A shaper (or shaping machine) is a reciprocating type of machine. It is used for removing unwanted material and producing flat surface on a given workpiece. In a shaper, a single point cutting tool undergoes linear reciprocating motion over a stationary workpiece. A driving mechanism is used to achieve reciprocating motion.
The three commonly used driving mechanisms are:
- Crank and slotted lever mechanism
- Whitworth quick return mechanism
- Hydraulic drive mechanism
Working of a shaper:
A typical shaping machine consists of five basic components. They are base, column, ram, tool head and table.
Base and column are primarily used for supporting other components of the shaper. Ram is mounted on the top of the column. Tool head is mounted on the front of the ram. The tool head is used for holding the cutting tool. Workpiece is mounted on the table.
When the machine is switched on, the ram (along with the tool head) reciprocates. It undergoes two strokes:
- Cutting Stroke
- Return Stroke
Unwanted metal is removed from the workpiece during cutting stroke. During return stroke (or idle stroke), no metal is removed. For one pass of the ram, there exists one cutting stroke and one return stroke. Inorder to reduce the time taken for one pass of the ram, the time taken for return stroke should be decreased i.e., the return stroke should be much faster than the cutting stroke. To achieve this, a quick return mechanism is used. Usage of quick return mechanism drastically reduces the time taken for shaping operation.
A Shaper machining a Flat Surface
Types of shaper:
Shapers can classified into many types based on several criteria:
- Based on the type of driving mechanism used:
- Crank and slotted lever driving mechanism type
- Whitworth quick return driving mechanism type
- Hydraulic driving mechanism type
- Based on the table design:
- Plain Shaper
- Universal Shaper
- Based on the position of the reciprocating ram used:
- Horizontal shaping machine (Most common type of shaper used)
- Vertical shaping machine
- Travelling head shaping machine
- Based on the type of cutting stroke of the tool:
- Push out type
- Draw cut type