Technology Flashcards
Ferrous
Metals which contain iron, is magnetic and rusts
Nonferrous
Metals which don’t contain iron so are not Magnetic and don’t rust
Alloy
A mixture of metals with other elements, to improve upon its properties or working performance
Natural-Hardwood
Deciduous trees
Grow slower
More expensive
More dense
Close grain
Natural-Softwood
Coniferous trees
Grows quicker
Less expensive
Less dense
Wide grain
Man made-manufactured boards
Are left over pieces of wood pressed with glue
Disadvantages of natural wood
-natural defects
-knots
-warps, twists, bows and splits
-limited by the size of the tree
Advantages of man-made wood
-Available in large sheets
-No natural defects
Disadvantages of man-made wood
-Edges need to be finished
-Not as aesthetically pleasing
Strength
force is applied to material without it bending, shattering and deforming in anyway
Hardness
The ability of a material to resist scratching from wear to tear, bending and indentation
Brittleness
Materials can not withstand much stretching and will crack, brake and change shape
Toughness
The ability to resist breaking or shattering
Durability
The ability to withstand repeated use, wear and tear, weathering and corrosive attack
Ductility
The ability of a material to change shape (usually stretching)
Malleable
The ability of a material to be hammered
Ergonomics
how a product interacts with the user
Aesthetics
It’s the appearance of the product (colour, shape and texture)
Design process steps
Design opportunity
Research
Design brief
Specification
Idea generation
Development
Manufacture
Testing and evaluation
Design opportunity
A problem or scenario you wish to solve by designing a product
Research
Looking at existing solutions to identify areas of improvement or design strength
Design brief
A short statement outlining what you hope to achieve
Specification
A list of specific requirements, the product will do, have or be
Idea generation
Coming up with initial ideas and a lot of ideas should be considered
Development
Improve on initial ideas
Planning for manufacture
Creating a final idea
Manufacture
Making the final prototype
Testing and evaluation
Testing to see if the product meets the specification
Evaluate to find any future improvements
Thermoplastic
Can be heated and shaped over and over again
Thermosetting
Can only be heated and shaped once
Hardening
(Only) high carbon steel is heated until it glows red and is quenched in clean water immediately becoming very hard but brittle
Heat treatment
Heating and cooling metals to improve on it physical and mechanical properties without changing shape
Tempering (done after hardening)
Used to increase toughness of iron based alloys
Heating the metal to some temperature below the critical point for a certain period of time after allowing it to cool in still air
Annealing
A metal is heated to a specific temperature/colour and then allow to cool slowly which softens the metal making it easier to cut and shape
Normalising
It’s a heat treatment process to make metal more ductile and still get hard
Steps of making a product
Design opportunity
Research
Design brief
Specification
Idea generation
development
Manufacture
Testing and evaluation
Form
Is the appearance of the product
Function
The intended use of a product
Form follows function
Thought about form first
Function follows form
Thought about function first
CAD advantages
Easier to make changes
Accurate measurements
Can see all angles
Share designs easy
Send design straight to CAM
CAD disadvantages
Expensive
Training required
CAD what it does
Creates drawings or models on the computer
Let’s you see a product in detail, test the product on screen and add realistic appearances
Modeling
cheap and quick model to test the function, size, preportions and if the idea works.
Modeling benefits
You can see the whole product
Test manufacturing technique
It’s quicker and cheaper than a full prototype
Prototype
It’s a fully functional version of a product made before manufacturing
Prototype benefits
Allows to test the function
Identify flows before production-saves money
Allows you to see how materials will preform
What does Working drawings do
communicates all relevant details required to manufacture a product
What a working drawing is
2-D line drawings displayed in orthographic with dimensions and materials
Line bending steps (thermoplastics only)
1.Mark bend line-dashed line-steel ruler, tri square, marker
2.the dashed line gets lined up with the wire of the line bender
3.wait until the plastic is heated and flexible
4.bend to desired angle
5.let it cool while holding it in the angle
Former or jig
MDF
cut to desired shape
Plastic could clamp on to or in between
Metal bending steps
1.mark the bend line-dashed line-scriber, blue marker, engineer square
2.place into vice
3.use a scrap block of wood and a mallet and tap metal until it reaches desired angle
Vacuum forming steps
1.get the mould and place it on top then lower it down
2.get the plastic and place it on top then lock it in
3.start to heat the plastic when it’s floppy bring the mold up and activate the vacuum pump
4.let it cool the take it out and remove the mould
Blow moulding steps
1.plastic is inserted into the mould
2.is squeezed by mould and air is blown into it
3.it expands to fill the mould
4.finished product
Compress or press moulding steps
1.a mould is made in two halves
2.sheet of plastic is placed between
3.then heated and pressure applied
4.enabling the plastic to take a new shape
Laminating steps
1.cut thin strips of wood
2.put glue on the strips
3.clamp them into a mould
Polishing
Use polisher to make the material shiny and smoother
Painting
Adds colour to wood or metal
Water based paints
Offer no weather protection
Oil paints
Offer weather protection
Vanished
Adds clear layer for weather protection and variety of shiny finishes
(Glass, satin matt)
Stain
Adds colour to wood but can see grain offers no protection
Dip coating
Adds layer of thin plastic to a piece of material
Dip coating offers
Weather protection Insulation Doesn’t need redone/topping up
Colour Texture
Process of dip coating
1.Prepare the surface by cleaning away any oil/grease
2.Heat the metal
3.dip heated metal into plastic powder and remove
4.allow metal to melt/cool
Galvanising
Coat steel in a layer of zinc
Galvanising adds
Weather protection, doesn’t need redone
Process of galvanising
Prepare cleaning and smoothing
Dip metal into molten zinc
CNC router
Produces 2D and 3D
Used on foam, wood and metal
Used for model making moulds
Laser cutter
Cuts and engraves thin sheets of plastic, metal and wood
Laser beam that cuts the material and doesn’t need clamped
3D Printer
Plastic only
3D shapes created can do internal and external pans interlinking parts made limited to size of the bed
CNC milling machine
Cute wood, metal and plastic
Accurate measurements
Cuts complex shapes and curves in a flat piece of material
CAM
converts drawings created by CAD into actual products
Conductor
Material which allows electrical current to pass through it
Metal examples of a conductor
Copper, gold, graphene and graphite
Insulator
Material which doesn’t allow electrical current to pass through it
Semi-conductor
Material that had both conductive and non-conductive properties-used for resistors
Examples of semiconductor
Silicon
Germanium
Input and examples
Component that detects or gets changed
LDR, thermistor and switches
Control/process and examples
Component that controls the change or function of a circuit
Transistor
Thyristor
Output and examples
Component that changes or gives something off
LED, bulb, buzzer, motor
Voltage
Force that makes electrons flow in a conductor
Current
Electrical current is a Flow of electrons
Resistance
Measure of how easily electrons flow through a conductor
Transistor
Electronic switch or an amplifier
Transistor legs
Collector
Base
~>emitter
Transistors activates
When the base leg receives 0.6-0.8 volts
Ohms law
Voltage=current x resistance
Voltage
V
Volts
Current
Amps
A
I
Resistance
Ohms
Omega
Battery
Power source
Converts chemical energy to electrical energy
Thermistor
Temperature dependent resistor
As temp rises the resistance increases
Variable resistor
Adjustable resistor
Increase or decrease the amount of resistance
Controls brightness of a bulb and flow of electricity
LDR (Light Dependent Resistor)
Semiconducting
Low resistance in light conditions and high resistance when it’s dark
Diode
Protects motors and allows current to flow in one direction
Resistor
Used to protect LEDs
Motor
Output device that produces rotary motion
Bulb
Output device that gives of light
Buzzer
Output device that gives of sound
LED
Diode that emits light when electrons pass through it
Mega (M)
1 000 000
Kilo (k)
1000
Knots
Shows where a branch used to be
