DECLARATION

I certify that this project report, which I now submit for examination, is entirely my own work

and has not been taken from the work of others, save and to the extent that such work has

been cited and acknowledged within the text of my work.

The work reported on in this report conforms to the principles and requirements of the Dublin

Institute of Technology’s guidelines for ethics in research.

The Institute has permission to keep, lend or copy this report in whole or in part, on condition

that any such use of the material of the thesis is duly acknowledged.

Signature ____________________________ Date_______________

Author

i

ACKNOWLEDGEMENTS

I would like to acknowledge the help and advice I received from industry personnel and

college staff who provided me with information that aided in completion of this report.

Mr Byrne Martin, Mechanical and Transport Engineering, who help me, put the 555 Mono

stable Switch Kit together. Without he help this project could not been realised.

My class mate Grahame Byrne, who helps me with the Solid Works.

I would also like to extend my gratitude to my supervisor Ray English who gave me great

guidance and advice throughout the project. And I am happy that I have him as a supervisor.

ii

ABSTRACT

The project was to design and manufacture a Stainless Steel Pipe End Assembly. Stainless

Steel Pipe End Assembly is currently manually welded. This project will mechanise this

process. As the part to be welded is a pipe end, the pipe was placed on a rotating rollers and

TIG welded. A timer will control the TIG torch operation. All that will be required by the

operator will be to assemble the end plate and place the pipe on the rotating rollers and press

the start for the torch. This project will provide an economic advantage over the cost of

manual welding.

iii

Contents

DECLARATION...................................................................................................................................... i

Acknowledgements........................................................................................................................... ii

Abstract................................................................................................................................................. iii

Contents................................................................................................................................................. iv

CHAPTER 1:....................................................................................................................................... 1

1 Introduction................................................................................................................................ 1

1.1 Aim........................................................................................................................................ 2

CHAPTER 2:....................................................................................................................................... 3

2 Literature Review.......................................................................................................................3

2.1 What is welding?.............................................................................................................. 3

2.1.1 There are three parts to the welding process:...................................................3

2.1.2 TIG welding process................................................................................................5

2.1.3 Process characteristics.............................................................................................5

2.1.4 Applications................................................................................................................ 6

2.1.5 Power source...............................................................................................................6

2.1.6 Arc starting..................................................................................................................7

2.1.7 Electrodes.....................................................................................................................7

2.1.8 Shielding gas...............................................................................................................7

2.1.9 Welding torch...........................................................................................................11

iv

2.2 Mild steel.......................................................................................................................... 12

2.2.1 Type of Mild steel (plain carbon steel)...........................................................12

2.3 Stainless steel..................................................................................................................15

2.3.1 Types of Stainless steel.........................................................................................15

2.3.2 The available forms................................................................................................16

CHAPTER 3:.....................................................................................................................................16

3 Project design..........................................................................................................................16

3.1 Safety on plasma cutting.............................................................................................17

3.2 Manufacture...................................................................................................................18

3.3 The guide rollers.......................................................................................................... 25

3.4 Torque Experiment & calculating.........................................................................27

3.5 Calculate the length of time taken to weld........................................................30

3.6 Motor.................................................................................................................................31

3.7 555 Mono stable Switch Kit.....................................................................................33

CHAPTER 4: Analysis &conclusion.................................................................................37

4 Assembly of final and testing components.................................................................37

4.1 Test and Result..............................................................................................................44

4.2 Conclusions.....................................................................................................................48

4.3 COST OF THE PROJECT..............................................................................................51

5 Bibliography.............................................................................................................................52

CHAPTER 6:.....................................................................................................................................55

v

Appendices......................................................................................................................................... 55

vi

Table of figures

Figure 1 (Welding wire) [7]..............................................................................................................3

Figure 2 (TIG welding process) [8]...............................................................................................5

Figure 3 (Properties of shielding gas) [9]....................................................................................9

Figure 4 (Welding torch TIG)[11]...............................................................................................11

Figure 5 (Plasma cutting with a CNC machine).....................................................................17

Figure 6 (Scaffold)............................................................................................................................ 17

Figure 7 (Show the base built in .Dxf. format)........................................................................18

Figure 8 (Scaffold cut out)............................................................................................................. 18

Figure 9 (Base cut out).................................................................................................................... 18

Figure 10 (Putting it together to see if it work).......................................................................19

Figure 11 (Welding two scaffolds together).............................................................................19

Figure 12 (Fixture)............................................................................................................................ 20

Figure 13 (Welding table)...............................................................................................................20

Figure 14 (Base being grinder down).........................................................................................21

Figure 15 (The pipe).........................................................................................................................21

Figure 16 (The end plate)................................................................................................................22

Figure 17 (Spot welder)...................................................................................................................23

Figure 18 (The two end plate welder together).......................................................................23

Figure 19 (The end of the pipe being fitted to the pipe).......................................................23

Figure 20 (The ends of the ends plate being welded to the pipe)......................................24

vii

Figure 21 (The stainless steel pipe on the base)......................................................................24

Figure 22 (Definitions) [13]...........................................................................................................27

Figure 23 (A screw was drilled into the pipe).........................................................................27

Figure 24 (Guide rollers is fix in place using some screw).................................................28

Figure 25 (The pipe is put on the fixture).................................................................................28

Figure 26 (Hanging weight)...........................................................................................................29

Figure 27 (Testing)............................................................................................................................29

Figure 28 ( The motor fixed in)....................................................................................................31

Figure 29 (Motor)..............................................................................................................................31

Figure 30 (Variable speeds)...........................................................................................................32

Figure 31(Transformer mitsubishi).............................................................................................32

Figure 32 (The 555 time kits)........................................................................................................33

Figure 33 (The 555 timer put together)......................................................................................34

Figure 34 (555 timer connected to the torch)...........................................................................34

Figure 35 ( 24DC power supply (DIT)).....................................................................................35

Figure 36 (The wire is connected into the 24DC power supply and the torch)............35

Figure 37 (TIG power source).......................................................................................................36

Figure 38 (Testing 1 of the guide rollers and scaffolds distance).....................................37

Figure 39 (Testing2 of the guide rollers and scaffolds distance).....................................38

Figure 40 (The steel welded into the guide rollers)...............................................................38

Figure 41 (Tasting the distance is right and it rollers)..........................................................38

viii

Figure 42 (Building the new guide rooler)...............................................................................39

Figure 43 (The new guide roller fixed and welded into the steel)....................................40

Figure 44 (This shows everything in set)..................................................................................40

Figure 45 (Smoothing the steel into the scaffold)..................................................................40

Figure 46 (The surface fines)........................................................................................................ 41

Figure 47 (The guide rollers in place)........................................................................................41

Figure 48 (The torch hold)............................................................................................................. 42

Figure 49 (The torch in place).......................................................................................................43

Figure 50 (Base plant)......................................................................................................................43

Figure 51 (Testing the speed with a Cordless drills).............................................................43

Figure 52 (Assembly of the rotation device)............................................................................44

Figure 53 (Test1 first result)..........................................................................................................44

Figure 54 (Test1 second result)....................................................................................................44

Figure 55 ( 1 show the first end plate and 2 show the new end plate)...........................45

Figure 56 (The new two end plate welder together)..............................................................45

Figure 57 (The new end of the pipe being fitted to the pipe)...........................................45

Figure 58 (Test 2 result)..................................................................................................................46

Figure 59 (The steel roller that cost the test 2 mistake)........................................................46

Figure 60 (The steel roller with the rubber on it)...................................................................47

Figure 61 (The final testing)..........................................................................................................48

ix

Table of Table

Table 1 (Shielding gases for TIG welding) [10].....................................................................10

Table 2 (Typical properties)...........................................................................................................15

Table 3 (Guide rollers distance)...................................................................................................25

Table 4 (The amps and time).........................................................................................................30

Table 5 (Mitsubishi Inverter).........................................................................................................32

Table 6 (Sequim chart)....................................................................................................................36

Table 7 (Established final parameters).......................................................................................49

Table 8 (Manually welding Cost and Mechanised Welding Cost)...................................50

Table 9 (Cost of the project)..........................................................................................................51

x

CHAPTER 1:

1 Introduction

Stainless steel pipes end are currently being welded manually using the TIG process. This

project will look to design and build a welding rotation device, to mechanise this procedure,

and build a 555 timer integration of TIG torch operation to rotation device. This project will

look to design and build a welding rotation device, to mechanise this procedure.

One of the reasons TIG welding is being unitised is that; TIG welding not only possesses

high integrity but also has an aesthetic surface finish. The welds are manually left as welded

with no post weld cleaning. By mechanising the process the end result should be cleaner,

with better weld quality. Typical applications for TIG welding include architectural stainless

steel fabrication, such as balustrades.

Mild steel will be used to build the Fixture. Mild steel is great choice for large projects, or

coated or painted projects, or any internal structural components, because it’s less expensive.

When command to stainless steel?

Stainless steel type 304 is strongest, aesthetically luminous, and most expensive. Stainless

steel does not readily corrode, rust or stain with water as ordinary steel does. The pipe in this

project is stainless steel.

Aluminium is great option for light pieces, also good for malleability and ductility, relatively

corrosion resistant.

Currently welding stainless steel pipes end manually cost approximately 80 euro p/hr for a

welder. (Probably 10-15€ for welded – 80 including caped equip / depreciation etc. ).

This project aims to mechanise this operation which will reduce the cost about 50% of

compared to manual welding.

1

1.1 AimThe aim of this project is to

Design the base

Manufacture

Test a TIG welding mechanism rig, device, motorised drive, rotation device, arc

start/stop,

Deign a mechanised rotation device for producing stainless steel parts

Integrate a TIG torch

Test the design

2

CHAPTER 2:

2 Literature Review

2.1 What is welding?Welding is the connection of metal together to form one piece by heating the metals to their

melting points. Extra metal, also called filler metal is added during the heating process to

help bond the two pieces together. A welding machine is used to create the heat and apply the

filler metal.

2.1.1 There are three parts to the welding process:

2.1.1.1 The welding Arc:

Welding machines create an electric arc, comparable to a continuous spark that comes from

the electric circuit created between the machine and the metal being welded. The Arc is used

to melt the metal being combined. The arc creates heat, up to 6500 degrees Fahrenheit.

2.1.1.2 The filler metal:

The filler metal is supplementary metal added to the welding Arc to strengthen the welding

joint.

2.1.1.2.1 Welding wire:

This comes in two type’s Solid wire, also called bare wire, and flux-cored wire, also called

tubular wire. The type of metal it is made from and in its thickness or length can vary.

Figure 1 (Welding wire) [7]

3

2.1.1.3 Shielding the weld:

The weld needs to be protected while it’s in a molten state, which is called shielding the

weld. The surrounding air can contaminate a weld, causing it to weaken. Shielding covers the

area where the filler metal melts until the weld can set up. The shield is created by using gas

added to the welding process. The weld sets up reference in fractions of a second, so not

much gas is needed.

Shielding gas is delivered to the welding area in one of two ways:

The first way is from a gas cylinder that has been connected to the welding machine

and it’s a standard method when solid, or bare wire, is being used.

The second way is from a special chemical that has been added to the filler metal and

this chemical releases the gas as it melts. When these filler metals are used, no gas

cylinder is needed. All stick electrodes and flux-cored wire are used without a gas

cylinder. (1)

4

2.1.2 TIG welding process

Figure 2 (TIG welding process) [8]

Tungsten inert-gas (TIG) it is also known as Gas tungsten arc welding (GTAW), and it is a

shielded-arc welding process that uses a non-consumable tungsten electrode to produce the

weld. TIG arc is very hot; TIG welding is clean, cost-effective, although a bit slow compared

with metal inert gas (MIG) and metal active gas (MAG) welding. It can be used by hand or

automated and will weld a vast range of metals and thicknesses in several different modes.

2.1.3 Process characteristics

In the TIG process the arc is formed between a pointed tungsten electrode and the work piece

in an inert atmosphere of argon or helium. The small intense are provided by the pointed

electrode is ideal for high quality and exactness welding. Because the electrode is not

consumed during welding, the welder does not have to balance the heat input from the arc as

the metal is deposited from the melting electrode. When filler metal is required, it must be

added separately to the weld pool. (1)

5

2.1.4 Applications

The TIG Welding or GTAW process can be used to weld almost all metals and metal alloys

in use today. It is a particularly effective and economic way for welding light gauge metals

(less than 3mm thickness) and for welding metals difficult to weld with the conventional

welding process.

Such metals include the following:

Aluminium and aluminium alloys

Copper and copper alloys

Nickel and nickel alloys

Magnesium and magnesium alloys

Low alloy steel and carbon steels

Reactive materials (for example, titanium and tantalum)

Joining carbon and alloy steels

2.1.5 Power source

TIG must be operated with a drooping, constant current power source-either DC or AC. A

constant current power source is essential to avoid excessively high currents being drawn

when the electrode is short-circuited on to the work piece surface. This could happen either

deliberately during arc starting or inadvertently during welding. If, as in MIG welding, a flat

characteristic power source is used, any interaction with the work piece surface would

damage the electrode tip or fuse the electrode to the work piece surface. In DC, cause arc heat

is distributed approximately one-third at the cathode (negative) and two-thirds at the anode

(positive), the electrode is always negative polarity to prevent overheating and melting.

However, the alternative power source connection of DC electrode positive polarity has the

advantage in that when the cathode is on the work piece, the surface is cleaned of oxide

contamination. For this reason, AC is used when welding materials with a tenacious surface

oxide film, such as aluminium. (2)

6

2.1.6 Arc starting

The welding arc can be started by scratching the surface, forming a short-circuit. It is only

when the short-circuit is broken that the main welding current will flow. However, there is a

risk that the electrode may stick to the surface and cause a tungsten inclusion in the weld.

This risk can be minimised using the ‘lift arc’ technique where the short-circuit is formed at a

very low current level. The most common way of starting the TIG arc is to use HF (High

Frequency). HF consists of high voltage sparks of several thousand volts which last for a few

microseconds. The HF sparks will cause the electrode – work piece gap to break down or

ionise. Once an electron/ion cloud is formed, current can flow from the power source.

HF is also important in stabilising the AC arc; in AC, electrode polarity is reversed at a

frequency of about 50 times per second, causing the arc to be extinguished at each polarity

change. To ensure that the arc is reignited at each reversal of polarity, HF sparks are

generated across the electrode/work piece gap to coincide with the beginning of each half-

cycle. (2)

2.1.7 Electrodes

Electrodes for DC welding are normally pure tungsten with 1 to 4% thoria to improve arc

ignition. Alternative additives are lanthanum oxide and cerium oxide which are claimed to

give superior performance (arc starting and lower electrode consumption). It is important to

select the correct electrode diameter and tip angle for the level of welding current. As a rule,

the lower the current the smaller the electrode diameter and tip angle. In AC welding, as the

electrode will be operating at a much higher temperature, tungsten with a zirconia addition is

used to reduce electrode erosion. It should be noted that because of the large amount of heat

generated at the electrode, it is difficult to maintain a pointed tip and the end of the electrode

assumes a spherical or ‘ball’ profile. (2)

2.1.8 Shielding gas

Shielding gases are needed in TIG to protect the welding area from atmospheric gases such as

nitrogen and oxygen which cause defects. The gas also transmissions heat from the tungsten

electrode to the metal, and it helps start and maintain a stable arc.

7

2.1.8.1 The assortment of a shielding gas depends on:

the type of material being welded

joint design

desired final weld appearance

The standard gas for TIG welding is argon (Ar) or helium (He). In some cases nitrogen (N 2)

or hydrogen (H2) is added in order to achieve special properties. For instance, an addition of

hydrogen can be used for many conventional stainless steels to increase productivity. (1)

2.1.8.2 Argon

This is the most common and economical gas used in TIG welding. It is heavier than air, 10

times heavier than helium and provides a better shielding blanket than helium at lower flow

rates because it has fewer tendencies to float away or be blown out from the welding area.

Argon is less expensive than helium and can be supplied in cylinders as gas or liquid. Argon

provides smooth, quiet arc and can be used at a lower arc voltage and so argon can be used

for welding thin metals. Argon has special characteristics when used with alternating existing

which is mainly important for welding aluminium, so argon is almost used for aluminium

welding. The use of argon results in high weld quality and good appearance. (2)

8

2.1.8.3 Helium

Helium is an ideal shielding gas, and can be used alone or in combination with argon. Helium

demands a higher arc voltage than argon. Because helium is lighter than argon, it demands

higher flow rates 2 to 3 times better than argon to provide acceptable gas shield to the weld

area. Helium is used for welding thick metals and foe welding metals with high heat

conductivity because they lose heat rabidly. Such metals demands higher arc voltages with

helium.

Figure 3 (Properties of shielding gas) [9]

9

2.1.8.4 Recommendations for shielding gases used in TIG welding of different stainless

steels are given in the table.

Shielding gases for TIG welding

Parent metal (type of material)

Austenitic

stainless

steel

Duplex

stainless

steel

Super-

duplex

stainless

steel

Ferritic

stainless

steel

High-alloy austenitic

stainless steel

Nickel

alloys

Ar ● ● ● ● ●

He ● ● ● ● ● ●

Ar + He ● ● ● ● ● ●a

Ar + (2-5)% H2 ●b - - - ●b ●b

Ar + (1-2)% N2 - ● ● - - -

Ar + 30% He + (1-2)% N2 - ● ● - - -

a=> Ar + 30% He improves flow compared with Ar.

b=> preferably for automatic welding, high welding speed, Risk of porosity in

multi-run welds.

Table 1 (Shielding gases for TIG welding) [10]

10

2.1.9 Welding torch

TIG torches come in different sizes, shapes, amperage and capacities. TIG torches provide a

means for holding and changing the tungsten electrode that conducts the current to the arc

and carry shielding gas, electricity and cooling water. The major components of a typical

welding torch are shown in (Fig 4) There are two main types of GTAW torches; the gas

cooled welding torches used for welding thin metals at currents under 200 amperes, and the

water cooled torches used for welding medium and thick metals.

Figure 4 (Welding torch TIG) [11, 12]

2.1.10 Safety operation for welding

1. Never do any welding, cutting, or hot work on used drums, barrels, barrels, tanks, or other

containers.

2. Be sure the welder is properly installed and grounded.

3. Never weld without adequate ventilation.

4. Take proper precautions to prevent fires.

5. Protect your entire body with fire retardant clothing shoes, and gloves.

6. Wear eye protection at all times.

7. Weld only in a fire safe area.

8. Mark metal “HOT” with a soapstone.

9. Keep a well-stocked first aid kit handy.

11

2.2 Mild steelMild steel also known as plain carbon steel is the most shared form of steel because its price

is comparatively low while it provides material possessions that are acceptable for many

applications, in general engineering (finishes galvanize paint).

Mild steel (plain carbon steel) is steel in which the main interstitial alloying base is carbon in

the variety of 0.12-2.0%. The term “carbon steel” might also be used in reference to steel

which is not Stainless steel; in the use carbon steel might comprise alloy steels. As the carbon

percentage content rises, steel has the ability to become harder and stronger through heat

treating; however it becomes less ductile. Regardless of the heat treatment, higher carbon

content reduces join ability. In carbon steel, the higher carbon gratified lowers the tender

point.

2.2.1 Type of Mild steel (plain carbon steel)

2.2.1.1 Low-carbon steel:

It contains approximately 0.05–0.320% carbon creation it malleable and ductile. Mild steel

has a relatively low tensile strength, nevertheless it is inexpensive and informal to form;

surface hardness can be increased through carburizing.

2.2.1.1.1 Carburizing,

This is a heat treatment procedure in which iron or steel absorbs carbon liberated when the

metal is heated in the attendance of a carbon bearing material, such as charcoal or carbon

monoxide, with the intent of making the metal harder. Contingent on the amount of time and

temperature, the pretentious area can vary in carbon content. Longer carburizing times and

higher temperatures typically increase the depth of carbon dissemination. When the iron or

steel is cooled rapidly by slaking, the higher carbon content on the outer surface becomes

hard via the transformation from austenite to martensitic, while the core remains soft and

tough as a ferritic and/or pearlite microstructure.

This manufacturing process can be characterized by the following key points: It is applied to

low-carbon work pieces; work pieces are in contact with a high-carbon gas, liquid or solid; it

produces a hard work piece surface; work piece cores largely retain their toughness and

ductility; and it produces case hardness depths of up to 0.25 inches (6.4 mm). In some cases it

12

serves as a remedy for undesired decarburization that happened earlier in a manufacturing

process. Low carbon steel will be used to build the base.

2.2.1.2 Medium carbon steel:

Approximately 0.29% to 0.54% carbon fulfilled with 0.60 to 1.65% manganese content (e.g.

AISI 1040 steel). Equilibriums ductility and strength and has good wear resistance; used for

large parts, forging and car parts.

2.2.1.3 High carbon steel:

Approximately 0.55% to 0.95% carbon contented with 0.30 to 0.90% manganese content.

Very strong, used for springs and high-strength wires.

2.2.1.4 Very high carbon steel:

Approximately 0.96% to 2.1% carbon contented specially processed to produce specific

atomic and molecular microstructures.

Steel can be heat-treated which allows parts to be fabricated in an easily-formable soft state.

If sufficient carbon is present, the alloy can be hardened to intensification strength, wear, and

impact confrontation. Steels are often wrought by cold-working methods, which is the

shaping of metal through deformation at a low equilibrium or metastable temperature.

13

Composition Typical properties

Range %Carbon Yield or

0.1%

PS(Proof

stress)

(N/mm2)

UTS

(Ultimat

e tensile

stress)

(N/mm2)

Elongation

(%)

IZO

D (J)

Condition Comment Typical

applications

Low

carbon

steel

0.07 -

0.15

240 380 35 84 As-rolled Suitable for

welding, cold

forming,

carburising.

Does not

respond to

quench

hardening.

Rivets, rod,

wire, cold-

rolled

385 415 20 42 Cold-drawn Properties

depend on

degree of cold

work.

Sheet, cat

body

pressings,

Tubes.

0.15 -

0.25

290 490 33 78 As-rolled Does not

significantly

respond to

quench

hardening.

Boiler plate,

365 520 35 110 Normalised Suitable for

more

moderate cold

working.

Steel sections,

280 515 32 76 Annealed May be

carburised.

Forgings,

570 670 12 30 Cold-drawn Used for hot

pressing.

Low-stressed

shafts

Table 2 (Typical properties)

14

2.3 Stainless steelStainless steel is not a single alloy and it’s an alloy of iron with a minimum of 10.5%

chromium. (3) They are chromium oxide current on the surface of stainless steel prevents

corrosion by stopping oxygen from touching the surface of the steel, blocking rust from

forming. So deterioration of the interior of the metal cannot happen when the surface is

protected. Because stainless steel does not readily corrode the way mild steel and aluminium

would, this makes stainless steel suitable for exposed surfaces of a project, even in exterior

applications Stainless steel does not readily corrode, rust or stain with water as ordinary steel

does. However, it is not fully stain-proof in low-oxygen, high-salinity.

Salinity is the saltiness or dissolved salt content of a body of water or poor air-circulation

settings. There are different grades and surface finishes of stainless steel to suit the setting the

alloy must endure. Stainless steel is used where both the possessions of steel and corrosion

resistance are required. Polished stainless is aesthetically pleasing and lasts the longest in the

face of the elements. (3)

2.3.1 Types of Stainless steel

Stainless Steel Type 304 is a variation of the basic 18-8 grade, Type 302, with a higher

chromium and lower carbon content. Lower carbon minimizes chromium carbide

precipitation due to welding and its susceptibility to intergranular corrosion. In many

instances, it can be used in the”as-welded“condition, while Type 302 must be annealed in

order to retain adequate corrosion resistance. (2)

Type 304L is an extra low-carbon variation of Type 304 with a 0.03% maximum carbon

content that eliminates carbide precipitation due to welding. As a result, this alloy can be

used in the”as-welded“condition, even in severe corrosive conditions. It often eliminates the

necessity of annealing weldments except for applications specifying stress relief. It has

slightly lower mechanical properties than Type 304.

2.3.2 The available forms

Stainless Steel produces Type 304/304L Stainless Steel in thicknesses from 0.01" to 0.25"

(0.025 to 6.35 mm) max, and widths up to 48" (1219 mm). For other thicknesses and widths,

inquire. The pipe and the end plate in this project are stainless steel type 304.

15

CHAPTER 3:

3 Project design

This (figure 5) shows the plasma cutting with a CNC machine. This was before the low-

carbon steel was cut. An old steel sheet was used, as it has the same length of the materials

needed to manufacture the part.

Plasma cutting with a CNC machine is used to cut the steel in this project. Plasma cutter

manufacturer builds CNC cutting tables, and some have the cutter built into the table. CNC

tables allow a computer to control the torch head producing clean sharp cuts. Modern CNC

plasma equipment is capable of multi-axis cutting of thick material, allowing opportunities

for complex welding seams that are not possible otherwise. For thinner material, plasma

cutting is being progressively replaced by laser cutting, due mainly to the laser cutter's

superior hole-cutting abilities.

Figure 5 (Plasma cutting with a CNC machine)

16

3.1 Safety on plasma cuttingProper eye protection but not gas welding goggles as these does not give UV protection and

face shields are needed to prevent eye damage called arc eye as well as damage from debris,

as per Arc Welding. It is recommended to use green lens shade #8 or #9 safety glasses for

cutting to prevent the retinas from being "flashed" or burned.

This is the Scaffold diagram in Solid Works as a DXF files. This was done to send the

scaffold to the Plasma cutter with a CNC machine as the part drawing will need to be in DXF

files form.

Figure 6 (Scaffold)

Figure show the base built in solid works and saves as DXF files. To sends the Base to

Plasma cutting with a CNC machine the drawing will need to be in DXF files.

Figure 7 (Show the base built in .Dxf. format)

17

3.2 Manufacture

This figure show the scaffolds cut out of the Plasma cutter with a CNC machine.

Figure 8 (Scaffold cut out)

This figure show the Base cut out of the Plasma cutter with a CNC machine.

Figure 9 (Base cut out)

This figure show the assembly of the base.

Figure 10 (Putting it together to see if it work)

18

This figure shows two scaffolds being welded together. Two scaffolds were welded together

because the hole was to big and they needed to fit more accuratly.

Figure 11 (Welding two scaffolds together)

Figure shows the completed fixture.

Figure 12 (Fixture)

19

Figure show the welding machine, arc welder.

Figure 13 (Welding table)

An angle grinder, also known as a side grinder or disc grinder, is a handheld power tool used

for cutting, grinding and polishing.

Figure shows the base being grinder down so that every part is smooth and there is less

surface roughness

Figure 14 (Base being grinder down)

20

Figure shows the stainless steel pipe that will be welded.

Figure 15 (The pipe)

Figure shows two end plate that were cut into two different sizes, the first radius was 25 cm

while the second was 23 cm. One end is smaller than the other so that it can fit into the pipe

with a tight fit. This was done so that it did not involve the use of tacking the piece together

Figure 16 (The end plate)

21

The spot welder is used to welder the two end plate together. Spot welder is a Resistance

Welding, process, in which work pieces are welded due to a combination of a pressure

applied to them and a localized heat generated by a high electric current flowing through the

contact area of the weld.

The following metals may be welded by Resistance Welding: 

Low carbon steels - the widest application of Resistance Welding

Aluminium alloys

Medium carbon steels, high carbon steels and Alloy steels (may be welded, but the

weld is brittle)

Figure 17 (Spot welder)

Figure shows a side profile of the two end plate. After cutting the end plate into two different

sizes, it was then welded together in this figures you can see that the end on top is smaller

than the one below it.

Figure 18 (The two end plate welder together)

22

Figure shows the end plate of the pipe being fitted to the pipe this was done because the ends

plate needed to stay tight so as not to fall off. It was then after fixed into the pipe and tacked

in. This was done to ensure that the ends plate stayed in place.

Figure 19 (The end of the pipe being fitted to the pipe)

Figure shows the end of the end plate’s being TIG welded to the pipe to compared results

between the manually welding the end plate and the machine welding the end plate

Figure 20 (The ends of the ends plate being welded to the pipe)

23

Figure 21 (The stainless steel pipe on the base)

This figure shows the stainless steel pipe on the base, this is where the pipe will be placed as it gets

welded.

24

3.3 The guide rollers

The guide rollers used in this project were bought from (Dickson Bearings and Transmissions

Limited). The guide rollers are made of high-quality thermoplastic polyurethane, 98° shore A

hardness, very low rolling resistance, high abrasion resistance, colour dark brown, non-

marking, non-staining, tread directly injected onto the ball bearing.

The bearing type is a stainless steel ball bearing, sealed, lubricated with long-life grease.

Table 3 (Guide rollers distance)

Guide Rollers Wheel∅

(D) (mm)

Wheel

Width

(T2) (mm)

Load

capacity

(kg)

Ball

bearing

Axle

bore ∅

(d) (mm)

Clamper

Length

(T5) (mm)

FPU40x16/12-

10K

40 16 50 6201

2RS

12 10

25

3.4 Torque Experiment & calculating

Torque is a measure of how much force acting on an object causes that object to rotate. The

object rotates about an axis, which we will call the pivot point, and will label 'O'. We will call

the force 'F'. The distance from the pivot point to the point where the force acts is called the

moment arm, and is denoted by 'r'. Note that this distance, 'r', is also a vector, and points from

the axis of rotation to the point where the force acts. (Refer to Figure 22 for a pictorial

representation of these definitions.)

Figure 22 (Definitions) [13]

Torque is defined as

 = d x F 

In other words, torque is the cross product between the distance vector (the distance from the

pivot point to the point where force is applied) and the force vector, 'a' being the angle

between rand F.

To get the torque of the rotation for the pipe, a screw was drilled into the pipe, so a wire were

be rolled around the screw and a hanging weight hook on the other side of the wire.

Figure 23 (A screw was drilled into the pipe)

26

Figure 24 (Guide rollers is fix in place using some screw)

The pipe is put on the fixture and the side with the screw is facing upped, because that is the

starting point.

Figure 25 (The pipe is put on the fixture)

27

Hanging weight with 1kg = 1000g = 9.81N

Each bar individually weighs 0.9806N

Figure 26 (Hanging weight)

The wire was rolled around the screw and the other end of the wire was rolled around the

hanging weight hook. The hanging weight was not enough.

28

Figure 27 (Testing)

It takes 3 hanging weight to get the pipe to move, so to get the force the 3 weight were be (x)

by 0.9806.

It takes 3 bars to get the pipe to move so:

The 3 bars x by 0.9806 = 2.9418 => F = 2.94

New to get the D,

π x D => π x 50.5 =158.65mm

= F x D

= 2.94 x 158.65 = 466.43 N/mm

= 466.43Nmm

3.5 Calculate the length of time taken to weld

Welding tests were carried out on straight pieces of stainless steel plate to calculate the length

of time taken to weld 163mm. This 163mm length is the circumference of the pipe 158mm

plus a 5mm weld over allowance.

Amps Time

Test run 1 35 1min 5sec

Test run 2 35 1min 3sec

Test run 3 35 1min 10sec

Average 3.55

Table 4 (The amps and time)

Given this the welding Amperage will be 35 Amps and welding speed 1min 20sec for

1rotation.

29

3.6 Motor

Figure 28 ( The motor fixed in)

This piece was re-used from a previous project. This motor was used for this project because

it had the facility to supply variable speeds, which allow for variable test conditions.

30

Figure 29 (Motor)

Figure 30 (Variable speeds)

Figure 31(Transformer mitsubishi)

Mitsubishi Inverter

Model FR-E540-0. 75K-EC

Power 0.57kw

Input 4. 1A 3PH AC380-480V 50Hz

3PH AC380-480V 60Hz

Output 2 6A MAX 3PH AC380-480V

0. 2-400Hz

Serial E44X24090

TC100A737G52

31

Table 5 (Mitsubishi Inverter)

3.7 555 Mono stable Switch Kit

The 555 Mon stable Switch Kit was bought from The Electronics Specialist Maplin.

Figure 32 (The 555 time kits)

3.8 Operation

Connect a 12V power supply to either the DC jack (centre positive, 2.1mm), or the terminal

block, X1 (observing polarity).

The circuit provides a timed output pulse when triggered. The RESET button will cut the

pulse short. Additional pads are located near the START and RESET button so external

switches can be used if desired.

Provides a timed output pulse when triggered

Trigger12v and reset inputs

Pulse duration adjustable from approximately 1 second to over 15 minutes

Single pole changeover relay rated at 24V 10A (not suitable for direct switching of

mains voltages)

Requires a 12V power supply

32

The 555 switch was set together. Then the wire from the touch switch was fixed into it. And

then a negative and a positive wire were connected to the opposite sides. Afterwards they

were both connected to the 24DC power supply.

The torch switch is normally pressed on and there is no timer in it. The torch needs to run for

one minutes two seconds for one rotation (29). So the 555 timer was there to start the torch

and stop it when the time runs out.

Figure 33 (The 555 timer put together)

The negative and positive were connected into the 24DC power supply. New that is done the

time was set and was test before connect to the power source.

33

Figure 34 (555 timer connected to the torch)

Figure 35 ( 24DC

power supply (DIT))

When the start button press the gas starts then the arc, and when1min 20 sec for 1rotation is

complete the arc stops and the gas continues to flow to stop the atmosphere from coming in

(33).

Figure 36 (The wire is connected into the 24DC power supply and the torch)

Sequim chart

Start Gas on

Arc on

34

End Arc off

Gas off

Table 6 (Sequim chart)

Figure 37 (TIG power source)

35

CHAPTER 4: Analysis & Conclusion

4 Assembly of final and testing components

To know the distance among the scaffolds and the guide rollers, an ASTM A194 Gr8M

Heavy Hex Nuts was put among the guide rollers and the scaffolds but the nut didn’t work.

The rollers weren’t tight enough on the screw and nut.

Figure 38 (Testing 1 of the guide rollers and scaffolds distance)

So to get the guide rollers which are 8cm wide to be tight a steel of 8cm was put in between

the guide rollers and the scaffold, a steel ruler was inserted in between. And the distance was

right both ends were welded in tight.

36

Figure 39 (Testing 2 of the guide rollers and scaffolds distance)

This was to determine whether the guide rollers would roll, when the motor is in motion. To

test a hand was used instead of the motor to turn it.

Figure 40 (The steel welded into the guide rollers)

Figure 41 (Tasting the distance is right and it rollers)

37

A new roller was built using steel to get greater contact between drive wheel and stainless

pipe. Because the steel needed wasn’t available, 3 pieces of steel were cut to the size of the

guide roller and welded together and then ground to a suitable finish.

Figure 42 (Building the new guide rooler)

It was then after fixed onto the steel and welded in the place. the tip was then screwed shut so

it would be able to move because the steel would be fixed into the motor

Figure 43 (The new guide roller fixed and welded into the steel)

38

Figure 44 (This shows everything in set)

To get the surface smooth an angle grinder was used to file it up to the smooth nature.

Figure 45 (Smoothing the steel into the scaffold)

39

Figure 46 (The surface fines)

This shows the final wheel assembly. The two guide rollers at both left side are both welded.

And on the right side are not. The top side at the right is screwed and the other side is free of

welded or screw because that is the place where the motor will be placed.

Figure 47 (The guide rollers in place)

40

A torch hold assembly was manufactured.

Figure 48 (The torch hold)

This torch hold was fixed position in the work shop and a location pin was positioned to get

the correct point of the torch.

Figure 49 (The torch in place)

41

Figure 50 (Base plant)

An Cordless drills was set in placed of the motor to test the movement of the guide rollers

Figure 51 (Testing the speed with a Cordless drills)

42

4.1 Test and Result

The motor was set to start when the switch on and continuous rotates until the motor is turned

off .The torch begins when the start button has being pressed, and after 1min and 20 second

the torch stops.

When for 35 amps => 1min 20 sec for 1rotation had complete the pipe will be take off and

insert the other side of the pipe.

Figure 52 (Assembly of the rotation device)

The first test didn’t work because the amperage was too high, 75amps.So because of that the

welding process over penetrated (29). So the amperage was adjusted to 60amps.

Figure 53 (Test1 first result)

After making an adjustment and after completing one rotation figure 55 is the result that was

achieved.

Figure 54 (Test1 second result)

43

After the adjustment on the first test and the reason why the system did not work was that the

first end plate that was put through the process the arc did not fully fill the gap in-between the

end plate and the pipe. Therefore a new end plate was manufactured with a bigger diameter

equalling the same diameter as the pipe that figures 56 shows.

Figure 55 ( 1 show the first end plate and 2 show the new end plate)

Figure 56 (The new two end plate welder together)

Figure 57 (The new end of the pipe being fitted to the pipe)

44

The second test did work but had problems during the process. When the test piece was

rotating the steel roller wasn’t smooth enough because of this manufacturing defect the test

piece was slowing down due to the roughness of the steel roller causing the arc to burn

through the pipe.

Figure 58 (Test 2 result)

.

Figure 59 (The steel roller is the cost of the test 2 mistake)

45

To achieve a smooth surface on the steel roller a heat resistant rubber was placed on the steel

rollers to achieve a smooth surface to allow the test piece to rotate freely around its axis, so

that the arc will not burn through the pipe during the rotation

Figure 60 (The steel roller with the rubber on it)

After fixing the problems from test 1 and test 2, the third test was a success as the welding

process was achieved because the arc had fully achieved one rotation without any burn

through or damage to the piece. For test 3 the amperage was changed from 60 to 50amps

because to be in a safer welding zone.

Figure 61 (The final testing)

46

4.2 Conclusions

The purpose of this final year project was to build and mechanization of a stainless steel pipe end

Assembly mechanise a TIG welding rotating device process. This included design, manufacture and

testing. The 3D modelling software used allowed further the continuous evolution of the design,

throughout the design and manufacturing stage.

TIG welding is used to weld the pipe end. TIG welding is also known as gas tungsten arc welding

(GTAW) is capable of achieving the highest quality welds and is the most versatile in terms of what

can be welded and the position of the welds. A 555 Mono stable switch kit circuit provides a timed

output pulse when triggered. The RESET button will cut the pulse short. Additional pads are located

near the START and RESET button so external switches can be used if desired. It is used to operate

the TIG torch.

Plasma cutting is a process that is used to cut steel and other metals of different thicknesses or

sometimes other materials using a plasma torch.

Mild steel is a great choice for large projects, or coated or painted projects, and any internal structural

components, this reduces cost. The Fixture is Low-carbon steel.

Stainless steel type 304 is sturdy, aesthetically luminous, and most expensive. Stainless steel does not

readily corrode, rust or stain with water as ordinary steel does. The pipe is stainless steel.

The reason behind the building of this project was to improve the efficiency of manually TIG welding

and the cost. It takes about 60-80 euro an hour to manually weld the pieces. Welders have to tack the

end plate to the pipe and weld the pieces together with the project 30-40 euro an hour as an unskilled

worker with small amount of training can operate the machine.

47

Established final parameters

TIG Amperage 56 amps

Rotation Time 62 seconds

Table 7 (Established final parameters)

Manually welding Cost Mechanised Welding Cost

Set up

Tacking = 6-8 min each

Welding

Welding = 3-4 min each

Cost 80 Euro Saving 50 % More efficient

Table 8 (Manually welding Cost and Mechanised Welding Cost)

48

4.3 COST OF THE PROJECT

COST OF THE PROJECT Bough

555 Mono stable switch kit 14.49 EURO The electronics

specialist Maplin

The guide rollers(4) 28.51 EURO Dickson Bearings

and Transmissions

Limited

Stainless steel Supplied

Low –carbon steel Supplied

Table 9 (Cost of the project)

49

CHAPTER 5:

5 Bibliography

[

1.] Gas tungsten arc welding. Wikipedia. [Online] Gas tungsten arc weldin, . [Cited: 7 July

2014.] http://en.wikipedia.org/wiki/Gas_tungsten_arc_welding.

[2. ]TWI. TIG welding. http://www.twi-global.com/. [Online] TWI, March 1995. [Cited: 2

3 2015.] http://www.twi-global.com/technical-knowledge/job-knowledge/tungsten-

inert-gas-tig-or-gta-welding-006/.

[3.] ASSOCIATION, BRITISH STAINLESS STEEL. The basics about stainless steel.

BRITISH STAINLESS STEEL ASSOCIATION. [Online] [Cited: 2 04 2015.]

http://www.bssa.org.uk/about_stainless_steel.php.

[4.]Impact Ireland Metals Ltd, Engineering Steel Stockist. Ireland's leading multi-

metal stockholder and distributor. Ireland's leading multi-metal stockholder and

distributor. [Online] Engineering Steel Bar. [Cited: 11 October 2014.]

http://www.impactirl.ie/engineering-steel-bar-bright-free-cutting-en1a-leaded-bs-en-

10277-3.php.

[5.] J.F.Lancaster. Metallurgy of welding. London : Allen & Unwin, 1980,1887. ISBN 0-

04-669010-7.

[6.] Welding Metallurgy of Stainless steels. Hall, Abington. Eagland : Abington

publidhing, 1994, Vol. 1. ISBN 1-85573-173-8.

50

Images

[7](Figure 2) (TIG welding process) (2012) (Accessed on 4.4.2015)

At: http://www.wballoys.co.uk/TIG/what-is-tig-welding.html

[8] (Figure 1) (Welding wire) (Accessed on 2.3.2015)

At: http://www.steelwirechina.com/gas-shielded-welding-wire.html

[9](Figure 3) (Properties of shielding gas) (Accessed on 2.3.2015)

At: http://www.esabna.com/us/en/education/blog/what-shielding-gas-should-i-use-

when-welding-aluminum.cfm

[10] (Table 1) (Shielding gases for TIG welding) (Accessed on 2.3.2015)

At: http://www.smt.sandvik.com/en/products/welding-products/shielding-gases/

shielding-gases-for-tig/

[11] (Figure4) (Welding torch TIG) (Accessed on 2.3.2015)

At: http://i00.i.aliimg.com/wsphoto/v0/1621519686_2/TIG-KIT-TIG-Welding-Torch-

Consumables-Accessories-Alumina-Gas-Lens-TIG-Back-Cap-Collet-Bodies-FIT.jpg

[12] (Figure 4) (Welding torch TIG) (Accessed on 2.3.2015)

At: http://www.millerwelds.com/resources/tech_tips/TIG_tips/images/TIGExplodedC

ALLOUTS_001.jpg

[13] (Figure 22) (Definitions) (Accessed on 22.3.2015)

At: https://www.physics.uoguelph.ca/tutorials/torque/Q.torque.intro.html

51

52

CHAPTER 6:

Appendices

53

54

55

56