Introduction to Engineering

Starter - What is Engineering?

• Write down your own brief definition of Engineering.
• What does Engineering mean to you?

What is Engineering?

Definition: ‘The activity of applying scientific knowledge to the design, building and control of machines, roads, bridges, electrical equipment, etc.’ oxfordlearnersdictionaries.com

Another way of putting this is that: ‘Engineers are people that see problems or inefficiencies in the world around them and use science, maths and practical skills to design and manufacture creative solutions and thereby make consequential improvements to people’s lives.’ Mr Stear

So why study Engineering?

As on the previous slide, Engineering is about problem solving. This is something that you will find useful in your adult life, regardless of what career you choose to have, or whether you have none.

You may learn skills in this subject that you will use for the rest of your life, even if you can’t currently envision how.

If you should choose a career in Engineering, you will be extremely sought after to help solve some of the world’s most challenging issues e.g.

Engineering Project Director

Engineering Production Manager

Field Engineering Manager

Engineering Research and Development Manager

Electrical Engineering Manager

Engineering Planning Manager

Mechanical Engineering Manager

Engineering Key Account Manager

Equipment Engineering Manager

Wind Energy Operations Manager

Engineering Project Manager

Engineering Consultant

Engineering Sales Manager

Proposal Manager

Drafting Manager

Robotics Engineer

Engineering Chief Designer

Forestry Strategic Planner

Engineering Project Coordinator

Safety Manager

Engineering Project Analyst

Engineering Account Manager

Mechatronics Engineer

Electromechanical Engineering Technologist

Electrical Engineer

Mechanical Design Engineer

Communications Engineer

Geotechnical Engineer

Product Engineer

Photonics Engineer

Service Engineer

Assistant Chief Engineer

Mechanical and Electrical Engineer

Design Engineer

CAD Design Engineer

Product Development Engineer

Sales Engineer

Generation Engineer

Genetic Engineer

Civil Engineer

Oil and Petrochemical Engineer

HVAC Engineer

Mechanical Engineer

Principal Cost Engineer

Licensed Aircraft Engineer

Rail Engineer

Energy Engineer

Marine Engineer

Planning Engineer

Project Engineer

Solar Engineer

Instrumentation Engineer

Automation Engineer

Test Development Engineer

Engineer

Production Engineer

Irrigation Engineer

Supply Chain Specialist

Field Engineer

Control Systems Engineer

Wind Energy Engineer

Structural Engineer

Instrumentation Manager

Industrial Engineering Technologist

Principal Support Engineer

Quality Assurance Engineer

Geological Engineer

Controls Engineer

Process Engineer

Mechanical Inspector

Fire Engineer

Wastewater Engineer

Industrial Engineer

Locomotive Engineer

Structural Analysis Engineer

BMS Engineer

Environmental Engineer

Contract Associate Engineer

Principal Engineer

Broadcast Engineer

Staff Engineer

Manufacturing Engineer

Acoustics Engineer

Maintenance Manager

Safety Engineer

CAE Engineer

Engineering Lab Technician

Highway Engineer

Facade Engineer

Biochemical Engineer

Drilling Engineer

Mining Engineer

Pipeline Engineer

Scheduling Engineer

Static Equipment Engineer

Avionic System Support Engineer

Verification Engineer

Corrosion Engineer

HVAC Supervisor

Instrument Engineer

Instrumentation and Control Engineer

Transportation Engineer

Validation Engineer

Materials Engineer

Commissioning Engineer

Optical Engineer

Equipment Engineer

Materials Researcher

Photonics Technician

Piping Engineer

Maintenance Engineer

Product Safety Engineer

Ceramics Engineer

Purchasing Engineer

Stress Engineer

HSE Professional

Stationary Engineer

Associate Engineer

Technical Engineer

Tender Engineer

Structural Designer

Controls Software Engineer

Estimator

Condition Monitoring Engineer

Technical Support Engineer

Mechanical Designer

Robotics Technician

Assembly Engineering Technician

Engineering Safety Coordinator

Engineering Technologist

Surveyor

Product Development Technician

Engineering Technician

Safety Inspector

Materials Technician

Fabrication Specialist

Work Planner

Structural Technician

Autocad Operator

Drafter

CAD Designer

Process Operator

Fiber Analyst

Bridge and Lock Tender

Heavy Equipment Mechanic

Piping Designer

Technical Affairs Officer

Electromechanical Equipment Assembler

Optical Instrument Assembler

Safety Officer

Technical Assistant

Electrical Draughtsman

Pressure Vessel Inspector

Fabricator

Engine Assembler

PCB Assembler

Maintenance Fitter

Fitter and Turner

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Just some of the careers within engineering:

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Careers in Engineering

• As you can see, the opportunities available in engineering are extremely varied and broad.
• Engineers can find work anywhere in the world that they choose.
• Engineers are highly paid, especially as they gain experience.
• Engineers have job satisfaction as they know that they are helping to make the world a better place.
• An engineering qualification (especially at degree level) can also get you into positions in finance, business, management, law, technical sales, etc.

Engineering as a GCSE Option

• In Y10 and 11 Engineering, instead of doing a GCSE, we complete a Vocational Certificate: The EAL First Certificate in Engineering Technology, Level 2
• This is equivalent in status to a GCSE, but instead of getting a grade 0-9, you receive a Pass, Merit or Distinction.
• To pass the course, you complete in-class mini-tests and mini-coursework pieces at the end of each of four modules. You must pass each of these, but you may repeat them as necessary until you have.
• Your grade is then made up from the results of a Synoptic module (a summary of everything you have covered in the other 4 modules) and an online multiple choice exam.

Engineering as a GCSE Option

• This Y9 course will mimic the EAL Certificate, so will provide a good introduction to those of you who choose Engineering as an option subject.
• We will cover aspects from the course which if you pick this subject you will go on to practice and learn in more depth in Y10 and 11 .
• On the other hand, we hope that if you should decide not to continue this subject next year, that you will nevertheless have learnt some useful skills for your future life and that you will have fun in the process.

The course structure this year

• We are going to begin today by talking about health and safety regulations and codes of practice in engineering .
• We will then move on to learn about communication methods in Engineering, including Orthographic drawing.
• After this we will learn about the properties of metals.
• Then we will put all our new skills to use by learning how to manufacture and assemble a multi-component product in metal.
• Finally we will evaluate the product we have made to determine how accurately we have made it and what we have learnt in the process.
• There will be mini-assessments throughout and your final grade will reflect all components of the project.

So, with introductions done, lets begin!

Health and Safety in the workshop

• Activity – On the sheet provided, circle the health and safety hazards and explain what the danger is in each case.
• What is a hazard?
• A hazard is something that has the potential to cause injury, either to yourself or others.

Health and Safety in the Workshop

• Vices – Are not to be touched unless you have been asked to do so.
• Tommy Bars that are dropped are both exceptionally irritating and also can cause nasty pinch injuries.
• Do not put anything other than wooden or plastic work-pieces in the woodworking vices.
• Do not over-tighten, or leave wide open.

Health and Safety in the Workshop

• Metalworking vices are to be used exclusively for metalwork, and occasionally plastics.
• Again, no fiddling with the tommy bars
• Be careful when carrying and installing them. They are heavy. Refer to the manual handling posters for more info.
• Put them away at the end of the lesson.

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Health and Safety in the Workshop

• E-Stops – Cut off power in the event of an accident or emergency.
• Located next to each machine tool are individual emergency stops for each machine, e.g. the pillar drill has a foot activated stop button. Other machines may have different style buttons.
• These are for use by students to quickly shut off the machine in the event of something going wrong.
• Located on each wall of the classroom are whole-room emergency stops. These cut the power off to the entire room.
• These are for use by teachers ONLY, UNLESS your teacher is the person in danger or has been incapacitated in some way. In this instance ONLY, students should press one of these buttons and seek help from another member of staff.

Health and Safety in the Workshop

• PPE – stands for Personal Protective Equipment.
• During practical activities, you must wear:
• When using machinery, you must wear the appropriate safety equipment as you will be taught. Eg. Safety glasses on the drill press etc.

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Apron – protects our clothes from dust and dirt. Keeps any loose clothing together and safe from, rotating machinery

Health and Safety in the Workshop

• Stools MUST be stacked away for ALL practical work.
• No practical may be carried out while seated.
• You should nevertheless remain at your station (as per the seating plan) unless you have been asked to collect something by your teacher.

Equipment Passport Scheme

• In order to be permitted to use a piece of equipment, be that a tool, a piece of machinery, or certain chemicals, you must have a valid passport sticker for that application.
• Stickers are earnt by demonstrating under one-to-one supervision by a member of staff that you understand how to use a piece of equipment safely. Most equipment will also require a written piece of work that demonstrates your understanding.
• Stickers must be signed by you, the teacher who has supervised your training and they will be dated.
• They will be stuck inside the cover of your exercise book.

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Equipment Passport Scheme

• If you do not have the relevant sticker you WILL NOT BE PERMITTED to use that piece of equipment.
• Stickers may be rendered VOID if ANY staff member sees you using a piece of equipment unsafely. This will be done with a stamp on the relevant sticker.
• If your sticker is stamped void, that carries a penalty of a LUNCHTIME DETENTION and you will have to retrain on that piece of equipment before you can be recertified and are able to use that piece of equipment again.
• Recertification will not happen until after the lunchtime detention has been sat.
• Anybody found using equipment without the relevant sticker will receive an AFTERSCHOOL DETENTION.

Equipment Passport Scheme

• Stickers available to collect in Y9 Engineering:
• File
• Scribe
• Centre Punch
• Hammer
• Dividers/Odd-leg Calipers
• Hack Saw
• Engineer’s Vice
• Pillar Drill (Extended)
• Taps

Regulations and Codes of Practice

Part of EAL Certificate Unit 1: Engineering Environment Awareness

What is a Regulation?

• A regulation is a law, introduced by Parliament.
• You MUST follow regulations
• If you do not follow regulations, criminal charges may be brought against you and/or your company
• Examples include:
• Health and Safety at Work Act (1974)
• Personal Protective Equipment at Work Regulations (2002)

‘Regulations’ in School

• In school, we have school rules that we must follow, for example, students must wear school uniform.
• In the Technology and Engineering workshops, we also have rules.
• Failure to follow these rules will result in disciplinary measures.
• These rules are:

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Workshop Regulations

• Behave sensibly and respectfully at all times.
• Wear appropriate PPE (Personal Protective Equipment) as instructed.
• The class must be kept clean and tidy at all times.
• No tools or materials to leave the room without express permission from a member of Technology/Engineering department staff.
• When the teacher says STOP, stop what you are doing IMMEDIATELY.
• Students must have a valid equipment passport sticker to use any tool or piece of equipment.

What is a Code of Practice?

• A code of practice is a document that complements regulations
• It provides practical guidance on how to comply with relevant regulations in a specific field
• Examples include:
• BS4163 (2014) Health and safety for design and technology in educational and similar establishments.
• CLEAPSS Model Risk Assessments
• It is not a LEGAL requirement, but it would hold significance in a court of law, because it demonstrates best practice. You would have to demonstrate that your system was equally safe.

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Regulations and Codes of Practice

• Activity – sort the cards to identify which documents are regulations and which are codes of practice.
• Additionally, match the excerpts to the documents they came from.

Safety Signage

• In order to keep us safe in the working environment, we have standardised signage to notify us of hazards and inform us of health and safety issues.
• These signs are grouped into categories and each category has a common design.
• This enables us to see, at a glance, what a sign means.

Warning Signs

• Warning signs inform us of hazards and dangers to be aware of.
• They are TRIANGULAR, YELLOW, with a BLACK border and BLACK central image. e.g.

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Electricity

Hot surface

Naked flame/flammable

Wet floor

Mandatory Signs

• Mandatory Signs tell us things that we MUST do.
• They are CIRCULAR, BLUE, with a WHITE outline and WHITE central image e.g.

Wear gloves

Wear ear defenders

Wear hard hat

Wear overalls

Prohibition Signs

• Prohibition Signs tell us things that we MUST NOT do.
• They are CIRCULAR, WHITE with a RED outline and a RED DIAGONAL BAR through the centre. The central image is in BLACK. e.g.

No food or drink

No smoking

No drinking water

No welding

Safe Information Signs

• Safe information signs tell us safety information such as evacuation routes and first aid station locations.
• They are SQUARE OR RECTANGULAR, GREEN with WHITE text and images. e.g.

Eye Bath Station

Fire Safety Signs

• Fire safety signs give us information useful in the event of a fire.
• They are SQUARE, RED, with WHITE text and images. e.g.

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Homework – Regulations and Codes of Practice

• For homework, please research 3 examples of Health and Safety Regulations AND 3 examples of Health and Safety Codes of Practice, that each apply to Engineering in School and/or in industry.
• EXPLAIN in broad terms, what topics they cover and who they apply to.
• Identify the date that they came into force/were last updated.
• Further details will be on Show My Homework.
• https://www.hse.gov.uk/pubns/books/index-legal-ref.htm This government site gives a comprehensive list of health and safety approved codes of practice.
• https://www.legislation.gov.uk/ This government site allows you to read every law of the United Kingdom in full, including Health and Safety Regulations.

Plenary

• Hands up.
• I will ask each person for a piece of Health and Safety information that you have learnt today.
• When you have given your answer, put your hand down and listen quietly.

Reading Engineering Drawings

Part of EAL Certificate Unit 2: Engineering Techniques

Starter – Orthographic worksheet

What is an Engineering Drawing?

• Engineering drawings are used to communicate design ideas
• They conform to national or international standards e.g.
• International Standards Organisation ISO 128
• British Standards Organisation BS8888
• The most common types are:
• Isometric drawings (for 3D views)
• Orthographic drawings (2D representations of 3D parts)

Orthographic Drawings

• Individual faces of a 3D object are drawn.
• Views are laid out in a specific format, either First Angle Projection or Third Angle Projection.
• All dimensions are to scale.

Third Angle Projection

• Most orthographic projection is done in Third Angle Projection.
• This means that as we look at the object:
• The Top face (sometimes called the plan view) is above the front view
• The Right hand side face is on the right of the front view
• The Left hand side face is on the left hand side of the front view
• Etc.

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Third Angle Projection

• An important thing to remember is that the views must line up with each other.
• If you draw some faint lines on your page, this can help to get things lined up properly.

Drawing tools

• Sharp Pencil
• Ruler
• Protractor
• Compasses
• Eraser
• Set Square

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Standard Drawing Formatting

• As we have already learnt, all engineering drawings conform to standards
• Standards create consistency and ensure other people know exactly what we mean.
• All drawings start with certain key requirements for how we lay out the page.
• These include:

Page Layout

• Title block – Contains varying information. Examples can include:
• Name of creator
• Drawing number
• Drawing Title
• Drawing Scale
• Date of drawing creation
• Unit system
• Drawing Standard
• Page border
• Defines the page boundary. Very important in industry as only information contained fully within the page border is legally binding. Usually 10mm from the edge of the page
• Projection Symbol
• Tells us whether we are using First or Third angle projection.
• Drawn in the bottom left hand corner of the page.
• Essentially a third angle projection of a truncated cone.

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Title Blocks for school drawings

• The title block that we are going to produce for drawings on this course will contain 6 pieces of information:

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• As with ALL text on an engineering drawing , use BLOCK CAPITALS.
• Please draw this title block in your book. Make a special note of this.

Projection Symbol

• The projection symbol tells us whether we are working in Third Angle Projection or First Angle Projection.
• If we give our drawing to a manufacturer without specifying the type of projection, we may receive back a mirror image of the part that we want.
• First Angle projection puts the views on the opposite side to Third Angle, resulting in a mirrored part if we don’t specify correctly.

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• Please draw this in your exercise book

Page Layout for an orthographic drawing.

• We are now going to draw a page-layout incorporating a 1omm border, a title block and the third angle projection symbol.
• Use a sharp pencil
• Be accurate and neat.
• Ensure that any lines are either Horizontal or Vertical, not at a weird angle to the page. Remember “Ortho” is short for “Orthogonal” or 90°
• You can ensure this with a ruler and a set square.

Orthographic drawing

• Have a go at drawing this block in third angle orthographic projection. Be careful to lay-out the views correctly.

Homework

• Please complete the drawing that you began in class.
• Ensure that each view is drawn in the correct location for third angle projection
• Ensure that your measurements are accurate (Use a sharp pencil and be careful with your ruler)
• Make sure that your page border and title block are correctly drawn and that you have drawn the third angle projection symbol.

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Plenary - Orthographic Drawing

• Demonstrate your knowledge of orthographic drawings.
• Draw a quick sketch of some simple 3D shapes: a cube, a cylinder and a triangular prism using Third Angle Orthographic projection.

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Starter – Orthographic Drawing

Line Types

• In Engineering Drawing, we use different styles of line to represent specific information.
• Solid lines form the edges of our component that are visible from one viewing direction.
• Dashed lines represent hidden detail. This means edges that we know exist, but may not be visible from the direction that we are viewing.
• Dot-Dash-Dot lines represent centre lines, for example lines of symmetry or axes of rotation.

Scale

• Engineering drawings are always drawn accurately to scale.
• This means that every measurement on the drawing corresponds, with the same ratio, to the real life part.
• For small parts, we would prefer to draw at 1:1 scale.
• Where parts are too large to draw comfortably on a page, we may choose a scale of 1:2, 1:5, 1:10, 1:20 etc. where each measurement on the drawing is larger in real life by the given scale.
• Where parts are too small to be clearly visible on a page, we may choose a scale of 2:1, 5:1, 10:1 etc. where each measurement on the drawing is smaller in real life by the given scale.

Accuracy

• You must take care when drawing to ensure that your lines are accurately drawn to within 0.5mm either side of the intended value.
• This requires your pencil to be sharp and your measurements made carefully.
• Take your time, be very patient and CHECK your work as you go.
• Drawing accurately is a skill that must be practiced.

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Hidden detail

• Sketch the part below in Third Angle Projection, incorporating all hidden detail and any relevant centre lines. Use a scale of 1:1.

This is a through hole.

Dimensioning

• In order to communicate all the relevant information about a component, we need to add dimensions to our drawings.
• Dimension lines are fine lines, half the width of our drawing outline.
• They have solid arrow heads at either end that have a 30° point.
• The number is placed above the line and does not have a unit. (Units are defined in the title block)
• Dimensions are read from the bottom of the page, or looking from the right hand side.
• Leader lines are used to extend surfaces for measurement. These are also thin lines. They do not touch the part.

Solid 30° arrow heads

Dimensions positioned above the line as viewed from the bottom of the page, or from the right hand side.

Leader lines used to extend surfaces for measurement. Thin lines with a small gap to the part surface.

Centre line:

Dot-Dash-Dot

Hidden Detail:

Dashed lines

10mm Border

Title Block

Drawing Units

Types of drawings

• So far we have learnt about part drawings. These show us how to manufacture individual components.
• We also have Assembly drawings, which show us how to put these components together to form a complete product.
• Sometimes we produce exploded drawings, where each of the parts is spread out on the page to show the assembly process more clearly.
• We are used to seeing such drawings in IKEA assembly manuals, Lego assembly instructions etc.

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Assembly drawings

• Assembly drawings show all of the components of an assembled product, each identified with a numbered bubble.
• A table on the drawing sheet then refers to each item in the assembly giving more details about that part, often including the part drawing name or number which gives the detailed information about each part.
• The table of parts will also identify how many of each part are present where parts are duplicated.

Numbered bubbles

Table of Parts

Exploded Drawings

• Exploded drawings are assembly drawings where we take each item and separate it from the items it attaches to.
• This enables us to see more clearly how something is assembled.
• Often we see similar drawings in Lego instruction manuals and IKEA assembly guides etc.

Homework

• Complete the Orthographic drawing begun in class today.
• Add dimensioning and double check that you have completed each view, incorporating hidden detail, correct line weights etc.
• Make sure that your dimensions:
• are drawn with fine lines
• that you use leader lines correctly
• that your arrow heads have a fine 30° head and that they are solid
• that your numbers are positioned above the line as we look from the bottom of the page, or in the case of vertical dimensions, from the right of the page.

Plenary -

• Write a set of 5 questions to test your colleagues’ understanding of engineering drawing.

Starter – Properties of Materials

• Find all the different material properties in the word search.

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Properties of Metals

Part of EAL Certificate Unit 3: Engineering Principles

Properties of Metals

• There are several properties of metals that are useful to us as Engineers.
• We need to know their names and what they mean for two reasons:
• 1) Knowing this information will allow us to design better components by selecting construction materials appropriately for function.
• 2) We are required to know these properties for our Certificate Qualification.
• Here follows a list of the TEN properties that we need to learn.

Properties of Metals

• Strength
• Hardness
• Toughness
• Brittleness
• Malleability
• Ductility

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• Elasticity
• Plasticity
• Conductivity
• Dielectric Strength

Properties of Metals - Strength

• Strength is defined as ‘The ability to support heavy loads’

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• There are three types of strength:
• Tensile Strength – The ability to support heavy loads in a PULLING direction, e.g. a tow rope
• Compressive Strength – The ability to support heavy loads in a PUSHING direction, e.g. a pillar
• Shear Strength – The ability to support heavy loads in a SLIDING direction, e.g.

LEARN THIS WORD FOR WORD!

Properties of Metals - Hardness

• Hardness is defined as ‘The ability to resist scratching or denting’

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• You can test hardness using a file. If the file cuts the material, then the material is softer than the file. The easier it cuts, the softer the material.
• Hardness is measured by pressing something into the surface of a material and measuring the size or depth of the indent left behind.
• Types of hardness testing include: Rockwell, Brinell and Vickers hardness tests.

LEARN THIS WORD FOR WORD!

Properties of Metals – � Toughness and Brittleness

• Toughness is defined as: ‘The ability to resist repeated bending or shock loading’

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• An example of something tough would be a hammer head, which doesn’t break despite numerous impacts.

• Brittleness is the opposite of toughness.
• Brittleness is defined as: ‘Breaking suddenly without much distortion’

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• An example of a brittle material is glass, which cannot bend very far or be struck very hard at all before it shatters

LEARN THIS WORD FOR WORD!

LEARN THIS WORD FOR WORD!

Properties of Metals – � Malleability and Ductility

• Malleability is defined as: ‘The ability to be hammered into shape’

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• This means permanent deformation under COMPRESSION (Pushing force) without breaking.
• Example: Lead is very malleable

• Ductility is similar to malleability, but in TENSION (Pulling force)
• Ductility is defined as: ‘The ability to be drawn out like a wire’

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• An example of a ductile material is copper, which we do in fact make wires from.

LEARN THIS WORD FOR WORD!

LEARN THIS WORD FOR WORD!

Properties of Metals – � Elasticity and Plasticity

• Elasticity is defined as: ‘The ability to return to original shape after loading’

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• Example: Natural rubber

• Plasticity is the opposite of Elasticity
• Plasticity is defined as: ‘Maintains new shape after loading’

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• An example of a plastically deforming material is steel. After you deform steel beyond its yield point, it holds the new shape.

LEARN THIS WORD FOR WORD!

LEARN THIS WORD FOR WORD!

Properties of Metals – � Conductivity and Dielectric Strength

• Conductivity is defined as: ‘Conducts heat or current easily’

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• You MUST remember both HEAT and CURRENT.
• Examples include copper

• Dielectric Strength is the opposite of Conductivity
• Dielectric Strength is defined as: ‘Resists the flow of current or heat’

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• Again, you MUST remember both CURRENT and HEAT.
• Examples include glass, Nylon, Teflon etc.

LEARN THIS WORD FOR WORD!

LEARN THIS WORD FOR WORD!

Homework

• Revise the material properties definitions.
• Material Properties test on SMHW

Plenary-Material properties quiz

• https://www.satchelone.com/quizzes/57588890-material-properties-test

Starter – Workshop priorities

• Arrange the following in order of importance:
• Chatting with friends
• Handing in homework
• Getting to Break/Lunch/Next Lesson/Home on time
• Completing class theory work
• Leaving the workshop tidy
• Listening to and following instructions

Answer

1. Listening to and following instructions
2. Leaving the workshop tidy
3. Completing class theory work
4. Handing in homework
5. Getting to Break/Lunch/Next Lesson/Home on time
6. Chatting with friends

What is missing from this list?

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Practical lessons

• Practical lessons are a PRIVELEGE, not a right.
• Practical will ONLY be permitted where EVERYBODY in the class is operating SAFELY.
• Individuals who demonstrate UNSAFE behaviour will be REMOVED from the class. Depending on severity, this may or may not be preceded by WARN and MOVE.
• Practical lessons are CONDITIONAL upon THEORY being complete and HOMEWORK being handed in ON TIME.
• Those who have not completed homework to a proper standard will be required to do so before they are permitted to undertake practical work.

Project: BBQ Spatula

Incorporating skills required for EAL Certificate Unit 17: Fitting and Assembly Techniques

BBQ Spatula

• The project that we are going to make is going to be a BBQ Spatula.
• It has four components to it:
• One Spatula Blade
• One Spatula Handle
• Two Spatula Grips
• To the right, you can see the exploded assembly drawing.
• Also labelled are the two types of fasteners that we are going to use.

Marking out/Layout

• When we begin practical work, you will be provided with a blank.
• A blank is a piece of the required material, cut approximately to length.
• You will then need to transfer the drawing measurements to your blank.
• This will require you to learn how to use some engineering tools that you may not have used before.
• These include:

Layout tools

• Engineers’ Square:
• This is used to transfer a line at 90° to one edge of the part.
• Scriber:
• Used to scratch lines on the surface of our metal just like using a pencil on paper.
• Engineers’ Blue:
• Used to coat the surface of the steel before marking out to provide a high contrast to our scribed lines.
• Dividers:
• Used just like compasses to scratch circles or arcs onto the surface of the part.
• Centre Punch:
• Used to mark the centre of holes to help our drill bit to start where we want it to.

Demonstration

Quiz

• Q) What is the first thing you do when preparing to mark out a piece of metal?
• A) Apply Engineer’s Blue

Quiz

• Q) How do you scribe a line onto your part that is 90° to an edge?
• A) Press the Engineer’s square against one of the factory edges.
• Holding your scriber with the point angled into the square and with firm pressure, pull the scriber along the square towards you.

Quiz

• Q) Where do you start measuring from on a Steel Rule?
• A) From the very end of the rule.

HERE, at the very end.

NOT HERE, at the first line! This is 1mm!

Quiz

• Q) How do you mark a hole position for drilling?
• A) Mark the centre of the hole by scribing lines at the two measurements that locate the hole.
• Line the point of your centre punch up carefully where the two lines cross and give it a sharp tap with the hammer.
• Check that the dent formed by the punch is perfectly in the right place.

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Quiz

• Q) How do we adjust a centre punch dent that is in the wrong place?
• A) Locate the point of your centre punch in the dent created, then angle it towards the direction that you want the dent to move.
• Give the centre punch a sharp tap with a hammer.
• Check that the dent is now centred where you want it.
• Repeat as necessary until the dent is centred at the point where the lines cross.

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Layout Tools Part 2

• In addition to the layout tools we have already learnt about, there are some others that we need to learn to use. These are:
• Odd-leg Calipers
• Surface Plate
• Height Gauge
• Angle Plate

Odd Leg Calipers

• Odd leg Calipers look a little like dividers, but instead of two points, they have one.
• The second leg has a metal hook that rests up against a factory edge.
• Set the distance between the hook and the point using a steel rule.
• Rest the hook against the factory edge and drag the point along the work piece, creating a line parallel to the factory edge at the set distance.

Surface Plate

• A surface plate is a reference plane that is calibrated to be exceptionally flat.
• It is used for measurement and layout in conjunction with other measurement tools.
• They are often made from cast iron or granite due to their thermal stability.
• Considered the MOST IMPORTANT TOOL in a professional machine shop as it is the baseline for all measurements taken in the shop.

Height Gauge

• The height gauge is used in conjunction with a surface plate to scribe lines at a desired height from the surface.
• It is much more accurate means of marking out than a steel rule.
• Height gauges are typically accurate to ±0.01mm

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Angle Plate

• An angle plate is used with a surface plate to hold a part at a perfect 90° angle to the surface plate.
• This makes it very helpful to use with a height gauge or marking block to scribe lines on the surface of thin sheet metal or plate.

Height Gauge Demonstration

Health and Safety Passport

• Before you begin your practical work, you will each need to earn your health and safety passport sticker for each piece of equipment that you will be using.
• To do this, there is a sheet for you to fill out to demonstrate your understanding of the hazards and risks of each tool.
• I will then allow you to use the tool and if I am happy that you are using it safely, I will award you the sticker.
• Remember that inappropriate use of tools will result in your sticker being voided and an automatic lunchtime detention being issued.
• If you are found using a tool without having been awarded your sticker or with a void sticker, except under my direct supervision during the process of earning the sticker, then an automatic after-school detention will be issued.

Health and Safety Passport stickers eligible for award today:

• File
• Scriber
• Centre Punch
• Hammer
• Dividers/Odd-leg Calipers

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Before we begin marking out:

• IMPORTANT HEALTH AND SAFETY NOTICE!
• Before we begin, we MUST deburr our parts.
• Deburring is the process of filing the edges of a piece of material to remove any sharp tags of metal that may have occurred during preparation of the blanks.
• Please ensure all edges of your part are free of any burrs before you start marking out.
• This reduces the chance of you:
• a) cutting or scratching yourself.
• b) getting incorrect measurements when you set your square against the edge of the blank.

Practical-Deburring and Marking Out

• You will:
• be handed an Aluminium blank.
• deburr the edges with a file.
• apply Engineer’s Blue.
• mark out the edges of the part and the hole positions.
• centre punch each hole position.
• check ALL of your measurements TWICE.

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Homework

• Revise the names of the layout tools and revise their uses.
• I will put the relevant section of the PowerPoint on SMHW for revision purposes.
• Complete the quiz on Show My Home Work.

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Plenary - Layout tools health and safety refresher

• I am going to ask each person in the class for one Health and Safety consideration when marking out.
• Each person must provide a unique answer, so unless you’re lucky enough to be asked first, you’ll need to have a few options ready!
• Quick fire answers please!

Starter – True or False?

• Anybody can use the workshop equipment and tools.
• There are no consequences to using equipment without a sticker.
• Once you have your sticker it is valid indefinitely.
• You must demonstrate safe use of equipment before a sticker will be granted.
• Stickers are to be stuck inside the front cover of your exercise book.
• It doesn’t matter how many times your sticker is voided, you can always get another.

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Starter – True or False? Answers

• Anybody can use the workshop equipment and tools.
• There are no consequences to using equipment without a sticker.
• Once you have your sticker it is valid indefinitely.
• You must demonstrate safe use of equipment before a sticker will be granted.
• Stickers are to be stuck inside the front cover of your exercise book.
• It doesn’t matter how many times your sticker is voided, you can always get another.

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• Only students who have earnt their passport sticker will be permitted to use equipment and tools.

• Students found using equipment without a valid sticker (unless in the process of earning a sticker under the direct supervision of a sticker-awarding member of staff) will receive an after school detention. NO exceptions.

• Your sticker is valid for a period of a year, OR until it is marked VOID.

• Stickers are awarded to students who demonstrate safe use of equipment under direct supervision and who can recognise and understand how to appropriately control the risks of that piece of equipment.

• Students who are found in breach of their health and safety sticker more than 3 times will not be permitted to use that equipment for the rest of this course and are unlikely to be accepted onto the Y10 course.

• Stickers are to be stuck on the inside cover of your exercise book, starting with the inside front cover and continuing to the inside rear cover if required.

Metal Cutting

• When cutting metal by hand, we use a Hack Saw.
• This gives us a rough finish and is not particularly accurate, so we need to cut a little bit on the waste side of our marked line.
• We can then use a File to finish to our final dimension.
• We must hold our work in an Engineer’s Vice.

Hack Saw

• Hack Saws are designed for cutting metal. Occasionally we might also use it for cutting plastics.
• They have small, sharp teeth that point forwards.
• They therefore cut on the FORWARD stroke.
• We hold our work in a metal working vice in such a way that we can cut close to the vice.
• When we have finished cutting, we will need to deburr our part (remove any small sharp spiky bits of metal from the cut edge) using a file.

Using a Hack Saw

Filing

• Engineer’s files are used for smoothing and shaping metal.
• They cut on the FORWARD stroke ONLY.
• Holding the handle in our dominant hand and resting our other hand on the opposite end of the file, we can keep a little pressure on the file as we push it forwards.
• We then lift the file to return it to the start of the cut.
• This is called CROSS FILING.

Cross Filing

Types of Files

• Engineer’s files come in two distinct styles. These are:
• Single Cut – Parallel rows of teeth running the full width of the file, often at an angle approximately 65° to the centreline. Good for fine finishing work.
• Double Cut – Diamond shaped teeth formed by the intersection of two sets of parallel grooves at approximately 90-120° angles to each other. Good for fast material removal.

Cut of a File

• Besides just single cut and double cut styles, each of these types come in varying coarseness of cut.
• The cut of the file refers to how coarse the teeth are.
• There are 5 standard cuts, these are Very Smooth, Smooth, Second, Bastard and Rough. The two extreme ends are quite rarely seen.

Cut of a File

• Be aware that it is only possible to accurately compare files of the SAME SIZE.
• This is because as the length of the file increases, the coarseness of the file also increases.
• A 12” smooth cut file may therefore be as coarse as a 6” Bastard cut file.

Practical – Cutting and Filing

• You are now going to cut and file your metal components to size.
• You will need to complete your Hacksaw Passport sticker and your Engineer’s vice sticker in order to do this.

Homework

• Produce an informational poster on different types of file to guide other students to choose the correct one for their application.
• Incorporate common cross-sectional shapes of file, single vs double cut, coarseness and anything else that you think is relevant.
• Give examples of when you might use a particular file.

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• Marks will be awarded for content and presentation.

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Plenary

• What do you think we are going to learn about next lesson?
• Ideas?
• Tip: What do we need to do next in our practical?

Starter – Using the pillar drill

• Write down three Health and Safety issues when using the pillar drill.
• Try to find three that are different to what the others on your table have written.

Using the Pillar Drill

Using the Pillar Drill

• As this formula is a little tricky to use, we have a simpler solution.
• We use a graph or table of pre-calculated values.
• The speed that we need to drill is affected by two factors.
• 1) The material that we are drilling
• 2) The diameter of the drill in mm
• By drawing a line on the graph between our drill diameter and the material that we are drilling, we can calculate the speed that we should set the drill at.

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Using the Machine Speeds Chart

• Draw a line from:
• The drill diameter on the left
• To the material that you are drilling on the right.
• Read the RPM from the middle column
• Select the nearest speed that is LOWER than the RPM figure that you read off.

Quiz

• Q) If you are drilling a 10mm hole through Bronze, what speed should your drill be set to?
• A) 1000 RPM

Quiz

• Q) If you are drilling a 5mm hole through Mild Steel, what speed should your drill be set to?
• A) 1300 RPM

Quiz

• Q) If you are drilling a 12mm hole through Aluminium, what speed should your drill be set to?
• A) 1600 RPM

Quiz

• Given that the speeds available on a particular pillar drill are: 420RPM, 670RPM, 1250RPM and 2150RPM
• Q) If you are drilling a 10mm hole through Plastic, what speed should your drill be set to?
• A) You should read off a value of approximately 1100RPM, so the nearest lower speed is 670RPM

Quiz

• Given that the speeds available on a particular pillar drill are: 420RPM, 670RPM, 1250RPM and 2150RPM
• Q) If you are drilling a 10mm hole through Aluminium, what speed should your drill be set to?
• A) You should read off a value of approximately 2000RPM, so the nearest lower speed is 1250RPM

Quiz

• Given that the speeds available on a particular pillar drill are: 420RPM, 670RPM, 1250RPM and 2150RPM
• Q) If you are drilling a 6mm hole through Stainless Steel, what speed should your drill be set to?
• A) You should read off a value of approximately 600RPM, so the nearest lower speed is 420RPM

Quiz

• Given that the speeds available on a particular pillar drill are: 420RPM, 670RPM, 1250RPM and 2150RPM
• Q) If you are drilling a 12mm hole through Stainless Steel, what speed should your drill be set to?
• A) You should read off a value of approximately 300RPM, so you would need to use a DIFFERENT DRILL! This particular drill does not have a slow enough gear to drill a 12mm hole through stainless steel.

Quiz

• Q) What happens if we try to drill a material using a speed that is too high?
• A) Huge amounts of friction are created, which heat up the drill and the workpiece. This causes the workpiece to work harden and the drill to anneal. The result? The drill gets blunt and the workpiece gets harder to drill, even with a fresh drill bit.

Quiz

• Q) What happens if we try to drill a material using a speed that is too slow?
• A) The hole takes a couple of seconds longer to drill. There is also a slightly higher chance of drill breakage the more slowly the drill turns, increasing with distance from the ideal speed.

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• In summary, there are far fewer consequences to having the drill set a little too slow, than a little too fast, but we should be aiming to be fairly close to the ideal speed.

Changing the Speed on the Pillar Drill

• Each pillar drill is slightly different, but there are three main types.
• 1) Belt driven with pulleys.
• This is true of most of the drill presses currently in use at Chalfonts
• By changing which pulleys the belts are on, you can change the drill speed
• 2) Gear driven
• The blue drill in Rm 12 is a gear driven drill.
• By changing the position of the levers on the side, different gears are selected.
• 3) Variable Speed Drive
• These machines have an electrical speed controller
• By turning a dial on the front of the machine, the motor spins at a different speed.
• Often there is a display to tell you what speed the machine is set to.

Demonstration

Drill bit selection – The three Ss

• When you select a drill bit, there are a few things to look out for:
• Is the drill bit the correct Size?
• Is the drill bit Sharp?
• Is the drill bit Straight?

Is the drill bit the correct size?

• Although the drill bits are in an index, sometimes people put the wrong bit in a location, so take a look at it. Does it have the right number on it? If the size is worn away, measure it!
• If you are handed a drill bit by somebody, even your teacher (Yes we all make mistakes!), check that it is the size that you need.
• If you have not checked, you only have yourself to blame if the work-piece that you have spent hours on, now has a hole that is the wrong size. In industry, you would be held responsible for costing the company money as the part would have to be scrapped. If it happened regularly, you might lose your job.

Is the drill bit sharp?

• First we need to know a little bit about twist drill geometry:

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• Drill bits tend to wear first at the corners, where the cutting edge, meets the margin.

Is the drill bit sharp?

Note the chewed-up corner on this blunt drill…

compared to the crisp corner on this sharp drill

Is the drill bit straight?

• You may not immediately be able to tell if your drill bit is bent, however it will become apparent when you turn the drill on.
• A bent drill bit will visibly wobble when the chuck spins.
• To confirm our diagnosis, a simple roll of the drill along the flat surface will show you whether the drill bit is straight. If both the cutting points do not touch the surface once every rotation, then the drill bit is bent.

Practical

• You will now have an opportunity to earn your Pillar-Drill extension sticker.
• Once you have received this sticker, you will be able to drill the holes in your spatula components.
• TIP: For any hole over approximately 8mm, drill a small (3-4mm) pilot hole first to allow the drill to centre properly.

Homework

• Write a risk assessment for using the pillar drill. What hazards can you identify? Who might these hazards affect? What is the risk associated with each of these hazards? How can we control those risks?
• Use the template to assist you.
• Think about hazards associated with the drill itself and its operation, with the environment that the drill is in, with the operator and with those around them.
• Be aware that we expect that medium to high risk hazards should already have control measures in place, so make sure that you consider why that is!

Plenary

• To help get you started with the homework…
• Label the diagram with any potential hazards of using the drill press.

Starter - Drilling

• What are the 3 Ss when drilling?
• How do we work out the correct drill speed?
• Give two ways that we might be able to change the speed on a pillar drill?

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Homework – Peer Assessment

• Please pass your homework to your neighbour.
• Each of you are to read through the other’s risk assessment and individually:
• Find three positive things that your neighbour has done well. (Be specific)
• Add two improvements that you think they could make.
• Now hand your work back and with your neighbour:
• Discuss what you both feel you have done well with
• Discuss something that you feel you both need to improve
• Finally:
• Consider each improvement and add to or edit your risk assessment to address them.

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Class Discussion

• For each pair, present your:
• Best point
• Most interesting improvement

Countersinking

• Countersinking is done using a countersink drill bit:
• This is used AFTER the required hole size is drilled.
• The drawing will say something like:

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• The first line tells you to drill a 4.00mm diameter hole all the way through the part
• The second line says “Countersink Diameter 8mm by 90 degrees” i.e. using a 90° countersink bit, drill until the top of the cone is 8mm in diameter

Ø4.0 THRU ALL

V Ø8.00 x 90°

Countersinking – Angular component

• Countersinks are form tools
• This means that they transfer the shape of the tool to the work.
• Therefore, when the instruction specifies a 90° countersink, the tool must be a 90° countersinking bit.

Countersinking - diameter

• The diameter of the top of the conical shape produced is achieved by changing the depth that the tool is pushed to.
• By reducing the depth, a smaller diameter is achieved and vice versa. With a 90° countersink, for every 1mm of additional depth, the countersink diameter will increase by 2mm.
• Whilst in industry, we would use a depth stop and some mathematics to work out the depth to stop at, in school, we may also just take measurements of the diameter frequently and creep up on our final dimension.

Homework

• Research Jigs and Fixturing.
• What are they?
• What are the differences?
• Design a simple Jig to enable drilling the holes in the grips in the correct place.
• Design a simple fixture to safely hold and line-up the grips to enable cutting the end radius using a Ø25 drill bit.
• Resources:
• https://www.youtube.com/watch?v=CA3GnfImGmw
• https://www.brighthubengineering.com/machine-design/47444-jigs-vs-fixtures/

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Plenary

• What advice would you give the class regarding what you have practically learnt today – did something go right/wrong?
• Write a step by step plan on using a counter sink bit.

Starter

• Material Properties Recap
• Match the Material Properties to their definitions
• Extension – For each material on the list below, give them a score from 0-10 for each property.
• Oak, Pine, Mild Steel, Aluminium, Copper, High Carbon Steel, Acrylic, Glass.

Jigs and Fixturing

• To ensure repeatability when making multiple identical parts, we use jigs and fixtures.
• A Jig is something that guides our tool to the correct location for an operation.
• A fixture holds a part in a repeatable correct location underneath a tool but does not actively guide the tool.

Jigs in the spatula project

• We are going to use the handle that we have made as a jig, to guide our drill bit when drilling the holes for the grips. This will ensure that the grips will
• A) line up with each other
• B) line up with the handle
• C) line all the holes up to allow the grips to be fastened on.
• By clamping the two grips together with the handle on top, we will drill the three holes so that they line up through all three pieces.

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Picture of drill jig setup

Fixtures in the spatula project

• We are going to use a couple of fixtures in the spatula project.
• One fixture will ensure that the Ø25 hole will line through properly.
• Another will help us to get a consistent chamfer at either end of the part by using the belt sander.

Picture of Drill Fixture for Ø25 radii

Homework

• Pick a topic from one of the lessons so far.
• Produce a simple educational game that teaches that topic that we might be able to play in class.
• Examples may include:
• Crossword puzzles
• Word-searches
• A set of cards for a card-sort activity
• A quiz
• Charades (You decide the topics to act out and present the actions to the class)
• Scattergories (You produce a list of categories)
• Bingo (Mark words on paper grids. Draw random letters. First to a full grid wins)
• Etc.

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Plenary

• Go back through your book and choose a topic that you think you can use for the homework task.
• Brainstorm some ideas for your game and write a few notes to plan your idea.

Starter

• List as many different ways that you can think of to join together two or more pieces of material (Material in the general sense of the word, e.g two bits of Steel, or a bit of wood and a bit of Aluminium etc.).
• For each idea, is this an example of a permanent joint or a temporary joint?
• Permanent Joint = Something must be broken to separate the two pieces
• Temporary joint = Pieces can be taken apart and reassembled as required.

Homework - Games

• Take 10 minutes to try a few student produced games.

Assembly processes

• We are going to use two methods to join the pieces of our spatula together:
• Threaded fasteners
• Rivets
• These are both examples of mechanical fastenings.
• Threaded fasteners make semi-permanent joints (disassembly is possible without damage to either the parts or the fastener)
• Rivets make permanent joints (in order to disassemble, destruction of either the rivet or the part is necessary)

Screw Threads

• A screw thread is a helical (3d spiral) ridge wrapped around a cylinder
• A screw thread converts rotational motion into linear motion.
• This makes it useful for fasteners as by turning the fastener, we can clamp two objects together.

ISO Metric Threads

• Just as we have standards in drawing, we also have standards for screw threads.
• This ensures that you can buy fasteners from different suppliers and be sure that they will fit together.
• The International Standards Organisation has created a few different thread standards, the most common of which is ISO Metric Coarse
• This is the most common type of thread and is signified by a capital M, preceding the nominal diameter. E.g. M6

Creating a screw thread

• In our project, we will be creating a screw thread in our part to allow us to thread in a bolt to tighten our two pieces together.
• We do this with a tool called a Tap, in conjunction with a tap handle.
• A tap cuts a thread into the walls of a pre-drilled hole.
• The size of our pre-drilled hole is very important and is determined by the thread standard. (In our case ISO metric coarse)

Calculating the tapping drill size

• If we know that we want an M6 thread, then we can look up the tapping drill size in a table compiled from the ISO standards.
• Example: M6 thread requires a 5mm tapping drill
• Can you work out what size tapping drills you would need for: M3, M8 and M12 taps?
• How about working out what size taps you would be using if you had drilled holes that were diameters: 3.3, 4.2, 8.5?

Answers: 2.5mm, 6.8mm, 10.2mm

Answers: M4, M5, M10

The Tap Set

• Each tap size (e.g. M5, M6 etc.) come in sets of three. These are:
• Taper tap
• Second tap
• Plug tap
• They are all the same size and create the same thread, but they have a different amount of taper at the start of the thread.
• We use them in sequence when tapping threads in blind holes.

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Tapping a Thread

• For our thread, because it is a through hole, we will only need to use the taper tap.
• Put the M6 taper tap in a tap handle and locate the point in the 5mm hole.

Tapping a Thread

• Being careful to hold the tap vertical, apply a little downward pressure and turn the tap handle in a clockwise direction.
• Turn the handle two complete clockwise rotations.

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x2

Tapping a Thread

• Now turn the handle anticlockwise by half a rotation. You should feel the small chips of metal breaking off.
• Now repeat this process, two turns clockwise, half a turn anticlockwise, until the tap spins freely.
• If you forget the half turn anticlockwise, you will find that in thicker metal, your tap is EXTREMELY likely to break and then you will have to scrap your work and start again.

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x 1/2

Assembly Processes - Rivetting

• Rivetting is a MECHANICAL joining process.
• A piece of metal with a head formed on one end (a rivet) is passed through a hole in two pieces of metal.
• The plain end is then hammered until the malleable material that the rivet is made of deforms, thus pinching the two pieces of metal together.
• Sometimes a tool called a rivet snap is used to produce a particular head shape
• This is a Permanent Joint.
• You would need to destroy the rivet to separate the two pieces.

Rivetting Demonstration

• Your teacher will now demonstrate Solid Rivetting to you.
• Take two or more pieces of material, with a suitably sized hole through them, and a countersink on the outside faces.
• Insert the rivet until the head sits just proud of the surface.
• Mark the shank of the rivet one rivet diameter above the surface and cut the excess away.
• Reassemble and put a steel block behind the head of the rivet.
• Hammer the plain end until it deforms to fill the countersink.
• Finally, file away any excess until the two surfaces are flush.

Spatula Assembly

• You are now ready to assemble your spatula.
• First, rivet the grips to the handle. Make sure to get them the right way around!
• Then, use a machine screw to fasten the blade to the handle.
• Congratulations, your spatula is nearly finished.

Homework

• Read the article on Screw threads, Thread standards etc.
• Answer the questions on the homework sheet (See Google Classroom).

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• Resource:

Plenary

• Describe the process of tapping a thread.
• Each person gives one point.

Starter

• Write a list of everything that you have left to do to complete your Spatula.

Final operations

• Today we are going to finish off the practical tasks on our spatula.
• The last thing for us to complete is to round off the handle.
• We are going to use a fixture for this to hold our spatula handle to the belt sander.
• We will then rotate the fixture to create the radius.

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Abrasive paper

• You may already know that abrasive paper comes in different levels of coarseness or “grits”.
• Much like a file, we start off removing the most material using a coarse grit and then reduce the size of the scratches using progressively finer grits.
• Grits are described using a number, which is larger the finer the finish that is created.
• The belt sander is commonly fitted with a coarse 60 grit paper.
• A suitably fine grit for wood final finishing might be 320 grit
• Abrasive papers for harder materials e.g. steel, may enter into the 1000s in order to produce a polished surface.

Finishing

• Hand sand any remaining sharp edges and sand the grips with a fine grit sandpaper to remove any remaining scratches.
• Apply some wax to the grips using a cloth.
• Leave it for a few minutes to soak in and solidify.
• Buff it off using a dry cloth.
• Repeat as necessary until a satisfactory finish is achieved.

Homework

• Pull out some popcorn, sit back and watch the video documentary on the origins of precision.
• https://www.youtube.com/watch?v=gNRnrn5DE58
• There will be a discussion in class next week about what you have learnt. Everybody will be expected to contribute something. E.g.
• Something you found interesting
• Something that surprised you
• Something that helped you understand a concept from the course
• Something that you found confusing
• Something that you can explain to the class
• A tool that you hadn’t heard of before
• A type of measurement that you didn’t know about before
• Something that requires precision that you didn’t realise required precision
• Etc.
• TIP: It may help you to note down a few points as you watch.

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Plenary

• Provide a success criteria for the finished Spatula – what would a pass look like, a merit, and a distinction?

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Starter

• How do we know that we have produced a ‘good’ part?
• Discuss with your neighbour.
• How can we test?

Homework Discussion

• Ask each person to present something from the video.
• Each person should provide at least one UNIQUE piece of information.

Quality Control

• The final aspect of this project, as with all projects that we do in Engineering is quality control.
• We are going to check all of our measurements to assess whether we produced the part correctly and accurately.
• We are going to measure the part with a tool called a Vernier Caliper.
• Most Vernier Calipers measure to an accuracy of 0.02mm, that is 1/5 of the thickness of a sheet of paper!

The Vernier Scale

• The Vernier scale has two scales, the Main scale and the Vernier scale that work together to give the final reading.
• We read the whole number of mm from the Main scale, where it touches 0 on the Vernier scale.

The 0 mark on the Vernier scale crosses the Main scale at a point between 11mm and 12 mm, so the whole number of mm is 11mm

This Vernier caliper reads to ±0.05mm

The Vernier Scale

• We read the fraction of a mm from the line on the Vernier scale which BEST LINES UP with a line on the Main scale.
• We then add together the two parts to get our final value.

The line which best lines up with one on the main scale is 6.5, so we have 0.65mm MORE than 11mm i.e. 11.65mm in total.

This Vernier caliper reads to ±0.05mm

Demonstration

Practice - Vernier Scale

• Complete the worksheet questions on reading a Vernier Scale.

The Vernier Caliper

• We can use Vernier Calipers to measure:
• The diameter of parts
• The depth of holes
• The diameter of holes
• Linear measurements
• Etc.
• Modern Digital Verniers have a digital readout instead of a Vernier scale.

Practice – Using a Vernier Caliper

• You are now going to be given a Vernier caliper and a selection of small items to measure.
• Your task is to take measurements and record the size of each of the parts.
• Record your results on the worksheet.

Tolerances

• Something that we need to understand is that in Engineering, we can never measure something ‘perfectly’.
• By this we mean that there will always be a more accurate measurement that could be taken.
• My measurement could be 8cm using a ruler that only measured in cm, but if I were to measure in mm, I could find that the actual measurement was 79mm.
• I could then use my Vernier calipers and find that actually, the measurement was 79.26mm
• This can be repeated indefinitely.

Tolerances

• So how do we know whether we are measuring accurately enough?
• Well engineering drawings have an answer:
• Tolerances.
• A tolerance is a permitted range within which our dimension can fall, either side of the NOMINAL value (The actual measurement intended).
• We might say for example that our part should be NOMINALLY 80mm, but that the tolerance is ±2mm (± means ‘plus or minus’) i.e. anything between 78mm and 82mm is a good part.
• The part is ‘in tolerance’.

Tolerances

• However, isn’t there still a problem?
• What if we took a measurement that was 78mm? How do we know that it isn’t, for example, 77.9mm and we’re just not reading accurately enough?
• We get around this problem with a rule of thumb that says that we should ALWAYS measure with an instrument that is at least 10 TIMES as accurate as our tolerance.
• i.e. If our tolerance is ±0.2mm, we should use a measuring device with an accuracy of AT MOST 0.02mm (For example a Vernier Caliper)

Why do we need tolerances?

• We need tolerances to ensure that components fit together consistently.
• In history, tradesmen used to each have their own system of measurement. Once upon a time, the ‘foot’ used to mean literally the length of the tradesman’s foot.
• This doesn’t work so well when you only produce part of the finished product. What if the person producing the other parts has different sized feet?!
• To remedy this problem, we developed standardised units of measurement such as the metric system.

Why do we need tolerances?

• Tolerances allow us to make multiple parts that are all very slightly different in size and still be CERTAIN that the parts will still fit together.
• By selecting our tolerances carefully, we can ensure that any two parts will fit together, even if they are at the opposite extremes of their tolerance range.
• If we do not use tolerances, then we must FIT every component to its corresponding one by adjusting each pair slightly.
• This would be very time consuming and expensive and doesn’t work for mass produced items.

Tolerances on the Lap Joint project

• There are many different ways that we can specify tolerances on an engineering drawing, some of which you will learn later in the course.
• For now, we are going to use what is called a ‘General Tolerance’.
• This is a tolerance that applies to ALL DIMENSIONS on the drawing sheet.
• The general tolerance for our components is ±0.5mm, as shown in the title block of our drawing.

Evaluation

• Write a report using the template.
• Are your dimensions in tolerance?
• What did you find difficult?
• What new processes did you learn?
• What could you improve upon in future?
• Measure and record some of the key measurements using a Vernier Caliper.

Evaluation

• You should have already evaluated all of the individual components that you have made. Now evaluate the completed, assembled BBQ Spatula.
• Use the template and consider:
• Were your dimensions within tolerance?
• What did you find difficult?
• What new processes did you learn?
• What could you improve upon in future?
• Measure and record some of the key measurements using a Vernier Caliper.

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Homework

• Lucky you, there is no homework this week!
• I will be marking your practical work and your exercise books in order to give you your final grade on this course.

Plenary

• What have you learnt on this course?
• Give an example of a skill you have used that you think that you might use in later life.
• What has been your favourite thing about this course?
• And your least favourite?

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• Have a great time in your next rotation topic!