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