SHAPER MACHINESHAPER MACHINE

Introduction of shaper machine

The metal working shaper was developed in the year 1836 by James Nasmyth.

The shaper is a reciprocating type of machine tool used for producing flat surfaces

Sometimes irregular or curved shape also produce by shaper.

It is widely used in machine shop It is easy to setup and operate.

Image of shaper machine

Working principle

The job is held in the suitable device (vice) clamped rigidly on the machine table.

The cutting tool is held in the tool post mounted on the ram of the shaper.

The ram move in reciprocate motion so it cut the material from work piece during the cutting stroke.

The job is given a feed motion perpendicular to the direction of tool movement.

Generally cutting action take place in the forward stroke, which is also known as cutting stroke.

No cutting material take place during the return stroke of the arm its called the idle stroke.

At the end of one cycle consisting of one to and fro motion of cutting tool.

Principle parts of shaper

Base :

it consist of a heavy cast iron structure, which supports all the other parts of the machine.

Column:

it act as a housing of eclectic circuits and operating mechanism of shaper.

Table:it is box type construction with T-slots cut on it to hold vice and the job rigidly.

Ram:it is reciprocating part of shaper, semi circular in shape.

It gets it drive from quick return mechanism, which is inside the column

Tool head:The tool head of shaper is used for holding the tool rigidly.It is also provides vertical and angular feed movement of the tool and allow tool to lift automatically to provide relief during idle stroke.

Classification of shaper

1. According to the length of the stroke 30 cm shaper 45 cm shaper 60 cm shaper

2. According to the movement of the ram. Horizontal type Vertical type

3. According to the type of design of the table Standard shaper Universal shaper

4. According to the type of the drive Geared type Crank type

6. According to the type of the cutting stroke Push type shaper Draw type shaper

1. Horizontal shaper: it is very popular type of shaper. In this shaper ram is holding the tool head

reciprocate in the horizontal axis.

2. Vertical shaper: The ram holding the tool reciprocates in a

vertical axis.

In some of the vertical mechanism provision is made to allow the adjustment of the ram to an angle of about 10 degree from the vertical position.

Vertical shaper may be crank drive or hydraulic drive.

It is for key way, groove or slots.

3. Crank shaper This is the most common type of shaper in

which crank and slotted mechanism is used to give the reciprocating motion to the ram.

4. Geared shaper The reciprocating motion of the ram is given

by means of a rack and pinion.

This type of shaper in not very widely used

5. Push type shaper This is the most general type of shaper. Metal is removed in the forward stroke.

6. Draw type shaper In this type shaper the metal will remove in

the backward stroke

7. STANDARD OF PLAIN SHAPER: A shaper is termed as standard or plain when

the table has only two movements, vertical and horizontal, to give the feed.

Shaper size and specification

Length of stroke 610mm Maximum vertical travel

of table 475mm Maximum horizontal

Travel of table 450mm Power of the motor 3 HP

Approximate net weight 1750 kg Floor space required 1981 x 1067

(mm)

Quick return mechanism

In the standard type shaper metal is remove by the forward stroke and return stroke goes idle.

During this operation period reduce the machining time it is necessary to reduce the time taken by the return stroke.

It required the forward stroke move slowly and backward stroke move fats to reduce machining time

This mechanism is known as quick return mechanism

1. Crank and slotted link mechanism

2. Hydraulic mechanism

Crank and slotted link mechanism

Slotted link mechanism

A - Clamping nutB - RamC - Link DD - Crankpin A E - Slotted crank BF - Bull WheelG - Slot

Slotted link mechanism is very common in mechanical shapers. The mechanism is simple and compact.

It converts the rotary motion of the electric motor and gearbox into the reciprocating motion of the ram

The slotted link mechanism gives the higher velocity during the return non cutting stroke than during its forward cutting stroke thereby reducing the time wasted during the return stroke

The bull gear is driven by a pinion which is connected to the motor shaft through a gearbox with four, eight or more speeds available.

The bull wheel has a slot. The crank pin A is secured into this slot; at the same time it can slide in the slotted crank B.

When the bull wheel rotates, the crank pin A also rotates and side by side slides through the slot in the slotted crank B. This makes the slotted crank to oscillate about its one end C.

This oscillating motion of slotted crank (through the link D) makes the ram to reciprocate. The intermediate link D is necessary to accommodate the rise and fall of the crank

The position of the crank pin A in the slot in the bull wheel decides the length of the stroke of the shaper.

The further it is away from the centre of bull wheel, the longer is the stroke.

The cutting stroke of the ram is completed while the slotted link goes from left to right.

Similarly, during return stroke crank pin changes its position from right to left.

Hydraulic Shaper Drive Mechanism

A - Return stroke

B - Shaper ram

C - Cutting Stroke

D - Base

E - 4- Way value

F - PumpG - Motor

A hydraulic shaper has the same major parts as the mechanical one. However, the ram is driven by a hydraulic cylinder.

The speeds of the shaper ram and the feeds of the work table are controlled by hydraulic mechanism.

A lever operates a valve that varies the quantity of oil delivered to the rain cylinder and thereby governs the ram speed.

In these mechanism oil supply under pressure by the pump to the left side of the cylinder where it is used to push the piston and with it ram of the shaper

Flow control valve is used the regulate the oil supply. Oil from the other side of the cylinder is return to the

sump via 4- way valves. When the ram reaches far end of the stroke

the position of the for way valves is changed by the action of pilot valves.

Now oil enter from the right side and return through the left side.

The cutting speed of the ram remain constant throughout most of the stroke.

Advantages and disadvantages:- The control of rate of flow and pressure is

quite easy. The drive has built the protection against

overload Moving parts are less Drive has self lubricating properties Its smooth and jerk free. Power consumption is low

Disadvantages :- Primary cost is high Not suitable for difficult job Oil leakage is major problem Any change in the properties of the oil due to

temp. variation may lead to slight variation in the draive.

Shaper feed mechanism

The feed of the shaper usually obtain by the means of ratchet and pawl

Pawl and ratchet type mechanism is used to move the small distance of machine parts such as shaper table

The pawl is move back and forth with help of eccentricity pushes the ratchet through one or more teeth in each forward stroke while it just slide over the ratchet teeth in the backward stroke

The angular displacement of the ratchet screw is converted into linear movement of the sliding member.

Slotting Machine

Introduction:1. A Slotting machine or slotter may be

consider as a vertical shaper.2. The slotter has the vertical ram and a

hand or power operated rotary table.3. In some slotter m/c the ram inclined at

100 to either side of the vertical position when cutting inclined surface.

4. Slotting machine is use for key way .

Principal parts of slotter

Base: The base is rigidly built and is cast integral with column. The top of the bed and the front face of the vertical column are accurately to provide guide ways for the saddle and ram.

Saddle: The saddle is mounted on the guideways and moved towards the column.

Cross-slide: the cross-slide is mounted on the guideways of the saddle.

Rotary table: The rotary table is a circular table mounted on the top of the cross-slide.Its rotate by hand or by automatic device.

Ram: Ram reciprocates vertically up and down. At its bottoms it carries the cutting tool. A slot is cut on the body of the ram for changing the position of the stroke.

Types of slotting Machines

Puncher slotter Production slotter Tool room slotter Puncher slotter: The puncher is the heavy

duty machine with power full motor. It is designed It is designed large amount of metal from large casting. The length of the stroke is also large.

Production Slotter: This is the common type of slotter used for general production work. The drive of the ram is by means of slotted disc and connecting ram.

Tool Room Slotter: This slotting machine is of precision type is used for very accurate machining. It is lighter machine and is operated at very high speed.

Specification of Slotter

Maximum stroke :457 mm Diameter of rotary table :915 mm Longitudinal movement :762 mm H.P required :7.5 HP

Operation performed on a slotter

Machining flat surface Machining cylindrical surface Machining irregular surface Machining slots, keyways and grooves.

PLANER MACHINE

Planer machine

A planer is a type of metalworking machine Tool That is some what similar to a shaper, but

larger, and with the entire work piece movingbeneath the cutter, instead of the cutter movingabove a stationary work piece. The work table ismoved back and forth on the bed beneath thecutting head either by mechanical means, suchas a rack and pinion gear, or by a hydrauliccylinder.

Planers and shapers were used generally for two types of work:

generating accurate flat surfaces and cutting slots

Principle parts of Planner machine

Double Housing Planer

It is the most common type of planer. It consists of mainly a massive bed on which the

worktablereciprocates, and two vertical columns or housing, one on each side of the bed.

Each column carries a tool head that canbe slide up and down on the column. A cross railfitted between the two columns may carry one ortwo tool heads that can slide horizontally on thecross rail.

All the tool heads can be clamped inposition, and can be used collectively orindividually depending on the requirements

Open Side Planer

Open side planer consists of only one vertical

column or housing on which the cross rail ismounted.

The column and the cross rail carrysingle and double tool heads respectively. Thistype of machine permits machining of widework pieces.

Pit Type Planer

Construction and Working of Pit Type of Planer

A pit type planer differs from other planer in the sense that, the table and the work piece resting on it remain stationary and the tool reciprocates across the work surface. Pit type planer is preferred for very large work, where the weight of the work piece and the tool required table would make reciprocating movement difficult.

The job is either mounted on a stationary table, or on the floor inside a pit, and hence the name pit type planer. Once or two tool heads are mounted on the cross rail and two side tool posts the housings, if required. The entire unit travels along the horizontal ways and fro and, thus the tool moves past the work surface during operation.

Edge Type Planer

This type of machine is used for machining the edges of heavy

work pieces. The work piece is clampedon the bed and the side mountedcarriage supporting the cutting tool isreciprocated along the edge of thework piece.

Deference between Shaper and Planer Machine

Shaper

1. It is comparatively light machine.

2. Less space required.3. It is use for small size

and light work piece.4. Generally single tool is

used.5. Less time is required to

setting the job.

Planer

1. It is comparatively heavy machine.

2. Large space required.3. It is used for large size

and heavy work piece.4. More than one tool can

used simultaneously. 5. More time is required

to setting the job.

6. Shaper consume 15-20 HP.

7.Stroke length is small.

8. Machine cost is less

6. Palner consume 120 HP.

7. Stroke length is small

8. Machine cost is high.