Abstract: The existing method of five-axis flank milling to machine undevelopable ruled surface is
researched, through the analysis of the geometric characteristics of the undevelopable ruled surface, a
new method is proposed to calculate the cutter location data of five-axis flank milling with
undevelopable ruled surface impeller. The global error optimization between the tool envelope surface
and the design surfaces is the goal, and a method to calculate the cylindrical cutter location when flank
milling the undevelopable ruled surface is established, putting forward a four-point method to
determine the initial cutter location, optimizing it using the least squares method, establishing cutter
correction model to further optimize the cutter location to reduce the over-cut error. By analyzing the
example, it is proved that processing error can be reduced to some extent through this method.

Key words: undevelopable ruled surface, 5-axis flank milling, offset method of four points, cutter
location calculation