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ACKNOWLEDGEMENTS

It was a great opportunity to me for completing my industrial training in one of Sri Lanka’s

most important establishments such as Sri Lanka Air Force which is South Asia’s one and only

establishment overhauling helicopters. It was even more enthusiastic to work with a group of very

highly skilled professionals, who were very friendly from the commencement of my training session.

First of all I must thank Industrial Training and Career Guidance Unit (ITCGU) of faculty of

Engineering, University of Peradeniya and National Apprentice and Industrial Training Authority

(NAITA) for conducting the training program and allowing us to get the required industrial exposure

for achieving challenges which should overcome by engineers in the industrial environment.

Then I offer my sincere thanks to the Commanding Officer of Mechanical Transport Repair and

Overhaul Wing (MTR&OW) Group Captain Eng. Senarathna who was in-charge of us during the

training session and to Squadron Leader Eng N.S. Dikkumburage, Flight Lieutenant Eng. Chamila

Mallawarachchi, Squadran Leader Eng. Chamila Kahadakoralage who were in-charge of the training

session and also to Squadron Leader Eng. G.G.I.D. Viraj who was in-charge of workshop Engineer.

I must further thank, all workers who were at Air Craft Engineering wing, General Engineering

Wing, Mechanical Transport Repair & Overhaul Wing for helping me without any hostility to improve

my knowledge. Actually it was a strange experience for me at the beginning of the training period and

I could spend valuable and pleasurably 11 weeks with aid of all the personnel who has given the

support and the assistance in completing my industrial training session.

E.M.K.S. Edirisooriya

Faculty of Engineering

University of Peradeniya

iii

CONTENTS

Acknowledgements i

Contents iii

List of Figures v

List of Abbreviations vi

Chapter 1 INTRODUCTION

1.1 Introduction to Sri Lanka Air Force 1

1.2 SLAF’s vision & mission 1

1.3 Rank Structure 3

1.4 Decorations & medals 3

1.5 Sri Lanka Air force base, Katunayaka 4

Chapter 2 DISASSEMBLY OF A DEFFENDER TDI ENGINE

2.1 Disassembling process 8

2.2 Important points to be considered 8

Chapter 3 ASSEMBLY OF DEFENDER TDI ENGINE

3.1 Assembling process 10

3.2 Settling tappet clearance 11


Chapter 4 DISASSEMBLY OF DEFENDER TDI GEAR BOX

4.1 Disassembling process 14


Chapter 5 ASSEMBLY OF DEFENDER TDI GEAR BOX

5.1 Assembling process 16


Chapter 6 THE TRANSFER BOX

6.1 Function of a transfer box 18

iv

Chapter 7 LATHE MACHINES

7.1 Main parts of lathe machine 19

7.2 General operation of lathe machine 20

7.3 External Threads cutting operation 21

7.4 Important points to be consider 21

Chapter 8 WELDING

8.1 Metal inert gas welding (MIG) 23

8.2 Gas welding 23

8.3 Tungsten Inert gas welding (TIG) 24

Chapter 9 NON DESTRUCTIVE TESTING

9.1 Radiographic testing 26

9.2 Magnetic particle testing 26

9.3 Ultrasonic testing 26

9.4 Eddy current testing 27

9.5 Penetrate testing 27

Chapter 10 CONCLUSIONS 28

v

LIST OF FIGURES

Figure 2.1 Cross section of a diesel V engine 8

Figure 2.2 Cross section of a Pushrod and overhead cam engine 9

Figure 3.1 Measuring by using a dial gauge 10

Figure 3.2 Measuring gap of a piston ring 10

Figure 3.3 A piston ring compressor(Ring Clamp) 11

Figure 3.4 Adjusting tappet clearance 11

Figure 3.5 Setting tappet clearance 12

Figure 3.6 The Engine head 13

Figure 4.1 The components of a gearbox 13

Figure 4.2 Separation of the gearbox 14

Figure 4.3 Dog teeth in a gearbox 14

Figure 5.1 Components of the Gearbox 15

Figure 5.2 Components of the hub 15

Figure 6.1 Components of a transfer box 16

Figure 6.2 Components of a transfer box 17

Figure 7.1 Main Components of a Lathe Machine 17

Figure 7.2 A Lathe Machine 19

Figure 8.1 The welding process 20

Figure 8.2 Welding process 21

Figure 8.3 The diagram of the MIG welding 21

Figure 8.4 The diagram of the Gas welding 22

Figure 8.5 The diagram of the TIG welding 22

Figure 9.1 NDT testing 23

Figure 9.2 Ultrasonic testing 24

Figure 9.3 Eddy current testing 25

vi

LIST OF ABBREVIATIONS

AEW AIRCRAFT ENGINEERING WING

GEW GENERAL ENGINEERING WING

LROW LAND ROVER OVERHAUL WING

MTR&OW MECHANICAL TRANSPORT REPAIR & OVERHAUL WING

SLAF SRI LANKA AIR FORCE

TDI TURBOCHAEGED DIRECT INJECTION

1

Chapter 1 INTRODUCTION

1.1 INTRODUCTION TO SRI LANKA AIR FORCE

Sri Lanka Air Force has been reputed to occupy the most advanced technology and machinery

in the country out of the three military forces operating in Sri Lanka at present. It has 16 base stations

covering the entire island, and 3 training bases. There are 5 stations which carry out Flying Formation

- Katunayake, Rathmalana, Higuraggoda, Anuradhapura and Vauniya. The 12 squadrons are situated at

these 5 bases. Housing flying formations are where they carry out day to day flying activities.

SLAF is a child of Royal Air Force in United Kingdom. Before the independence Royal Air

Force was carrying operation in Sri Lanka. SLAF was established by an act of parliament in 1949, act

number 41 of 1949. The exact date of the formation of the Air Force is however, taken as 3rd

March

1951. The first commander of the Air Force, Air Commodore G. C. Blaydon and Royal Air Force was

appointed to command the Royal Ceylon Air Force. On 22nd

may 1972, when Sri Lanka was declared

a republic, the name of the Royal Ceylon Air Force was changed to the Sri Lanka Air Force.

In our training period, the commander of the Sri Lanka Air Force is Air Chief Marshal Roshan

Gunathilake who is a son of the former Air Commander Air Vice Marshal W.D.H.S.W Gunathilake.

As well as Sri Lanka Air Force is dedicating for welfare activities. The objectives of those

activities are offering support to service personnel and their families to improve their living conditions

and morale.

1.2 SLAF’S VISION & MISSION

1.2.1 Vision

TO ESTABLISH AN AIR FORCE OF HIGH OPERATIONAL EFFICIENCY

TO PRESERVE THE SOVEREIGNTY

OF SRI LANKA

2

1.2.2 Mission

TO PROVIDE HEAVY MAINTENANCE FACILITIES FOR

THE AIRCRAFT OPERATIONAL FORMATIONS. FURTHER, THE RESOURCES

AVAILABLE MAY ALSO BE USED TO UNDERTAKE COMMERCIAL PROJECTS WITH

PRIOR

1.2.3 Vision of DAE

To achieve flight safety and aircraft serviceability to its

highest standard, through improved competency and

work perfection.

3

1.3 RANK STRUCTURE

1.3.1 Commissioned Officers

Air Chief

Marshal Air

Marshal Air Vice

Marshal Air

Commodore Group

Captain Wing

Commander Squadron

Leader Flight

Lieutenant Flying

Officer Pilot

Officer

1.3.2 Other Ranks

Warrant Officer Flight Sergeant Sergeant Corporal Leading Aircraftman

1.4 DECORATIONS & MEDALS

Parama Weera

Vibushanaya

Weerodhara Vibhushanaya

Weera Wickrama

Vibhushanaya

Rana Wickrama Padakkama

Rana Sura

Padakkama

Vishishta Seva Vibhushanaya

Utthama Seva

Padakkama

Videsha Seva Padakkama

Republic Of Sri

Lanka Armed

Services Medal -

1972

Sri Lanka Air Force 25th

Anniversary medal - 1976

Queen Elizabeth II

Coronation

Medal - 1953

Ceylon Armed Services Long

Service Medal - 1968

Sri Lanka Armed

Services

Long Service

Medal-1979

President's Inauguration

Medal - 1978

50th Independence

Anniversary

Commemoration

Desha Putra Sammanaya

North & East

Operations Medal

Purna Bhumi Padakkama

Vadamarachchi

Operation Medal

Sri Lanka Air Force 50th

Anniversay Medal

Riviresa Campaign

Service Medal

Ceylon Armed Services

Inauduration Medal -1956

United Nations' Service

Medal (CONGO)

http://airforce.lk/org/colornew.htm





































4

1.5 SRI LANKA AIR FORCE BASE, KATUNAYAKE

The Sri Lanka Air Force Base Katunayake,

the largest Air Force Base in Sri Lanka , is situated in

close proximity to the Bandaranayke International

Airport. The Base provides administrative, logistical,

general and civil engineering services to all lodger

formations located within the Base. The following

flying Squadrons are among the major lodger

formations in the base

No. 04 Helicopter Squadron

No. 05 Jet Squadron

No. 10 Fighter Ground Attack Squadron

No. 14 Squadron

In addition to the above flying formations the following formations are also located within the Base.

Supply & Maintenance Depot

Electronic & Communication

Command Argo Unit

Runway Maintenance Wing

Aeronautical Engineering Wing

General Engineering Wing

Aircraft Spares Depot

Air Defence Cmd & Control Center

Hospital

Radar Maintenance Wing

Motor Transport Repair Operating Wing

No 26 Regiment Wing

Air Field Construction Wing

No 43 Color Wing

No 62 Intelligence Wing

Parachute Training School

Mechanical & Electrical Wing

Dental Unit

SLAF Band

No 01 Air Defence Radar Squadron

Special Project Unit

Equipment Provisioning and Accounting Unit

5

A fully equipped gymnasium, a swimming pool and a cinema are among the many recreational and

sports facilities offered by the Base for its personnel. The housing complex located within the Base

provides accommodation to several hundred families of the AF personnel serving at the SLAF Base

Katunayake.

6

ORGANIZATION OF SLAF

3 O

F 7

CO AP &

SU

BASE

COMMANDERS

CO’S OF

SQUADRONS

CO

AEW

OCM

NO 2 (HTS)

SQUADRON

OCM

NO 1 (FTW)

SQUADRON

OCM

NO 3 (MARI)

SQUADRON

OCM

NO 14 (JET)

SQUADRON

OCM

NO 11

(UAV)

SQUADRON

OCM

NO 7 (HELI)

SQUADRON

OCM

NO 4 (HELI)

SQUADRON

OCM

NO 9 (AHS)

SQUADRON

OCM

NO 10 (KFIR)

SQUADRON

OCM

NO 5 (JET)

SQUADRON

OCM

NO 6 (HELI)

SQUADRON

OCM

NO 8 (LTS)

SQUADRON PILOTS

COMMANDER OF SRI LANKA AIR FORCE

DAE DIRECTOR OF

AERONAUTICAL

ENGINEERING

CHIEF OF STAFF

DGE DIRECTOR OF

GENERAL

ENGINEERING

DOPPS DIRECTOR OF

AIRCRAFT

OPERATIONS

DHS DIRECTOR

OF HEALTH

SERVICES

DW DIRECTOR

OF

WELFARE

DP

DIRECTOR OF

PLANNING

DETE DIRECTOR OF

ELECTRICAL &

TELECOMMUNICATION

ENGINEERING

DA DIRECTOR OF

ADMINISTRATION

DT DIRECTOR

OF

TRAINING

DCE DIRECTOR OF

CIVIL

ENGINEERING

DL DIRECTOR

OF

LOGISTICS

MINISTER OF DEFENSE

PRESIDENT OF SRI LANKA

7

ORGANIZATION OF AEW

SNCO I/C

CIVIL

CONTROL

SNCO I/C

DISCIPLIN

ARY

SNCO I/C

ORDERL

Y ROOM

OC

SPECIAL

PROJECT

WIN

G

WAR

RAN

COMMANDING OFFICER

OC TECH

PLANNING

&

CONTROL

OC

ADMINISTRATION

OC

AR &

SS

OC

PSES

OC

AVIONICS

OC

LOGIST

IC

WO I/C

SAFETY BAY

WO I/C

COMPO

NENT

BAY

WO I/C

NDT LAB

WO I/C

ROTOR

BAY

WO I/C

AR &

SS

WO I/C

SPECIAL

PROJECT

WO I/C

ENGINE

BAY

WO I/C

ELECTRICAL

BAY

WO I/C

INSTRUMENT

BAY

SNCO

I/C

FORWA

RD

SNCO I/C

ORDERLY

ROOM

WING

WARRAN

T

OFFICER

WO I/C

COMPONEN

T BAY

WO I/C

ROTOR

BAY

WO I/C

AR & SS

WO I/C

TECH

PLANNING

& CONTROL

WO I/C

SPECIAL

PROJECT

WO I/C

ENGINE BAY

SNCO I/C

FORWAR

D SUPPLY

UNIT

8

Chapter 2 : DISASSEMBLY OF A DEFENDER TDI ENGINE

Figure 2.1: Cross section of a diesel V engine

2.1 Disassembling process

The procedure is initiated by removing the oil sump by removing purge nut sump. Next attempted the

drain water in the cooling system, but since the drain nut system is corroded cooling becomes difficult

and there the water in the system that was in the system without removing. Then the injector pump,

vacuum pump, oil filter and the front cover were removed. After that the pressure plate, clutch plate,

inlet and exhaust manifolds were removed. Then the flywheel, the tappet cover, rocker shaft, push

rods, intor nozzles, heater plugs, valve tips, engine head and the cam followers were removed. After

the motor is turned upside down and the crankcase oil filter end bearings and main bearings were

removed and the pistons were removed. Next the cam shafts and the oil swans were removed.

All components except the engine head, injection pump, oil pump, water pump and front cover washed

using Auta and was cleaned with pressurized water components jet. Finally well dried with

compressed air and They were oiled to prevent rusting.

2.2 Important points to be considered

1. Engine heads are never washed using Auta. If not the gasket will perish and sealing the engine

head to the engine block want happen properly.

2. As soon as the components are dried, it should be oiled to prevent the formation of rust. But

not all need to be oiled. Finally component surfaces and surfaces with fine surface finish.

Eg: cylinder bores, cam faces, bearing sleeves, cam rollers and crank shafts are the components

that need to be oiled. After that the engine block was washed using Auta and was cleaned and

dried. Finally, the cylinder bores were oiled.

9

3. Banjo bolts should not be tightened using excessive torques. If so they will fail under torsion

4. Nuts and bolts smaller M10 tight are must always be removed using a hexagon socket.

(Open end wrenches can be used. But tend to slip damaging the hexagonal nut or bolt. When

this repetition, gradually impossible to be removed or secured with a key becomes.)

Figure 2.2: Cross section of a Pushrod and overhead cam engine

10

Chapter 3: ASSEMBLY OF A DEFENDER TDI ENGINE

3.1 Assembling process

The assembly process began by fixing the swans. Next oil hoses main bearings and thrust bearings

were fitted and were oiled. Then, the crankshaft is placed in place and the remaining halves of bearings

(bearings main) is attached and bearing caps were fixed. The end-play of the crankshaft was checked

using a dial gauge.

Figure 3.1: Measuring by using a dial guage

The final game is usually set to 7 min. After the gap of piston rings were measured. This as is done by

inserting a ring into the hole, pushing the piston and then measure the gap using thicknesses gauges.

The process was repeated three rings. (the gap for the compression ring should be 0.6mm, whereas for

compression and rings should be 0.4 mm.)

Figure 3.2: Measuring gap of a piston ring

Then, the piston rings inserted into the pistons using a circlip plier. Next pistons inserted into the hole

using a clamp ring and piston were pushed into place using a hammer and a wooden pole. Then

11

bearings were inserted head and covered it attached. The carrying handle is rotated after setting each

piston in order to ensure that there are no obstructions and the crank rotates continuously.

Figure 3.3: A piston ring compressor (Ring Clamp)

Then the camshaft is mounted and the feed pump and vacuum pumps fixed. Then the bell was

attached. After that the gears were set and the timing belt was overlooked and so tense using suitable

matrix tensioner .Then the cover was fixed and the damper pulley, pulley fan, power steering pump

pulley attached. Then the wheel set and twice crankshaft is rotated to ensure obstructions. After

absence of ant oil filter and drain cap were fixed. Next the cam followers were fixed. Then the motor

head and push rods were inserted. After noticed that the rocker was placed correctly and was fixed.

The game Valves set to 0.2 mm using the 'nine method'. After the cover pusher respite unit, injection

pump, injectors and glow plugs were fixed. Finally the inlet and exhaust manifolds were fixed.

Figure 3.4: Adjusting tappet clearance

3.2 Settling tappet clearance

First rocker arm adjuster adjuster is loosened completely. Next decreased to almost touch the valve

end. Then the valve tip and 0.2 mm thickness gauge is placed over the valve was placed to tip. After

the adjuster is reduced to gauge. Finally touched firmly held probe adjuster closed place by tightening

the screw.

12

Figure 3.5: Setting tappet clearance

The Nine methods

This method is used only for the defender TDI engine. The process involve four steps.

1. Turn the crank and observe the valves to see which valve is rising.

2. Turn the crank continuously until the rising valve stops its motion(At the beginning of the

‘Dwell” of the valve cam)

3. If the valve is the nth

valve then tappet clearance is set to the (9-n)th

valve.

4. Tappet clearance is set as mentioned above


When tightening bolts a torque wrench should be used(Specially in fixing the flywheel,

connecting rods and the engine head)

1. A torque of 40 Nm is used for flywheels.

2. A torque of about 40 Nm is used for the connecting rods.

13

At the top of the engine; Initially all nuts are tightened with a torque of 40 Nm. Next whole nut is

rotated by 60 0 .After all nuts are rotated once again by the two central rows 60

0.Finally nuts is further

rotated by other 20 0(This is done in order to ensure that the nuts are tightened to the proper torque). If

not at times due to the presence of rust etc. the actual torque may be less than the value set in the

torque wrench.

Figure 3.6: The Engine head

3. When fastening the nuts of the connecting rods and the engine head a diagonal pattern ( Nuts

are tightened alternatively, starting at the middle and progressing to the ends.)should be used in

order to prevent distortion.(The reverse of the pattern must be used in removing the nuts)

14

Chapter 4 DISASSEMBLY OF DEFENDER TDI GEAR BOX

4.1 Disassembling process

Figure 4.1 : The components of a gearbox

First the transfer case is removed from the gearbox. Then the gear selector switch and four-wheel drive

was removed. Then the bush in the gearbox is removed by heating using an oxyacetylene cutter and

lever out of position using two types levers. After that the accommodation and the gear assembly was

taken retired out. Next shaft top, main shaft, lay shaft and idler wheel removed. Then reverse forks

hubs. Next withdrew from the security rings, brushes, O-rings, needle bearings and tapered roller

bearings possible were removed and the main shaft It was taken to the hydraulic pressure. Bearing

larger tapered roller was not removed and the gears were eliminated one after the other. Next to dogs

and retaining springs are eliminated.

Figure 4.2 :Separation of the gearbox

15


1. When removing the bush, care should be taken not to damage the edges.(If the edges get

damaged the oil seals at the ends of the bush will get turn off)

2. After removal of the components, dog teeth of the hubs and gears should be checked. If that

have disappeared and have been rounded pointy teeth, the wheel or the axle has to be replaced.

If not want to participate adequately gears. Also the tip of the gear teeth should be checked for

cracks or fractures. If a crack or a broken gear wheel is located, should be replaced

Figure 4.3: Dog teeth in a gearbox

16

Chapter 5 ASSEMBLY OF A DEFENDER TDI GEARBOX

Figure 5.1: Components of the Gearbox

5.1 Assembling process

First retaining springs are fixed to the hub and the struts (tooth struts / Dogs) held in a person place.

While all three keys simultaneously pressed into the sleeve is inserted into position by another. Both

hubs were assembled similarly. Next sprockets cones brass, bronze and slippers cone centers are

arranged in order in the splined shaft and the components were Locke in place with security rings

when needed. Then the completed main shaft was placed in the holder and the other hub was inserted

onto the shaft. Next the forks of that hub was fixed. Then the reverse ideal wheel was mounted on the

shaft and the link slides in and out of position fixed. After the shaft holding the forks fixed in position

after placing the upper shaft forks. Next remained place and the lay shaft was fixed. Then the gear

assembly was inserted into the housing properly and the screws were tightened. After the oil seal,

guides, and the bell were fixed. Finally the gear selector was fixed and coupling speed checked.

Figure 5.2: Components of the hub

17


1. Care must be taken in setting the tapered roller bearings in the middle, and in the end. They

never be beaten. Should be placed using a hydraulic press. Even in the process, the force must

be applied with intense care. (Applying pressure should be stopped if you feel an obstruction

to waive force. If bearing damage.)

2. It should be clear that the two fork slots and slot the shifter idle must be aligned before

inserting the set of gears in the housing. (If not certain gears may not engage)

18

Chapter 6 THE TRANSFER BOX

Figure 6.1 : Components of a transfer box

The transfer case is connected to the transmission and the front and real axles per unit means of shafts.

This also known as "gearbox transfer", “Transfer Case "," Jockey box "or" T-box ")

6.1 Function of a transfer box

1. Power transmission is received and sends it to the front and rear axles. This can be done either

by gears or chain drivers. In some transfer cases operating mode can be switched between "four

wheels" and "two-wheel drive "through a shifter, while others are operated using switches. The

guy who left is not selectable transfer boxes (box Defender transfer is selectable transfer box

with a driven gear shifter,)

2. In the transfer path boxes synchronize the rotation difference between the front and rear

wheels. This necessary when front and rear types rotate at different speeds because of the

difference in tire sizes. (In simple terms transfer boxes act as central differential gear)

3. In off-road vehicles, transfer boxes acts as differential locks.

Figure 6.2 : Components of a transfer box

19

Chapter 7 LATHE MACHINES

Around a power driven, general purpose machine tool used for production of the cylindrical work

piece. As the metal piece to be machined is rotated on the lathe, a single tool cutting point is advanced

radially into the work piece a specified depth and longitudinally moved along the axis of the work

piece, the removal of metal in the form of chips. Both inside and outside surfaces can be machined on

a lathe. By using attachments and accessories, other operations such as drilling, boring, and the conical

shape and angle of rotation, screw thread persecution, knurling, milling, grinding and polishing can be

done.

Figure 7.1: Main Components of a Lathe Machine

7.1 Main parts of lathe machine

1. Headstock

The head is attached on the left side of the bed, which is formed by the spindle drive gear and

shift levers. Three jaw chuck jaws and four plate are most commonly used to hold or clamp the

work piece to be cut.

2. Tailstock

The counterpoint is on the right side of the bed. It can be locked in any position along the bed

of the lathe tailstock clamp. It can be used to support long work piece during the cutting

process. Counterpoint spindle is used to receive the deadlock, which provides support for the

far right of the work.

3. Bed

The bed is a heavy, rugged casting made to support the working parts of the lathe. On its top

section are machined ways that guide and align the major parts of the lathe.

20

4. Lathe carriage

Around the truck carrying the cutter (tool post) and precisely controls the movement is parallel

to the ways called turning straight or right angle to form, called front. The car mount has three

main parts, the compound rest, and an apron.

5. Face Plate

A faceplate is used to drive a lathe dog which in turn is firmly attached to the work piece.

Contains more open slots or grooves in T so that the bolts or screws T can be used to secure the

work piece to the face plate. Many types of work that can not be kept in baboons may

conveniently be machined when mounted on the faceplate.

6. Three jaw universal Chuck

A three jaw chuck work holding cylindrical or hexagonal. The three jaws move together to

bring the work in the center. Two sets of interchangeable jaws are provided. These are called

inside and outside jaws.

7. Four Jaw independent Chuck

The four-jaw independent chuck is used to hold most of the work for which a mandrel is

required. The jaws of hardened steel are reversible and sustain work of different sizes and

shapes. Each jaw can be moved independently of the others so that the work pieces can be

delivered accurately to run. A four-jaw independent chuck has several circular grooves around

the face of the body. The jaws can be approximately centered by adjusting the jaws to these

slots. The work piece is then inserted and tightened jaws enough to hold the job instead.

Reverse the tool, tighten finger tight only, and make it until it touches the work piece. Rotate

the dish by hand to locate the high or low point of the work piece. Adjust the jaws until the

work piece runs true. If more precision is required, using a test indicator.

7.2 General Operation of Lathe Machine

Turning Operation : Turning operation is used to reduce the diameter of a cylindrical work piece. A

single cutting tool removes the material from a rotating work piece to generate a

cylindrical shape.

Facing operation : Tool is fed radially inward direction and facing the work piece. Normal facing is

done from outer edge to the center of the work piece.

Taper Turning : The diameter of a work piece changes uniformly from one end to other.

21

Chamfering : Cutting edge cuts an angle on the corner of the cylinder forming a chamfer.

Figure 7.2: A Lathe Machine

7.3 External Threads cutting operation

First, the cutting of the thread is mounted on the tool post at right angles to the work that was aligned

correctly using a screw cut meter. Then a slow turn had to be selected so that the need for sufficient to

reverse or remove the cross slide and turn off the machine at the end of the thread time. The work

piece is turned required outer diameter and a beveled edge was machined on the free end of the work

piece. Each thread was cut in several steps. The depth of cut can not be great if you can not overload

the motor may fall or tip the tool. Turn back or remove the cross slide at the end of each cut, the motor

is reversed to bring the tool to the starting position. The tool is adjusted to a new cutting depth by

using reading hand wheel cross slide. Lastly, cleaning the cut thread profile he was done and cleaned

up the thread.


1. The cutting depth should be adjusted around 1mm per one step

2. After the cutting outline of the threads, it should be checked whether the cut is on desired pitch

by using a thread pitch gauge.

3. When the tool reaches the end of the cut quickly tool is turned to away from the work piece

using the cross slide crank.

22

Chapter 8 WELDING

Figure 8.1 : The welding proces

Figure 8.2 Welding process

WELDING

PROCESS

Fusion welding

process

Gas welding

Oxy acetylene

Oxy hydrojen

Arc welding

Unshielded arc Inert gas shield

arc

MIG welding

TIG welding

Atomic hydrogen arc

Submerged arc

Other processes

Pressure welding process

Black smith's forge welding

Electric Resistance

welding

Spot welding

Projection welding

Seam welding

Butt welding

Flash Butt welding

Cold pressure welding

Friction welding

23

8.1 Metal Inert Gas Welding (MIG)

First the machine was turned on and the CO2 cylinder valve was opened. Next metal strips are held in

place with a little space between them. The ends were then labeled. Finally he completed welding

accordingly

Figure 8.3:A diagram of MIG welding

8.2 Gas welding

First the oxygen cylinder valve and acetylene cylinders opened and the gas in the cylinders were

confirmed. Next both pressure adjusting screws (ie, oxygen and acetylene) were completely oxygen

valves closed. Then and acetylene cylinder valve is opened needle respectively. Next acetylene torch

was opened. the screw pressure was adjusted to obtain the desired pressure and the needle valve was

closed. The same was repeated with the needle valve. Then oxygen needle valve acetylene opened a

swing and ignited using a spark igniter or flame. After the oxygen needle valve was slowly opened

until the flame oxidant obtained. Finally strips metal were marked at the extreme ends are welded

accordingly

Figure 8.4: A diagram of Gas welding

24

8.3 Tungsten Inert Gas Welding (TIG)

First the tungsten electrode was checked to confirm that the tip is in good condition, Next machine

became a cylinder valve argon opened. Then settings were chosen to adapt accordingly the material to

be welded. Next the metal strips were kept in place with a diameter equal to the gap filler wire. After

labels are placed on the welding was completed ends.

Figure 8.5: A diagram of TIG welding

25

Chapter 9 NON DESTRUCTIVE TESTING

Non-destructive testing (NDT) is a new synthetic scientific technology that is a powerful tool for

reducing costs, improving product quality, and maintaining quality levels. It is a test that includes all

possible methods of detection or measurement of the properties or performance capabilities of

materials, parts, assemblies or structures, which don’t impair their serviceability. There are six

methods using in NDT lab of AEW.

Visual testing

Radiographic testing

Ultrasonic testing

Eddy current testing

Magnetic particle testing

Liquid penetrant testing

Procedure of NDT.

Inspection

Measurement

Monitoring

Figure 9.1: NDT testing

26

9.1 Radiographic testing (RT)

When rays pass through the matter, some of these rays are absorbed. The amount of absorption

depends upon the thickness and density of the matter; therefore, the intensity of the rays emerging

from the matter varies. The intensity of rays at the point where there is no defect is greater than that

where defect exists. When this variation is detected, the quality of the matter can be determined.

9.2 Magnetic particle testing

When there exists a discontinuity in the material, magnetic force line will make a detour round the

discontinuity. If the flaw is on or near the surface of material, some magnetic force line will run out of

the material, and magnetic leakage field is produced. Then when you spray some magnetic particles or

liquid on surface, the leakage field will adsorb particles and form a flaw indication. From the magnetic

indication, flaws can be easily determined

9.3 Ultrasonic testing

Ultrasonic wave can enter into material, and it will be reflected at the interface between two agents.

Ultrasonic waves are generated and accepted by probe, which is one part of the ultrasonic detector and

includes straight probe and slope probe. The piezoelectric crystal of them is the key unit for energy

transducer, the function of it is generating longitudinal wave and finishing conversion between

acoustic energy and electric energy.

Figure 9.2 Ultrasonic testing

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9.4 Eddy current testing

Eddy current is produced in the tested material. And for different material or in different state, the

eddy current is different. If there lies a flaw, the eddy current field at the flaw will be different from

that at the other place. So we can determine whether or where the flaw lies.

Figure 9.3 Eddy current testing

9.5 Penetrate testing

Color liquid or fluorescent liquid suck into the out crack in the work piece. Then clear the surface of

work piece. If you use a sorbent to suck out the liquid, the image of crack will appear

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Chapter 10 CONCLUSIONS

Engineering is not an easy task as a career. It is essential to have good practical knowledge and also

experience to do the task effectively. As engineers we are responsible to do several occupations. He

must play various characters once he is an advisor, once he is a manager, once he is a manager

likewise an engineer should have good personality to handle everything properly. As an engineer he

should be able to associate with every person in the site as well. He should be able to create good

communication with each other to enhance the work in the site. And he has the ability of labor

handling.

The efficiency of the SLAF was incredibly high and the quality of the outputs were unmatchable any

other production. But massive scale safety of the workers were questionable. Workers were safety

shoes and eye protection but hardly wear hearing protection and better masks. In some arrangements

can do to complete workers to use safety equipment.