SE13-17 U1/2 Student Name:
Unit 1 Mechanical Engineering Fundamentals Page 1. Student Learning Guide & Record Unit 1 TASK Page TASK TITLE Task 1 7 Energy Task 2 9 Draw a block diagram Task 3 16 Exercise Law of the lever Task 4 22 Exercises Pulleys Task 5 24 Exercises Wheel and axle Task 6 28 Exercises Inclined plane, wedge and screws Task 7 33 Exercises Gears and gearboxes Task 8 35 Friction Task 9 38 Belt drive and velocity ratio calculations Task 10 39 Speed calculation Task 11 40 Type of motion Task 12 42 Changing the direction of motion Task 13 45 Types of forces acting on a structure Task 14 48 Review questions Task 15 52 Hydraulic systems Task 16 54 Complete the following exercises to display your understanding of Pascal s principle Task 17 56 Draw a system block diagram of your mechanical, electro-mechanical system Task 18 59 Record factors that influence your design Task 19 60 factors that influence design, planning, production and use of system Task 20 61 Decide on a mechanical, electromechanical system to plan, design and produce Task 21 62 Carry out research Task 22 66 List of materials, components and subsystems Task 23 67 Perform basic calculations Task 24 68 Use measuring and/or test equipment Task 25 69 Carry out the measuring and testing Task 26 70 Evaluation criteria Task 27 72 Concept drawings Task 28 74 Design options Task 29 78 Draw preferred design option Task 30 80 Match surfaces of orthogonal drawing Task 31 81 Transfer letters 1 Task 32 81 Transfer letters 2 Task 33 82 Orthographic drawing of preferred design option Task 34 83 Make a scale model of your preferred design option Task 35 84 Justification of preferred option Task 36 84 Produce a production plan Task 37 88 Identify tools, equipment and machines Task 38 90 Identify range of processes required Task 39 91 Make your mechanical, electromechanical system Task 40 94 Group work OH&S and risk assessment Task 41 94 Carry out risk assessment Task 42 99 Record processes used and decisions made during production process Task 43 106 Evaluate your mechanical, electromechanical system DATE COMPLETED TEACHER S SIGNATURE Copyright LAPtek Pty. Ltd.
Page 2. Unit 2 Electrotechnology Engineering Fundamentals Student Learning Guide & Record Unit 2 TASK Page TASK TITLE Task 1 112 Summarise electrons and matters Task 2 116 What is electricity Task 3 121 OHM s law, switching and circuits Task 4 125 Voltage drop Task 5 130 Parallel circuits Task 6 139 Types of switches Task 7 145 Semi conductors Task 8 148 Solenoid and relays Task 9 153 Producing alternating current and sine wave form Task 10 156 Producing direct current Task 11 158 Transformers Task 12 163 Capacitors Task 13 168 Resistance values Task 14 174 Batteries Task 15 176 Make your PCB (optional) Task 16 176 Check all components (optional) Task 17 183 Review questions for power and energy Task 18 186 Identify uses for microcontrollers Task 19 188 Summarise photovoltaric cells Task 20 188 Identify common circuit symbols Task 21 191 Record factors that influence your design Task 22 192 Factors that influence design, planning, production and use of system Task 23 193 Decide on a electromechanical system to plan, design and produce Task 24 194 Carry out research Task 25 198 List of materials, components and subsystems Task 26 199 Perform basic calculations Task 27 200 Use measuring and/or test equipment Task 28 202 Carry out the measuring and testing Task 29 203 Evaluation criteria Task 30 205 Concept drawings Task 31 210 Draw preferred design option Task 32 211 Orthographic drawing of preferred design option Task 33 212 Make a scale model of your preferred design option Task 34 213 Justification of preferred option Task 35 213 Production plan Task 36 217 Identify tools, equipment and machines Task 37 218 Identify range of processes required Task 38 219 Make your electromechanical system Task 39 219 Carry out risk assessment Task 40 224 Record processes used and decisions made during production process Task 41 231 Evaluate your mechanical, electromechanical system DATE COMPLETED TEACHER S SIGNATURE Copyright LAPtek Pty. Ltd.
SYSTEMS ENGINEERING PROCESS
Page 20. Unit 1 Introduction to Mechanical Systems Moveable Pulley In the case of the moveable pulley, to move the load upward both of the supporting ropes must be shortened by the same amount. Therefore the load will move up a distance half that of the effort. For a moveable pulley: MA = VR = Load = 2 Effort Distance moved by theeffort Distance moved by theload = 2 For a moveable pulley: The Mechanical Advantage and Velocity Ratio are the same. Moveable pulley Block and Tackle The block and tackle is a machine with a large mechanical advantage employing the use of any number of moveable and fixed pulleys. In some blocks, the pulleys are all of the same size and mounted side by side, while in others they are of different size and mounted one below the other as shown. Regardless of size, the function of each pulley is simply to reverse the direction of the effort so that the same tension exists through the supporting rope. In raising the load, each of the four ropes supporting it must be shortened by the same amount, therefore the effort moves four times the distance of the load. For the block and tackle shown: MA = VR = Load 4 = = 4 Effort 1 Distance moved by theeffort Distance moved by theload = 4 In general, the mechanical advantage of any block and tackle is given by the number of parallel ropes supporting the load. The load includes the weight of the lower block. A block and tackle Copyright L.A.P.tek Pty. Ltd.
Unit 1 Introduction to Mechanical Systems Page 21. Block and tackle used to make work easier EFFICIENCY For a block and tackle with three pulleys in each block, the velocity ratio is six (6). An effort of 10N will lift a useful load of 48N (refer to following picture). When the effort moves six meters we do work. Use the formula Work = force x distance to calculate the work done. Work = force x distance = 10 x 6 When the load is raised 1m = 60 joules (J) of work Work = force x distance = 48 x 1 = 48 joules (J) of work So we see that more work is put into the machine than we get out. The missing 12 joules (J) of work has been used in overcoming friction and lifting the lower pulley block. The fraction tells us how efficient the machine is. This is usually calculated as a percentage. Percentage efficiency = x 100 = x 100 = 80% Block and tackle Velocity ratio 6 Copyright L.A.P.tek Pty. Ltd.
Page 22. Unit 1 Introduction to Mechanical Systems TASK 4: EXERCISES PULLEYS Answer the following questions to display your understanding of pulleys. 1. What is the velocity ratio of the system shown on the right.... 2. If a load of 50 newton is lifted a distance of one meter by an effort of 40 newton calculate the mechanical advantage of the machine.......... 3. If a load of 50 newton is lifted a distance of one meter by an effort of 20 newton calculate the following. a) The mechanical advantage of the system b) The distance moved by the effort c) The efficiency of the machine 4. Give reasons why the machine is less than 100% efficient. Copyright L.A.P.tek Pty. Ltd.
Page 40. Unit 1 Introduction to Mechanical Systems MECHANICAL SYSTEMS Common place items like bicycles, electrical switches and kitchen taps all involve some form of input force and motion. This force and motion is transmitted to provide a desired output force and motion. The types of motion include rotational, linear, oscillating and reciprocating. Definitions: Rotational motion Linear motion Oscillating motion Is to revolve around a centre or axis, like a wheel. Is movement along a straight line path. Is a linear motion that alternates backward and forward such as a pendulum. Reciprocating motion Is a repetitive up-and-down or back-and-forth motion. TASK 11: TYPE OF MOTION The four situations below show four different types of motion: Rotational, Linear, Oscillating and Reciprocating. Can you work out which is which? a)... b)... c)... d)... Copyright L.A.P.tek Pty. Ltd.
Unit 1 Introduction to Mechanical Systems Page 57. UNIT 1 OUTCOME 2 INTRODUCTION TO MECHANICAL SYSTEMS PRODUCING AND EVALUATING MECHANICAL SYSTEMS This area of study provides you with the opportunity to produce, test and evaluate an operational system. The operational system that you produce will contain mechanical components and elements, but may integrate some electro-technology components or sub-systems. Refer to Systems Engineering Study Design pages 15-17 Throughout the study you should use the Systems Engineering Process to continually reevaluate and modify your system engineering project (Page 3) and record your progress and the decisions that you made in relation to the production of your mechanical, electromechanical system (Pages 98 104) On completion of this unit you should be able to make, test and evaluate a mechanical or electromechanical system or sub-system using the System Engineering Process. To satisfactorily complete Outcome 2 you must draw on key knowledge and key skills outlined in Area of Study 2 (VCE Study Design Systems Engineering, page 16) Drive system Stirling engine Alternate drive system Steam engine Copyright L.A.P.tek Pty. Ltd.
Page 58. Unit 1 Introduction to Mechanical Systems DESIGN AND PLAN A MECHANICAL, ELECTROMECHANICAL SYSTEM You have gained a lot of knowledge in mechanical principles and concepts. Now it is time to apply what you have learnt, by designing and planning your mechanical or electromechanical system. You will manage your product throughout all phases of the Systems Engineering Process. FACTORS THAT INFLUENCE DESIGN Factors that influence design The picture above gives an outline to some of the many factors that affect the development of a product. Below is more detail regarding some of the points mentioned above. Cost. The cost of the materials required to manufacture the product. The price that you are prepared to pay for the product. Ergonomics. The product may be designed for human use. As a result ergonomics (sizes etc.) will pay a major role. Materials. The availability of materials and the development of new, hi-technology materials will have an influence on the final design of a product. Production. When designing a product the most desirable production technique may influence the way the final product looks. Aesthetics. The shape and form of the product may determine the layout of circuits or mechanisms etc. inside it. Products are often designed to look stylish. The style applied to the outside of a product can quite easily influence the technology inside it. Aesthetics can also alter the production / manufacturing techniques through which it is made. Copyright L.A.P.tek Pty. Ltd.
Page 124. Unit 2 Introduction to Electrotechnology Systems In the diagram on the right we know the current is 0.5 amps and the total resistance is R 1 + R 2 + R 3 or 50 + 150 +200 = 400 Ω, but we do not yet know the applied voltage. OHM s law states that: V = IR V = 0.5 x 400 = 200 volts The voltage drops can easily be found: V R1 = 0.5 x 50 = 25 volt V R2 = 0.5 x 150 = 75 volt V R3 = 0.5 x 200 = 100 volt The resistance and the current are known. What is the value of the voltage? Therefore the applied voltage equals 200 volts. NOTE: The sum of the voltage drops is 200 volts and is the same as calculated earlier for the applied voltage. In the diagram on the right, we know the applied voltage (100 volts) and the voltage drops across the resistors, but we do not know the value of the resistors. The current is 100 ma or 0.1 amp. According to OHM s law: R = The voltage drops across R 1 is 50 volts, so R 1 = = 500Ω The voltage applied to R 2 is 25 volts, so R 2 = = 250Ω The voltage drops and the current are known. What are the values of the resistance? The voltage applied to R 3 is 25 volts, so R 3 = = 250Ω NOTE: The problem can be proved by working it backwards. The total resistance equals R T = R 1 + R 2 + R 3 or 500 + 250 + 250 = 1000 Ω. I = or I = = 0.1 amp. Same as the current flow in the circuit. LAWS OF A SERIES CIRCUIT 1. In a series circuit the total resistance is equal to the sum of all the individual resistors. 2. In a series circuit, the current flowing in all part of the circuit is the same. 3. In a series circuit the sum of the voltage drops is equal to the applied voltage. Copyright L.A.P.tek Pty. Ltd.
Unit 2 Introduction to Electrotechnology Systems Page 125. TASK 4: VOLTAGE DROP Complete the following problems to display your understanding of voltage drop in a series circuit. 1. Determine the following: I = current... R T = resistance in ohm... V = applied voltage... V R1 = voltage drop across R 1 and R 2... R T... I:... V R1 :... V R2 :... 2. Determine the following: V =... R 1 =... R 2 =... R T =... V:... Copyright L.A.P.tek Pty. Ltd.
Page 146. Unit 2 Introduction to Electrotechnology Systems SOLENOIDS AND RELAYS The Effects Of Current Flowing In A Circuit You are more or less familiar with the electrical appliances that you use daily at home: the electric light, electric toaster, electric iron, refrigerator, vacuum cleaner, washing machine etc. All of those devices depend for operation on one or more of four general effects produced by electric current flowing through a conductor. These are: 1. the magnetic effect, 2. the mechanical effect, 3. the chemical effect, and 4. the heating effect To understand how solenoids, relays and transformers operate you will need to understand the important principles involved in the first two of these different phenomena: the magnetic effect and the mechanical effect. Magnetic effect A magnetic field exists around every current carrying wire. The field forms continuous lines around the conductor. Magnetic field through and around a single loop of wire carrying an electric current. Magnetic properties of a solenoid Illustrated on the right is a coil of several turns of wire. A coil of wire of this kind is sometimes referred to as solenoid. The magnetic line of force are such that one end of the coil acts like an N magnetic pole and the other end acts like an S magnetic pole. Outside the coil the magnetic lines of force go from the north to south in the same way they do in a permanent bar magnet. Magnetic field around a solenoid carrying an electric current Copyright L.A.P.tek Pty. Ltd.
Page 148. Unit 2 Introduction to Electrotechnology Systems TASK 8: SOLENOID AND RELAYS Answer the following questions to display your understanding of solenoids and relays. 1. What are the four effects of electric currents? What specifically, is the magnetic effect? 2. What effect does the soft iron core have upon the strength of the magnetic field around a solenoid? Does a current have to flow to produce the field? 3. Describe a function of a relay and how it operates. Copyright L.A.P.tek Pty. Ltd.
Unit 2 Introduction to Electrotechnology Systems Page 189. UNIT 2 OUTCOME 2 INTRODUCTION TO ELECTRO-TECHNOLOGY SYSTEMS PRODUCING AND EVALUATING ELECTRO- TECHNOLOGY SYSTEMS This area of study provides you with the opportunity to produce, test and evaluate an operational system. The operational system that you produce will contain mechanical components and elements, and integrate some electro-technology components or sub-systems. Refer to Systems Engineering Study Design pages 21 22. Throughout the study you should use the Systems Engineering Process to continually reevaluate and modify your system engineering project (Page 3) and record your progress and the decisions that you made in relation to the production of your electromechanical system (Pages 222 228). On completion of this unit you should be able to make, test and evaluate an electro-mechanical system or sub-system using the System Engineering Process. To satisfactorily complete Outcome 2 you must draw on key knowledge and key skills outlined in Area of Study 2 (VCE Study Design Systems Engineering, pages 21). Electro-mechanical vehicle Crane Wind turbine Copyright L.A.P.tek Pty. Ltd.