Section 7 Flashcards
Consideration of material selection
aesthetic, and functional properties
CAD software to visualise and work out stress loading and weight distribution
Component selection - what is it
a pre-madepart that composes a final product
3 aspects of consideration in functionality for materials and components
strength - how body responds to stress loadings that may be experienced in the product
Movement - elasticity. flexibility, and other types of movement
electric and thermal conductivity - some products need this for their function
speed and cost consideration
triangle between availability/speed, quality, cost
high speed and quality = high cost
quick, but cheap = low quality
high quality, low cost = low priority so high availability
tolerance
maximum amount of error that a component allows. measured with +-
higher tolerance equals product had to be made more precisey and slower so hi9gher costs
tolerance of electric components
resistor - Ohmage shown by first 3 bands, fourth band shows tolerance
silver 10% tolerance gold 5% tolerance
ca[acitor - intake charge slowly and release all quickly, can have tolerance of up to 20%
allowances
extra length of material that is attached beyond the final surface so that it can be neatly cut, planed or sanded later for a perfect fit
preventing waste when marking materials
start cutting from the most effective edge to leave most usable material
use a larger sheet when cutting different smaller shapes to leave less waste
tesellation and nesting
tessellation - interlocks shapes on material so there is no gaps in between the leftover material and therefore waste material is reduced
nesting - when irregular shapes are fit as closely together as possible for same reasons
units for measurement and material requirements
mm or metres is typically used to avoid confusion between Cm and SI unites
gathering materials of correct area involves knowing what needs to be made, in what size and tolerances and grain
Datum point and benefit
a permanent, fixed point of reference used to measure sides of a shape. with this greater accuracy is achieved as all measurements are made from a comm point
grain matching
matching the direction of pattern on materials for aesthetic purposes(like sewing clothes) or for strength(corrugated cardboard)
Templates, Jigs and patterns
tools that ensure there is repetitive accuracy when cutting or marking out a shape so that material is cut identicallv.
often used in batch production (automatic production will have machines)
tools for measuring and cuttings
ruler, engineer square, mitre square
sliding bevel, protractor
shears, cutting wheel,
health and safety measures
tools are oiled, lubricated visually checked and tested under low load cleaning spillages or marking spillages wearing PPE
turning equipment off when not using
data sheet
set of instructions and guidance on using specialist tools to prevent accidents or to keep safe from hazardous materials
risk assessment
full look at the potential risks of a procedure or process what are the risk factors, who are at risk, evaluation of likelihood and severity, implement control measures to stop risks from happening, review risk assessment
outsourcing
commissioning a professional to do specialist work who may be more accurate and less prone to accident
how does surface treatment and finishes help functionality
providing protection from weather, water, insect providing insulation
increases toughness and resistance to knocks bumps scratches ensures hygiene by adding antibacterial or dirt properties, or make it easier to clean
how can surface treatments improve aesthetic
applying a sheen - gloss, matte finish colouring by printing dyeing staining embellishing with decals and surface decorations
issues that surface finishes can fix
UV degradation - breaks down colour pigment in textiles and weakens them
biological attack - wood, paper can be attacked by termites, mice, hornets
rot - wood that gets damp is proline to fungal attack which weakens wood
oxidisation and corrosion - iron can rust and become weak, aluminium has its aesthetic change
preparation for surface treatments
dust, dirt,grease free, smooth
providing a key
some surfaces need to be rough/scratched for finishes to be able to be applied on them
methods of application of surface treatments
spraying, painting
pressure bonding and heat
electroplating
adhesive
printing, laminating
