Design & Technology (KS3)
UK Key Stage 3 design and technology: design process, materials, structures, mechanisms, electronics and sustainability.
Ämne: Teknik · Nivå: Högstadium (13–15) · 408 kort
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- The design process is iterative: identify a problem, research user needs, write a brief, generate ideas, prototype, test, evaluate, and refine.
- A design brief is a short statement that describes the problem to be solved and who the product is for.
- Anthropometrics is the study of human body measurements; ergonomics is the study of how people interact with products and environments.
- ACCESS FM is a specification checklist covering Aesthetics, Cost, Customer, Environment, Size, Safety, Function and Materials.
- Orthographic projection shows a product as flat 2D views from the front, side and top.
- Isometric drawings use lines at 30 degrees to the horizontal so vertical edges stay vertical, giving a 3D look without perspective distortion.
- CAD (Computer-Aided Design) is used to draw and model products on a computer; CAM (Computer-Aided Manufacture) uses that data to control machines like 3D printers and laser cutters.
- Hardwoods come from deciduous broadleaf trees that usually grow slowly; examples include oak, beech, mahogany and ash.
- Softwoods come from coniferous trees that grow faster; examples include pine, cedar and spruce.
- Manufactured boards such as MDF, plywood, chipboard and hardboard are made from wood fibres or layers, giving large, uniform sheets that are cheaper than solid timber.
- Ferrous metals contain iron and tend to rust unless protected; examples include mild steel, high-carbon steel and cast iron.
- Non-ferrous metals contain no iron and do not rust; examples include aluminium, copper, brass and tin.
- An alloy is a metal made by mixing two or more metals (or a metal with another element) to improve properties; brass is copper and zinc, bronze is copper and tin.
- Thermoplastics can be heated and reshaped many times. Common examples are acrylic, polythene, PET, polypropylene and PVC.
- Thermosetting polymers set permanently once they are heated and cannot be melted down again; examples include epoxy resin, urea-formaldehyde and melamine.
- Natural textile fibres come from plants or animals: cotton and linen come from plants; wool and silk come from animals.
- Synthetic textile fibres such as polyester, nylon, acrylic and elastane are made from chemicals, usually derived from oil.
- Smart materials respond to a change in their environment; thermochromic pigments change colour with temperature and photochromic materials change with light.
- Shape memory alloys such as Nitinol return to a remembered shape when heated, even after being bent.
- The five main forces acting on structures are tension (pulling apart), compression (squashing), shear (sliding past), torsion (twisting) and bending.
- Triangulation adds diagonal members to a frame structure so it cannot deform, which is why bridges and roof trusses use triangles.
- A cam converts rotary motion (turning) into reciprocating motion (back-and-forth) by pushing a follower up and down as it spins.
- An LED (light-emitting diode) is a polarised component, meaning it must be wired the correct way round to light up.
- A microcontroller, such as an Arduino or BBC Micro:bit, is a small programmable computer used as the brain of an electronic product.
- The 6 Rs of sustainable design are Rethink, Refuse, Reduce, Reuse, Recycle and Repair.
- Iterative design loops through research, ideas, prototypes and tests many times, while linear design goes through each stage only once from start to finish.
- User research methods include questionnaires (many short answers), interviews (deeper one-to-one), observation (watching people use products) and focus groups (small guided discussions).
- A design specification is a measurable list of requirements a product must meet, such as 'must be under 200 g' or 'must withstand 5 N of force', while a brief is a shorter statement of the problem.
- In third-angle orthographic projection (used in the UK) the top view is drawn above the front view, and the right side view is drawn on the right of the front view.
- Common engineering line types include a continuous thick line for visible edges, a dashed line for hidden edges, and a long-dash short-dash line for centre lines.
- Drawing scales tell you the ratio of the drawing to the real object. 1:1 is life size, 1:10 means the drawing is ten times smaller, and 2:1 means it is twice as big as the real part.
- Crating is a sketching technique where you draw a faint 3D box first and then build the product shape inside it, which helps keep proportions right.
- Vector graphics are built from lines, curves and shapes that can be resized without losing quality, while raster graphics are made of pixels and go blurry when enlarged.
- School CAD packages include TinkerCAD and SketchUp for beginners and Fusion 360 for more advanced 3D modelling; 2D Design is often used to prepare files for laser cutters.
- An STL file describes the surface of a 3D model as a mesh of triangles. A slicer program then cuts this model into thin layers and creates instructions for a 3D printer.
- Seasoning timber means drying it so that excess moisture leaves the wood. Air-dried timber dries slowly outdoors, while kiln-dried timber is dried in a heated chamber and is more stable.
- Common timber defects include knots (where branches grew), splits and shakes (cracks along the grain), and warping (twisting or bowing) caused by uneven drying.
- Common wood joints include butt joints (simplest, weak), dowel joints (hidden pegs), lap joints, mitre joints (45 degree corners), mortise and tenon (strong frame joint) and dovetails (interlocking pins for boxes).
- Heat treatments for metals include annealing (heating then slow cooling to soften), hardening (heating then quenching), tempering (gentle reheat to reduce brittleness) and normalising (cooling in air).
- Metal finishes include galvanising (a thin zinc coating to stop rust), electroplating (depositing one metal over another), powder coating and anodising aluminium to create a tough oxide layer.
- Acrylic is a clear, rigid thermoplastic that can shatter if hit hard. HDPE is a tougher, opaque polymer used for milk bottles and chopping boards.
- Injection moulding melts plastic granules and forces the molten polymer into a metal mould under high pressure. Once cooled, the mould opens and the part is ejected.
- Woven fabrics interlace two sets of yarns at right angles, knitted fabrics are made of looped yarns that stretch, and non-woven fabrics like felt are pressed or bonded fibres.
- Textile finishes can add useful properties: waterproof coatings keep rain out, flame retardants slow burning, and stain repellents stop liquids soaking in.
- Smart textiles include conductive thread that carries electricity, photo-luminescent fibres that glow in the dark, and breathable membranes like Gore-Tex that keep rain out but let sweat vapour escape.
- In a reinforced concrete beam the steel bars (rebar) carry the tension forces along the bottom, while the concrete takes the compression forces along the top.
- A life-cycle assessment looks at the environmental impact of a product through every stage: raw materials, manufacture, transport, use and disposal.
- The Bauhaus was a German design school open from 1919 to 1933 that promoted clean geometric forms and the idea that good design should suit mass production.
- William Morris was a leading figure in the British Arts and Crafts movement of the late 1800s, which valued handmade craftsmanship over factory-made goods and used nature-inspired patterns.
- PPE in a school workshop includes safety glasses to protect eyes, an apron to protect clothes, a dust mask when sanding, ear defenders for noisy machines, and sturdy closed-toe shoes.