WS Technology

8/12/2019 WS Technology

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Workshop technology

What is workshop………..?

Workshop is a place or a room or a building where mechanical works are done.

Why do we need a workshop?

We need a workshop to perform several mechanical tasks like welding,

machining, grinding and wood working etc.

Types of workshops:

There are four types of workshops which are…

Fitting work shop

Wood work shop

Welding shop

Machine work shop

Fitting Workshop Bench Work

In this workshop we do the work on work pieces by holding these pieces In Vice.

Vice:

Vice is a tool that holds a work piece or object firmly. It is an essential part of every workshop

specially fitting workshop.

Followings are the parts of vice…

Body

Square threaded screw

Two jaws

Nut handle



Machine Workshop:

In this workshop we perform many machining operations using different machines like lathe machine,

drill press, power hacksaw, shaper and planer machines etc.

Operations:

In this workshop we perform such as turning, facing, drilling, boring, knurling, etc.

Tools:

Venire caliper, thread gauge, lathe machine, power hacksaw, shaper, planer are the essential

tools for the machine workshop.

Cautions:

In machine shop one should use goggles to avoid him self from chips that could be harm his eyes

and cause serious problem. Dressing should be tight. There should be a first aid box in the workshop.

Wood workshop:

In this workshop we perform operations on wood.

Operations:

These operations contain cutting, joining, shaping, planning and molding operations on

wood.

Tools:

Hacksaw, nails, screw drivers, drill machines, hammers, pliers and vice are the basic

tools which are used in this workshop.



Welding workshop:

In this workshop we perform the operations of welding, cutting, disjoining, etc.

Tools:

Tongs, chipping hammer, file, electrodes, welding shield, hand gloves, welding holder, welding

table and welding machine are the basic tools which are used in welding workshop.

Welding:

It is a process of joining two metal pieces by application of heat or by pacing a material between

two pieces. This special material is called filler. In the result we get a single piece that is strong

decidedly.

Types of welding:

Followings are the types of welding:

Plastic/Pressure welding:

The process of joining materials when those are heated to a plastic state such as

resistance welding.

Fusion/Non-pressure welding:

In this process material is joined by heating till a molten state and is allowed to

solidify for example gas welding and arc welding.

Different types of machines are used in different types of welding such as arc welding machine,

Seam welding machine and spot welding machine.

Precautions:

Black glasses are necessary

Do not touch metal with hand



Wood working

Wood: Wood is a fibrous substance that is found in trees. Now days artificial woods are also present in

market. Wood is a material that is used from thousands years ago in making furniture’s and other usable

of life.

Structure:

Wood is basically a fibrous material. The outer side is called epidermis than cortex and in middle

there is endodermas. Different woods have different qualities. So is why there is a large variety is

available there as regarding to the specific application.

Some type of woods are chip board, balsa ply etc.Selection:

As the properties of wood vary so there is a large variety in the market having specific properties. So

one can easily choose the right type of wood for a specific use such as the chip board is used for

cupboards etc.

Machining Process of Wood:

Similarly as metals are machined to shape them wood is also machined. The tools in machining of

wood are saw, nail, planner, shaper and much type of other tools of such kind.

Types:

Tools can be classified in two ways.

1 Machining tools

2 Hand tools

Machining tools:

In machine tools we use power hacksaw, Shaper, planer, molding machine etc.

Hand tools:

In hand tools we use hammer, nails, screw, measuring tape, ruler, nuts and bolts, claw hammer, file,

sand paper etc.

Saw:

It is used to cut the wood, different types are there for the specific application like power

hacksaw, hand hacksaw etc.

Molding machine:

This machine is used to shape the wood without cutting it. This

process is called molding



Shaper:

A shaper machine is used to make the surface of the wood smooth.

Planer:

This machine is also used to make the surface of the wood smooth.

Hammer:

This is used to insert the nail in the wood.

Nail:

It is a stick like metallic piece that is used to join the wood. They are available in different sizes and

different friction factors and application.

Screw:

It is also metallic piece that is used to join the wood.

Screw driver:

It is used to apply the screw.

Measuring tape:

It is user to measure the size of the wooden piece.

Plier:

It is used in many ways especially in adjusting and removing the nail.

Claw hammer:

This hammer is used to fix as well as remove the nail and screw.

Types of nails:Steel nails: Are used where high strength is needed.

Iron nails: They are commonly used in wood working.

Head less nails: Are used where there is to plane the surface in which

a nail is to be fixed.

Angle:

It is an L like tool that is used to correct a joint at a right angle.

Types of joints:

• Lap joint

• T joint

• Corner joint

• Face joint



Lap joint:

Such type of joint in which some part of the wood is removed and similarly with other part. Then

these two parts are overlapped and then joined together.

Usually this type of joining is done in making long and straight piece of wood.

T joint:

Such type of joint in which joining is such a way that a T shape is

formed after joining two pieces.

Corner Joint:

If the joining of two pieces is at the corner than it is called corner joint.

Face joint:When the joining of two wooden pieces are face to face than it is called face joint.

Every joint has its own uses and are useful in different ways. These types of joints are applied in

considering the application and the use.



Grinding

Definition:

It is process of finishing in which we remove some material by using abrasive material. This

abrasive material can be on a wheel or a belt etc.

Surface Finish:

The degree of smoothness of a surface is called the surface finish.

It is measured in units of RA, RY, RZ.

RA is defined as the average of heights of crusts and troughs.

RY is the largest depth of the trough of the surface.

RZ is the average of the single roughness of the specific part of the surface. It is also called RY5.

Explanation:

For some vary hard materials those we cant machined economically we use a process of

grinding. Usually this process is used to make the surface smooth, to sharpen the tools and to decreasethe tolerance level. The grinding process is a material removing process. In this process the amount of

material removed is very less so the waste of material also decreases.

Grinding Wheel:

It is the tool which is used to grind a material or metal piece.

Composition:

A grinding wheel is consist of too hard tiny particles embaded in a matrix. The hard tiny particles

are called abrasive and the matrix is called bond. The bond kept the abrasive particles firmly that

removes the material due to friction.

Bond is the matrix which when mixed with abrasive hold together enabling the mixture to be shaped to

the form of the wheel. Usually they could be vitrified, silicate, shellac, rubber etc.

Abrasive is the tiny very hard small particles or grains that remove the material from the work piece by

friction. Usually they could be silicon carbide and aluminous oxide.



Selection of a Wheel (By composition):

In selecting the grinding there are two common factors which are size of the abrasive particles

or grit and grade or the bond. These two parameters are varied according to the particular application of

the grinding wheel.

Size of grain:

The size of abrasive varies from 8 to 240 generally and depends upon the size of the screening

mesh.

Hardness of bond:

While the grade that is the hardness of the bond vary from A to Z in which M,N are the medium

hardness of the bond.

Hardness of abrasive:

It should be considered that the hardness of the abrasive should be greater than the hardness

of the material which is to be grind.

Grain density:

It is the term used to define weather the particles are packed closely or not. When the %age ofbond will b increased then the grain density of the grinding wheel will be decreased.

Selection of wheel (By Shapes):

A variety of shapes of grinding wheels are there in market to perform specific type of grinding.

Such as for surface grinding, Exterior grinding, cylindrical grinding etc.

How to check the crack of grinding wheel…….?

To check the crack of grinding wheel we use the ring test method. According to this method

strike the wheel with a small wood piece and observe the sound. If it is the sharp sound then the wheel

is not cracked at that point and where it does not give the sharp sound there may b a crack. This is called

the ring test.



Wheel classification:

The abrasive industries association has adopted a British Standardized Marketing system for

grinding wheels.

According to this system the hardness of the bond vary from A to Z where M and N grades are mediumhard.

Bond type, grain size, grade are written.

According to this classification the sequence is:

1. prefix 2. Abrasive 3. grain size 4. Grade 5.structure 6.bond type 7.suffix

Types :

o Surface Grinding

o Exterior Cylindrical Grinding

o Interior Dia Cylindrical Grinding

o Center less Grinding

o Special Purpose Grinding

Surface Grinding:

It is a type of grinding in which a flat surface is made smooth using usually a grinding wheel.

machine have a horizontal spindle connected with a grinding wheel.



Exterior Cylindrical Grinding:

Such type of grinding in which out side of a round piece or cylindrical piece is made smooth. In

this process there is a relative motion between the work piece and the grinding wheel.

Internal Dia Cylindrical Grinding:

It is a process of making the internal surface of the diameter of a part or work piece, or finish

the boring. This process is specially used for bearings, bushes etc.



Center less grinding:

This type of grinding is performed when a piece has no definite or regular shape. There

is a relative motion between work piece and the grinding wheels. The process involves more than one

grinding wheels.

Special Purpose Grinding:

This type of grinding is that is used for some specific purposes like making the internal surface ofthe threads smooth. In this type the grinding wheels are specially designed.



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