. The test result shows that the machining efficiency of flank milling using drum-taper type cutter is improved by 37.44% comparing with ball end milling at the same scallop height. It suggests that flank machining is an effective means for improving machining effi-ciency and quality.

Key words: Drum-taper type cutter, Flank machining, Scallop height, Signed Dupin indicatrix