DT Flashcards
Iterative design
a cyclic approach: each iteration of a design is tested and then altered accordingly
iterative design advantages
- each iteration is fully tested/evaluated so issues will be discovered and fixed earlier
- it encourages focus on the most critical aspects of a design
- user feedback is constantly gathered
- evidence of progress is easily provided to stakeholders
Iterative design disadvantages
- it can be time consuming
- it can be expensive to make so many iterations?
- designers can lose site of the bigger picture when focusing on an iteration
User centred design
the needs and wants of a user are considered extensively at each stage of the design process.
user-centred design advantages
- The end user feels listened to and is more likely to be satisfied with the product
- the user feels a greater sense of ownership of the product due to input
user-centred design disadvantages
- it requires extra time to meet/discuss with the client and then alter the design
- It can become focused on one specific person: it is then unavailable to sell to the wider population
Systems thinking
a top down approach that starts with an overview of a product in terms of : input, process and output. The details of each component are considered later.
- often used in electronic/mechanical systems
Systems thinking/approach advantages
- does not require specialist knowledge to design system overview
- this approach is easy to explain / communicate to non-specialists e.g. clients/stakeholders
- The system is designed in blocks so it is easier to discover faults in the design
Systems thinking/approach disadvantages
- it can lead to the use of unnecessary components
- this can lead to larger systems and extra cost
Structure of a system
input device –> process –> output device
input devices take a’real world’ signal e.g. light/movement/sound and turn it into an electronic signal.
Output devices take this electronic signal and turn it into a real world signal e.g speakers produce sound and lamps produce light
CIRCUIT SYMBOLS
P.11 revision guide
Microcontrollers
a small computer or an integrated circuit that can be programmed to provide functionality, timing counting and decision making.
- process
push to make switch
allows current to flow through when pressed
- input
LDR
a resistor that changes depending on light level
- input
buzzer
produces a buzzing noise when current flows through it
- output
speaker
turns electronic signals into sounds
- output
lamp
produces light when current flows through it
- output
Apple (The Work of Others)
- multinational consumer electronics company
- initially solds personal computers such as the Macintosh
- later they introduced the aesthetically iconic iMac G3, portable iPod and the iPhone.
- The iPhone combined components of the iPod and the G3.
Primark (the work of others)
- international clothing retailer
- low cost, fashionable products
- produces clothes in factories in china, bangladesh, india etc.
- fast fashion contributor
Zara (the work of others)
- uses a Just in time approach (JIT)
- began working with Greenpeace in 2011 to eliminate harmful toxins from its clothing
Deforestation
forests are removed so land can be used for other uses. this causes:
- loss of habitat
- increased CO2 levels
Mining
some raw materials must be mined from the ground e.g. metal ores. This causes:
-erosion
- contamination of soil
- visual pollution
- loss of habitat
- non renewable
Drilling for oil
- non renewable
- oil spills are detrimental to the local area
Things to consider when designing a product (environmental) (x6)
- obtaining raw materials
- distance/mileage to place of manufacture
- manufacture
- distribution
- use
- disposal
The 6 Rs
Refuse - should it be produced?
Rethink - what can be changed (e.g. less packaging)
Reduce - use less/produce less
Reuse - use it again
Repair - fix instead of repurchasing
Recycle - reuse materials
Fair Trade
A movement that works to aid people in developing countries in receiving a fair wage for the products that they produce
- producers are paid an agreed minimum rate even if global prices fall
Market research
the collection of information to find out gaps in the market, client requirements, price etc.
focus group (what and why)
- a focus group is a group of people that match the target user group: ideally 7-10 people. This to ensure a range of opinions/feedback however if it is too big, people may not all be able to share their ideas.
product analysis
the detailed investigation or analysis of current or previous products. Aspects considered include:
- aesthetics
- function
-price
- societal impact
- environmental impact
Primary data
firsthand data / original research e.g. a questionnaire produced by the designer themselves
secondary data
freely available data that is taken from other sources e.g. available data sheets
Ergonomics
Human factors: involves how the user interacts with the product.
ergonomic factors include safety and comfort.
Anthropometrics
The study of the human body and how it moves.
Anthropometric data is taken from millions of people to create well suited products e.g. a helmet uses average head circumferences, doors use average heights etc.
- Designers often work with 5th to 95th percentile
Design brief
a short description of the design problem and how it is to be solved
Design specification
a list of measurable design criteria that the product must meet.
A good specification should include:
ACCESS FM :
- Aesthetics
- Client
- Cost
- Environment
- Safety
- Size
- Function
- Materials
Manufacturing specification
contains the information needed to successfully manufacture the design.
It should include :
- scale of production (e.g. batch/mass etc.)
- description and/or drawing of final design
- assembly and construction details
- details of materials needed
- how quality will be ensured
Freehand sketching (uses/pros/cons)
uses: getting initial thoughts onto paper
pros:
- does not follow conventions so can be done quickly and freehand
cons:
- needs to be followed by a more formal design
modelling (uses/pros)
use: to gain insight on how a product will look and function in 3D. This is often done with card because it is cheap, easy to cut, crease and fold.
pros:
- can be presented to clients for feedback
cons
- issues can be found and sorted early before the use of more expensive materials
Toiles
a test version of a piece of clothing made from cheap material
- used to check the effectiveness of a sewing pattern
- design can be improved without wasting expensive material
Breadboarding circuits
Breadboards consist of rows of metal strips, covered by plastic holes.
Components and wires are placed into these holes to form a circuit.
- circuits can be quickly tested
- components can be reused
- better than CAD since it uses real components: software is not always accurate in predicting problems.
- temporary model, a more permanent construction method should be used for the final product.
3D sketching
can be produced by: freehand, perspective or by isometric projection. It creates a realistic view of a product e.g. to show to clients.
- The drawing is not to scale
- has a horizon line
- one or two vanishing points sit on the horizon line
Exploded drawings
These show how components fit together, the parts should be lined up and in proportion to the other components of the drawing.
- often used in furniture assembly instructions
Orthographic drawings
- Third angle orthographic projection (plan, front and side)
- to scale
- follow conventions
PRACTICE ORTHOGRAPHIC DRAWINGS
!!!
schematic diagrams
represents the elements of a system using standard symbols, they show which components are linked together
- often used in circuits
Virtual meeting software
Allows face to face meetings to take place from various locations.
- no wait time for responses
- visuals can be shared
- no misinterpretation as there is with text/email
CAD uses
CAD:
- drawing / modelling / simulating ideas
- designs can be viewed from all angles
- CAD files can be directly sent to CAM
- CAD files are easily shared: email, USB etc.
Prototypes
- full sized, actual versions of a product
- used to check aesthetics and functionality
- ensures money is not wasted on large scale manufacture if there is an issue
Evaluating prototypes
CAFE QUE :
Cost
Aesthetics
Function
Ergonomics
Quality
User
Environment
Fossil Fuels
- inc. coal/oil/natural gas
- They are burned to create steam which turns turbines which drive generators that produce electricity
- releases greenhouse gases e.g. CO2 (contributes to global warming)
- reliable
- non-renewable
Nuclear Power
- Nuclear Fission
- Non Renewable (Uranium)
- If radioactive material is released, it can cause serious health issues
- Nuclear waste must be disposed of carefully and stored for thousands of years
Solar Power
- Photovoltaic cells convert solar energy into an electric current
- renewable
- no waste products
- unreliable
- high initial cost, but no ongoing cost
- converts less than 10% of sunlight
Wind power
- wind turns the turbine
- the turbine turn the generator
- the generator produces electricity
- unreliable
- renewable
- visual and sound pollution
hydro-electrical
- water is held in a reservoir behind a dam
- the water is released downhill, this turns turbines as it goes
- renewable
Biomass fuel
- fuel from organic materials
- readily available
- can be expensive
- can drive up prices of food
- CO2 to grow the fuel
storing energy
- batteries: transfers chemical energy into electrical energy
- kinetic pumped water storage
4 types of motion
reciprocating
linear
oscillating
rotating
rotating motion
movement in a circle
linear movement
motion in a straight line in one direction
reciprocating motion
back and forth motion
oscillating motion
swinging back and forth motion
Levers function
to reduce the amount of effort required to move a load
first order lever (mechanical advantage and examples)
- fulcrum in the middle between effort and load
- there is mechanical advantage if the effort is further from the fulcrum than the load
e.g. scissors, seesaw
mechanical advantage second order lever (and example)
- Load in the middle between effort and fulcrum
- there is always a mechanical advantage because load is closer to the fulcrum than effort
e.g. wheelbarrow
Linkages
- used to transfer motion between two positions
third order lever (mechanical advantage and example)
- effort in the middle between fulcrum and load
- no mechanical advantage: effort is greater than the load HOWEVER movement of load is greater
e.g. tweezers
push-pull linkage
reverses the direction of linear motion
- 2 moving pivots, 1 fixed
PRACTICE DRAWING THIS
bell crank
changes the direction of motion by an angle
- 2 moving pivots, 1 fixed
PRACTICE DRAWING THIS
cams
convert rotary motion to reciprocating motion
follower meaning
- a rod that is moved as the cam rotates
- normally connected to the object that wants moving
- followers can: rise, dwell or fall
