report

PREFACE

My industrial training report represents the outcomes of 22 weeks training period that I had

spent at the Industrial Development Board of Ceylon as an Engineering trainee from 01 th of

April 2010 to 17thof August 2010.

Report contains three chapters. Chapter one is dedicated to the Industrial Development Board

current status strengths and weaknesses.

Chapter two describes the training experience that I have gathered. My Training experience

focuses on machinery, manufacturing processes and projects that I have taken part in.

And the final chapter is the “conclusion”. This consists of summary of my overall training

and comments on training establishment and my suggestions to improve the training given by

Industrial Development Board.

At the end of the report 10 annexes are attached and they contain the project reports and

drawings done by my self

i

Piyanka W.P.G.T (070367R)

Department of Mechanical Engineering

Faculty of Engineering

University of Moratuwa

ACKNOWLEGEMENT

I think I must grateful to the training division specially Mr.Gunawardhana and

Mr.Wijewikrama for tackle my training place problem, Department of Mechanical

Engineering and NITA for taking initiative to deliver us such a successful training period.

Also I thanks to the Industrial Development Board of Ceylon for taking me as an in plant

trainee.

I also want to express my heartiest gratitude to the Engineering Department of IDB Chief

Engineer Mr.Rathnamala, training coordinator Mr.Razool, Workshop Engineer Mr.Premasiri

and Technical Assistant Mr.Dissanayake, and all the machine operators and workers those

who spent their precious time for us.

I also wish to express my sincere gratitude to Mr.Ariyadasa Jayawardhana the Personal

Director for his kindly support and offering a payment for us to complete training at

Industrial Development Board successfully.

A word of big thanks must also go to my fellow colleague who trained with me at Industrial

Development Board for sharing his knowledge and time with my self.

Thank again you all for your generous support toward to myself.

More than all, it is the effort of my family, who made me what I am today. The blessing that

they gave me helped more than in one way to overcome the challenges that I faced during my

entire life. So a very special tribute must also go to my family, since I owe them for

everything they had done.

ii

Piyanka W.P.G.T (070367R)

Department of Mechanical Engineering

Faculty of Engineering

University of Moratuwa

Table of ContentsPREFACE................................................................................................................................................. i

ACKNOWLEGEMENT.............................................................................................................................. ii

List of Figure..........................................................................................................................................v

CHAPTER 1: INTRODUCTION TO TRAINING ESTABLISHMENT................................................................1

1.0.1. Mission of the IDB.........................................................................................................1

1.0.2. Structure of the Industrial Development Board.............................................................2

1.0.3. Act of Incorporation Set out the Object of the IDB As Follows:....................................3

1.1. FUNCTIONAL DIVISION...................................................................................................3

1.2. RELATIONSHIP BETWEEN SME SEECTOR...................................................................4

1.3. IDB SERVICES.....................................................................................................................5

1.3.1. Planning.........................................................................................................................6

1.3.2. Regional Development...................................................................................................6

1.3.3. Entrepreneurship Development......................................................................................7

1.3.4. Technical Services.........................................................................................................7

1.3.5. Engineering Services.....................................................................................................8

1.3.6. Marketing assistance....................................................................................................10

CHAPTER 2: TRANING EXPERIENCE......................................................................................................11

2.1. MAIN LATHE COMPONENTS AND THEIR IMPORTANCE.............................................11

2.1.1. The Lathe Bed Slide Way..................................................................................................11

Figure 2.01...................................................................................................................................12

2.1.2. The Carriage or Saddle......................................................................................................12

2.1.3. Headstock..........................................................................................................................12

2.1.4. The Cross Slide..................................................................................................................12

2.1.5. The Compound Slide.........................................................................................................13

2.1.6. The Tool Post.....................................................................................................................13

2.1.7. The Tailstock.....................................................................................................................13

2.1.8. Steadies..............................................................................................................................14

2.1.9. Work Holding Methods.....................................................................................................14

2.1.10. Tool Holding Method......................................................................................................15

2.1.11. Production of Chips.........................................................................................................17

2.2. BASIC LATHE MACHINE PROCESSES..............................................................................19

2.2.1. Turning..............................................................................................................................19

iii

2.2.3. Facing................................................................................................................................20

2.2.3. Parting................................................................................................................................20

2.2.4. Drilling..............................................................................................................................21

2.2.5. Boring................................................................................................................................21

2.2.6. Single Point Thread Turning..............................................................................................22

2.2.7. Work Carried Out Using the Lathe Machine.....................................................................22

2.3. BASIC SHAPING MACHINE PROCESSES..........................................................................23

2.3.1. Work Holding....................................................................................................................23

2.3.2. Tools..................................................................................................................................24

2.3.3. Types of Shaping Machine................................................................................................24

2.3.4. Operation of the Shaping Machine.....................................................................................24

2.3.5. Safety on the Shaping Machine..........................................................................................25

2.3.6. Work Carried Out Using Shaping Machines......................................................................26

2.4. BASIC MILLING MACHINE COMPONENTS AND PROCESSES......................................27

2.4.1. Rotating the Head..............................................................................................................28

2.4.2. Squaring the Vise...............................................................................................................28

2.4.3. Types of Milling Cutters....................................................................................................28

2.4.4. Removing and Installing Milling Cutters...........................................................................29

2.4.5. Climb and Conventional Milling.......................................................................................29

2.4.6. Calculating Speed and Feed...............................................................................................30

2.4.7. Setting Spindle Speed........................................................................................................30

2.4.8. Using the Edge Finder.......................................................................................................30

2.4.9. Using the Micrometer Dials...............................................................................................31

2.4.10. Face Milling.....................................................................................................................31

2.4.11. Milling Slots....................................................................................................................31

2.4.12. Advanced Work Holding.................................................................................................32

2.5. GRINDING MACHINES.........................................................................................................32

2.5.1. Bench Grinder....................................................................................................................32

2.5.2. Surface Grinder..................................................................................................................33

2.5.3. Work Carried Out Using Grinding Machine......................................................................33

2.6. OXY-ACETYLENE CUTTING AND ELECTRIC ARC WELDING.....................................33

2.6.1. Oxy-Acetylene Cutting......................................................................................................34

2.6.2. Electric Arc Welding.........................................................................................................35

2.6.3. Work Carried Out At the Welding Section........................................................................37

iv

2.7. ELECTRIC DISCHARGE MACHINE PROCESS..................................................................38

2.7.1. Advantages and Disadvantages..........................................................................................39

2.7.2. Work Carried Out Using the Lathe Machine.....................................................................39

CHAPTER 3: CONCLUSION...................................................................................................................40

3.1 Review of Training Experience.............................................................................................40

3.2 Comments on training establishment.....................................................................................40

3.3 Suggestions............................................................................................................................41

ANNEXES..............................................................................................................................................42

List of Figure

Figure 1.01 : structure of IDB ..................................................................................................02 Figure 2.01 : Lathe machine ……………………………………………………………………………………………….12 Figure 2.02 : 3-Jaw chuck ……………………………………………………………………………………………………14 Figure 2.03 : 4- jaw chuck …………………………………………………………………………………………………..14 Figure 2.04 : Face plate ………………………………………………………………………………………………………15 Figure 2.05 : Lathe machine tool ………………………………………………………………………………………..16 Figure 2.06 : Turning process ……………………………………………………………………………………………..19 Figure 2.07 : Facing process ……………………………………………………………………………………………….20 Figure 2.08 : Parting process ………………………………………………………………………………………………20 Figure 2.09 : Drilling process ………………………………………………………………………………………………21 Figure 2.10 : Boring process ……………………………………………………………………………………………….21 Figure 2.11 : Single thread cutting ………………………………………………………………………………………22 Figure 2.12 : Shaping machine ……………………………………………………………………………………………23 Figure 2.13 : Head position …………………………………………………………………………………………………24 Figure 2.14 : Milling machine ……………………………………………………………………………………………..27 Figure 2.15 : Milling machine and Components ………………………………………………………………….27 Figure 2.16 : Types of milling cutters ………………………………………………………………………………….28 Figure 2.17 : Conventional milling and Climb milling …………………………………………………………..29 Figure 2.18 : Face milling ……………………………………………………………………………………………………31 Figure 2.19 : Face milling ……………………………………………………………………………………………………31 Figure 2.20 : Milling slots ……………………………………………………………………………………………………31 Figure 2.21 : Bench grinder …………………………………………………………………………………………………32 Figure 2.22 : Surface grinder ………………………………………………………………………………………………33 Figure 2.23 : Oxy-Acetylene welding station and components ……………………………………………34 Figure 2.24 : Equipment used in welding ……………………………………………………………………………35 Figure 2.25 : Welding power source ……………………………………………………………………………………36 Figure 2.26 : Electric arc welding station …………………………………………………………………………….37 Figure 2.27 : EDM machine …………………………………………………………………………………………………38 Figure 2.28 : Operation of the EDM machine ……………………………………………………………………..38 Figure 2.29 : Operation of the EDM machine ……………………………………………………………………..38 Figure 2.30 : Elbow crutch ………………………………………………………………………………………………….39

v

INTRODUCTION TO TRAINING ESTABLISHMENT

CHAPTER 1: INTRODUCTION TO TRAINING ESTABLISHMENT

The Industrial Development Board (IDB) of Ceylon, in its present form was incorporated as a

statutory body by industrial development board Act No. 36 of 1969 and was affiliated to the

then ministry of industries and scientific Affairs until 1986. The Head office of IDB was

situated at No.16 Gregory‘s Road, Colombo 07.

From1986 to 1994 it came under the ministry of textile and rural industrial development and

the ministry of tourism and rural development. From 1994 on wards it functioned under the

ministry of industrial development till the present government came into power. Since then it

is affiliated to the ministry of rural industries and self employment promotion.

At the inception the IDB consisted of a few divisions, namely finance, establishment,

economic research and documentation and publication. In addition there were special

functional centers which were located at different places in Colombo.

In 1972 the management development and productivity center split into two and one emerged

as the national institute and business management (NIBM).

The act grants the IDB power under section 33(2) (a) establish, maintain and carry on

industrial estate in Sri Lanka. Accordingly the industrial estate run by the former industrial

estates corporation came under the management of IDB.

In 1973 the different section of the IDB which operated from geographically apart locations

shifted to one center place in Katubedda. The technical service institute which was located in

same premises merged with the IDB.

1.0.1. Mission of the IDB

To Provide and facilitate the demand driven quality services to make Sri Lankan enterprises

globally competitive through an island wide network of dedicated and innovative team to

achieve business excellence.

1

HEAD OF ENGINEERING DEPARTMENT

HEAD OF INTERNAL AUDITHEAD OF PERSONAL DEPARTMENTHEAD OF FINANCE DEPARTMENT HEAD OF CITIS

HEAD OF MARKETING DIVISIONHEAD OF PLANNING DEVISION

HEAD OF REGIONAL DEVELOPMENTHEAD OF TECHNICAL SERVICE DIVISION

HEAD OF IDB WORKSHOP

HEAD OF IDB FOUNDRY

CHAIRMAN

GENERAL MANAGER


1.0.2. Structure of the Industrial Development Board

Figure 1.01

2


1.0.3. Act of Incorporation Set out the Object of the IDB As Follows:

The industrial development act no 36 of 1969 clearly spells out the objectives incorporation.

To assist in the encouragement, promotion and development of industries in Ceylon.

To assist in the proper co-ordination and in the inter-related growth of all

industrial undertaking in the private and public sectors of the economy of the

country.

To foster industrial research with the object of utilizing the natural resources

of Ceylon, improving the technical process and equipment for local industrial

and discovering processes and methods for the better utilization of waste

products.

To foster the export of local industrial products to overseas markets.

To assist such measure in the field of international trade and regional co-

operation as are necessary or conductive to industrial development.

To provide for services and facilities of every description required by or in

connection with any industrial undertaking or industrial establishment in

Ceylon.

To advice on matters relating to the promotion and development of industries

in Ceylon.

To take all such measure as may be necessary for, or conductive to, the

attainment of the object specified hereto. (industrial development act No: 36 of

1969, P5)

1.1. FUNCTIONAL DIVISION

In order to carry out its services the organizational set up comprises the following divisions.

Administration

Finance

Planning

Rubber product development and services

Engineering Services

Regional development

Industrial Estate

Marketing

3


Centre for entrepreneurship development and consultancy services

Centre for industrial technology information (including library) services

Centre for rubber products development and consultancy services

Centre for leather products and footwear development

1.2. RELATIONSHIP BETWEEN SME SEECTOR

Small and medium enterprise sectors the small and the medium enterprise (SME) sector in

any country is the key driver of the nation’s economy growth. In terms of generation of

employment, reducing poverty level and reducing urban rural disparities, this sector plays

very vital role.

There is a growing need to focus on the development of regional economy and giving priority

to cluster development as a strategy by moving away piece meal approaches to SME

development.

IDB during its past years of service to the nation has contributed enormously towards the

development of SME’s. The development of the SME sector is a high priority in the agenda

of government too. On its part IDB stands ready to fully support the initiatives and broader

objectives of the industrial policy of the government over the long term.

The promotion of SEM sector forms an integral part of employment generation, poverty

alleviation and the regional development Programs implemented by the government.

Now the war is over, the focus is on development. Post conflict Sri Lanka has embarked on a

massive development drive that embraces all part of the island including the north and the

east where the people are very enterprising. Such an approach will lead to lasting peace,

harmony and prosperity in our motherland.

SME sector has great potential to generate socio-economic benefits to the country with a low

level of a investment. SME’s have the capacity and to mobilize and divert financial recourses

and to promote balanced regional development.

Now that peace has dawned there is greater impetus on development which can continue

unhindered. The industry faced many bitter challenged due to terrorism and thanks to the

resilient nature of SMEs we are now in a position to envision a better and brighter future.

4


IDB Industrial Estate in Atchchuveli and Vavuniya which was abandoned during the past

three decades are now being restructured. Difficult time ignite the opportunity to redesign,

reshape and revive business. Tamil Diaspora now has an opportunity to participate in the

rebuilding of the north and east. It is imperative that we move fast in the new era of peace.

The significance of the role that entrepreneurs play in achieving the industrial development

targets and economy prosperity of the country is indispensable. IDB acknowledges the role

played by the entrepreneurs in the social fabric of the country and their services to the

country. It is through the success of SMEs that the targeted economic growth of the country

could be achieved.

1.3. IDB SERVICES

The keeping with the above objects it was incumbent upon the IDB to design suitable service

packages to promote industrialization especially in the small and medium (SMI) sector. The

concept of industrialization was new during the initial phase and knowledge was micro small

and medium entrepreneur advise during the insipient stage the service packages since

inception had some common feature but somewhat varied from time to time depending on the

needs and prevailing industrial environment.

Services provided at present

These services include

Industrial information

Marketing services and assistance

Investment analysis and feasibility studies

Technical assistance and laboratory service

Engineering assistance

Workshop and foundry facilities

Management training and consultancy

Factory space and comment services

Entrepreneurship development

Infrastructure for establishment of industries

5


1.3.1. Planning

The planning division is vested with the overall responsibility for monitoring the progress of

the activities carried out by the Functional divisions

It offers the following services to assist the industrial community.

Preparation upgrading of model projects reports

Preparation, implementation, monitoring and revision of the co-operate plan

Preparation of the project proposals for foreign funding

Preparation of statistical abstracts

Conduction special studies and surveys

1.3.2. Regional Development

The regional development division is responsible for coordinating, monitoring and

supervision of the services rendered by the extension officers through the network of

provincial and district officers.

The division is responsible for the implementation of the programs at regional level in order

to promote balanced regional development. The services offered are

Identification of regional investment opportunities/potential investors.

Establishment of new industrial units.

Assistance to develop existing industries.

Promoting self employment projects.

Preparation of model project report for obtaining credit facilities and

coordination.

Conducting market studies.

Preparation of directory of industries.

1.3.3. Entrepreneurship Development

6


The mandate of the centre for entrepreneurship development and consultancy services

(CEDACS) is to inculcate a new entrepreneurship culture and impart latest managerial skills

in order to encourage the promotion of industries.

With this view in mind CEDACS carry out the following programs

Entrepreneurship development programs

Entrepreneurial awareness building workshop/programs

Business creation programs

Programs to empower women entrepreneurs

Technology transfer programs

Management development programs

1.3.4. Technical Services

Technical services Division (STD) one of the key divisions of the IDB caters to the

technological needs of the industrial community in Sri Lanka. It consists of four units namely

Food, Chemicals, Oils, and Fiber and building materials.

TSD provides technological assistance to entrepreneurs from conception through formulation

to implementation of new industries and expansion, modernization diversification and quality

and productivity improvement.

A teem of specialized technologist provide technological assistance to SMEs through

consultancy and training programs to transfer technology. The TSD is equipped with a

laboratory for products/process development work.

The main activities of the division covers

Technological demonstration

Technology transfer workshop

Development of products and process

Preparation of technology packages

Preparation and upgrading of technological reports

Resuscitating sick industries and providing technical support for troble-

shooting in industries

Coordinating activities of production village development programs

7


Conducting computer hardware servicing programs

1.3.5. Engineering Services

The engineering division consist of the workshop, foundry and the engineering division at the

head office, Electroplating centre Peliyagoda, common services centre at Mathara and

brassware centre at Pamunuwa.

The main functions cover

Consultancy and extension service

Technology transfer training / workshop

Machinery / equipment / process development

Expansion of machinery and equipment resources

Fabrication casting and metal finishing services

Development of prototype machinery

Laboratory testing services for foundry sector

Development of appropriate machinery

Valuation services

Electroplating services

Leather products and footwear development

Considering the vast potential for the development of leather sector in Sri Lanka the centre

provides both technology and training facilities to manufacture quality products with and

export potential. It also provides common services to SMEs engaged in the leather products

and footwear manufacture. The activities of the division covers

Technology transfer and training

Skill development

Common facilities

Sub-contracting facilities

Consultancy and information services

The services offered are footwear design, footwear cutting and clicking, footwear upper

closing, footwear lasting and finishing, upgrading skills.

8


Rubber product development and services centre provide technical services and information

on rubber and rubber products manufacturing industry expert consultancy and advisory

services.

The laboratories of the centre are equipped with a range of physical and mechanical testing

equipment for quality testing of rubber compounds and finished products.

Semi commercial activities

Compounding of dry rubber and rubber latex

Retail sale of chemicals and other processing agents

Hiring of portable machinery to execute pilot projects

Limited facilities for utilization of machinery for special processes

Sub contracting facilities

Information technology

Providing access to information technology has taken on paramount importance especially in

the wake of rural empowerment. IT plays a crucial role in accelerating the economic growth

and harnessing of global opportunities. This will facilitate the SMEs to compete with the rest

of the world on a level playing field.

The centre of industrial technology information services (CITIS) comprises of the library,

industrial information unit.

Industrial infrastructure

One of the main constraints in setting up industries in rural sector has been the difficulties

encountered in finding suitable locations to set up the industries and the need to incur heavy

capital expenditure initially on land and infrastructure facilities. In order to facilitate them

industrial estates have been set up throughout of the country under the industrial estate

division with infrastructure facilities such as internal road ways, telecommunication, water

supply, three-phase electricity – street lightning, storm/ rain water drains.

9


Industrial estate are located in Ekala, Pallekale, Horana, Pannala, Galigamuwa,Wavulugala,

Pussella, Beleatta, Karandeniya, Matale, Negampaha, Vauniya, Buthala, Lunuvila,

Mihinthale and Kotagala.

1.3.6. Marketing assistance

Yet another major constraints faced by the rural and medium scale industrialist is the market

problem. In order to increase and establish the market share of the existing industries of the

SME sector and the potential entrepreneurs the following services are offerd by the marketing

division.

Marketing information

Managing and coordinating sale centers “Laknipayum” in Colombo and “Lakkam

trade center” at he head office katubadda.

Sub-contracting facilities

Organizing and conducting exhibition and trade Eras.

Provision of metal scrap to SMEs and medium light engineering industrialist.

10

TRAINING EXPERIENCE CHAPTER 2

CHAPTER 2: TRANING EXPERIENCE

My first week on Industrial Development Board I was assigned to mechanical workshop to

develop my knowledge on machines and machine processes and also to get hands on

experience of them. Basically mechanical workshop can divide into several sections. They

are lathe and milling, cutting, welding.

On the first day workshop engineer Mr.Premasiri assigned me under supervision of Technical

Assistant Mr.Dissanayake to get a good knowledge about manufacturing processes. Since

first week I spent my time in lathe and milling section to gain knowledge about lathe and

milling processes. Then I focused on Shaping Grinding and Welding operations.

First I started learning about milling machine with the help of machine operator. So there he

told me about basic components if a milling machine first. Then I observe those components

and recognized them very well (like lathe Bed, carriage or saddle, tool post, slide ways,

tailstock, chuck, spindle speed selector, and etc). Machine to machine the some of

components vary their positions and the availability.

Then he taught me the importance of those components. So I listed those components and

their importance as bellow.

2.1. MAIN LATHE COMPONENTS AND THEIR IMPORTANCE

2.1.1. The Lathe Bed Slide Way

It cast with a box-like cross section made of gray cast iron. It has two main functions.

To give the necessary stiffness for resisting the twisting and other stress, which occur in

practice and which if they strained the bed, would destroy the accuracy of lathe.

To ensure that the lathe-cutting tool moves accurately along a path that is parallel to the

machine spindle axis.

Page 11


Figure 2.01

2.1.2. The Carriage or Saddle

This is a flat-shaped casting, planed on its underside to fit the ways of the bed so that it may

slide along.

2.1.3. Headstock

Gear trains enable for driving spindle, feed shaft, lead screw and Gears for changing speeds

are housed in the headstock.

2.1.4. The Cross Slide

This provides,

Support for the compound slide.

Movement of the cutting tool at 90 Degrees to the rotating axis of the work piece.

Motion of the cross slide is obtain by a hand wheel, but on the majority of centre

Page 12


lathes a gear mechanism is fitted to give automatic traverse both towards the spindle

axis and away from it.

2.1.5. The Compound Slide

This is mounted on the cross slide and has two main functions.

To provide location and support for the tool post

To enable the tool to be place at angle to the axis of the spindle

Compound slide movement is obtained by using a hand wheel, no automatic traverse is

provided. The slide can be rotated about its mounting. The circular scale on the base indicates

the angle through which the slide has turned.

2.1.6. The Tool Post

This has two main functions.

Positioning the cutting tool

Securing the cutting in that position

There are two type of tool post,

Single tool post

Four way tool post

2.1.7. The Tailstock

This is the counter part of the headstock, and carries the right hand centre for supporting

work when turning centers. It is also used for supporting and feeding drills, reamers, etc.

when it is necessary to use these for drilling work held in the chuck.

Using the lateral adjustment screw can make sideways adjustment of the barrel. By this, the

centre of the barrel can move off centre with the headstock spindle centre. (Live centre)

Page 13


2.1.8. Steadies

For supporting long, slender work against the pressure of the cut, a steady is used. The fixed

or three jaw steady is clamped to the bed of the lathe and supports the bar, being turned by

means of three jaws set at 120 degrees with each other.

2.1.9. Work Holding Methods

The self - centering chuck (3 – Jaw Chuck)

The independent centering chuck (4 – Jaw Chuck)

Driving plate and centers

Face plate

The self-centering chuck (3 – Jaw Chuck)

This is the most convenient and most used method of work holding.

This can take wide range of diameters. When adjusting jaws move equal

amount light cuts should carry out, because the work may slip in the jaws. In addition, the

work should be firmly round to fix in this chuck.

The independent centering chuck (4 – Jaw Chuck)

Each jaw is individually adjust and moves along its own slot. One advantage of this four-jaw chuck is that work can be located in the centre to run true or off centre. One of the most useful applications of this type is to hold square or rectangular material positioned either centrally or off centre. Setting time is greatly increased when

compared to three-jaw chuck. However, for highly accurate work, this is the most suitable method.

Page 14

Figure 2.02

Figure 2.03


The faceplate

This is used to hold works, which can neither be turned on centers nor held in a chuck. It has

bolt slots for accommodating the necessary clamping bolts.

2.1.10. Tool Holding Method

I have mentioned some components and their importance above as I learned. Then I learned

about machine processes. Thereafter I was learned how to mount a work piece and how to

center it. First I found little bit difficult to mount the work piece correctly and also I learned

how to use surface gauge to center the work piece. Some times work piece is not reasonably

symmetrical.

When it wasn’t symmetrical I had to check the space between surface gauge and the work

piece surface opposite side of the chuck because I couldn’t see continuous equal space

between those two surfaces. I use 3-jaw and 4-jaw chucks to center work piece according to

the irregularities of the surfaces.

Once I mount the work piece I choose a cutting tool to mount on the tool post. When

choosing a cutting tool there are some factors to consider,

Cutting tool geometry varies with the type of work to be done.

Page 15

Figure 2.04


Facing tools are ground to provide clearance with a center.

Roughing tools have a small side relief angle to leave more material to support the

cutting edge during deep cuts.

Finishing tools have a more rounded nose to provide a finer finish. Round nose tools

are for lighter turning. They have no back or side rake to permit cutting in either

direction.

Left hand cutting tools are designed to cut best when traveling from left to right.

Aluminum is cut best by specially shaped cutting tools (not shown) that are used with

the cutting edge slightly above center to reduce chatter.

And also when installing a cutting tool there are some instructions to follow,

Lathe cutting tools are held by tool holders. To install a tool, first clean the holder,

and then tighten the bolts.

The tool post is secured to the compound with a T-bolt. The tool holder is secured to

the tool post using a quick release lever.

And for the positioning,

In order to move the cutting tool, the lathe saddle and cross slide can be moved by hand.

There are also power feeds for these axes. Procedures vary from machine to machine.

A third axis of motion is provided by the compound. The angle of the compound can be

adjusted to allow tapers to be cut at any desired angle. First, loosen the bolts securing the

compound to the saddle. Then rotate the compound to the desired angle referencing the dial

indicator at the base of the compound. Retighten the bolts. Now the tool can be hand fed

Page 16

Figure 2.05


along the desired angle. No power feed is available for the compound. If a fine finish is

required, use both hands to achieve a smoother feed rate.

The cross slide and compound have a micrometer dial to allow accurate positioning, but the

saddle doesn't. To position the saddle accurately, you may use a dial indicator mounted to the

saddle. The dial indicator presses against a stop (often a micrometer as shown in the clip

below).

Feed, speed, and depth of the cut,

Cutting speed is defined as the speed at which the work moves with respect to the tool

(usually measured in feet per minute). Feed rate is defined as the distance the tool travels

during one revolution of the part. Cutting speed and feed determines the surface finish, power

requirements, and material removal rate. The primary factor in choosing feed and speed is the

material to be cut. However, one should also consider material of the tool, rigidity of the

work piece, size and condition of the lathe, and depth of cut. For most Aluminum alloys, on a

roughing cut (.010 to .020 inches depth of cut) run at 600 fpm. On a finishing cut (.002

to .010 depth of cut) run at 1000 fpm. To calculate the proper spindle speed, divide the

desired cutting speed by the circumference of the work. Experiment with feed rates to

achieve the desired finish. In considering depth of cut, it's important to remember that for

each thousandth depth of cut, the work diameter is reduced by two thousandths.

2.1.11. Production of Chips

The production condition of chips in cutting work varies according to the quality of

work material, cutting speed, shape of tool, etc.

Cutting Resistance

In case of cutting work, bigger strength than the work acts. This strength is called

cutting resistance, and the strength, which is equal in size and opposite in direction to this

cutting resistance, acts on the work. This is called cutting force, having effects on the motive

power necessary for cutting, the life of tools, the finished surface and so on.

a) Three Force components

Page 17


i. Main force component

The force acts in the direction of pushing tools down, is biggest, and

consumes the majority of motive power.

ii. Back force component

Is the force pushing back tools from the work, becomes smaller, with bigger

rake angle, and may become minus force.

iii. Feed force component

Is the force to act pushing back tool opposite to feeding direction, and

various according to entering angle of tool.

b) Factors changing cutting resistance

i. Shape of tool tip

Cutting resistance is reduced lineally (up to about 30 Celsius Degree), according

to rake angle becoming larger. However, there is limit in enlarging rake angle, if

the strength of chip of cutting tool is considered.

ii. Cutting speed

In case of high-speed cutting, cutting resistance is reduced with the increase of

cutting speed.

iii. Entering angle of tool tip

Cutting resistance vary according to the entering angle of tool tip. Main force

component are increased, with the decrease of entering angle. Cutting resistance is

increased, with the increase (Cutting Volume) of out Depth x Feed (Cutting Area).

Page 18


iv. Cutting oil

With the use of adequate cutting oils and agents, friction is reduced by the

lubrication of cutting oil and cutting resistance is reduced.

v. Material

Hard material and tenacious material make cutting resistance bigger. The

quality of tool has no effect on cutting resistance almost.

2.2. BASIC LATHE MACHINE PROCESSES

Then I learned about basic machining processes like Turning, Facing, Parting, Drilling, and

Boring, Thread cutting.

2.2.1. Turning

The lathe can be used to

reduce the diameter of a

part to a desired

dimension. First, clamp

the part securely in a

lathe chuck. The part

should not extend more

that three times its diameter. Then install a roughing or finishing tool. If you're feeding the

saddle toward the headstock use a right-hand turning tool. Move the tool off the part by

backing the carriage up with the carriage hand wheel, then use the cross feed to set the

desired depth of cut. In the clip below, a finish cut is made using the power feed for a

smoother finish. Remember that for each thousandth depth of cut, the work diameter is

reduced by two thousandths.

Page 19


2.2.3. Facing

A lathe can be used to create a smooth, flat, face

very accurately perpendicular to the axis of a

cylindrical part. First, clamp the part securely in a

lathe chuck. Then, install a facing tool. Bring the

tool approximately into position, but slightly off

of the part. Always turn the spindle by hand

before turning it on. This ensures that no parts

interfere with the rotation of the spindle. Move

the tool outside the part and adjust the saddle to take the desired depth of cut. Then, feed the

tool across the face with the cross slide. The following clip shows a roughing cut being made;

about 50 thousandths are being removed in one pass. If a finer finish is required, take just a

few thousandths on the final cut and use the power feed. Be careful clearing the ribbon-like

chips; they are very sharp. Do not clear the chips while the spindle is turning. After facing,

there is a very sharp edge on the part. Break the edge with a file.

2.2.3. Parting

A parting tool is deeper and narrower than a

turning tool. It is designed for making narrow

grooves and for cutting off parts. When a parting

tool is installed, ensure that it hangs over the tool

holder enough that the holder will clear the work

piece (but no more than that). Ensure that the

parting tool is perpendicular to the axis of

rotation and that the tip is the same height as the

center of the part. A good way to do this is to

hold the tool against the face of the part. Set the height of the tool; lay it flat against the face

of the part, then lock the tool in place. When the cut is deep, the side of the part can rub

against sides of the groove, so it's especially important to apply cutting fluid. In this clip, a

part is cut off from a piece of stock.

Page 20

Figure 2.07

Figure 2.08


2.2.4. Drilling

A lathe can also be used to drill holes accurately

concentric with the centerline of a cylindrical part. First,

install a drill chuck into the tail stock. Make certain that

the tang on the back of the drill chuck seats properly in the

tail stock. Withdraw the jaws of the chuck and tap the

chuck in place with a soft hammer. Move the saddle

forward to make room for the tailstock. Move the tailstock

into position, and lock it. (Otherwise it will slide backward

as you try to drill). Before starting the machine, turn the spindle by hand. You've just moved

the saddle forward, so it could interfere with the rotation of the lathe chuck. Always use a

center drill to start the hole. You should use cutting fluid with the center drill. It has shallow

flutes (for added stiffness) and doesn't cut as easily as a drill bit. Always drill past the

beginning of the taper to create a funnel to guide the bit in. In this clip, a hole is drilled with a

drill bit. Take at most one or two drill diameters of material before backing off, clearing the

chips, and applying cutting fluid. If the drill bit squeaks, apply solvent more often. The drill

chuck can be removed from the tail stock by drawing back the drill chuck as far as it will

easily go, then about a quarter turn more. A pin will press the chuck out of the collet.

2.2.5. Boring

Boring is an operation in which a hole is enlarged

with a single point cutting tool. A boring bar is used

to support the cutting tool as it extends into the hole.

Because of the extension of the boring bar, the tool

is supported less rigidly and is more likely to

chatter. This can be corrected by using slower

spindle speeds or by grinding a smaller radius on

the nose of the tool.

2.2.6. Single Point Thread Turning

Page 21

Figure 2.09

Figure 2.10


External threads can be cut with a die and internal threads can be cut with a tap. But for some

diameters, no die or tap is available. In these cases, threads can be cut on a lathe. A special

cutting tool should be used, typically with a 60 degree nose angle. To form threads with a

specified number of threads per inch, the spindle is mechanically coupled to the carriage lead

screw. Procedures vary for different machines.

In addition to that I learned little bit of advanced work piece holding techniques,

Some parts require special techniques to hold them properly for lathe work. For instance, if

you wish to cut on the entire outside diameter of a part, then the part cannot be held in a

chuck or collet. If the part has a hole through it, you can press it on to a lathe arbor (a slightly

tapered shaft), and clamp onto the arbor rather than the part itself. The hole must have an

adequate aspect ratio or the part will not be firmly supported. If the part has a very large hole

through it, a lathe arbor may not be a practicable solution. You may instead use the outside of

the jaws to hold the inside diameter of the part. If the part has a very complex geometry, it

may be necessary to install the part onto a face plate. The face plate is then attached to the

spindle.

2.2.7. Work Carried Out Using the Lathe Machine

I was given some parts used in clay mixing machine to finish. I have finished all the parts that

were given to me within few weeks. There I learned to cut a taper angle, learned to cut

threads and carried out a break drum cutting operation too. All the drawings are attached to as

annexes.

In addition to that I involve repairing a lathe machine having a problem with its self action

unit. In the self action unit a inspected all the gear wheels because first I thought it was due to

metal dust stuck within the gear wheels. But it wasn’t the issue. Issue was guide ways of a

gear wheel displaced to wards a side. So they were contact with each other generating friction

between those two. So I had to realign and clean all the iron partials inside of the self action

unit.

Page 22


2.3. BASIC SHAPING MACHINE PROCESSES

The main function of the shaping machine is the production of flat surfaces, which are

obtained by combining a line tool cut with a perpendicular feed. To understand how this

machine generates a plane surfaces, it is easiest to consider the surface parallel to the machine

table. The ram of shaping machine moves the cutting tool backward and forward in straight

line. Each time the tool moves backward the tool lifts clear of the work piece and the work

piece moves across in a path perpendicular to the tool movement. The work remains

stationary during the forward (Cutting) stroke of the tool, and only moves across by one

cross-traverse increment during the return (Non-cutting) stroke. The appearance of the

machined surface is of a succession of closely spaced, straight line cuts. For this reason, it is

often referred to as a ruled surface.

2.3.1. Work Holding

There are several ways of holding the work piece on a shaping machine. The most

usual is to use a swivel vise. In order to produce accurate work, it is essential that the fixed

jaw and the upper surfaces of slides of the vice be accurately aligned with the machine

worktable. After the vise has been positioned for a particular job, it should be checked for

alignment. Large job may be mounted directly on the machine table using clamps or dogs.

Surfaces may be machined perpendicular to each other using the side of the table. The side of

the table is often provided with a ‘V’ for holding cylindrical too.

Page 23

Figure 2.12


2.3.2. Tools

One of the great advantages of the shaping machine for jobbing- shop work is the fact

that it uses cheap, single point tools similar to lathe tools. Further, these tools can be ground

off-hand when it is necessary to change their shape to suit a particular job, or to re-sharpen

them. Some typical shaping machine tools, in which the similarity to lathe tools is evident.

2.3.3. Types of Shaping Machine

Shapers are mainly classified as standard, draw-cut, horizontal, universal, vertical, geared,

crank, hydraulic, contour and traveling head. The horizontal arrangement is the most

common. Vertical shapers are generally fitted with a rotary table to enable curved surfaces to

be machined. The vertical shaper is essentially the same thing as a slotter (slotting machine),

although technically a distinction can be made if one defines a true vertical shaper as a

machine whose slide can be moved from the vertical. A slotter is fixed in the vertical plane.

Very small machines have been successfully made to operate by hand power. As size

increases, the mass of the machine and it’s the power requirements increase, and it becomes

necessary to use a motor or other supply of mechanical power. This motor drives a

mechanical arrangement (using a pinion gear, bull gear, and crank, or a chain over sprockets)

or a hydraulic motor that supplies the necessary movement via hydraulic cylinders.

2.3.4. Operation of the Shaping Machine

Page 24

Figure 2.13


A shaper operates by moving a hardened cutting tool backwards and forwards across the

work piece. On the return stroke of the ram the tool is lifted clear of the work piece, reducing

the cutting action to one direction only.

The work piece mounts on a rigid, box-shaped table in front of the machine. The height of the

table can be adjusted to suit this work piece, 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 automatic feed mechanism acting on the feed screw.

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 work piece. The tool-slide permits feeding the tool

downwards to deepen a cut. This adjustability, coupled with the use of specialized cutters and

tool holders, enable the operator to cut internal and external gear tooth profiles, splines,

dovetails, and keyways.

The ram is adjustable for stroke and, due to the geometry of the linkage, it moves faster on

the return (non-cutting) stroke than on the forward, cutting stroke. This action is via a slotted

link or whit worth link.

2.3.5. Safety on the Shaping Machine

We have already referred to safety in chapter 02. The shaper is not any more

dangerous than other machine, but as some people will get in to trouble in the most innocent

situations if may be worthwhile to issue a few words of advice. Most of the other machine

tools have their chief source of danger in members which rotate, the only rotating hazards on

the shaper is the squared shaft which projects from the side of the machine for setting the

stroke, and this can be dangerous if after setting a stroke we forget to remove the handle from

it before starting up. It is also a good precaution not to lean anywhere near this, as the rotating

squared end could wind up in the loose clothing. The ram is the only other real source of

danger, and accidents can occur both by forgetfulness and by knowingly taking chances.

On modern, moisturized, gear driven machines, the danger from an obstruction to the

ram is greater than it was on the earlier belt-driven types, since a belt would often save a

Page 25


serious situation by slipping off. A train of gearing from a high-speed motor, however, is not

so obliging. The ram, therefore, should always be considered as a source of danger, and this

should never be forgotten, neither should a known risk be entertained. After setting or

resetting a job, make sure that neither the tool nor any portion of the ram will foul anything

on the table before starting the machine. Better still; pull the machine round by hand to make

sure. There is sometimes a temperate to change the stroke or the setting of the ram while the

machine is running. This is taking a known risk and should be avoided. Special care is

necessary when a fine setting to the forward end of the stroke is necessary for shaping up to

an obstruction, and the machine should be pulled round several times before it is started up.

Many mishaps occur through work being insecurely clamped and supported against

the force of the cut and it should be remembered that the tool at the beginning of each stroke

exerts a considerable shock force. Stops should always be used when jobs are clamped direct

to the table and clamping should be arranged to come on to solid metal. Faulty clamping and

setting up, as well as being dangerous, lead to inaccurate results due to work either moving or

distorting. Even if a job is well clamped, it may be pushed off the table, or the tool broken, by

winding in to a large cut that was not checked or has jumped on due to a loose head slide.

The collection of the cutting chips on a shaping machine is a problem that has never

been solved, and when dealing with hard steel particularly it is advisable not to stand at the

front of the machine. Also, sweep the floor often if you value the leather on your shoe soles.

2.3.6. Work Carried Out Using Shaping Machines

In my training at the IDB I Frequently used this machine to complete works assigned to me.

Among them I shaped some parts that use in clay mixing machine. There were key ways and

taper angle to cut so I performed those operations also using the shaping machine. I have

attached all the drawings of the parts, carried out by my self. Clay mixing machine is one of

the on going project in IDB these days. It was the main project and also there are some other

projects too. Purpose of making those products is to improve the productivity of the local

industries as well as the self employment. I was very lucky to contribute my effort and

knowledge to empower self employees in the country because I believe it’s the true

development of this country.

Page 26


2.4. BASIC MILLING MACHINE COMPONENTS AND PROCESSES

1.Face milling cutter

2.Spindle

3.Spindle head

4.Column

5.Table

6.Saddle

7.Knee

8.Base

9.Spindle switch

10.Spindle speed gear lever

11.Spindle speed control lever

12.Oil tank

Milling machines are very versatile. They are usually used to machine flat surfaces, but can

also produce irregular surfaces. They can also be used to drill, bore, cut gears, and produce

slots. The type of milling machine most commonly found in student shops is a vertical

spindle machine with a swiveling head. Although there are several other types of milling

machines, this document will focus only on the vertical milling machine.

A milling machine removes metal by rotating a multi-toothed cutter that is fed into the

moving work piece. The spindle can be fed up and down with a quill feed lever on the head.

Page 27

Figure 2.14

Figure 2.15


The bed can also by feeding the x, y, and z axes manually. In this clip the z axis is adjusted

first, then the y, than the x.

Once an axis is located at a desired position and will no longer be fed, it should be locked

into position with the Gibb locks.

Most milling machines are equipped with power feed for one or more axes. Power feed is

smoother than manual feed and, therefore, can produce a better surface finish. Power feed

also reduces operator fatigue on long cuts. On some machines, the power feed is controlled

by a forward reverse lever and a speed control knob.

2.4.1. Rotating the Head

The head of a vertical milling machine can be tilted from side to side and from front to back.

This allows for versatility of the machine, but these adjustments can drift.

2.4.2. Squaring the Vise

Work on a milling machine is most often held in a vise clamped onto the bed. To make

features aligned with the edges of the stock, it's necessary to align the vise with the feed axes

of the mill. To do this, mount the vise on the bed and secure it with T-bolts, but only lightly

and do adjustments of the orientation of the vise to make it align. Then tighten down the T-

bolts be careful not to change the vise orientation. Recheck the alignment of the vise.

2.4.3. Types of Milling Cutters

Page 28

Figure 2.16

Climb Milling Conventional Milling


In vertical mills, milling cutters with solid shafts are usually used. Milling cutters with keyed

holes are predominantly for use in horizontal mills. End mills are designed for cutting slots,

keyways and pockets. Two fluted end mills can be used to plunge into work like a drill. End

mills with more than two flutes should not be plunged into the work. Ball end mills can

produce a fillet. Formed milling cutters can be used to produce a variety of features including

round edges.

2.4.4. Removing and Installing Milling Cutters

To remove a tool, move the quill to the highest position and lock it in place. Then, engage the

brake while loosening the draw bar with a wrench. Ensure that the draw bar's threads are still

engaged in the collet. Tap on the end of the draw bar to release the collet from the spindle. If

the threads of the draw bar are not engaged, the milling cutter will fall, and could be

damaged. Finally, unscrew the drawbar from the collet.

To install a tool, place the desired milling cutter in a collet that fits the shank of the cutter.

Insert the collet into the spindle. Ensure that the key way on the collet mates properly with

the key in the spindle. While holding the tool with one hand, start the threads of the draw bar

into the collet by hand. Use a wrench to tighten the drawbar down with one hand while

holding the brake.

2.4.5. Climb and Conventional Milling

When milling, one should be aware of the difference between conventional, and climb milling. In conventional milling, the work piece is fed into the rotation of the cutter. This type of cut requires lower forces and is preferred for roughing cuts. In climb milling, the work

Page 29

Figure 2.17


moves with the rotation of the cutter. This produces a better finish. It is not recommended if the work piece cannot be held securely or cannot support high forces.

2.4.6. Calculating Speed and Feed

Cutting speed refers to the speed at which the tool point of the cutter moves with respect to

the work measured in feet per minute. Feed is the rate at which the work moves into the

cutter measured in feed per tooth revolution. Feeds and speeds affect the time to finish a cut,

tool life, finish of the machined surface and power required of the machine.

The cutting speed is mostly determined by the material to be cut and the material of the tool.

To find the right speed for any task, refer to the Machinery's Handbook or other reference. To

calculate the proper spindle speed, divide the desired cutting speed by the circumference of

the tool expressed in feet. The feed rate depends on the width and depth of cut, finish desired

and many other variables. To calculate the desired feed setting from the feed rate, multiply

feed per tooth per revolution by number of teeth and rpm of the spindle.

2.4.7. Setting Spindle Speed

Spindle speed is varied by changing the geometry of the drive train. On many modern

machines, it can be adjusted continuously with a hand crank. The spindle must be turning to

make the adjustment. A dial indicator reads the speed in rpm. The spindle speed dial indicator

shown above has two scales, one for low range, and one for high range. The machine is

switched between ranges with a lever. Sometimes, the spindle must be rotated slightly to

allow the gears to mate properly.

2.4.8. Using the Edge Finder

Before doing precise work on a milling machine, one must locate the edges of a part

accurately. An edge finder is designed to help you do this. An edge finder is composed of two

concentric cylinders, spring loaded together. To use it, offset the two halves slightly so that

there is a wobble as it spins. Then, move the part into the tool slowly. The edge finder will

center up, and then break out of concentricity suddenly. At that point, reset the dial indicator

or digital readout for that axis of the machine to a value equal the radius of the edge finder.

Repeat the process at least once.

Page 30


2.4.9. Using the Micrometer Dials

Most milling machine manual feeds are equipped with dial indicators. If you know how far

you want to feed the bed, you can set the dial indicator to that number (in thousandths of an

inch). Just turn the locking ring counterclockwise to free the dial indicator, set the dial, and

lock in the setting. Be certain that the backlash in the mechanism driving the table is taken up

prior to setting the dial indicator.

Many modern machines have digital readouts. These are preferred since they measure the bed

position directly so you need not be concerned with backlash. They also read out bed position

in metric units if desired.

2.4.10. Face Milling

It is often necessary

to create a flat face

on a large part. This can be done best with a facing cutter.

Select a cutter about one inch wider than the work piece

so that the facing can be accomplished in one pass.

2.4.11. Milling Slots

End mills are designed to cut square slots. They will

produce a slot to within two one thousandths of an

inch in one pass. If greater accuracy is required, use an

end mill a little smaller than the desired slot. Measure

the slot produced and opens it to the desired

dimension with a second pass. The following clip

shows and end mill cutting a slot. Note that the depth

of cut is approximately equal to the diameter of the

cutter.

Page 31

Figure 2.18

Figure 2.20


2.4.12. Advanced Work Holding

To hold round stock more securely in a vise, use a v-block. The work can be held vertically

or horizontally. Round stock often cannot be held securely in the vise without damaging the

work. A collet block is designed to hold round stock. Square collet blocks allow the part to be

indexed to put in features at 90 degree increments. To mill features at 60 degree increments,

use a hexagonal block.

A work piece can be set up easily when the desired features are parallel with or perpendicular

to the work piece edges. When the features are at an angle to the edges, more ingenuity is

required. Here, an angle plate is used to set the position of a vise within a vise. Thus a slot

can be milled into a work piece at any desired angle.

Some parts don't fit well into a vise. These parts can be secured directly to the bed of the

machine with hold down clamps. It is good practice to create a gap between the bed and the

work with parallels. The clamps should be tilted down slightly into the work.

To create circular features on a mill, a rotary table can be installed onto the bed. The table

allows the work piece to be rotated. A dial indicator allows precise control of the angle of

rotation.

2.5. GRINDING MACHINES

At the IDB training I was also able to use grinding machines. There were two types of

grinding machines. They are Bench grinder and Surface grinder.

2.5.1. Bench Grinder

A bench grinder is a type of bench top grinding machine used

to drive abrasive wheels. A pedestal grinder is a larger version

of a bench grinder that is mounted on a pedestal, which is

bolted to the floor. These types of grinders are commonly used

to hand grind cutting tools and perform other rough grinding.

Depending on the grade of the grinding wheel it may be used

for sharpening cutting tools such as lathe tools or drill bits.

Alternatively it may be used to roughly shape metal prior

Page 32

Figure 2.21

http://en.wikipedia.org/wiki/Workbench


to welding or fitting. A wire brush wheel or buffing wheels can be interchanged with the grinding

wheels in order to clean or polish work-pieces. Grinding wheels designed for steel should not be used

for grinding softer metals, like aluminum. The soft metals get lodged in the pores of the wheel and

expand with the heat of grinding. This can dislodge pieces of the grinding wheel.

2.5.2. Surface Grinder

Surface grinding is used to

produce a smooth finish on

flat surfaces. It is a widely

used abrasive

machining process in which

a spinning wheel covered in

rough particles (grinding

wheel) cuts chips of metallic

or non metallic substance

from a work piece, making a

face of it flat or smooth

2.5.3. Work Carried Out Using Grinding Machine

Mostly I used bench grinding machine to sharpen tools and etc. when I use grinding tool I used eye protecting glasses too. Because some heated small metals particles can cause damages to our eyes.

Also I used surface grinding machine to get a shining surfaces to metal parts. When we want precise measurements to our work piece these machines very helpful achieve those precise dimensions.

2.6. OXY-ACETYLENE CUTTING AND ELECTRIC ARC WELDING

Within the last few weeks of my training I was granted an opportunity to work in welding

section. In the welding section mainly there are two types of categories used to perform

cutting and welding. They are,

Page 33

Figure 2.22


2.6.1. Oxy-Acetylene Cutting

Within the first week of welding section I learned about oxy-acetylene cutting process. First I

started learning oxy-acetylene cutting fundamentals. At the begging I was familiar with all

the components used in oxy-acetylene cutting like torch, regulators, hoses, striker, etc. and

some basic steps like, how to fire up the torch, how to keep hoses when cutting the metal,

importance of holding breath till the cutting finished and how to control oxygen and

acetylene percentages to get the required flame. Also studied about the safety equipments that

will mention in another section and few safety procedures to follow when cutting metals as I

mentioned bellow,

a. Make sure the regulators are tight

b. Never use oily rags around cylinders and regulators

c. Check hoses and make sure mixing knob is off before lighting the torch.

d. Make sure regulators are in the proper settings. (15 psi max. acetylene 40 psi max.

oxygen)

e. Light acetylene first then mix oxygen

2.6.2. Electric Arc Welding

Page 34

Equipments used in gas weldingFigure 2.23


Once I got experience of oxy-acetylene cutting I started learning electric arc welding. Same

as above mentioned I learned basics, familiar with equipments and started practicing it.

Regarding the electric arc welding section I found that there are so many safety issues while I

was practicing. Cables and other equipments are damaged. Safety equipments are broken. No

replacement for those broken equipments. Also there were no any notices regarding the safety

steps so I prepared a one and put it in the notice board to enlighten others about safety.

I listed some of them bellow,

Always wear proper clothes when welding.

Place ground lead on material before turning machine on.

Check cables for cuts in the insulation.

Never stand in water when welding.

Never weld near flammable objects.

Equipments used in arc welding,

Welding Power source

Electrode holder

Ground clamp

Welding cables and connectors

Accessory equipments (chipping hammer, wire brush)

protective equipments (helmet, gloves, etc)

Page 35

Figure 2.24


Welding power source

Welding may utilize either alternating current (AC) or direct current (DC), but in either case,

the power source selected must be of the constant current type. This type of power source

will be deliver a relatively constant, the welding beads produced will be uniform in size and

shape.

Whether to use an AC, DC, or AC/DC power source depends on the type of the welding

to be done and the electrodes used. The following factors should be considered,

i. Electrode selection- using a DC power source allows the use of the greater range of

electrode types. While most of electrodes are designed to be used on AC or DC, some

will work properly only on AC.

ii. Metal thickness – DC power source may be used for welding both heavy sections and

light gauge work. Sheet metal is more easily welded with DC because it easier to

strike and maintain the DC arc at low currents.

iii. Distance from work – if the distance from the work to the power source is great, AC

is the best choice since voltage drop through the cables is lower than DC. Even

though welding cables are made in copper or aluminum, the resistance in the cables

becomes grater as the cable length increases.

iv. Welding position - because DC may be operated at lower currents, it is more suitable

for overhead and vertical welding than AC. AC can successfully be used for out of

position work if proper electrodes are selected.

Page 36

Figure 2.25


v. Arc blow- when welding with DC, magnetic fields are set up throughout of the

weldment. In weldments that have varying thickness and protrusions, this magnetic

field can affect the arc by making it stray of fluctuate in direction. This condition is

especially troublesome when welding in corners. AC seldom causes this problem

because of the rapidly reversing magnetic field produced.

2.6.3. Work Carried Out At the Welding Section

At the welding section I was able to get hands on experience with oxy acetylene and electric

arc welding processes. Then I was assigned to cut metal patters to make a ribbon for the clay

mixing machine. It was a very hard process. I had to weld those pieces to a shaft and bend to

get the required shape. So I took help from another experienced welder. There he told me

how the welding should perform and how the to bend those metal parts to get the correct

shape. I followed his advice but it was very difficult me to complete it. So with his help

finally I was able to complete it.

Page 37

Figure 2.26


2.7. ELECTRIC DISCHARGE MACHINE PROCESS

Electric discharge machining (EDM), sometimes colloquially also referred to as spark

machining, spark eroding, burning, die sinking or wire erosion, is a manufacturing process

whereby a desired shape is obtained using electrical discharges (sparks). Material is removed

from the work piece by a series of rapidly recurring current discharges between

two electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the

electrodes is called the tool-electrode, or simply the ‘tool’ or ‘electrode’, while the other is

called the work piece-electrode, or ‘work piece’.

When the distance between the two electrodes is reduced, the intensity of the electric field in

the volume between the electrodes becomes greater than the strength of the dielectric which

breaks, allowing current to flow between the two electrodes. This phenomenon is the same as

the breakdown of a capacitor. As a result, material is removed from both the electrodes. Once

the current flow stops, new liquid dielectric is usually conveyed into the inter-electrode

volume enabling the solid particles to be carried away and the insulating proprieties of the

dielectric to be restored. Adding new liquid dielectric in the inter-electrode volume is

commonly referred to as flushing. Also, after a current flow, a difference of potential between

Page 38

Kerosene bath

Electrode holder

TableOperational tower

Figure 2.27

Figure 2.28


the two electrodes is restored to what it was before the breakdown, so that a new liquid

dielectric breakdown can occur.

2.7.1. Advantages and Disadvantages

Some of the advantages of EDM include machining of:

Complex shapes that would otherwise be difficult to produce with conventional cutting

tools

Extremely hard material to very close tolerances

Very small work pieces where conventional cutting tools may damage the part from

excess cutting tool pressure.

There is no direct contact between tool and work piece. Therefore delicate sections and

weak materials can be machined without any distortion.

Some of the disadvantages of EDM include:

The slow rate of material removal.

The additional time and cost used for creating electrodes for ram/sinker EDM.

Reproducing sharp corners on the work piece is difficult due to electrode wear.

Specific power consumption is very high.

2.7.2. Work Carried Out Using the Lathe Machine

At the end of the training period I obtained a chance to follow bit

about EDM Machines. In the IDB workshop there is a one EDM

machine. So once I got the opportunity I learned about the process

and the operation I was able to link to an undergoing project. It was

about cutting mold to a plastic guard of the elbow crutch. Mold is

use to make the plastic guard through the injection molding

process. So we took a steel cube as the work piece and mount it on

the EDM machine table. Then mount the electrode (tool) on the

EDM machine and turn on the machine. The cutting was performed

inside the kerosene bath. All the work piece particles dissolve in the kerosene and electrode

sank into the work piece.

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Figure 2.30

CONCLUSION CHAPTER 3

CHAPTER 3: CONCLUSION

3.1 Review of Training Experience.

During my twenty two weeks of training at Industrial Development Board I worked in IDB

workshop function under the Engineering department. At the IDB workshop I learned

practical applications of mechanical engineering. I was able to gain fair amount of knowledge

about the machine and machine processes above mentioned. Most of the time I have done

studies by my self. During my training period I was able to participate in few of on going

projects.

More importantly during my training experience I had to work with various people from chief

engineer to workers of the IDB. I learned the way to move with them quite easily and at the

end of training they became very good friends of mine. When we were carrying out projects

we had chance to discuss with machine operators and workers. I think I gained more

knowledge from them than the workshop engineer and chief engineer.

Industrial development board gave us opportunity to involve in their new project carried out.

I think these were vital opportunities that we were able to work with different people and to

apply our knowledge.

3.2 Comments on training establishment

I think that the Industrial development board has the capacity of giving a useful training for

the mechanical engineering undergraduates. Facilities available at there are acceptable.

Machines operators, workers and fitters and IDB management gave their best to us. These

people are little bit busy in a working time of a day. But we were able to interact with them

frequently. Though they had some problems with IDB administration they guided us towards

the correct path.

Normally IDB is not profit oriented but its duty is to help small and medium

industries and promote self employment. But today for many reasons they haven’t been able

to achieve those objectives. So IDB has become a semi government company that destroys

the public money. But there was a time IDB functions to achieve the company objectives. But

unfortunately to day that has changed. But I believe the present authorities will find a way to

recover those burning problems and fulfill the country needs.

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CONCLUSION CHAPTER 3

3.3 Suggestions

I think it is better to give a training schedule at the beginning of the training period to each

trainee. I think training division has to point out this to IDB management.

I also think our industrial training should be shift to level 4 semesters 2 because it will helpful

to trainees to find there jobs.

Finally must say my training at Industrial development board of Ceylon was successful and I

met my most of the expectations during my training periods I must grateful to the effort

taken by the training division with NAITA deliver us a industrial training for our future

benefits.

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ANNEXES

ANNEXES

Annexes contain reports and drawings that I have prepared during training period.

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report

Documents

training experience

industrial training

training establishment

training division

training coordinator

overall training

complete training

engineering services