All DT Key Terminology Flashcards
Collaborative design
Working with others, especially at the development stage. Promotes motivation, problem solving, communication and support.
User-centred design
Focus is on the user or client for every stage of the design. It includes observation of the user, continuous consultation and testing.
Systems approach
Sequences of actions used in the design process. This is a linear process relying on inputs, processing and outputs.
Iterative design
Making and testing a product, then evaluating its successes and failures before redesigning with improvements and repeating this process.
Planned obsolescence
The deliberate designing of a product to fail prematurely.
Perceived obsolescence
A product going out of fashion therefore becoming less desirable.
Design fixation
Loss of innovation or creativity in designs due to the influence of existing ideas.
Sketching
Producing a rough record of ideas.
Modelling
Producing a simple physical translation of an idea.
Non-destructive testing
Testing without harming the subject.
Destructive testing
Testing a product until it fails to see how much wear it can take.
Market testing
The target market testing the product to see its effectiveness.
Name 6 circuit inputs:
Toggle switch; push to make; push to break; light dependent resistor; thermistor; pressure switch
Name 5 circuit outputs:
Light emitting diode (LED); lamp; buzzer; speaker
Analogue signal
A signal with an infinite amount of values along a range.
Digital signal
A signal that is either on or off, often represented by 1 or 0 correspondingly.
Monostable circuit
A circuit that will switch on once, but once turned off, will stay off.
Astable circuit
A circuit that is constantly alternating between on and off.
Name 7 modern materials and their properties;
Biodegradable polymers - made from vegetable starches, biodegradable alternatives to plastics;
Titanium - often alloyed with other metals, lightweight, very strong, doesn’t react with the body;
Fibre optics - carry light through a thin glass core, used in cable TV and broadband infrastructure, has medical applications such as endoscopes;
Graphene - uses are still being discovered and developed, could be used in flexible electronics or biomedicine, 200x stronger than steel;
Liquid crystal display (LCD) - screens can be very small and lightweight, can feature bespoke monochrome layouts, low power consumption, does not emit light, so requires back lighting;
Nano materials - very tiny materials used for small-scale parts, between 1 and 1000nm in size;
Metal foam - very lightweight compared to solid metal, 25% of the solid metal mass, made by injecting gas into aluminium or titanium, recyclable
What are the four types of motion?
Linear; reciprocating; oscillating; rotary
Name four cam shapes
Eccentric; pear; snail; heart
How do you work out mechanical advantage?
Load/effort
What is a first order lever?
Load - fulcrum - effort
What is a second order lever?
Effort - load - fulcrum
What is a third order lever?
Load - effort - fulcrum
Name 3 linkages
Reverse motion linkage; parallel motion linkage; bell crank linkage
How do you work out force required of a pulley system?
Force required = load/no. pulleys
How do you work out the speed and force ratios of gears?
The ratios of the teeth.
What is an idler gear?
A smaller gear placed between two others so the two turn in the same direction.
What are the names for the gear that is turning others and the gear that is being turned?
The drive gear and the driven gear.
What is a smart material?
A material that reacts to an external stimulus by changing their characteristics or properties.
Name 4 smart materials and what they react to
Self-healing polymers - can mend cracks in themselves as they react to air being introduced or a pressure change.
Thermochromic pigments - changes colour in specific temperatures.
Photochromic pigments - reacts with UV light to give off visible light.
Shape memory alloys (SMAs) - metals that can be deformed into different shapes, reacts to heat or electricity.
Name 5 renewable energy sources
Wind; solar; tidal; biomass; hydroelectric
Name 2 non-renewable energy sources
Fossil fuels (coal, oil, gas); nuclear
What is fracking?
Drilling into layers of shale rock deep in the earth to release pockets of gas. Water, sand and chemicals are injected to force the gas out.
What is a composite material?
A material made up of multiple other materials.
What is the process of creating carbon reinforced plastic (CRP)?
- prepare mould
- apply release agent
- apply gel coat (for GRP) or first resin coat for (CRP)
- apply glass fibre matting or woven carbon fibre
- work a second coat of resin onto the material
- repeat this to achieve the correct thickness
- clamp and leave to cure
- release from mould
What is Gore-Tex?
A fabric membrane both waterproof and breathable.
What are aramids?
Cut and tear resistant, flame proof, thermally insulating, high in strength, hard-wearing. E.g Kevlar.
Name 4 examples of micro-encapsulation:
Thermochromatic dyes; antibacterial materials; pesticides; perfumes
What is paper measured in?
gsm (grams per square metre)
Describe the qualities of bleedproof paper.
It doesn’t allow ink to soak through and is around 70-80gsm with its smooth surface coating.
Describe the qualities of cartridge paper.
It is thick and high quality with a slight texture, around 200gsm. It is ideal for watercolour or acrylic, without a coating.
Describe the qualities of layout paper and tracing paper.
They are translucent papers, layout more so.
What kind of fibres are used to make papers and boards and where do they most commonly derive from?
Papers and boards are made from cellulose fibres which are usually derived from:
- Wood (more often, softwoods)
- Bamboo
- Cotton
- Flax
- Hemp
- Straw
- Sugarcane
Name and describe the 5 stages of making paper.
Pulping: debarked, chipped wood is cooked under pressure with a chemical solution producing pulp.
Internal sizing: further additives are beaten in to reduce final absorbency.
Draining: the pulp is placed onto a mesh which allows the excess water to drain out.
Rolling: the pulp passes through a series of rollers which squeeze out more of the water before passing it through a series of drying rollers.
Calendaring: the paper finally goes through one last set of calendar rollers which add any additional coatings or surface sizing.
What are boards measured in?
Microns (1mm = 1000microns)
Name and describe 6 types of board.
Corrugated cardboard: lightweight but strong with a smooth surface.
Foil lined board: stiff card lined with aluminium. Resistant to oils and liquids.
Duplex board: exterior wax coating (moisture barrier). Suitable for printing on, good at folding.
Foam board / foamcore: polystyrene between two layers of paper. Rigid and lightweight. Cuts cleanly without a sharp blade. Good for architectural models or prototypes.
Solid white board: high quality board with a strong, smooth surface, good for book covers and product packaging.
Ink jet card: designed form inkjet printer, special surface for ink to sit on.
What are the two types of barcode?
Universal Product Code version ‘a’: can only represent numerical digits
Code 128: used in transport and shipment tracking and can represent both letters and numbers.
What is technology push?
New technology being pushed into the market, often driven by research.
What is market pull?
Consumer-driven pressure for new technology.
What is a cobot?
A ‘collaborative robot’ allowing greater human-robot communication.
How does culture impact design?
Different cultures have a different needs which impact design greatly. This includes things like icons, colours, ways of living and more.
What is inclusive design?
Designing things so they are suitable for everyone to use.
What is a flexible manufacturing system (FMS)?
A manufacturing system often used in short-run production lines consisting of automated machines that can easily be recalibrated and reprogrammed.
What is lean manufacturing?
Optimising manufacturing by eliminating areas of waste, such as:
- overproduction
- waiting
- transportation
- inappropriate processing
- excessive inventory
- unnecessary motion
- defects
What is just in time production (JIT)?
Creating items as they are demanded. There are no surplus stocks or raw material so no warehouse costs. Stock also does not become obsolete. However, stock is not available immediately and it relies on a high quality supply chain.
What are ‘early adopters’?
People attracted to new technology upon release.
What is the warp thread?
The tread running straight up the fabric in a woven fabric.
What is the weft thread?
The thread running side to side up the fabric in a woven fabric.
What are the qualities of woven fabrics?
- hard wearing
- will fray
- simple and common
- breathable
What are the qualities of knitted fabrics?
- stretchy
- absorbent
- unravels easily
- thermal properties
- loses shape without added Lycra
- prone to shrinking
What are the properties of non-woven or bonded fabrics?
- non-elastic
- won’t fray
- easy to shape and mould
- additional properties
- lacks strength
What is malleability?
The ability to be shaped or extended.
What is durability?
The ability to withstand wear and damage.
What is elasticity?
The ability to return to its original shape.
What is strength?
The ability to withstand forces.
What is hardness?
The ability to resist scratches, cuts and abrasions.
What is toughness?
The ability to resist deforming or changing shape.
What are eight ways of stiffening materials?
- Folding
- Webbing
- Lamination
- Fabric Interfacing
- Reinforcing
- Ribs
- Gussets
- Fillets
What is tension?
A pulling force out from each end.
What is compression?
A pushing force in from both ends.
What is bending?
Forces at an angle to a material.
What is torsion?
A twisting force.
What is shear?
Forces acting across a material.
What are the steps of injection moulding?
- Plastic pellets fed into hopper.
- Archimedes screw brings pellets towards mould.
- Heated cylinder melts pellets.
- Mould-clamping cylinder clamps mould to machine.
- Injection cylinder injects plastic into mould.
- Mould is removed and product is left to dry.
- Excess material is trimmed off.
What are the qualities of injection moulding?
- High-volume production process
- Parts produced at a rapid rate
- High tooling cost, low unit cost
What is extrusion process?
- Plastic from the injection moulder is instead squeezed through a shaped die, which creates a uniform shape.
- It is fed through a water tank to cool and harden.
- Pull rollers feed the plastic through.
- A machine coils or cuts off the product.
What is the blow moulding process?
- An injection moulder produces an extruded hollow tube (a parison).
- The parison is placed in a mould, and compressed air is injected into it.
- The plastic fills the mould.
- The mould is removed and the product is left to harden.
What are the benefits of laser-cutting?
- Can follow a design to a very fine tolerance.
- It’s safe.
What are the benefits of laser-cutting?
- Can follow a design to a very fine tolerance.
- It’s safe.
What’s the process of laser-cutting?
- Design in CAD
- Send to machine
- Adjust machine settings
- Check material
- Run machine
- Laser cuts based on CAD, extraction removes toxic fumes
- Quality check
How can you run a quality control?
- Dimensional accuracy within a tolerance
- Weight
- Pressure testing and testing for leaks
- Flammability test
