Shaping

Introduction

Shaper

 A shaper is a type of machine tool that uses linear relative motion between the workpiece and single point cutting tool to machine a linear toolpath. Its cut is analogous to that of a lathe,except that it is [archetypally] linear instead of helical.

A metalworking shaper is somewhat analogous to a metalworking planer, with the cutter riding a ram that moves relative to a stationary workpiece, rather than the workpiece moving beneath the cutter. The ram is typically actuated by a mechanical crank inside the column, though hydraulically actuated shapers are increasingly used. Adding axes of motion to a shaper can yield helical toolpaths, as also done in helical planing.

Working Principle of Shaper

A metalworking shaper is somewhat analogous to a metalworking planer, with the cutter riding a ram that moves relative to a stationary workpiece, rather than the workpiece moving beneath the cutter. The ram is typically actuated by a mechanical crank inside the column, though hydraulically actuated shapers are increasingly used. Adding axes of motion to a shaper can yield helical toolpaths, as also done in helical planing.

Types of shapers

Shapers are classified according to various aspects.

1) Based on type of mechanism employed for the movement of the cutting tool i.e. tool carrying ram the shapers are classified in to three types
a. Crank type 
b. Gear type
c. Hydraulic type

2) According to position and movement of ram the shapers are classified in to three types
a. Horizontal type
b. Vertical type 
c. Travelling head type

3) Shapers are classified in to two types based on design of the work table
a. Standard shaper
b. Universal shaper

4) Based on type of cutting stroke employed these are classified in to 
a. Push type 
b. Draw type

Crank type shaper

In these shapers the reciprocating ram is driven by crank mechanism. In this a single point cutting tool is employed to do the operation. A crank is connected to the ram and the bull gear to which the power is given through an individual motor. These are most common type of shapers being used. The reciprocating length of tool will be always is equal to the length of stroke.

Gear type shaper

These are the rarely used shapers. In these shapers a rack and pinion are employed the rack is attached to the lower part of the ram and on which the pinion moves. The power is transmitted from the bull gear. A grain train is engaged for the transfer of power from the bull gear to pinion.

Hydraulic type shaper

Hydraulic Shaper

Hydraulic Mechanism

These shapers run on hydraulic power. The end of the ram is connected to a piston fitted in to a cylinder. Oil is fed in to the cylinder initially the oil acts in one direction and the ram moves in one direction. A varying pressure is applied on the oil so as to obtain the reciprocating motion of the ram. One of the main advantage of this shaper is a constant speed can be obtained from the starting of the machining operation. There will be no fluctuations in the cutting speed and stroke of the ram. Another important advantage of this shaper is no sound will be produced hence a noise free environment can be obtained.

Horizontal shaper

Horizontal Shaper

Horizontal Shaper

As the name indicates these shapers have the motion of ram along the horizontal axis. This type of shapers is generally used for generation of fine and flat surfaces.

Vertical shaper

Vertical Shaper or Slotting Machine

Vertical Mechanism

In these shapers the tool containing ram has its motion in vertical direction. In some of the shapers a provision of 100 rotation of the ram is also provided. In vertical shaper the ram may be driven by various types like crank driven, screw driven, gear driven, or by hydraulic power. Vertical shaping machines finds many applications in deep hole boring, machining internal surfaces, keyways, grooves etc. vertical shaper has a very robust table which can have cross, longitudinal, and rotational movement. The tool used on a vertical shaper is totally different from that of the normal tool which is employed on a horizontal shaper.

Travelling head type shaper

Travelling Head Caption

This type of shaper is generally employed for machining very large objects that cannot be mounted on the table of the machine and cannot be moved. In this machine the ram having reciprocating movement also provides crosswise movement simultaneously such that the tool can cut the required shape on the work piece.

Standard shaper 

Standard Shaper

In these shaper the table has only two movements i.e. vertical and horizontal. The table may or may not be supported on the other end. These are not generally used

Universal shaper

Universal Shaper

In these shapers in addition to the above mentioned two movements of the standard shaper it provides two more directions. 
1) By swelling the table about a axis ram ways.
2) The table can be tilted about an axis perpendicular to the 1 st one
So due to these two features any operation at any angle can be performed very easily. So due to these features the shaper is termed as a universal shaper

Push type shaper

Push Type Shaper

It is one of the most commonly used shaper. In this the metal is removed when the ram is moving away from the column. This type of shaper pushes the work piece while removing the work piece away from it so this shaper is called as push type shaper.

Draw type shaper

Draw Type Shaper

It is just a converse of the push type shaper. In these machines the metal is removed from the work piece when the ram is moving towards the column. So due to this the work piece takes a force in the direction towards the column of the work piece. Due to this action the forces over the column and bearings are somewhat reduced. The tool is required to be mounted in opposite direction to the normal conditions. The vibrations on machine components are also damped to some extent.

Operation

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. Table motion may be controlled manually, but is usually advanced by an automatic feed mechanism acting 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 along the stroke axis. This tool-slide holds the clapper box and tool post, from which the tool can be positioned to cut a straight, flat surface on the top of the workpiece. The tool slide permits feeding the tool downwards to deepen a cut. This adjustability, coupled with the use of specialized cutters and toolholders, enable the operator to cut internal and external gear tooth.