The Technological World Exploring How Technical Objects Work

Technological World Sub-Units Engineering What engineers do Their tools Diagrams & documents Technological Systems What a system is & its components Forces and Motion Types of motion & their origins Motion transmission & transformation

Why do we learn about technology? How many technological objects have you used today? Make a list.

Engineering What is engineering? What do engineers do?

What is engineering? Engineering comes from the Latin ingenium meaning “talent” or “ability”. A branch of science and technology that focuses on the analysis and execution of technological projects such as building bridges, roads, bicycles, cars, televisions, etc. It is divided into various areas of specialization, including civil engineering, computer engineering, and electrical engineering, mechanical engineering, etc.

What do engineers do? Engineers design, and execute technological projects. They usually work as a team, each member with specialized skills.

The Design Process In industry, the design process consists of 3 phases: Design – developing a project for purpose of creating a product Production/manufacturing = all operations resulting in the construction of an object conceived by designers Marketing = introduces the manufactured object to the people who might need it Engineers are involved only with the design phase and the first stage of the production process, but they must be aware of the processes involved in marketing & take them into account when designing.

A Closer Look at Steps in the Design Process Identify a need Analyze the technological problem Has the problem already been solved? (if yes, present existing solution) Write a set of specifications Prepare a design plan Manufacture a prototype Test the prototype: does it meet specifications? Apply for a patent

2. Production: Prepare a manufacturing process sheet Prepare a flow-process grid Manufacture the product Write an instruction manual & maintenance manual

3. Marketing: Market the product Maintain the product Discard or recycle the product

Specifications A written document called set of specifications (a manual) is prepared before any tech object gets manufactured. It is a report which describes the nature & purpose of the desired product. It includes: Function of the object Requirements for manufacturing, use & maintenance Standards the object must meet (a set of rules set by specialists) Object’s characteristics Manufacturing costs Completion deadline for each stage Project’s feasibility (Is the project possible, taking into account timetables, technical knowledge, as well as political & financial situation?)

Technical Diagrams Technical diagrams are used in the design phase. They explain the functioning & essential elements of the object Used in creating a prototype (the first copy of an object which can serve as a model for testing). There are several types of technological diagrams. The 2 you will learn about are: Design plan Technical drawing (a.k.a construction diagram)

Assisted Exercises: Exercise 2: C-Clamp 13 Standard symbols 13 Original material created by Emmanuel Fournier

What are the similarities & differences? Design Plan for a C-Clamp Technical Drawing/Construction Diagram for a C-Clamp Fixed Jaw Fixed Jaw Frame Moveable Jaw Frame Moveable Jaw Handle Handle Adjusting Screw Adjusting Screw F Materials Legend Bottom View Steel 14 Original material created by Emmanuel Fournier

Simple (like a stick figure drawing) Design Plan Design Plan is Simple (like a stick figure drawing) It explains forces and movements of the technical object A Design Plan must have the following elements: 1. Different colors for different parts. Standardized symbols 2. Labels. 3. Motion arrows (skinny) 4. Force arrows (thick) 5. Links and guiding controls. 15

Technical Drawing/Construction Diagram Construction diagram is Detailed (shows the exact configuration of the object) It tells you how to build the object in real life. A Construction Diagram must have 1. Different colors for different parts. Standardized symbols 2. Labels. 3. Show materials used (with a legend @ the bottom) 4. Measurement arrows and extension lines 5. Links and guiding controls. 16

Standard Symbols Standard are used in preparing technical diagrams Can quickly describe motion & links Illustrate the mechanisms of motion transmission & transformation at work in a device Are essential so that anyone, anywhere can read the technical diagram with no confusion.

Symbols of Movements and of Forces Standardized symbols Unidirectional Translation Tension Bidirectional Translation Compression Unidirectional Rotation Torsion Bidirectional Rotation Shearing Helical Movement (Rotation and Translation) 17

Basic Lines in Technical Drawing

Standardized Symbols Page 10

A Design Plan for a pair of scissors Free in rotation and fixed in translation Upper Blade F Shearing Paper F A Design Plan: 2. Labels. 3. Movement arrows. 4. Force arrows. 5. Any guidance and links, (if necessary). 1. The parts in different colors. A Design Plan includes the following elements: 2. The name of the parts (designation). 3. The movements carried out by the parts. 1. The parts represented in different colors. A Design Plan includes the following elements: 1. The parts represented in different colors. 22 Pivot 2. The name of the parts (designation). F Lower blade Bidirectional rotation The Components (parts) Movements Forces 22

Technical Drawing/Construction Diagram of a pair of scissors Upper handle Upper blade a. The materials used; c. Relative size of the components; 1. The pieces making up the technical object: d. The name of the components. A Technical Diagram contains the following: b. The shape of the components; a. Different colors for diff parts c. Labels 2: a. The links between the parts; b. The guidance between the parts. 1: d. Size and extension lines A Technical Drawing : b. Materials used and legend; Pivot Lower blade Lower handle Legend of materials Steel Plastic 23

Exercice 1: Staple Remover Your Turn Exercice 1: Staple Remover Top Lever Pivot Spring Bottom Lever Symboles normalisés 24 Original material created by Emmanuel Fournier

Assisted Exercises: A Design Plan: 1. The parts in different colors. Design Plan for a Staple Remover Technical Diagram/Constuction Diagram of a Staple Remover A Design Plan: 2. Labels 3. Movement arrows 4. Force arrows 5. Any guidance and links. 1. The parts in different colors. Top Lever Protector Top Lever Torsion Spring Pivot Pivot Torsion Spring a. Colors for diff parts; c. Measurements 2: a. Links between the parts; b. Guidance between the parts. 1: d. Labels A Construction Diagram: b. Materials used and legend; Protector Bottom Lever Bottom Lever Material Legend Steel Plastic 25 Original material created by Emmanuel Fournier

Manufacturing Process Sheet = a document describing every stage in the manufacturing of the object’s parts. It is usually written by the designers for the producers. It lists all of the materials & tools to be used; indicates the order of each operation to be performed; tells how much time it will take & how many workers needed. It is accompanied by another document called a flow-process grid which describes each stage in the assembly process. These 2 documents are like recipes for making the object.

What are Tech Objects Made of? Raw materials and materials A raw material is a substance of natural origin that undergoes a transformation. Raw materials are transformed into materials. Ex: Raw Material Material Trees Planks , plywood, paper, etc. Iron Steel beams Sand Glass Clay Ceramics, bricks Bauxite Aluminum

Categories of Materials & Their Properties

Main Categories of Materials Used in Industry Wood Ceramics & Glass Metals Stone & concrete Polymers (plastics) Composites (e.g. fibreglass & plastic combined) Textiles

Equipment Equipment = any object, instrument, tool or machine that is used to extract or transform raw material, or to manufacture products.

Selecting Appropriate Materials All technical objects are made of 1 or more materials. Every tech object must be made of appropriate materials if it is to work properly & last. The selection of suitable materials is determined by the properties of the materials & the stresses (constraints) & deformations to which they will be subjected. The properties of materials (ex: strength, durability, flexibility, stiffness, malleability, ductility, resistance to corrosion, conductor of heat or electricity, etc.) must be considered before selecting an appropriate one.

Technological Systems Is an assemblage of the following elements designed to accomplish a specific function or task: Inputs (energy or initial matter) A transformation process Outputs (energy or resulting matter) Ex: A bicycle is a system: Its function is to support a person’s weight & enable the person to move. Input = the muscle force required to pedal the bike (your body uses chemical energy in food to enable you to move your muscles) Transformation Output = Kinetic energy of the bicycle

Inputs & Outputs In a technological system, the force applied to make the machine work constitutes one of the inputs. Inputs are anything that enters a system. Outputs are everything that exits a system. Inputs can be transformed by the system, or not. The task that machine performs constitutes a transformation process. The result of the process is an output.

Systems Have Subsystems Systems are made up of several subsystems which interact. Every subsystem has its own function. Each subsystem includes several parts called components. Everything that plays a role in a technical object’s functioning constitutes a component. If one of the components is missing, the system cannot operate properly. Ex: The subsystems of a bicycle include: the frame, seat, wheel, transmission, steering, braking, & lighting

An Apple Peeler is a Technological System What are the inputs & outputs?

Inputs & Outputs of 2 Systems Apple Peeler Dishwasher Inputs Initial Material Apples Dirty dishes Water Dishwasher detergent Verification & Control Mechanisms Manual adjustment of the apple Selection of an automatic wash cycle Energy Source Muscle force Electricity Outputs End Material Peeled apples Clean dishes Info given to person using machine Red light Waste & Residue Apple peels Waste water Drawbacks Noise of the system operating

Basic Mechanical Functions A function is the role played by an object, system, subsystem or part. Basic mechanical functions are at the root of most technical objects. The most frequently used are the link and the guiding control.

Links Links are fastening units that connect 2 or more parts. There are 8 different possible types of links: direct or indirect; rigid or elastic; removable or non-removable; complete or partial.

Characteristics of Links Direct Indirect when 2 parts hold together without a linking component when the parts require a linking component to hold them together Rigid Flexible when the linking component or surfaces of linked parts are rigid when the linking component or surfaces of linked parts can be deformed. Springs & rubber are often used in flexible links. Removable Non-removable when the linked parts can be separated without damaging either their surfaces or the linking component (if present). Ex: Nuts & screws when separating the linked parts damages their surfaces or the linking component. Complete Partial when it prevents the linked parts from moving independently of one another when at least one part can move independently of the other parts.

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Test Your Understanding What kind of links are these? Handle on paint brush & bristles Calculator & calculator cover Hammer handle & head Write down 4 more examples of your own.

Guiding Controls A guiding control enables an element to move in a certain way. There are 3 types: Rotational guiding – allows the part to rotate only (circular or oscillatory rotation). This type of guiding control generally uses cylindrical parts. Translational guiding – allows the part to move only in a straight line (rectilinear or alternating). This type of guiding control generally uses parts in the shape of a rectangular prism.

Guiding Controls 3. Helical guiding – ensures the translational motion of a part while it rotates around the same axis.

What kind of guiding is it?

Write down your own 4 examples of guiding controls, and indicate whether each is rotational, translational or helical guiding.

Machines A machine is any device that helps people do work. A machine does not decrease the amount of work that is done, but it changes the way in which the work is done. For example, lifting a box by hand, with a ramp, or with a crane. All mechanical machines, no matter how complex, are made up of any of six simple machines.

Simple Machines Machines that use force to make work easier. Have no or very few moving parts. They are found in many objects. There are 6 types: Lever Inclined plane (Screw) Pulley Wedge Wheel & axle

Simple Machines Perform 3 Main Functions: They transmit forces. They change the direction of the force. They modify the intensity (size) of the force.

Lever A simple machine used for moving or raising weights centered on a fulcrum (or turning point). Has 3 components: Fulcrum: In a lever, a moveable bar rests on a supporting point called a fulcrum (a pivot point). Load: At one end of the bar is the load, the object to be lifted or moved. Force: A force must be applied to the other end of the bar. The portion of the bar between the fulcrum & the force is the lever arm. The portion of the bar between the fulcrum & the load is called the load arm.

Examples of levers: Hockey stick Baseball bat Your arm Door Laptop lid

3 Types of Levers The positions of the lever’s components can be changed. There are 3 types of levers: First class Second class Third class

First Class Levers The fulcrum is in the middle & the load & force (effort) are on either side. Ex: see-saw, crowbar, scissors

Second Class Lever The fulcrum is at the end. With the load in the middle. Ex: wheelbarrow, bottle opener, nutcracker

Third Class Lever The fulcrum is at the end, but the force (effort) is in the middle. Ex: Tweezers, broom, shovel, fishing rod

Inclined Plane Is a flat surface that is higher on one end. Make work of moving things easier Ex: ramp, hill, slide, doorstop

Screw Is an inclined plane wrapped around a shaft or cylinder. Allows the screw to move itself when rotated. Ex: jar lid, light bulb, clamp, jack, wrench, key, rings, spiral stair case

Wedge 2 inclined planes joined back to back. Are used to split things. Ex: chisel, fork, nails, ice scraper, blade of an axe or a knife

Wheel & Axle Is a rod that goes through a wheel which allows the wheel to turn. Gears are a form of wheels & axle Ex: Screw driver, roller skates, steering wheel, door knob, electric fan

Pulley Is a wheel & axle with a groove around the outside. Needs a rope, chain, or belt around the groove to make it work. Ex: top of flag pole, clothes line, on sailboat, blinds, crane

There are 2 Types of Pulleys: Fixed Pulley: is attached to something that holds it steady. It makes work easier by changing the direction of the work. Moveable Pulley: One end of the rope is fixed & the load is attached to the wheel.

Energy Transformation In technology, we define energy as a system’s capacity to do work, especially to make objects move. There are many forms of energy, and it is possible to change from one form to another, i.e., to transform energy or convert it.

There Are Many Forms of Energy There are many sources of energy all around you, & you use many to fulfill your needs. Write down as many forms of energy that you can think of.

There Are Many Forms of Energy: Potential Energy = energy an object possesses because of its position above a surface. a ball you hold has potential energy. If you let it fall, its potential energy transforms into kinetic energy, & it will fall to the ground. Potential energy is a specific form of mechanical energy.

Elastic energy = energy an object possesses when its shape is changed through stretching or compression. Ex: stretched elastic or compressed spring store elastic energy When a force ceases to be applied to them, they assume their original shapes It is a specific form of potential energy.

Kinetic Energy = the energy of objects in motion. Ex: a moving car or bicycle, a tossed ball It is a specific form of mechanical energy.

Radiant Energy = energy that enables you to see objects Radiant Energy = energy that enables you to see objects. When it hits your eyes, it triggers production of signals which travel to your brain & tells you what you are seeing. Ex: light bulb, sun, fire Radiant or radiation energy is a specific form of electromagnetic energy.

Electrical energy = energy resulting from the ordered movement of electrons from one atom to another. Ex: Makes machines like TVs & computers work, used to power lighting & heating systems

Magnetic energy = the form of energy that magnets possess due to their positions relative to each other. Like poles repel each other, opposites attract. It is a form of potential energy because it depends on the position of the object.

Thermal Energy = energy resulting from the random motion of all particles in a substance. It is present in all objects. When an object has a lot of thermal energy, the object is hot; if it contains very little, it is cold.

Chemical Energy = energy stored in molecular bonds Chemical Energy = energy stored in molecular bonds. It is released during a chemical reaction. Ex: Chemical energy in gas turns car engines; chemical energy in food is used by your body to do things like move.

Nuclear Energy = energy stored in nuclei of atoms Nuclear Energy = energy stored in nuclei of atoms. Special techniques are required to release the nuclear energy contained in radioactive substances, such as uranium.

Acoustic Energy (sound energy) = energy produced when matter vibrates Acoustic Energy (sound energy) = energy produced when matter vibrates. It makes the ossicles (small bones) in your ears move, which transmit signals to your brain to tell you what you are hearing.

Law of Conservation of Energy States that energy is not created nor destroyed, it is only transformed or changed from one form into another.

Mechanisms That Transform Energy There are different ways of making energy change from one form into another: Directly: Ex: Chemical → Kinetic (our muscles convert chemical energy in food you eat to muscle or kinetic energy) Ex: Chemical → Kinetic (motors use chemical energy in gas & transform it into kinetic energy to make a car run) Ex: Electrical → Thermal (home heating systems (radiators) convert electrical energy into heat to keep us warm)

Indirectly: (involves intermediate steps) Ex: Steam locomotive Chemical (burning coal) → Thermal (heats water to make steam) → Kinetic (steam activates pistons, making wheels turn) Ex: Hydroelectricity Potential Energy (water held above dam) → Kinetic energy (water flowing through dam turns turbines) → Electrical (turning turbines generates electricity)

Efficient Vs. Inefficient Energy Transformation When energy changes forms, it is never entirely transformed – some is lost to other forms. To determine the efficiency of an energy system, we can calculate the percentage of energy actually transformed into the desired form. If a system manages to transform most of the energy, we say it is energy efficient. If not, we say it is energy inefficient.

Energy Does not Disappear Energy that has not taken the desired form has not disappeared, it has simply taken another form. Ex: Incandescent light bulbs get hot when they are on – so this thermal energy (dissipated heat) is really wasted energy since it is not transformed into light.

Forces and Motion Motion is created by forces. A force is a mechanical action that sets an object in motion. A force can set something in motion, change its motion, or distort or break something. In a technological system, motion is either transferred or transformed from one part to another.

Forces Forces are measured in newtons (named after scholar & mathematician Isaac Newton). Force is measured with a device called a dynamometer (a.k.a. a spring scale).

There are 5 basic types of forces: compression, tension, torsion, flexion (or deflection), & shearing (review last set of technology notes for details & examples).

Types of Motion All motion is a combination of the following 4 types of simple motion: Rectilinear = a straight line, Ex: A skateboard Alternating = rectilinear in one direction, then the opposite direction, Ex: Trumpet’s piston valves

3. Circular = motion in a curve or circle, Ex: Ferris wheel 4 3. Circular = motion in a curve or circle, Ex: Ferris wheel 4. Oscillatory = back & forth around a central point, Ex: A swing

What Triggers Motion? Motion cannot be triggered on its own. A force is required to provoke it. Ex: When you let go of an object above the ground, it falls. Gravitational force provoked this motion.

What Slows Motion? Forces are also responsible for slowing motion. Ex: If a person pedals a bike a few times & then stops pedalling, the bike will eventually stop. Friction is the force opposing motion & responsible for stopping it. Friction with air, the moving parts of the bike, & the tires in contact with the ground.

Factors Affecting Friction Type of surface (the material & whether it is smooth or rough) Temperature Presence of a lubricant Shape of object (ex: some profile shapes are more aerodynamic) Note: Friction is not always something to avoid.

Mechanical Systems: Simple Machines Combined Recall there are 6 simple machines: the lever, inclined plane, screw, pulley, wedge, & wheel & axle. Two or more simple machines can be combined to create a mechanical system. Mechanical systems perform work & they often provide an even greater mechanical advantage (can move loads more easily) than a simple machine alone.

The Transmission of Motion Mechanical systems transmit motion from one part to another with the help of various mechanisms. Transmission mechanisms pass along the same kind of motion, without changing it. Ex: circular motion to circular motion

There are 5 common Motion Transmission Mechanisms Gears (a.k.a. gear train) Friction gears (a.k.a. friction wheels) Pulley Belt & Pulley Chain & sprocket

Gears Are interlocking, toothed wheels. If 2 or more are connected it is called a gear train. 2 gears in a set turn in opposite directions to each other. The gears are not necessarily the same size or orientation (ex: bevelled gears). Smaller gears turn faster than larger gears. Examples: inside a clock; a hand drill has gear set with bevel gears.

Friction Gears (Wheels) Are similar to gear trains, but have no teeth. They are touching & the rotational motion of one gear turns the other through friction. Like all gears, they turn in opposite directions to each other, & smaller wheels turn faster. Example: A printing press

Belt & Pulley A pulley is a grooved wheel (or several wheels) with a belt around it (them). When one wheel rotates, the motion is transmitted to the other wheels so that they rotate as well (all circular motion, so it is motion transmission). Example: Clothesline

Chain and Sprocket A chain connects 2 sprockets (gears). When a force is applied, it causes one of the sprockets to rotate. Since it is connected by a chain to another sprocket, the circular motion gets transmitted to the other sprocket. The sprockets rotate (same kind of motion) & in the same direction. Example: Bike pedals are connected with a chain & sprocket.

Motion Transformation Certain mechanisms make it possible to change from one type of motion to another. These mechanisms transform motion. There are 4 common motion transformation mechanisms: Connecting Rod & Crank Cam & Follower Rack & Pinion Screw & Nut

Connecting Rod & Crank Transforms circular motion into alternating motion. Example: In a combustion engine, an explosion pushes a piston which moves a connecting rod.

Cam & Follower Transforms a circular motion into an alternating motion. A cam can be various shapes. The follower slides on the turning cam. The follower moves closer or farther away depending on the shape of the cam. The follower, therefore, has an alternating motion. Example: Used in car motors, steam machines & sewing mahines

Rack & Pinion Changes circular motion into rectilinear motion & vice versa. Is composed of a toothed wheel (the pinion) that moves a toothed bar ( a rack). Example: a car’s steering system

Screw & Nut Transforms circular motion into rectilinear motion. When a screw (or bolt) turns, the nut moves along the screw in either direction. Example: A C-clamp, a car jack

END

Topics on Tech Test Set of specifications Technical Diagrams Know the differences & similarities between: Design Plans Technical drawings (construction diagrams) Standard symbols Tech Systems: Inputs vs. outputs

Links: Definition & Types Direct/indirect Rigid/flexible Removable/non-removable Complete/partial Guiding Controls Rotational, translational & helical Simple machines Change the way work is done, but not the amount

Energy transformations 6 types of simple machines – know some examples of each: Lever : 1st class, 2nd class, 3rd class Inclined plane (Screw) Pulley Wedge Wheel & axle Energy types: potential, elastic, kinetic, radiant, electrical, magnetic, thermal, chemical, nuclear, acoustic Energy transformations

Law of conservation of energy Forces: Definition, units = Newtons 5 types: compression, tension, torsion, deflection, shearing Motion Triggered by forces, gravity Opposed by friction (including air resistance) Factors affecting friction 4 types: rectilinear, alternating, circular, oscillatory

5 Motion transmission mechanisms: Gears (a.k.a. gear train) Friction gears (a.k.a. friction wheels) Pulley Belt & Pulley Chain & sprocket 4 motion transformation mechanisms: Connecting Rod & Crank Cam & Follower Rack & Pinion Screw & Nut