NC procedure for lathe - contour machining bar end and reducing rotary speed as tool nears bar centre numerical control

摘要

An N.C machine tool lathe system has a contour path (7) machined on the end of a bar section (1) by a rotating face cutter (3). The cutter moves across the surface of the bar as the bar is moved through an angle. The part programme is initially specified in terms of geometric coordinates and a constant cutting speed. When a contour path passes through the centre of the bar, this can imply a rotary speed about the 'C' axis that exceeds the max. permissable in attempting to maintain a constant cutting speed. The cutting speed is accordingly reduced by a defined amount. ADVANTAGE - Avoids exceeding permissable workpiece rotational speed.