ENGINEERING Revision Guide

1. ENGINEERINGRevision Guide Revision Tips: Make sure you use the revision guide to help you go over topics for your exam. Use your exercise book alongside the revision guide. Don’t just read notes. You could make flash cards, mind maps, make posters or use post it notes. Watching videos online can really help to bring your notes alive! Test yourself by completing past papers or asking a friend to test you! This will identify areas of strength and weakness Build in rewards for your revision e.g.: your favourite snack or using social media. Edition: 2018

2. CONTENTS PCB’s and SMT’s/ Soldering ___________________________ Page 2 Engineering Sectors _________________________________ Page 3 New Engineering Technologies ________________________ Page 5 How metal is made? ________________________________ Page 8 Metals ___________________________________________ Page 9 Power Metallurgy Process ___________________________ Page 10 Metallic Foams ____________________________________ Page 11 Modern Composite Materials ________________________ Page 12 Smart Materials ___________________________________ Page 13 Modern High Performance Materials __________________ Page 14 Joining Metals ____________________________________ Page 15 Casting and Moulding ______________________________ Page 17 Forging and Shearing _______________________________ Page 18 Health and Safety __________________________________ Page 19 PPE/RPE _________________________________________ Page 20 Machinery _______________________________________ Page 21 Engineering Tools __________________________________ Page 24 Lean Manufacturing ________________________________ Page 25 Robots ________________________________ Page 27 Production __________________________ Page 28 Life Cycle Assessment _______________ Page 29 Environment ______________________ Page 30 Renewable Energy Resources _________ Page 31 Notes ____________________________ Page 33 1

3. PCB’s and SMT’s SMT’s SURFACE MOUNT TECHNOLOGY SMT components are smaller than their PCB components. SMT components either have smaller / no leads at all. Because the board does not require as many drilled holes, and the components are more compact, higher circuit densities are possible on smaller boards. PCB’s PRINTED CIRCUIT BOARDS They are also known as through hole technology as leads are placed through the drilled holes and soldered together to hold them into place and create an electric current. 1. Designing the layout 1. Apply solder paste to copper pads 2. Producing the artwork 2. Place components using pick and place robot 3. PCB etching 4. Drilling the board 3. Conveyor belts are used to transport the boards to the reflow soldering oven 5. Populating the board and soldering 4. The board is heated to a temperature that melts the solder plate SOLDERING 5. Components are soldered to the surface of the board • SAFETY • Fume extraction • Check soldering iron • for damage • Do not touch the tip • PPE should be worn • Personal Protection i.e. hair up • Do not distract others. • DISADVANTAGE • Permanent fastening • Several application of heat can cause damage to the board/components • Component/material wastage • Time consuming • Soldering skill required • Increased health and safety risk 6. The finished board is then inspected for imperfections • Advantages of SMT • Components are much smaller and lighter • Reduced human intervention – process is highly automated • Increased production speeds • Complex circuits products on smaller boards • Reduced cost of components, labour, protection and overheads. 2

4. ENGINEERING SECTORS AREOSPACE Aerospace engineering is the primary branch of engineering concerned with the research, design, development, construction, testing, science and technology of aircraft and spacecraft.It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering. The former deals with aircraft that operate in Earth's atmosphere, and the latter with spacecraft that operate outside it. AUTOMOTIVE Modern automotive engineering, is a branch of vehicle engineering, the design, manufacture and operation of motorcycles, automobiles, buses and trucks and their respective engineering subsystems. BIOMEDICAL Biomedical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes. This field seeks to close the gap between engineering and medicine: It combines the design and problem solving skills of engineering with medical and biological sciences to advance healthcare treatment. CHEMICAL Chemical engineering is the branch of engineering that applies the physical sciences chemistry and physics and/or life sciences biology, microbiology and biochemistry together with mathematics to convert raw materials or chemicals into more useful or valuable forms. 3

5. COMMUNICATION Communications engineering is an engineering discipline that brings together electrical engineering with computer science to enhance telecommunication systems. The work ranges from basic circuit design to mass developments. A telecommunication engineer is responsible for designing and overseeing the installation of telecommunications equipment and facilities, such as complex electronic switching systems, copper wire telephone facilities, and fibre optics. Telecommunication engineering also overlaps heavily with broadcast engineering. ELECTRICAL Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics, and electromagnetism. MECHANICAL Mechanical engineering is a discipline of engineering that applies the principles of physics and materials for analysis, design, manufacturing, and maintenance of mechanical systems. It is one of the oldest and broadest engineering disciplines. TASK: Label the images with the appropriate sector. 4

6. NEW ENGINEERING TECHNOLOGIES • SURFACE NANOTECHNOLOGIES • In modern times surface nanotechnology has become increasingly important. It has many uses from developing sports equipment to medical applications. These are chemical systems that provide coatings to a range of surfaces. • For example: • Ceramics – produce hygienic surfaces • Metals – resistance to corrosion • Glass – cleaning process much easier • Plastics – easier surface cleaning • Textiles – surfaces become water and dirt repellent • Minerals – longer lasting materials • Examples used currently: • sports equipment: nanoparticles are added to materials to make them stronger whilst often being lighter. They have been used in tennis rackets, golf clubs and shoes • clothing: silver nanoparticles have been added to socks. This stops them from absorbing the smell of sweaty feet as the nanoparticles have antibacterial properties • healthcare: nanoparticles are used in sunscreens. They offer protection and can be rubbed in so there are no white marks. • OPTICAL FIBRES • Optical fibres are used in a variety of industries, although their greatest success has come in the communications sector. • An optical fibre is a thin rod of high-quality glass. Very little light is absorbed by the glass. Light getting in at one end undergoes repeated total internal reflection, even when the fibre is bent, and emerges at the other end. • Information such as computer data and telephone calls can be converted into electrical signals. These can be carried through cables, or transmitted as microwaves or radio waves. However, the information can also be converted into either visible light signals or infrared signals, and transmitted by optical fibres. • Originally considered to be too expensive for practical • applications, optical fibres have since revolutionized the • infrastructure of telephone networks. • They bring two main advantages over using the original copper wiring: • The ability to transmit data at higher speeds • The ability to do this with lower rates of transmission errors 5

7. BIONICS • In medicine, bionics means the replacement or enhancement of organs or other body parts by mechanical versions. Bionic implants differ from mere prostheses by mimicking the original function very closely, or even surpassing it. • This is the science of applying electronic principles and devices such as computers and miniaturised SMT circuits to solve medical problems. • An example is the development of artificial pacemakers to correct abnormal heart rhythms or the development of prosthetic limbs using a Bluetooth connection and specially enabled software to control the limb movement. TELEMATICS Telematics is a combination of telecommunications and information communications technology (ICT). This technology has improved the efficiency of many organisations but has had the most impact when used in vehicles. It provides an opportunity to monitor the location or movement of vehicles across the world using the Global Positioning Systems (GPS) technology. Telematics is now widely used on all mobile devices and we would most commonly use it to track a location for example: Find my Friends on Apple devices and also using a SatNav to guide where were we need to go. • BLENDED WING BODIES • As rising fuel costs and pressure to cut emissions drive most of the aerospace industry to seek even small improvements in aircraft efficiency, the development of blended wing bodies has seen fuel consumption reduced by as much as a third. • This hybrid design uses the wings of a conventional aircraft smoothly blended into a wide tailless body. With the airframe as smooth as possible, this reduces turbulent airflow, reducing drag. Combined with the use of lightweight composite materials, this improves the fuel efficiency of the aircraft. 6

8. HYDROGEN FUEL CELLS • Hydrogen is a versatile energy carrier that can be used to power most devices. The key to making this happen is the hydrogen fuel cell – a energy conversion device that captures and uses the power of hydrogen efficiently. • Fuel cells are used for the following reasons: • They directly convert the chemical energy in the hydrogen to electricity with pure water and useful heat as the only waste materials. • They operate very quietly and are very efficient – typically 2-3 times the efficiency of traditional energy generation methods. • Fewer moving parts mean very simple construction and so mass production costs are low. High energy production. Zero pollution – Water is the only by-product. Readily available – Comes from missing base metals with acid. Highly inflammable – Difficult to store and transport. Fossil fuels are needed to cause the chemical reactions that create the hydrogen. To make hydrogen fuelled cars a reality all petrol stations would need to be refitted at huge expense. Car tanks take minutes to refuel. 7

9. HOW IS METAL MADE? The Earth's crust contains metals and metal compounds such as gold, iron oxide and aluminium oxide, but when found in the Earth these are often mixed with other substances. To be useful, the metals have to be extracted from whatever they are mixed with. A metal ore is a rock containing a metal, or a metal compound, in a high enough concentration to make it economic to extract the metal. The method used to extract metals from the ore in which they are found depends on their reactivity. For example, reactive metals such as aluminium are extracted by electrolysis, while a less-reactive metal such as iron may be extracted by reduction with carbon or carbon monoxide. MAKING IRON Iron is extracted from iron ore in a huge container called a blast furnace. Iron ores such as haematite contain iron oxide. The oxygen must be removed from the iron oxide to leave the iron behind. Reactions in which oxygen is removed are called reduction reactions. In this reaction, the iron oxide is reduced to iron, and the carbon is oxidised to carbon dioxide. In the blast furnace, it is so hot that carbon monoxide can be used to reduce the iron oxide in place of carbon. Pure iron is soft and easily shaped. This is because its atoms are arranged in a regular way that lets layers of atoms slide over each other. Pure iron is too soft for many uses. Iron from the blast furnace is an alloy of about 96 per cent iron with carbon and some other impurities. It is hard, but too brittle for most uses. So, most iron from the blast furnace is converted into steel by removing some of the carbon. MAKING STEEL Carbon is removed by blowing oxygen into the molten metal. It reacts with the carbon producing carbon monoxide and carbon dioxide. These escape from the molten metal. Enough oxygen is used to achieve steel with the desired carbon content. Other metals are often added, such as vanadium and chromium. There are many different types of steel, depending on the other elements mixed with the iron. MAKING ALUMINIUM AND TITANIUM Aluminium and titanium are two metals with a low density. This means that they are lightweight for their size. They also have a very thin layer of their oxides on the surface, which stops air and water getting to the metal, so aluminium and titanium resist corrosion. Aluminium is used for aircraft, trains, overhead power cables, saucepans and cooking foil. Titanium is used for fighter aircraft, artificial hip joints and pipes in nuclear power stations. Aluminium extraction is expensive because the process needs a lot of electrical energy. Titanium extraction is expensive because the process involves several stages and a lot of energy. 8

10. ALLOY An alloy is a combination of metals put together to make one. METALS TYPES FERROUS A Ferrous metal contains Iron therefore does rust overtime. NON FERROUS A Non Ferrous metal does not contain IRON therefore does not rust. TASK: Which metal would you use for these image? There are a variety of different metals that are used for different jobs. Metals have different properties, strengths and can be a made from a combination of metals. ALLOY ALLOY ALUMINIUM Ductile, soft, malleable and light weight. MOST COMMON MATERIAL USED FOR WINDOW FRAMES, KITCHEN WARE, AIRCRAFT. MILD STEEL Tough. High tensile strength. Can be case hardened. MOST COMMON MATERIAL USED FOR GENERAL METAL PRODUCTS. ALLOY CARBON STEEL Tough. High strength. MOST COMMON MATERIAL USED FOR MAKING TOOLS SUCH AS DRILLS. COPPER Ductile. Conducts electricity and heat. MOST COMMON MATERIAL USED FOR ELECTRICAL WIRING, PIPES, TUBING. ALLOY SILVER Ductile, malleable, solders, resists corrosion. MOST COMMON MATERIAL USED FOR JEWELLERY/ ORNAMENTS. STAINLESS STEEL Tough. Resistant to rust due to alloy. MOST COMMON MATERIAL USED MAKING KITCHEN TOOLS.. ALLOY BRASS Hard, Casts and machines well. Tarnishes. Conducts Electricity. MOST COMMON MATERIAL USED FOR PARTS FOR ELECTRICAL FITTINGS. ALLOY CAST IRON Strong but brittle. MOST COMMON MATERIAL USED FOR CASTING, MANHOLES AND ENGINES. WROUGHT IRON Tough, Ductile, Resistant to Rust as 100% Iron. MOST COMMON MATERIAL USED FOR FANCY GATES. VERY EXPENSIVE. LEAD Soft, heavy, ductile, loses shape under pressure. MOST COMMON MATERIAL USED FOR PIPES AND ROOFTING. 9

11. POWER METALLURGY PROCESS The powders are then compacted in a die and heated in a controlled furnace atmosphere to bond the particles. Highly evolved method of producing consistently shaped components by blending elements or pre-alloyed elements together. • ADVANTAGES • It requires relatively low processing temperatures. • Final products require little finishing. • There is no waste. • Complex parts can be produced with precision and close tolerances. • It can be applied to all classes of materials. • DISADVANTAGES • High production of powder • Potential workforce health problems from atmospheric contamination • The tools and equipment required are very expensive • It’s difficult to produce large and complex shaped parts with powder metallurgy. • The parts produce by powder metallurgy have low ductility and strength. 10

12. METALLIC FOAMS Metallic foams have properties that make them very useful for most engineering sectors, particularly the automotive and aerospace sectors, including: A high strength-to-weight ratio, particularly when aluminium is used The ability to absorb large amounts of energy when crushed Being non-flammable in most cases Allowing the transfer of heat energy very easily. Metal foams are easily recyclable back into the original metal, making them more reusable than polymer foams. • ADVANTAGES • These advantages outweigh the main disadvantages, which are: • Their high cost means they are only used with advanced technology • Once crushed they do not spring back to shape like polymer foams, therefore they can only be used once. • APPLICATIONS • Typical uses of metallic foams include: • Sound dampening in cars or aircraft to reduce noise for the driver or passengers • Energy absorption to improve safety so passengers of a car are less likely to be injured during a collision • Taking heat from sensitive electronic components to reduce risk of product failure. 11

13. MODERN COMPOSITE MATERIALS Materials that combine 2 different materials together to create a new material with better properties CARBON FIBRE Carbon Fibre is a reinforced polymer. It is an extremely strong and lightweight fibre-reinforced polymer which contains carbon fibres. Aeronautical engineering: Wing part Automotive: engineering racing car bodies and suspension parts Stronger and stiffer than Aluminium. Lighter in weight than steel. Amazing strength to weight ratio and is easily moulded/shaped. Resistant to corrosion, rigid/stiff and quite expensive. • KEVLAR • para-aramid synthetic fibre • high-strength material • spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components. • bicycle tires and racing sails to body armor • high tensile strength-to-weight ratio; by this measure it is 5 times stronger than steel. • Lighter in weight than steel armour and Flexible. • High tensile strength to low weight ratio. • High chemical resistance, extremely tough and stable. • Non flammable. • GLASSFIBRE REINFORCED POLYMER (GRP) • Individual glass fibres (very thin) • woven to form a flexible fabric. • The fabric is normally placed in a mould, for instance a mould for a canoe and polyester resin is added, • water tanks, surfboards, canoes, small boat hulls + Aeronautics • good thermal insulation properties. • It has a high strength to weight ratio, • Flexible AND High Tensile Strength • Stronger and stiffer than plastics alone e.g. polypropylene 12

14. SMARTMATERIALS A material that can have one or more of its properties changed in a controlled manner by an external stimulus. SHAPE MEMORY ALLOY SHAPE MEMORY POLYMER Properties: Bendable, it will return to its original shape if heated above a certain temperature. Examples of use: Sprinklers in fire alarm systems, spectacle frames, coffee machine. Reasons for use: It’s easily shaped and keeps its shape. Improvements from traditional materials: Glasses had to be re-bended by hand but now you can use heat. Properties: Will return to its original shape if heated above a certain temperature. A good insulator. Examples of use: Window sealing foam, sensors and robots. Reasons for use: Strong, low cost, can be triggered by temperature and light. Improvements from traditional materials: Can be tailored to a broad range of materials and temperatures. ELECTROCHROMIC MATERIALS PIEZOELECTRIC ACTUATORS Properties: When electricity is applied to a Piezo Actuator is changes shape by a small amount. They can be stacked. Examples of use: Controlling hydraulic valves, adjusting machinery tools Reasons for use:Very small and precise movement, no motors or gears to go wrong. Improvements from traditional materials: Easy to control pumps and valve. Properties: Change colour when electricity is applied. Examples of use: Smart windows, electrochromic mirrors and display devices. Reasons for use:Windows, automatic tinting depending on sun. Improvements from traditional materials: Usually you have to choose the colour of the material and it can’t be changed easily. 13

15. MODERN HIGH PERFORMANCE MATERIALS • TUNSTEN • Practically indestructible • High Cost • Very High Melting Point (3420) • Resistant to corrosion • Attacked only slightly by most mineral acids. • TITANIUM • Low density • High strength • Resistant to corrosion • Low thermal conductivity • Not a good conductor of electricity • Nontoxic and generally biologically compatible with human tissues and bones • SUPER ALLOYS • Excellent strength at high temperatures • Very expensive • Resistant to corrosion • Hardwearing • Excellent mechanical strength • APPLICATION • Aerospace • Turbine blades and jet/rocket engines • Marine industry • Submarines • Chemical processing industry • Nuclear reactors • Heat exchanger tubing • Industrial gas turbines • CERAMICS • Very hard but brittle • Good wear resistant • Very stableand chemically inert 14

16. JOINING METALS MIG METAL INERT GAS More commonly called MIG welding this welding type is the most widely used and perhaps the most easily mastered type of welding for industry and home use. The MIG process is suitable for fusing mild steel, stainless-steel as well as aluminium. • Suitable for large scale production. • Varying thickness of materials can be joined. • Reduced cost because the production of neat and clean metal deposits on the work piece means there is no need for extra cleaning. • Less skill required in this process. • Wire rod automatically feeds to the surface. • Automatic or semiautomatic welding process. TIG TUNGSTEN INERT GAS TIG welding is comparable to oxy acetylene gas welding and needs a lot more expertise from the operator. Employed for carrying out high-quality work when a superior standard of finish is needed without making use of excessive clean up by sanding or grinding. • Much more skill is required for TIG welding and time is • needed to practice to get the required finish. • Creates high quality welds. • Can be done in any position i.e. overhead. • Much more expensive process due to the high labor costs. OXY-ACETYLENE A gas welding process where a flame is produced using a mixture of oxygen and acetylene. No pressure on the product is required – heat is there to control the welding of the parts. If a filler rod can be used for any gaps but it should be the same material as that being joined. • Easy of controlling the low and high temperatures needed for welding, brazing and soldering as the gas can be mixed manually. • Relatively inexpensive in comparison with other welding processes and commonly found in school or college workshops 15

17. Earth clamp is needed to be able to complete the circuit. • Cost – equipment for arc welding is well-priced and affordable, and the process often requires less equipment in the first place because of the lack of gas • Portability – these materials are very easy to transport • Works on dirty metal. • Lower efficiency – more waste is generally produced during arc welding than many other types, which can increase project costs • High skill level – operators of arc welding projects need a high level of skill and training, and not all professionals have this. ELECTRIC ARC This generates sufficient heat to melt the joint edges by creating an electric current through a gap (arc) between the materials being joined and the filler rod (electrode). The electrode is coated in a flux which, when melted, prevents the joint area becoming oxidised. SPOT/SEAM WELDING A type of electrical resistance welding generally used to join sheet material together. The basic principle uses a transformer with 2 electrodes. When they trap the sheet material they generate enough heat to fuse the two together. • The process is free from fumes or spatter. • Requires little or no maintenance. • Cost effective. NUTS& BOLTS WASHERS RIVETS Countersink Rivet’s are used when the surface needs to be flush. Pop Rivet’s are used when it’s impractical to work on both sides of material. Washers are used alongside Nuts and Bolts to help to distribute the load when tightening a nut, used as spacers and amethod of sealing when gases or liquids are involved. Nuts and Bolts are temporary joints that can beundone and reused an infinite number of times. They come in a variety of different shapes and sizes. 16

18. CASTING AND MOULDING SANDCASTING DIE CASTING Sand casting is a process that utilizes non-reusable sand moulds to form metal castings. It is a common production method for metal components of all sizes, from a few ounces to several tons. Sand casting isn’t only versatile in the size of its products – it can also create exceptionally complex or detailed castings, and can be used to cast nearly any metal alloy. • Advantagesover other moulding: • it is inexpensive, • it is easily recycled, and • it can withstand extremely high temperatures. • Disadvantagesover other moulding: • I requires large tolerances • Imperfections on the surface, surface finish is not high quality. • It needs very skills workers. Die casting is an efficient method of creating a broad range of shapes, die castings are one of the most mass produced components today and are found in many items in and around the home. Many toy cars use die casting in their production, as do real vehicles. Die casting offers high accuracy in its products with a good quality surface finish which is suitable for many products without the need for extra polishing or machining. Die casting first requires the creation of a steel mould (called a ‘die’) of the part to be cast, these moulds once created are fitted to the die casting machine and injected under pressure with the desired molten metal or alloy of choice. 17

19. Forging is a way of heating metal to soften (but not melt) it and then dropping a shaped Die on top to shape it. Basically anything steel that needs to be STRONG and withstand IMPACT. FORGING DROP FORGING In Drop Forging there is a metal Die (similar to Die Casting). A Billet (lump) of steel is placed in between the 2 halves. The top half is lifted and dropped repeatedly onto the bottom half until the steel is the right shape. PRESS FORGING Press Forging is VERY SIMILAR to Drop Forging. However… instead of dropping the upped Die it is PRESSED slowly down from above. Press Forging tends to be used for BIGGER industrial forged products. SHEARING • A process used to cut straight lines on a range of materials from sheet metal to angle bar stock. • An upper and a lower blade are forced past each other, usually one of the blades is stationary. • Materials that are sheared commonly include aluminium, brass, mild steel and stainless steel. • ADVANTAGES • the process works well with most softer metals • cost-effective for high-output operations • produces minimal or no kerf, with virtually no loss of material • DISADVANTAGES • less ideal with harder metals • cannot be considered burr free cutting since the force of the shearing action often creates burrs and end deformation 18

20. HEALTH AND SAFETY • There is a Health and Safety law covering the anyone working in production or in a workplace. The most important piece of legislation is the Health and Safety at Work Act (1974). • The Act makes it a legal requirement for manufacturers to undertake a risk assessment of all the stages of product manufacture, to ensure the safety of workers and prevent industrial accidents. The Act specifies that: • safety procedures must be displayed for all to see • workers must be trained to use machines and equipment • appropriate protective clothing must be worn • all risks must be controlled and monitored In a workplace signs must be visible to direct employees to potential hazards or to remind individuals about specific PPE that may need to be worn in those areas or when using specific machinery. TASK: Write a risk assessment for using the Pillar Drill. ____________________________________________________________________________________________ What is a risk assessment? A risk assessment considers all the risks that are present and identifies steps to reduce the risk for a person, the working environment or machinery being used. • Identifying and reducing the risks • An engineer needs to consider health and safety throughout the manufacturing process. • Safety of the product when it is used • To ensure safety of the product when it is used, the engineer needs to check that: • the product is strong enough to support the loads involved. • the materials are suitable for the purpose and have no adverse effects. • all hazards are sufficiently guarded (electrical insulation, moving parts, folding components, etc.). • Safety of the finished product when disposed of after use • To ensure safety when a product is disposed of, an engineer should consider the following points: • Can the component parts and different materials be dismantled without harm? • will dismantling result in the release of toxic or harmful substances? • Will recycling materials, e.g. melting down, cause release of toxic or harmful substances? • An engineer must consider how the product could affect the safety of the user. If someone could be injured by using or disposing of the product, it should be redesigned. 19

21. PPE (Personal Protective Equipment) • Making the workplace safe includes providing instructions, procedures, training and supervision to encourage people to work safely and responsibly. • Even where engineering controls and safe systems of work have been applied, some hazards might remain. These include injuries to: • the lungs, e.g. from breathing in contaminated air • the head and feet, e.g. from falling materials • the eyes, e.g. from flying particles or splashes of corrosive liquids • the skin, e.g. from contact with corrosive materials • the body, e.g. from extremes of heat or cold • PPE is needed in these cases to reduce the risk. • HOW TO PREPARE YOURSELF? • Ensuring that all hair is tied/ • Ensuring all PPE is worn and provided by the workplace. • Any loose clothing, jewellery or items are taken off or secured in place. • Follow all safety instructions. • The above protects you from entrapment/ entanglement or harm to yourself when using machinery or working in the workshop. TASK: Complete the missing PPE sections below for a Welder. RPE (Respiratory Protective Equipment) Respiratory Protective Equipment (RPE) is a particular type of Personal Protective Equipment (PPE), used to protect the individual wearer against the inhalation of hazardous substances in the workplace air. TASK: Which engineering sectors may require your to wear RPE? ___________________________________________________________________________ 20

22. MACHINERY CENTRE LATHE The Centre Lathe is used to manufacture cylindrical shapes from a range of materials including; steels and plastics. Many of the components that go together to make an engine work have been manufactured using lathes. These may be lathes operated directly by people (manual lathes) or computer controlled lathes (CNC machines) that have been programmed to carry out a particular task. Knurling (adding grip or pattern to metal) Turning and Facing (reducing diameter, making shorter or neater) Boring (making a hole bigger) Cutting a Thread Parting Off (object is chopped off) Drilling on a Lathe (use a centre drill first) PRODUCTS MADE ON A CENTRE LATHE Clamping Knob Brake Disk Plumbing Fitting Drill Chuck PILLAR DRILL The pillar drill is an accurate way of putting holes in materials. Each pillar drill comes with an adjustable table and depth gauge to ensure the work is accurate. When using a pillar drill, a machinist vice is needed to be able to accurately secure the metal in place. Larger diameter drills need to be run at low speeds, which in turn means lots of torque (a twisting force) being exerted, and in this situation it is better to secure your drilling vice properly. 21

23. MILLING MACHINE Milling is the most common form of machining, a material removal process, which can create a variety of features on a part by cutting away the unwanted material. The milling process requires a milling machine, work piece, fixture, and cutter. The work piece is a piece of pre-shaped material that is secured to the fixture, which itself is attached to a platform inside the milling machine. The cutter is a cutting tool with sharp teeth that is also secured in the milling machine and rotates at high speeds. By feeding the work piece into the rotating cutter, material is cut away from this work piece in the form of small chips to create the desired shape. Milling Machines are used to make accurate parts with holes, slots and flat sections. It is used for SHAPING metal objects using a rotating bit that con both drill down and cut sideways. Drilling Holes Cutting Slots Cutting Shoulders (Steps) PRODUCTS MADE ON A MILLING MACHINE Alloys Engine Parts Brackets & Mounts Golf Clubs BUFFERING MACHINE Buffing Machine is used to polish soft metals including mild steel, copper and brass. The two ‘mops’ spin at high speed when the ‘on’ switch is pressed. If the material is carefully pressed against the mop and moved backwards and forwards it will be polished. The material must be filed to removed scratches and then wet and dry paper or emery cloth is used to further smooth the surfaces. Only then can it be polished on the buffing machine. 22

24. COMPUTER NUMERICALLY CONTROLLED (CNC) MACHINERY A CNC machine uses programming information to automatically execute a series of machining operations. For example, a CNC milling machine has the same basic functions as a traditional milling machine but it also has a computer that controls the spindle and the movement of the table, allowing for a range of shapes and forms to be cut accurately. Most CNC machines also have a facility that will monitor and detect any wear in the cutting tool as a result of continuous use and adjust or change the tool automatically without stopping production. Today CNC machining is often referred to as computer aided manufacturing (CAM). This is essentially the same type of machine but CAM usually relies on the use of computer aided design (CAD) programs to create drawings of products that can be directly converted to the Cam machines for manufacture. This impacts on the speed of production and the accuracy and consistency of the finished engineered products. These benefits come at a cost as the software and machines, together with the necessary maintenance and training, are very expensive. But organisations striving to improve their product and production quality should see this as a good investment for the future. • ADVANTAGES • CNC machines can be used continuously 24 hours a day, 365 days a year and only need to be switched off for occasional maintenance. • CNC machines are programmed with a design which can then be manufactured hundreds or even thousands of times. Each manufactured product will be exactly the same. • CNC machines can be updated by improving the software used to drive the machines. • Modern design software allows the designer to simulate the manufacture of his/her idea. There is no need to make a prototype or a model. This saves time and money. • DISADVANTAGES • CNC machines are more expensive than manually operated machines, although costs are slowly coming down. • The CNC machine operator only needs basic training and skills, enough to supervise several machines. In years gone by, engineers needed years of training to operate centre lathes, milling machines and other manually operated machines. This means many of the old skills are been lost. • Less workers are required to operate CNC machines compared to manually operated machines. Investment in CNC machines can lead to unemployment. 23

25. Complete the ‘use’ for each tool. ENGINEERS TOOLS SCRIBER CENTRE PUNCH ENGINEER’S VICE & JAWS ENGINEER’S SQUARE ENGINEER’S BLUE ODD LEGGED CALIPERS FILE, EMERY CLOTH, WET & DRY TAP, DIE & CUTTING COMPOUND 24

26. LEAN MANUFACTURING Lean provides tools and processes to eliminate waste from the manufacturing process resulting in improved efficiency, effectiveness, and profitability. Lean Manufacturing is about creating the ultimate factory. There are 7 areas that cause waste when manufacturing. Over production, bad quality, inventory, transport, processing, idle time, operator motion. What else is Lean Manufacturing? Easy to read ways of tracking jobs. No time wasted finding tools. Less area to walk around. Quick ways to quality check work. Clear description of who should be doing what. • KAIZEN MANUFACUTING • Kai stands for Good and Zen stands for Change. • Also known as ‘continuous improvement’, this is a policy of constantly introducing small changes to improve quality and efficiency. This technique puts the workers at the heart of the decision making as they are the best people to suggest improvements. • Advantagesof this system include: • Improvements are based on small changes rather than large changes as a result of research and development. • As the ideas come from the workers they are less likely to be much different than existing processes and are therefore easier to implement. • Small changes generally do not cost a great deal of money when compared with any major process/production changes. • It encourages workers to take ownership of their work and reinforces team working leading to improved worker motivation. 25

27. JUST IN TIME MANUFACUTING • Just in Time manufacturing is aimed primarily at reducing flow times within production system as well as response times from suppliers and to customers. Here are some examples of (JIT): • Advantages of this system include: • Parts are available when you need them. • Equipment is available when you need it. • Workers only move when they need to. • Products are build to customer demand. • There is no stock waiting to be sold. • Production time is the least time possible. • Automation is used to speed up manufacturing. • Nissan • On Tuesdays the company assembles the car chassis, and the • workers put the windshield in on Thursdays. Nissan have parts • delivered exactly one day before they need them; the chassis • would be delivered on Monday and the windshield on Wednesday. • Tesco • Tesco receive a daily delivery of fresh food. They could for example • order 100 fresh baguettes to sell that day in the shop. At the end • of the day almost all baguettes will be sold (minimising waste) • and a new order to be delivered the following day will be processed. • Amazon.co.uk • Amazon are an online company who rely on an order from the • customer to pull stock through. No stock is stored by the company. • POKA-YOKE MANUFACUTING • This is a technique for avoiding simplistic human error in the workplace also known as ‘mistake proofing’ and ‘fail-safe work methods’. The idea is to take over all the repetitive processes/tasks performed by humans that rely on memory or vigilance and replace them with a simple system to improve productivity and quality. • Advantages of this system include: • Eliminating set up errors, therefore improving quality • Decreasing set up time and improving production output • Increased safety as workers do not get injured through • lack of concentration • Reduced costs through improved production efficiencies • and reducing the need for skilled labour • Improved motivation of workers, as tasks are not so mundane 26

28. ROBOTS Although you may think of a robot as something resembling a human being, robots can come in all shapes and sizes, and are already very much a part of the manufacturing industry around the world. So what exactly are they? Robots are usually mechanical devices that can move in every direction using sophisticated electronics to control that movement. ‘Robot’ is a Czech word that simply means ‘worker’. They were first used in the 1960s to carry out hazardous operations, including handling radioactive and toxic materials. Many organisations rely on robots to produce their products cheaply, accurately and consistently over long periods of time. This is possible if there are processes in place to monitor the performance of each and every robot. Examples of the functions that robots perform in today’s world include the following; EXPLORATION Space exploration and the search for ships at the bottom of the ocean have been made possible through the use of Remote Operated Vehicles (ROVs)> fitted with cameras and sensory devices, they allow personnel to control the vehicle well away from any danger at the site of exploration. ASSEMBLY Manufacturing systems use robotic arms to perform dangerous tasks such as welding the frame of a car and spray painting parts without endangering the life of the workmen. • DISADVANTAGES • Robots are very expensive therefore the capital cost needs to be considered. • Whilst industrial robots are excellent for performing many tasks, as with any other type of technology, they require more training and expertise to initially set up. • In recent years the number of industrial robots and the applications they can be used for has increased significantly. However, there still are some limitations in terms of the type of tasks they can perform. • One of the biggest concerns is the impact of jobs for workers. If a robot can perform at a faster, more consistent rate, then the fear is that humans may not be needed at all. • ADVANTAGES • Robots used in manufacturing create efficiencies all the way from raw material handling to finished product packing. • Robots can be programmed to operate 24/7 in lights-out situations for continuous production. • Robotic equipment is highly flexible and can be customized to perform even complex functions. • With robotics in greater use today than ever, manufacturers increasingly need to embrace automation to stay competitive. • Automation can be highly cost-effective for nearly every size of company, including small shops. 27

29. PRODUCTION ONE OFF PRODUCTION This production is used when a customer requires a product specifically for them or when a prototype needs to be made. There may be one person or a number of people working on the production from beginning to end but in each case the produce is unique. This method of production usually results in high unit costs because a great deal of time is spent on producing one item, e.g. a prototype of a new smartphone. BATCH PRODUCTION When a customer requires a certain quantity of identical products they are usually produced through this production. There is flexibility in this production process; large quantities can be produced but it is also relatively easy to change the production line to suite another type of product. Examples include specific sizes and quantities of flat bar aluminium or alloy wheels. MASS PRODUCTION This production method is used to produce products in very large quantities. It usually involves dedicated machines and assembly lines that will repeat the manufacture of the same product over and over again. There may be a number of stages along the production line with workers repeatedly performing their tasks to assemble the finished product. Examples include the production of cars and televisions. CONTINUOUS PRODUCTION As the name suggests this method involves the continuous production of products over a period of time. This method usually means that the product is relatively inexpensive to purchase as thousands of identical products will be produced. Examples include machine screws, paper clips and plastic sheet material. 28

30. LIFE CYCLE ASSESSMENT • Life-cycle assessment (LCA, also known as life-cycle analysis) is a technique to assess environmental impacts associated with all the stages of a product's life from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling. Engineer’s use this process to help critique their products. LCAs can help avoid a narrow outlook on environmental concerns by: • Compiling an inventory of relevant energy and material inputs and environmental releases; • Evaluating the potential impacts associated with identified inputs and releases; • Interpreting the results to help make a more informed decision. • Companies are increasingly being asked to account for the impact their products and businesses have on the environment. • They have to calculate environmental impact at each stage of a product lifecycle. This includes: • Extracting materials • Processing • Manufacturing • Transportation • Use of the product • Disposing of the product Useful questions to help with the LCA. MATERIALS: What materials were used to make it? What impact did that have on the land and how were they process? PRODUCTION: How and where was it made? What energy was involved in the manufacture? DISTRIBUTION: How was it distributed? SALES: How was it sold and marketed? What packaging may be used? USE: How is it used? Does it need an energy source? DISPOSAL: How can it be disposed of? Can it be recycled? 29

31. ENVIRONMENT The 4 R’s are an important checklist. They are used by engineer’s to reduce the environmental impact of products. They can also be used to evaluate the environmental impact of other products. The 4 R’s stand for: REDUCING: MATERIALS AND ENERGY Probably the most important of the four R’s: preventing waste in the first place means there is less to dispose of in the end. Organisations need to consider reducing the amount of materials and energy used to manufacture their products. Examples could include making products such as mobile phones smaller or exploring different formats such as e-books. REUSE: MATERIALS AND PRODUCTS WHERE APPLICABLE The next most important consideration because if you can reuse waste material then it will no longer be considered as waste. This will reduce costs of disposal and materials/products can be put to further good use. Examples include giving unwanted clothes to charity shops or stripping an old bicycle down and reusing its parts for another bicycle. RECOVER:ENERGY FROM WASTE Sometimes waste has to be disposed of, but finding ways to use this material to produce energy is what recovery is all about. Modern technology allows us to treat waste using thermal and non thermal processes to produce heat, gas, oil or electricity. RECYCLE: MATERIALS AND PRODUCTS OR USE RECYCLABLE MATERIALS Sometimes products cant be reused. Recycling keeps raw material in the system and slows down the depletion of the earth’s resources such as fossil fuels and trees. If we can keep recycling products then we will cut the amount of materials going to landfill, while also reducing the need to extract gas, coal and oil. 30

32. RENEWABLE ENERGY RESOURCES There is an increasing demand for energy in our fast developing world. Alternative forms of energy can slow down the depletion of the earth’s natural resources and safeguard energy supplies for many generations to come. HYDRO ENERGY Hydroelectricity is the use of running water-this could be a small stream, a large river or ocean waves-to generate electricity. Streams and rivers flow downhill and as water flows down it generates potential energy. Hydropower systems convert this potential energy into kinetic energy using a turbine. Simply, as water passes through the turbine, it spins the propeller blades. The turbine is connected to a generator, which produces electricity. The faster the water flow, the more energy is produced. This system usually comes in the form of a hydro dam where turbines are built at the base of the dam and water is released at a controlled rate to generate sufficient power. This works 24 hours a day and produces electricity in abundance with no air or water pollution. Disadvantages include the high initial cost of producing the facilities to harness the natural resources power and in dry periods general water usage will need to be controlled around the country to ensure there is enough water to keep producing electricity. GEOTHERMAL ENERGY This system uses heat from rocks in the earth’s inner core that turns water into steam. Engineers drill down into the hot regions and the purified steam rises to drive turbines that produce electricity. Where there is no natural ground water, cold water can be pumped down to create steam. This form of energy does not produce any pollution so does not contribute to the greenhouse effect. There is no fuel required to run a geothermal power station and once built, the running costs are very low-just the energy needed to run a pump for the cold water, but even that can be taken from the energy being generated. 31

33. WIND ENERGY Wind is a natural and clean source of renewable energy that produces no air or water pollution. Most wind energy is harnessed through the use of wind turbines. The largest wind turbines generate enough electricity to power small towns and villages. Wind farms sometimes contain hundreds of turbines and are usually positioned in windy areas. Sometimes they are positioned off shore. Many governments offer incentives for companies to use wind turbines however some people think they are ugly and spoil the landscape. The constant spinning also causes noise pollution, this changes depending on the amount of wind however, and when there is no wind there is also no electricity produced. SOLAR ENERGY Most solar energy is produced through a series of panels that contain photovoltaic cells. These cells convert the heat produced from the rays of sun into electricity. There has recently been an increase in the use of photovoltaic cells on people’s roofs. The electricity produced can be used to power a home and even heat water directly. Solar panels initially cost thousands of pounds to install, but they can significantly reduce electricity bills. In fact the government pays the householder for any extra energy produced that is fed into the national grid. Disadvantages are their high cost to install and some people think they are ugly. Today, a lot of products use solar cells or panels to power everyday products, such as torches, mobile phones, and outdoor lights. This is because panels can store the electricity produced to use at night time. 32

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