Technology & Design // Engineering

Types of Motion

• Linear: movement in a straight line (e.g. drawer, piston)
• Rotary: movement in a circle (e.g. wheel, motor shaft)
• Reciprocating: back and forth in a straight line (e.g. piston in engine, sewing machine needle)
• Oscillating: swinging back and forth in an arc (e.g. pendulum, windscreen wiper)

Converting Motion

Mechanism	Input Motion	Output Motion	Example
Crank and slider	Rotary	Reciprocating (or vice versa)	Piston engine, steam locomotive
Cam and follower	Rotary	Reciprocating / oscillating	Engine valves, sewing machines
Rack and pinion	Rotary	Linear (or vice versa)	Car steering, lathe carriage
Screw thread	Rotary	Linear	Vice, car jack, clamp

Gear Systems

• Spur gears: parallel shafts, teeth mesh, direction reverses. Most common type
• Bevel gears: shafts at 90 degrees (right angle). Transfers drive around a corner
• Worm gear: worm (screw) meshes with worm wheel. Large speed reduction, non-reversible. Self-locking
• Gear train: multiple gears in series for larger ratios
• Idler gear: changes direction without affecting gear ratio

Belt & Chain Drives

• Belt drive: flexible belt connects two pulleys. Can slip (acts as overload protection). Quiet
• Chain drive: roller chain connects sprockets. No slip (positive drive). Needs lubrication. Used in bicycles, motorcycles
• Same ratio calculation as gears (using pulley/sprocket diameters or teeth)

Linkages

• Bell crank: changes direction of motion by 90 degrees (e.g. bicycle brake)
• Toggle clamp: over-centre action locks in position. Used for jigs and fixtures
• Parallel motion (push-pull): both ends move in same direction (e.g. tool box lid)
• Reverse motion (tongs): ends move in opposite directions (e.g. scissors, pliers, lazy tongs)

Levers

Class	Order	Examples
1st class	Fulcrum between Effort and Load	Seesaw, crowbar, scissors, pliers
2nd class	Load between Fulcrum and Effort	Wheelbarrow, nutcracker, bottle opener
3rd class	Effort between Fulcrum and Load	Fishing rod, tweezers, human forearm

Types of Force

Force	Description	Example
Tension	Pulling / stretching force	Tow rope, suspension bridge cable
Compression	Pushing / squashing force	Column supporting a roof, bridge pier
Shear	Forces acting in opposite directions across a section	Scissors cutting paper, rivet in shear
Torsion	Twisting force	Twisting a screwdriver shaft, drive shaft
Bending	Combination of tension and compression	Shelf loaded in middle, beam under load

Beams

• Simply supported beam: supported at both ends, free to rotate at supports. Bends under load (sags)
• Cantilever beam: fixed at one end only, free at the other. Greater deflection and stress at the fixed end (e.g. diving board, balcony)
• I-beam / H-beam cross-section provides maximum strength for minimum material (material placed where stress is highest -- top and bottom flanges)

Triangulation

• Triangles are the only rigid polygon -- they cannot be deformed without changing the length of a side
• Used in trusses, bridges, cranes, pylons, bicycle frames
• Members in a triangulated structure carry only tension or compression (no bending)

Stress, Strain & Young's Modulus

Systems Approach

• All electronic systems can be broken down into input, process, and output sub-systems
• Feedback can loop output back to input for control

Input Components

Component	Function	Notes
Push switch (push-to-make)	Momentary contact -- closes circuit when pressed	Doorbells, reset buttons
Toggle switch	Stays in on or off position	Light switches, power switches
Tilt switch	Closes circuit at certain angle (mercury or ball bearing)	Safety cutoff in heaters
Reed switch	Activated by magnetic field (two metal reeds in glass)	Door/window security sensors
Microswitch	Small lever-operated switch, very precise actuation	Limit switches, 3D printers, mouse buttons
LDR (Light Dependent Resistor)	Resistance decreases as light increases	Automatic night lights, light meters
Thermistor (NTC)	Resistance decreases as temperature increases	Temperature sensing, fire alarms, thermostats
Potentiometer	Variable resistor -- user adjustable	Volume control, dimmer, position sensor
Microphone	Converts sound waves to electrical signal	Audio input, voice control

Process Components

• Resistors: limit current, divide voltage, set bias points
• Capacitors: store charge, smoothing, timing circuits
• Transistors (NPN as switch): small base current switches larger collector current. Acts as electronic switch
• 555 Timer IC: versatile timing chip -- monostable (one pulse) or astable (continuous pulses)
• Op-amps: amplify signals, compare voltages
• Logic gates: AND, OR, NOT, NAND, NOR, XOR -- process digital signals
• Microcontrollers: programmable ICs (Arduino, PIC) -- can be programmed for complex logic

Output Components

Component	Function	Notes
LED	Emits light when forward biased. Low power, long life	Always use with series resistor to limit current
Buzzer / piezo	Produces sound	Alarms, indicators, feedback
DC motor	Continuous rotation, speed varies with voltage	Fans, toys, drives. Use PWM for speed control
Stepper motor	Rotates in precise steps (e.g. 1.8 degrees per step)	CNC machines, 3D printers, robotics
Servo motor	Rotates to precise angle (0-180 degrees typically)	RC cars, robot arms, control surfaces
Solenoid	Electromagnetic linear actuator -- pushes/pulls a plunger	Door locks, valves, pinball machines
Relay	Electromagnetic switch -- small signal controls large current circuit	Isolating control from power, switching mains
Speaker	Converts electrical signal to sound waves	Audio output

Power Supplies

• Batteries: portable DC supply. AA (1.5V), 9V PP3, lithium cells. Series connection adds voltages
• Regulated power supply: mains AC converted to stable DC via transformer, rectifier, smoothing capacitor, voltage regulator (e.g. 7805 for 5V)

Ohm's Law & Power

Resistor Colour Code

Colour	Value	Multiplier	Tolerance
Black	0	x1	--
Brown	1	x10	+/-1%
Red	2	x100	+/-2%
Orange	3	x1k	--
Yellow	4	x10k	--
Green	5	x100k	+/-0.5%
Blue	6	x1M	+/-0.25%
Violet	7	x10M	+/-0.1%
Grey	8	--	--
White	9	--	--
Gold	--	x0.1	+/-5%
Silver	--	x0.01	+/-10%

Series & Parallel Resistors

Potential Divider

• Replace R1 or R2 with a sensor (LDR, thermistor) to create a sensing circuit
• LDR as R1 (top): Vout increases as light increases (LDR resistance drops)
• Thermistor as R1 (top): Vout increases as temperature increases (NTC resistance drops)

Kirchhoff's Laws

• KCL (Current Law): The total current flowing into a junction equals the total current flowing out
• KVL (Voltage Law): The sum of all voltages around any closed loop in a circuit equals zero (i.e. supply voltage = sum of voltage drops)

Capacitors

• Store electrical charge (energy) in an electric field between two plates
• Charging: current flows into capacitor, voltage across it increases exponentially until it reaches supply voltage
• Discharging: stored energy released, voltage decreases exponentially

Transistor as a Switch

• When base voltage exceeds ~0.7V, transistor switches ON, allowing current from collector to emitter
• Small base current controls much larger collector current
• Darlington pair: two transistors connected to give very high current gain (hFE = hFE1 x hFE2). Used when sensor signal is very weak

555 Timer

Logic Gates

Gate	Symbol	Rule	A=0, B=0	A=0, B=1	A=1, B=0	A=1, B=1
AND	&	Output = 1 only when ALL inputs = 1	0	0	0	1
OR	≥1	Output = 1 when ANY input = 1	0	1	1	1
NOT	1 (single input)	Output = opposite of input	Input 0 gives 1; Input 1 gives 0
NAND	& + bubble	Opposite of AND	1	1	1	0
NOR	≥1 + bubble	Opposite of OR	1	0	0	0
XOR	=1	Output = 1 when inputs are DIFFERENT	0	1	1	0

Microcontrollers

Platform	Features	Typical Use
Arduino (ATmega328)	Simple, digital and analogue I/O pins, 5V logic, huge community, C/C++ based	Student projects, prototyping, simple control
PIC microcontroller	Microchip brand, various models, used in CCEA coursework, flowchart programming	Embedded systems, product development
Raspberry Pi	Full computer (runs Linux), GPIO pins, camera, networking, Python	IoT, media centres, robotics, server

Inputs & Outputs

• Digital inputs: switches, buttons -- HIGH (1) or LOW (0)
• Analogue inputs: sensors (LDR, thermistor, potentiometer) -- variable voltage read by ADC
• Digital outputs: LEDs, buzzers, relays -- on or off
• PWM outputs: Pulse Width Modulation -- rapid on/off to simulate analogue (motor speed, LED brightness)

Flowcharts for Programs

• Start/End: rounded rectangle (terminator)
• Process: rectangle (action to perform)
• Decision: diamond (yes/no question)
• Input/Output: parallelogram (read sensor / set output)
• Flowcharts must have clear flow, with arrows showing direction

Programming Concepts

• Variables: named storage locations for data (int, float, boolean)
• Loops: repeat code -- FOR loop (set number of times), WHILE loop (condition-based)
• Conditions: IF / ELSE statements -- make decisions based on input
• Functions / subroutines: reusable blocks of code

PWM (Pulse Width Modulation)

• Rapidly switches output on and off at fixed frequency
• Duty cycle: percentage of time the signal is HIGH. 50% = half power, 100% = full power
• Used for: motor speed control, LED dimming, servo position

ADC (Analogue to Digital Conversion)

• Converts continuous analogue voltage to a digital number the microcontroller can process
• Arduino ADC: 10-bit resolution -- values from 0 to 1023 (for 0V to 5V)
• Higher bit resolution = more precise readings

Applications

• Smart home: automated lighting, heating, security (PIR sensors, motorised locks)
• Robotics: sensor-driven movement, obstacle avoidance, line following
• Automation: conveyor control, sorting systems, pick-and-place

Inclusive Design & Ergonomics

• Inclusive design: designing products usable by as many people as possible, regardless of age, ability, or situation
• Ergonomics: designing products to fit the human body and its movements. Considers comfort, efficiency, safety
• Key factors: grip size, reach, force required, visibility of controls, feedback (tactile, visual, auditory)

Anthropometrics

• The study of human body measurements and proportions
• Data collected from large populations, presented as percentiles (5th, 50th, 95th)
• Design for the 5th to 95th percentile to accommodate 90% of users
• Examples: seat height, door width, handle diameter, screen viewing distance
• Adjustability built in to accommodate variation (e.g. adjustable office chair)

Aesthetics & Form

• Visual appeal: shape, colour, texture, proportion, symmetry
• Form follows function -- but aesthetics influence purchasing decisions
• Target market influences aesthetic choices (children vs professional, budget vs premium)

Product Life Cycle

• Introduction: new product launched, high costs, low sales, heavy marketing
• Growth: sales increase, competitors enter, costs reduce with scale
• Maturity: sales peak, market saturated, price competition
• Decline: sales fall, product becomes outdated, may be withdrawn or relaunched

Planned Obsolescence

• Deliberately designing products with a limited lifespan to encourage repurchase
• Technical obsolescence: product stops working (e.g. battery sealed in, software updates)
• Style obsolescence: product looks dated (e.g. fashion, phone design)
• Ethical concerns: waste, environmental damage, consumer exploitation

Sustainability & Environmental Impact

• 6 Rs: Reduce, Reuse, Recycle, Repair, Rethink, Refuse
• Life Cycle Assessment (LCA): evaluates environmental impact from cradle to grave -- raw materials, manufacturing, transport, use, disposal
• Carbon footprint, embodied energy, recyclability
• Design for disassembly: parts can be separated for recycling
• Use of recycled materials, biodegradable materials, renewable energy in production

Influential Designers

• James Dyson: iterative development (5,127 prototypes for cyclone vacuum), user-centred design
• Philippe Starck: aesthetics and form, accessible design (Juicy Salif lemon squeezer)
• Dieter Rams: "Less but better", 10 principles of good design. Influenced Apple design
• Ettore Sottsass: Memphis Group, bold colour and form in product design

Smart Materials (Advanced)

Material	Behaviour	Applications
Piezoelectric materials	Generate voltage when deformed / deform when voltage applied	Sensors, actuators, lighters, ultrasound transducers, energy harvesting
Electroluminescent materials	Emit light when electrical current passes through	Backlighting (watches, dashboards), safety strips, flexible displays
Quantum Tunnelling Composite (QTC)	Insulator when relaxed, conductor when compressed	Pressure sensors, touch-sensitive switches, NASA space gloves

Nanomaterials

• Materials engineered at nanoscale (1-100 nanometres)
• Graphene: single layer of carbon atoms in hexagonal lattice. Strongest material known (200x stronger than steel), excellent conductor, transparent, flexible. Applications: touchscreens, batteries, composites, water filtration
• Carbon nanotubes (CNTs): rolled graphene sheets. Exceptional strength and conductivity. Used in composite reinforcement, electronics, medical devices

Modern Composites

• Advanced fibre placement (AFP): automated layup of carbon fibre for aerospace parts
• Sandwich structures: lightweight core (honeycomb, foam) between strong skins
• Hybrid composites: combining different fibres (carbon + Kevlar) for optimised properties

Biomaterials & Bio-based Plastics

• PLA: derived from corn starch, biodegradable under industrial composting
• PHA: produced by bacteria, fully biodegradable in natural environment
• Bio-based PE: chemically identical to fossil PE but made from sugarcane ethanol
• Mycelium-based materials: mushroom root structures grown into packaging/insulation

Material Selection Methodology

• Define required properties (strength, weight, cost, corrosion resistance, etc.)
• Screen materials that meet minimum requirements
• Rank remaining candidates using weighted criteria
• Ashby charts: material property charts plotting two properties against each other (e.g. strength vs density) to identify best material families for an application
• Consider: availability, cost, sustainability, processability, joining compatibility

CNC Machining

• G-code: programming language for CNC machines (G00 rapid move, G01 linear feed, G02/G03 arcs)
• CAM software generates G-code from CAD model (toolpaths, speeds, feeds)
• Multi-axis CNC: 3-axis, 4-axis, 5-axis for complex geometries
• Advantages: high accuracy (+/- 0.01mm), repeatability, unmanned operation, complex shapes

Rapid Prototyping

• Quick production of physical models from CAD data
• FDM, SLA, SLS (as covered in AS1), plus: Multi Jet Fusion (MJF), Direct Metal Laser Sintering (DMLS)
• Advantages: fast design iteration, functional testing, reduced time to market
• Moving beyond prototyping into direct digital manufacturing for end-use parts

Laser Cutting & Engraving

• CO2 laser: cuts acrylic, MDF, plywood, card, fabric. Engraves glass, leather
• Fibre laser: cuts metals (steel, aluminium, brass)
• Kerf: width of material removed by the laser beam (typically 0.1-0.3mm)
• Vector cutting (through material) vs raster engraving (surface marking)

Automated Systems

• Industrial robots: 6-axis articulated arms for welding, painting, assembly, pick-and-place
• Flexible Manufacturing Systems (FMS): CNC machines + robots + AGVs (Automated Guided Vehicles) connected by computer. Can switch between products without retooling
• Computer Integrated Manufacturing (CIM): full integration of CAD, CAM, production planning, quality control, stock control under one computer system

Industry 4.0

• The "fourth industrial revolution" -- smart, connected, data-driven manufacturing
• IoT (Internet of Things): machines with sensors connected to internet, sharing data in real-time
• AI in manufacturing: predictive maintenance (anticipating failures), quality inspection, process optimisation
• Digital twins: virtual replica of a physical system. Simulate and optimise before making changes to real system
• Big data analytics, cloud computing, cyber-physical systems

Quality Systems

• ISO 9001: international standard for quality management systems. Documented procedures, audits, continuous improvement
• Six Sigma: data-driven methodology to reduce defects to fewer than 3.4 per million. DMAIC: Define, Measure, Analyse, Improve, Control
• TQM (Total Quality Management): quality is everyone's responsibility, company-wide culture of continuous improvement

Compound Gear Trains

• Two or more pairs of meshing gears on separate shafts
• A compound gear has two gears fixed on the same shaft (they rotate together)
• Used to achieve large gear ratios in a compact space

Torque & Efficiency

Cam Profiles

• Uniform velocity: linear rise and fall. Follower moves at constant speed. Causes sudden acceleration/deceleration at transitions (shock loading)
• Simple harmonic motion (SHM): smooth sinusoidal profile. Follower accelerates and decelerates smoothly. Used for medium speeds
• Uniform acceleration and deceleration: parabolic profile. Smoothest motion, lowest peak acceleration. Best for high-speed applications

Follower Types

• Knife-edge follower: simple point contact. Wears quickly. Good for complex cam profiles
• Roller follower: roller reduces friction and wear. Most common in engineering
• Flat-foot (mushroom) follower: wide contact area, lower contact stress. Cannot follow concave profiles

Crank Mechanisms

• Dead points: positions where the crank and connecting rod are in line (Top Dead Centre and Bottom Dead Centre). No force can be applied by the slider to turn the crank at these points
• Flywheel stores energy to carry mechanism through dead points
• Quick-return mechanism: output stroke takes less time than return stroke (e.g. shaping machine)

Operational Amplifiers (Op-Amps)

• High-gain differential amplifier IC (e.g. 741, TL081)
• Two inputs: inverting (-) and non-inverting (+)
• Requires dual power supply (typically +/-15V or +/-9V)
• Open-loop gain is very high (~100,000) -- practically infinite for calculations
• Negative feedback is used to set a controlled, predictable gain

Inverting Amplifier

Non-Inverting Amplifier

Comparator

• Op-amp used without feedback (open loop)
• Compares voltages at the two inputs
• If V(+) > V(-): output goes to positive saturation (+Vcc)
• If V(-) > V(+): output goes to negative saturation (-Vcc)
• Used with potential dividers and sensors for threshold detection (e.g. "turn on heater when temperature drops below set point")

Summing Amplifier

• Multiple inputs connected to the inverting input through separate resistors
• Output is the inverted sum of all inputs (scaled by their respective resistor ratios)
• Used in audio mixing, DACs (digital to analogue converters)

PCB Design & Manufacture

• PCB designed in software (e.g. KiCad, Eagle, EasyEDA)
• Schematic capture then PCB layout (routing tracks)
• Manufacturing: etching (photo-resist + UV exposure + ferric chloride) or CNC milling
• Through-hole (THT): component leads go through holes, soldered on opposite side. Easier to solder by hand, bulkier
• Surface mount (SMT): components soldered directly to pads on board surface. Smaller, automated placement (pick and place), suited to mass production

Open Loop vs Closed Loop

Feature	Open Loop	Closed Loop
Feedback	No feedback	Has feedback sensor
Accuracy	Cannot correct errors	Self-correcting
Example	Toaster (timer only)	Central heating (thermostat)
Complexity	Simple and cheap	More complex and expensive
Response to disturbance	Cannot compensate	Adjusts automatically

Feedback

• Negative feedback: output is compared to desired value; any error is corrected in the opposite direction. Stabilises the system. Most control systems use this
• Positive feedback: output reinforces itself, causing the system to move further from equilibrium. Usually unwanted (e.g. microphone feedback squeal). Used deliberately in oscillator circuits and comparator circuits with hysteresis

PID Control (Conceptual)

• P (Proportional): corrective action proportional to the current error. Large error = large correction. Fast but may oscillate around set point
• I (Integral): accumulates past errors over time. Eliminates steady-state error. Slow to respond
• D (Derivative): responds to rate of change of error. Anticipates future error. Reduces overshoot and oscillation
• PID combines all three for optimal control. Used in temperature control, motor speed, robotic arm positioning

Pneumatic Systems

• Use compressed air to create motion
• Single-acting cylinder: air pressure extends piston, spring returns it
• Double-acting cylinder: air pressure extends and retracts piston (ports on both sides)
• Valves: 3/2 valve (3 ports, 2 positions), 5/2 valve (5 ports, 2 positions)
• Advantages: clean, fast, safe (no electrocution risk), simple maintenance
• Disadvantages: noisy, limited force (compared to hydraulics), compressible air makes precise control harder

Hydraulic Systems

• Use pressurised fluid (oil) to transmit force
• Pascal's law: pressure applied to an enclosed fluid is transmitted equally in all directions

• Force multiplication: small piston (small area) pushes fluid to large piston (large area) = force multiplied
• Advantages over pneumatics: much greater force, incompressible fluid gives precise control, smooth operation
• Disadvantages: oil leaks are messy and hazardous, heavier, more expensive, slower
• Applications: excavators, car brakes, hydraulic presses, aircraft landing gear

Mechanisms & Structures

Electronics

Colour	Digit	Multiplier	Tolerance
Black	0	x1 (10^0)	--
Brown	1	x10 (10^1)	+/-1%
Red	2	x100 (10^2)	+/-2%
Orange	3	x1k (10^3)	--
Yellow	4	x10k (10^4)	--
Green	5	x100k (10^5)	+/-0.5%
Blue	6	x1M (10^6)	+/-0.25%
Violet	7	x10M (10^7)	+/-0.1%
Grey	8	--	--
White	9	--	--
Gold	--	x0.1	+/-5%
Silver	--	x0.01	+/-10%

A	B	AND	OR	NAND	NOR	XOR
0	0	0	0	1	1	0
0	1	0	1	1	0	1
1	0	0	1	1	0	1
1	1	1	1	0	0	0

A	NOT A
0	1
1	0

Metals Comparison

Material	Density (g/cm3)	Tensile Strength (MPa)	Hardness	Corrosion Resist.	Cost
Mild steel	7.85	400-550	Medium	Poor	Low
High carbon steel	7.85	600-900	High	Poor	Low-Med
Stainless steel	7.9	500-700	High	Excellent	Medium
Cast iron	7.2	150-400 (tensile)	Very high	Medium	Low
Aluminium	2.7	70-700*	Low-Med	Good	Medium
Copper	8.9	210-380	Low-Med	Good	High
Brass	8.5	340-470	Medium	Good	Med-High
Titanium	4.5	240-1400*	Medium-High	Excellent	Very high

* Range depends on alloy and heat treatment

Common Tolerances

Process	Typical Tolerance
Sand casting	+/- 1.5 mm
Die casting	+/- 0.25 mm
CNC milling	+/- 0.025 mm
CNC turning	+/- 0.025 mm
Grinding	+/- 0.005 mm
Laser cutting	+/- 0.1 mm
3D printing (FDM)	+/- 0.3 mm
3D printing (SLA)	+/- 0.05 mm
Injection moulding	+/- 0.1 mm

Structure Your Folio

• Follow the CCEA mark scheme closely -- it tells you exactly what they want
• Typical structure: Situation and Brief > Research > Specification > Design Ideas > Development > Planning for Making > Making > Testing and Evaluation
• Every page should have a clear purpose and title
• Use a consistent layout, font, and colour scheme throughout
• Page numbers and contents page for easy navigation

Writing a Strong Specification

• Each point must be measurable and testable
• Bad: "It should be strong" -- Good: "It must support a minimum load of 5 kg without permanent deformation"
• Bad: "It should look nice" -- Good: "The product must appeal to the target market (15-18 year olds) as confirmed by user survey"
• Include quantitative targets wherever possible (dimensions, weight, cost, performance)

Research That Scores Marks

• Analyse existing products: photograph, measure, note materials, evaluate strengths/weaknesses
• User surveys/interviews: show actual results, not just "I asked people"
• Material research: reference data sheets, not just internet descriptions
• Draw conclusions from research -- how will each piece of research influence your design?

Sketching Tips

• Use crating (construction lines) to build up 3D forms
• Sketch lightly first, then go over with confident, darker lines
• Always annotate sketches -- explain materials, dimensions, features, how it works
• Show multiple views: 3D perspective + orthographic for detail
• Sketch at least 4-6 different concepts before choosing one to develop
• Show design evolution -- how each idea builds on the previous one

Rendering Tips

• Identify your light source and keep it consistent across the drawing
• Use marker pens for broad areas of colour, coloured pencils for detail and blending
• Leave white highlights for shiny/reflective surfaces (metal, glass)
• Use a white pencil or gel pen for final highlights
• Show material textures: wood grain, brushed metal, matt plastic
• Add a shadow/ground plane to anchor the product

CAD Presentation

• Show multiple views: isometric, exploded, section, rendered
• Apply realistic materials and textures
• Use studio-style lighting and neutral background for renders
• Include dimensioned orthographic drawings (3rd angle projection preferred for CCEA)
• Show the product in context (in use, with a human figure for scale)

Model Making

• Start with quick card models to test ergonomics and proportions
• Use foam board or blue foam for 3D forms (easy to shape with hot wire cutter or sandpaper)
• 3D print key components to test fits and mechanisms
• Document the model-making process with photographs at each stage
• Evaluate the model -- what did you learn? What would you change?

Evaluation Frameworks

• Evaluate against every specification point -- use a table format
• Include user testing: get real users to try the product, record their feedback
• Be honest about weaknesses -- examiners value critical evaluation over unsubstantiated praise
• Suggest specific, realistic improvements (not "I would make it better")
• Consider commercial viability: could it be manufactured? At what cost? Who would buy it?

Photography for Portfolios

• Use good lighting -- natural daylight or softbox. Avoid harsh shadows
• Plain background (white or neutral) so the product is the focus
• Multiple angles: front, side, top, detail close-ups
• Include a scale reference (ruler or hand) in at least one photo
• Photograph the product in use (in context)
• High resolution, properly focused, no clutter

Documenting Manufacturing

• Create a detailed manufacturing plan before you start making
• Include: step sequence, tools/equipment needed, materials, safety precautions, quality checks
• Photograph each key stage of manufacture
• Note any changes from your plan and explain why
• Include time planning (Gantt chart)
• Show quality checks: measurements, fit tests, surface finish checks