Shaping is the machining operation used to generate flat surfaces. It is carried out by shaper. In shaping operation, workpiece is kept stationary whereas the cutting tool is given a reciprocating motion. The cutting action occurs during forward stroke only while the return stroke is made idle to ignore damage to tool and workpiece. To decrease machining time, the return stroke has higher velocity than forward stroke. This is obtained by Whitworth Quick Return motion mechanism. In shaping operation, velocity is maximum at the middle of the return stroke and is minimum at the beginning of forward stroke. Figure illustrated principle of shaping operation.
Figure: Shaping Operation
Planing is similar to shaping operation. Only difference being that the tool is stationary and workpiece is reciprocating to obtain the cutting. It is used for generating flat surfaces on workpiece that are too large.