A professional who sets up and operates vertical milling machine with spindle mounted within larger rotary head so that rotating cutter can move anywhere within given circle to mill complex shapes, such as arcs and tangents, without changing position of workpiece or machine table.

• Computes dimensions of shapes to be milled and successive positions of cutter in relation to rotary head, using knowledge of shop mathematics.
• Moves controls to position and move cutter in computed directions to mill specified shapes.