Abstract: Sometimes because of part structure or size in milling,when the workpiece need to inclined to clamp,the contour cannot parallel with the X axis and Y axis,which make the tool-setting difficult.The method to realize the semi-automatic tool-setting in milling this kind of parts by using photoelectric edge detector was introduced and combining with user macro program of CNC system,then using G68 to facilitate automatic processing.

Key words: rectangular-type workpiece, inclined, semi-automatic tool-setting, macro program