NSSCO Design and Technology (6187) key terms

A short written statement from a client or user that sets out the problem to be solved, who it is for, and the main constraints, without prescribing the final solution.

A detailed list of measurable requirements a product must meet, such as size, mass, cost, safety and finish, used to judge whether design ideas are acceptable.

Limits placed on a design, such as budget, available materials, time, manufacturing equipment, safety rules or legal standards, which restrict the solutions that are possible.

The process of judging a design or finished product against the specification and user needs, recording strengths and weaknesses so improvements can be identified.

Repeating the design cycle of research, idea, make and test so that a solution is refined step by step rather than produced perfectly at the first attempt.

A working or near-working model built to test an idea, check fit and function, or show a client how the final product will behave.

A simple full-size or scale model, often of card, foam or scrap material, used to check appearance, proportion and ergonomics rather than to function.

A three-dimensional drawing in which vertical edges stay vertical and the two receding axes are drawn at 30 degrees, giving equal scale along each axis without perspective.

A drawing method showing a three-dimensional object as separate flat views, usually front, plan and side elevation, arranged in first- or third-angle layout.

A pictorial drawing where the front face is drawn true shape and flat, and depth is shown by lines receding at an angle, often 45 degrees, usually half scale.

A drawing made in exact proportion to the real object, labelled with a ratio such as 1:10, so measurements can be read or scaled directly from it.

A fully dimensioned drawing giving sizes, materials, finishes and assembly details, complete enough for a craftsperson to manufacture the part without further instructions.

A drawing or diagram in which the parts of an assembly are separated along their assembly axis so the order and relationship of components can be seen clearly.

Timber from broad-leaved, usually deciduous trees, such as oak, mahogany or teak; generally slower growing and denser than softwood.

Timber from coniferous, needle-bearing trees such as pine, spruce or fir; usually faster growing, lighter and cheaper than most hardwoods.

A sheet material made by gluing wood fibres, chips, veneers or strips together, for example plywood, MDF or chipboard, giving consistent thickness and fewer defects.

A plastic that softens when heated and hardens on cooling, and can be reshaped repeatedly, such as acrylic, polythene, PVC and nylon.

A plastic that sets permanently when cured and cannot be softened or remelted by reheating, such as polyester resin, epoxy and urea formaldehyde.

A material made from two or more different materials combined so the result has better properties than either alone, for example glass-reinforced plastic or carbon fibre.

Joining layers of material, such as veneers or glass fibre and resin, with adhesive or resin so they act as one thicker, stronger component.

Controlled drying of timber to reduce moisture content, either in air or in a kiln, so the wood is stable and less likely to warp or split.

Distortion of timber or board caused by uneven moisture change or internal stress, appearing as bowing, cupping, twisting or springing out of flat.

The acceptable amount by which a dimension may vary from the stated size while the part still fits and functions correctly.

A joint where the shaft is slightly larger than the hole so the parts must be pressed or shrunk together, producing a tight, usually permanent connection.

A ready-made connector, such as a cam and dowel or block joint, that allows furniture to be assembled and taken apart with simple tools.

A moulding process in which softened thermoplastic is forced under pressure into a closed steel mould, giving fast, repeatable production of complex shapes.

A process where a heated thermoplastic sheet is drawn down over a mould by suction, then cooled and trimmed, suitable for shallow trays and casings.

A device that holds work and guides the tool, such as a drill bush, so repeated identical operations can be carried out quickly and accurately.

Physical protection fitted around moving parts of machinery, such as blades, belts and chucks, to prevent hands or clothing from being caught.

Safety items worn by the worker, including goggles, ear defenders, dust mask, apron and safety footwear, chosen to suit the hazards of the task.

The ratio of the load moved by a machine to the effort applied to it; a value above one means a smaller effort can move a larger load.

The relationship between the number of teeth on a driven gear and on its driver, which sets the change in speed and turning force through the train.

A rigid bar turning about a pivot, or fulcrum, used to multiply force or movement; class depends on whether the fulcrum sits between load and effort, or elsewhere.

The relationship that current through a conductor equals voltage across it divided by resistance, written V = I x R, used to calculate values in circuits.

A circuit where components are connected one after another so the same current flows through each, and the supply voltage is shared between them.

A circuit where components are connected across the same two points, so each has the full supply voltage and the total current is the sum of the branches.

A component that limits current and drops voltage in a circuit, with a fixed value read from its colour bands or a variable value in a potentiometer.

A semiconductor component that glows when current passes through it in the correct direction; it needs a series resistor to limit current and has a polarity.

Energy from sources that are naturally replenished, such as sunlight, wind, flowing water and biomass, rather than from finite fossil fuels.

The total energy used to extract, process, manufacture, transport and dispose of a material or product, considered when choosing sustainable materials.

A structured review of a product's environmental impact from raw material extraction through manufacture, use and disposal or recycling.

Designing a product so parts can be separated easily at end of life, using reversible fixings rather than adhesives, so materials can be reused or recycled.

The study and measurement of human body sizes and proportions, used to set dimensions such as seat height, reach and handle size in products.

Designing products and workplaces to fit the user's body, movements and comfort, reducing strain and improving safety and efficiency.

An organised record of a design project showing research, ideas, development, making, testing and evaluation, used to evidence the design process.

Checking work during and after manufacture against the specification, using measurement and inspection, so faults are found and corrected before the product is passed.