section 7

• two types of material selection

  aesthetics

  function
• how can CAD be useful in the design stage?

  CAD enables designers to create a precision drawing of the product

  CAD produces 2d or 3d

  colours and finishes can be trailed

  stress loadings and weight distribution can be tested
• what is a protoype?

  a first or preliminary version of a product either working, functional or visual

  3d can help create a precise concept model
• considering functiinality

  strength

  various types of strength may need to be tested to ensure that materials and components perform their roles successfully. this is a very broad area and covers factors including resilience to wear and tear,weathering proofing and chemical resistance
• considering functionality

  movement

  movement - elasticity,flexablity and other forms of movement may need to be tested when working out what interactions a product may need to go through
• considering functiinality

  electrical and thermal conductivity

  this should be taken into account for some products
• component selection

  a component is a part used in a product that is often pre fabricated as it may be too difficult to produce all parts of a product urself. they may require

  - special machinery

  - be too expensive to produce

  - be time consuming to produce

  - be purchased in bulk to reduce cost
• considering avalibilty and cost

  working to deadlines and budgets is common in the industry. factors relating to avalibity and cost need to be considered such as

  -is there enough supply to complete the project?

  -are materials available in the size required ?

  -is a consistent supply needed or available?

  -does delivery time affect the production schedule ?

  -how much of the budget does the material use?

  - are their any environmental concerns?
• how does comprimising help?

  compromise plays an important role. in an ideal world the product would be high quality, delivered quickly and at a cheap price but this is impossible. a principle called the project management triangle states that you can only ever achieve two of these three attributes and each pair has a comprised attached
• examples of comprising in the project management triangle

  cheap and quick = low quality

  cheap and high quality = low priority

  fast and high quality =expensive
• consider the items shown and justify whether the material has been selected for functional, aesthetics purposes or both and why

  circuit board contacts

  functional, conductor
• consider the items shown and justify whether the material has been selected for functional, aesthetics purposes or both and why

  rings

  aesthetic,soft metal looks good
• consider the items shown and justify whether the material has been selected for functional, aesthetics purposes or both and why

  astronaut helmet visor

  functional, solar radiation
• consider the items shown and justify whether the material has been selected for functional, aesthetics purposes or both and why

  surgical scissors

  functional,corrsoion resistant
• a designer has been asked to create a Childs toy for mass productuon

  state two primary factors that may influence their material selection

  aesthetics

  function
• suggest two possible ways to visualise your design before manufacture

  CAD

  prototype
• state the three factors when considering functionality

  strength

  movement

  conductivity - electrical and thermal
• what does material managment include?

  using appropriate stock forms

  marking out and cutting from the edge

  tessellation
• what is material management?

  material managemtn is an approach to planning and controlling material wastage within the manufacturing process
• reducing waste

  cutting parts or components from the edge of a piece of material saves space and reduces wastage
• what is tessellation?

  the nesting of similar shapes of parts or components together means that they can be cut from material more efficiently.the efficient interlocking of shapes is known as tessellation.
• explain one reason for tessellating shapes when marking out components

  limits the amount of waste material
• explain how template aids accuracy and marking out during batch production

  it ensures receptive accuracy as the measurements on the template remain consistent. it removes the need to cut out holes before cutting
• briefly describe how the template would be used when drilling holes

  the workpiece is clamped securely. the template is securely fixed the drill is then aligned with the marked out holes and cut through
• measuring units

  it is recommended to work in mm or m as cm tend to be more likely to be confused with the different SI units. mm are there preferred choice as they allow for greater accuracy without the need for a decimal point.
• what is a datum point?

  a datum point is appoint from which all measurements are taken

  accuracy is very important

  repetitve accuracy can be ensured by using jigs or formers
• why is pattern or grain matching important?

  for aesthetic reasons it is important to get the grain to line up or to flow around a product. likewise with cardboard you may need the corrugations to run in a certain direction so that it is strong enough for its intended purpose
• marking and cutting out tools advantages

  templates.jigs and patterns are used to ensure repetitive acccauracy when making outputting out to processing materials.

  it saves tie and effort when manufacturing multiples copies of a product or component.

  they are often used in batch production
• state the use of a steel rule

  measuring and helping to draw straight lines

  
• state the uses of a maun safety rule

  provides a safe edge to score or cut against as it prevents knife slipping

  
• state the uses of a mitre square

  measures 45degree and 135 degree angles

  
• state the uses of a marking gauge/mortise gauge


  marks out lines on wood parallel to an edge

  
• state the uses of a craft knife

  cutting and scoring various materials

  
• state the uses of an engineers square

  measures 90degree angles used on metal

  
• state the uses of a centre punch

  marks a point on metal where it is to be drilled

  
• state the uses of a micrometer


  measures fine detail up to 100th of a mm

  
• state the uses of a measuring tape

  measuring straight lines or curved shapes accurately

  
• state the uses of a rotary cutting wheel

  cuts lines and curves on paper, card and fabric

  
• state the uses of a try square

  measures 90degree angles

  
• state the uses of a sliding bevel

  marks out specific angles