GCSE Engineering revision notes

Medical & pharmaceutical - wheelchairs, inhaler

Electric & electronics - electric toothbrush, smoke alarm

Automotive - headlights, wheel hub

Computers, communications & ICT - radio, projector

Structural &civil - bridges, tunnels

Rail & marine - signalling system, life jacket

Chemical & process - shampoo, toothpaste

Aerospace - tail rotor, aircraft wings

Alloy - metal made by combining 2 or more metals e.g. solder, brass

Ferrous - contains iron e.g. steel, cast iron

Non-ferrous - does not contain iron e.g. copper, aluminium

Polymer - any plastic, formed when monomers bond e.g. acrylic, polythene

Composite - made up of reinforcing material and a bonding agent e.g. MDF, concrete

Ceramic - inorganic, non-metallic compound made from a metal and non-metal e.g. alumina, zirconia

Smart - materials that can adapt to their environment by responding to external stimuli e.g. thermochromic (responds to changed in temperature)

Modern - made by humans to suit a particular function e.g. ABS, stainless steel

All smart materials are modern, but not all modern materials are smart.

Uses - to control machines using numerical control so that less workers are needed to operate the machine

Advantages:

• less skilled workers required
• quicker
• information easily transferred

Disadvantages:

• less workforce
• may need a specialist if it goes wrong

Uses - produce designs and technical drawings electronically that can easily be sent to the client

Advantages:

• neater
• quicker
• make modifications quickly
• model in 3D
• transfer information quickly
• feedback is quick

Disadvantages:

• expensive outlay
• may need a specialist if it goes wrong
• people lose their jobs to machines

Uses - produce products on machines using information gathered from electronically produced designs

Advantages:

• 24 hour production - constant
• continual high quality
• cheaper
• more efficient

Disadvantages:

• expensive outlay
• may need a specialist if it goes wrong
• less workforce as people lose their jobs to machines
• can be slower than traditional methods

Design

Marketing

Production planning

Material supply and control

Processing / production

Assembly and finishing

Packing / dispatch

Disposal

Research

Analysing client brief

Generating design solutions

Modifying designs

Creating engineering drawings for manufacture

Presenting design solutions to the client

Inspections:

• against the drawing
• against the specifications

Quality control techniques:

• dimesions
• tolerances

Types of fit:

• clearance fit - when two components are assembled, they can move freely (the hole is bigger than the part)
• transition fit - when two components are fitted together there is no gap between parts
• interference fit - the two components are locked together (one part is bigger than the hole)

Impact:

• when manufacturing an engineered product - impact on workforce, company and local environment
• on engineered products - to end user
• on engineering industries - sustainability

Advantages:

• improved working conditions (and health and safety)
• increased availability of products
• improved transport system

Disadvantages:

• redundancy / workers need training
• high cost
• impact on environment

Types of finish (and hwo to check quality):

Powder coating - depth of coating

Chrome plating - bright shiny silver coating

Electroplating - size, thickness of coating

Hot dip coating - rough, smooth, roughness, waviness, form

Can be checked using 'micro-surface scales'.

Material removal - drilling, cutting, sawing, planing, chiseling, grinding

Shaping and manipulation - casting, forging, vacuum forming, injection moulding

Joining and assembly - threads (screw threads using tap/die), riveting, welding, soldering

Surface finishing - anodising, galvanising, painting, electroplating, polishing, etching

Heat and chemical treatment - hardening, pickling, annealing

Machine screws - generally stronger than wood screws, have finer threads, made more precisely, used with nuts or tapped holes

Coach bolt - has a square collar under the domed head, this locks into the wood when the nut is tightened, a washer is placed before the nut to stop it sinking into the wood as it is turned

Rivets - commonly being replaced with other methods such as welding, used to join plates together, especially good if the plates to be joined are quite small

Pop riveting - technique to join thin pieces of metal/plastic sheets, made of two parts (the pin and the rivet), the pop rivet pliers are used to pull the pin though the rivet, as this happens the rivet is deformed slightly so joins the pieces, not very strong joint

Split pins - usually made from 'soft' steel or aluminium, come in a range of sizes

Manufacturing

Quality control

Ordering stock

Moving products around the factory

Dispatching

Stock control

Retailing

Packaging

What's it for?

Used in industry to produce cylindrical shapes

How it works:

Everything revolves around the centre of the work piece. The chuck is specifically designed to hold round bars. The chuck revolves and the cutting tool is moved into a position where it will cut the revolving work piece.

Safety precautions:

• goggles
• hait tied up
• apron
• no loose clothing

What's it for?

Carve out materials e.g. metal and wood, vertical-cut slots, square edges and holes, horizonal slots and keyways.

How it works:

Cutting tool revolves and the work piece moves past it - material is cut from the work piece. The cutting tool comes in a variety of forms to produce different cutting profiles.

Safety precautions:

• goggles
• hait tied up
• apron
• no loose clothing

What's it for?

To produce holes in work pieces - e.g. bench drills, pillar drills (table can be adjusted more)

How it works:

Work piece clamped into place and drill piece revolves - it is then moved manually down and drills into the work piece.

Safety precautions:

• goggles
• hair tied up
• apron
• no loose clothing

Extra notes:

Marking out is very important

What's it for?

Smoothes materials e.g. woods and plastic and removes a small amount of waste material

How it works:

Work piece is carefully pushed against rotating disc and is moved from left to right

Safety precautions:

• goggles
• hair ties up 
• apron
• no loose clothing
• guard must be in place at all times

Extra notes:

Dust extractor pipe has to be connected

What's it for?

To produce a smooth, flat surface on wood with curves or detailed edges

How it works:

The spindle spins around as well as oscillates, meaning it will smooth any flat surface on wood

Safety precautions:

• goggles
• hair ties up
• apron
• no loose clothing

Extra notes:

Covered with gritty sand paper

What's it for?

To polish soft metals e.g. copper and brass - as well as plastics e.g. perspex

How it works:

Two mops spins at high speeds - the work piece is then moved back and forward in contact with these until polished

Safety precautions:

• goggles
• hair ties up
• apron
• no loose clothing

What's it for?

Cuts and shapes light materials e.g. MDF and polystyrene

How it works:

A blade moves up and down whilst the work piece is moved and rotated manually - the saw cuts into material - cutting and shaping it

Safety precautions:

• goggles
• hair ties up
• apron
• no loose clothing