Shaper

It is reciprocating type of machine tool used for producing flat surfaces.Surfaces may be horizontal, vertical or inclined.Modern shapers can produce contoured surfaces.

Types of shapers:

According to:

1. Mechanism used for reciprocating motion to the rama) Crank typeb) Gear typec) Hydraulic type

2. Type of rama) Horizontalb) Verticalc) Travelling head type

3. Design of tablea) Standard shaperb) Universal shaper

4. Cutting strokea) Push typeb) Draw type

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Shaper Operations:

It is a machine tool which uses single-point cutting tool to machine flat surfaces.

Machining horizontal surfaces:

It is mostly used for machining flat surfaces of work-piece held on vise.

Tool & work-piece are held tightly on tool holder and table respectively.

Stroke length is adjusted with overhangs. Proper cutting speed and feed is adjusted. Both rough and finish cut can be adjusted by rotating

downfeed screw. Tool is made to machine total work-piece.

Machining vertical surfaces:

Vertical cut is made at machining end of work-piece, squaring up a block.

Surface of work-piece is properly aligned with vertical axis of ram.

Vertical slide is set exactly at ‘zero’. Apron is swivelled in direction away from work piece. This helps in moving tool upward and away from work-

piece. Downfeed is given by rotating downfeed screw manually.

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Machining of angular surfaces:

Angular cut at any angle other than right angle to horizontal. Vertical slide is swivelled to the required angle. Apron is further swivelled to avoid tool interference during

return stroke. Downfeed screw is used to feeding tool. One universal shaper can be swivelled without swivelling

tool head.

Machining slots and keyholes :

With suitable tool, shaper can cut slot and keys on internal and external parts.

For external keyway, a hole of size larger than keyway is cut at the end of keyway for clearance of the tool (over travelling).

Clapper box is locked in position. Length and position is carefully adjusted. Cutting speed is less. Lubrication is essential.

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Machining irregular surfaces :

Shaper can produce convex or concave surface or combination of both.

Forming tool is used. Power cross-feed in conjunction with manual down-feed is

adjusted to trace the required contour. Round nose tool is used for irregular surface. For shallow cut apron may be set vertical.

Machining splines or cutting gears :

Using index centre, a gear or equally spaced splines can be cut on work-pieces.

Work is mounted between centres and spline is cut similar to a keyway.

After every spline the work is rotated at a predetermined angle using index plate.

While cutting gears forming tool is used.

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