Metal-cutting machine tool in which the workpiece is usually held in a vise or similar device that is clamped to a table and can be manually operated or power-driven at right angles to the path of a chisel-like cutting tool with only one cutting edge. A moving table feeds the workpiece in small, individual steps at the end of each stroke of the tool. The adjustable mounting of the tool permits the cutting of grooves and generating of surfaces at almost any angle to one another. The largest shapers have a 36-in. (0.9-m) cutting stroke and can machine parts up to 36 in. (0.9 m) long. Seealso planer.
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A shaper operates by moving a hardened cutting tool backwards and forwards across the workpiece. On the return stroke of the ram the tool is lifted clear of the workpiece, reducing the cutting action to one direction only.
The workpiece mounts on a rigid, box shaped table in front of the machine. The height of the table can be adjusted to suit this workpiece, and the table can traverse sideways underneath the reciprocating tool which is mounted on the ram, the table motion is usually under the control of an automatic feed mechanism which acts on the feedscrew. The ram slides back and forth above the work, at the front end of the ram is a vertical tool-slide that may be adjusted to either side of the vertical plane. This tool-slide holds the clapper box and toolpost from where the tool can be positioned to cut the straight, flat surface on the top of the workpiece. The tool-slide permits feeding the tool downwards to put on a cut it or may be set away from the vertical plane, as required.
The ram is adjustable for stroke and, due to the geometry of the linkage, it moves faster on the return (non-cutting) stroke than on the forward, cutting stroke. This action is via a slotted link or whitworth link.
Cutting fluid may be employed to improve the finish and prolong the tool's life.