How Things Work

Blender

Tip in the fruit, lock the lid to close the safety switch, pulse or blend it smooth and pour, then look through the base at the universal motor, star coupling, sealed blade assembly and speed switch.

Add fruit · Lock the lid · Blend · Pour

Bottle opener

A crown-cap opener multiplies a lift of the handle, staged on a table with cap replacement as a teaching control.

Hook · Lift · Reset

Can opener

An enlarged teaching model stages hand clamping, geared rim feeding and manual removal of a fully cut lid.

Clamp · Turn · Lift

Corkscrew

A teaching adaptation of the page 43 winged corkscrew uses two wing-mounted pinion sectors to lift a central rack, helix and cork.

Turn · Press wings · Reverse · Reset

Dishwasher

Load four plates and follow water through a dishwasher's fill, wash, rinse, drain and heated drying cycle.

Open / close door · Load plates · Add tablet · Start cycle

Egg whisk

A teaching adaptation of the hand-cranked egg whisk shows opposite crown-wheel faces driving two faster, counter-rotating beaters.

Crank · Speed up · Lift · Reset

Electric kettle

Switch it on and watch the water heat until steam runs down a tube onto a bimetal disc that snaps over and clicks the switch off.

Fill with water · Switch on · Pour a cup · Lift off base

Electric mixer

A teaching cutaway shows how a motor-shaft worm reduces speed and counter-rotates two beaters over an external bowl fixture.

Start · Change speed · Stop

Espresso machine

Fill the tank, lock in the coffee, and watch pressurized water brew espresso while the steam wand warms and foams milk.

Fill the tank · Switch on · Lock the portafilter · Pull a shot · Steam milk

Fridge

Open the door, stock the shelves and leave it open too long: watch the thermostat click the compressor on to pump the heat out through the coils at the back.

Open the door · Put in food · Leave it open · Close the door

Microwave

Pop a bowl of soup in, set the timer and start it, then look inside to see the magnetron beam microwaves down the waveguide while the door interlocks stand guard.

Open / close door · Bowl in / out · Set time · Start

Mincer

A teaching cutaway shows a hand mincer cutting model food with a crank-driven auger and blade against a fixed perforated plate.

Feed · Crank · Stop

Nutcrackers

A table-top teaching adaptation shows how paired second-class levers crack a walnut and gain force nearer the hinge.

Load · Squeeze · Move nut

Pour-over coffee set

Crank 15 g of beans through the burrs, tip the grounds into a paper filter, then bloom and pour 250 g of water from the gooseneck kettle and watch coffee drip into the carafe.

Grind beans · Add filter · Add grounds · Pour water

Salad spinner

A hand-cranked ring drives a faster basket through one planet and sun gear in a teaching model whose planet axis is fixed to the lid.

Spin · Stop drive · Empty bowl · Slow view

Sardine can

A staged teaching model winds a sacrificial sealing band onto its key, then lifts the freed lid; replacement supplies a new sealed can.

Fit key · Turn key · Lift lid · Replace specimen

Toaster

Push the lever and watch a bimetal strip warm up, bend and trip the latch, so the spring pops your toast.

Choose shade · Push the lever · Take the toast

Bathroom scales

A teaching model uses removable test masses to show how four platform levers stretch a spring and turn a mechanical dial.

Weigh · Add weight · Move load · Unload

Combination padlock

Dial right, left, right and three notched wheels line up under a fence; only then can the lever slip the latch out of the shackle's notch.

Dial a code · Pull shackle · Reset

Desk fan

Press a speed key and the blades spin up; push the oscillation knob down and a worm, gears and a crank swing the head from side to side, or tilt the head up and down.

Speed · Oscillate on / off · Tilt the head

Desk lamp

Switch it on, turn the dimmer and swing the spring-balanced arm to see how much light lands on the desk.

Switch on / off · Dim it · Bend the arm · Tilt the head

Electric shaver

A teaching adaptation of a rotary shaver shows how sprung cutters shear model hairs beneath slotted guards.

Start · Shave · Lift head

Electric trimmer

A teaching adaptation of a hedge trimmer shows how a motor and opposed eccentric cams slide two serrated blades past one another to clip a sprig.

Start · Feed · Slow

Flashlight

Slide the switch to close the circuit through two D cells, twist the head from spot to flood, and unscrew the tail cap to swap the tired cells for fresh ones.

Slide the switch · Focus the beam · Unscrew the cap · Swap the batteries

Heat pump

Reverse the refrigerant cycle to move heat into or out of a room, then see the coils, valves and fans at work.

Heat · Cool · Off · Outside

Lawn sprinkler

A teaching adaptation shows incoming water driving two worm reductions and a crank that swings an oscillating sprinkler.

Water · Slow view · Stop

Lever lock

A five-lever teaching adaptation shows how a matching key aligns gates so the bolt stump can pass.

Insert · Turn · Wrong key

Manual typewriter

A teaching key-action cutaway uses linked levers to strike inked type against paper and lowers the type-bar assembly for capitals.

Type · Shift and type · Release

Mechanical clock

A teaching adaptation of the page 42 weight-driven pendulum clock couples a falling weight, anchor escapement and twelve-to-one hand reduction.

Raise weight · Run · Slow view

Nail clippers

An enlarged nail clipper cuts an imitation nail strip to reveal its compound lever action.

Fold · Press · Release

A euro cylinder and mortise deadbolt cut open: the right key lifts all five pin stacks to the shear line so the plug can turn and the cam throws or pulls the bolt, while a wrong key leaves pins across the line and the plug only rocks.

Insert key · Turn key · Take key out

Robot vacuum

Press Clean and watch a lidar robot leave its dock, bump into the wall and sweep up the dust, then turn on See-through to see the spinning laser, bumper switches, brushes, fan and battery doing it.

Clean · Dock · Empty bin · Spill kibble

Roller blind

A scale teaching cutaway shows how pulling stores spring energy and the same hinged pawls hold or release a roller blind.

Pull · Let go gently · Tug sharply

Smart thermostat

Control a wired thermostat and reveal its sensor, relays, furnace and air conditioner in an accelerated, enlarged teaching model.

Turn it up · Cool it down · Night schedule · Away mode · Wi-Fi off / on

Smoke alarm

Puff test smoke at a ceiling alarm and watch it drift through the labyrinth into the dark chamber, scatter the infrared beam onto the photodiode and set off the piezo horn.

Press test · Blow smoke · Hush · Replace battery

TV remote

Send coded infrared flashes to a TV and discover which materials let them through.

Press Power · Press Volume up · Show the invisible light · Put in the way

Tap

A teaching adaptation of the screw-operated tap, with an external raised reservoir and catch basin, reveals how the spindle lowers a washer onto its seat.

Open · Close

Toilet flush

Press the handle and watch the flapper lift, the bowl siphon itself empty with a glug, and the float ride back up until it shuts the fill valve.

Drop paper · Flush · Water supply · Float height

Tweezers

A bead-gripping teaching adaptation of paired third-class levers shows how spring arms trade finger force for tip travel.

Squeeze · Lift · Release

Vacuum cleaner

Switch on an upright vacuum, brush dust into its cyclone bin, and empty it while exploring the motor, belt and filters.

Switch on / off · Push over the dust · Empty the bin

Video doorbell

Ring the chime, see a visitor on the phone, and follow motion alerts and two-way audio through a video doorbell.

Press the button · Trigger motion · Talk back · Night mode

Washing machine

Load the laundry, pour in detergent and press Start: the drum fills, tumbles the clothes clean, drains and spins at 1200 rpm, and see-through shows the motor, belt, pump, valves and springs at work.

Load clothes · Add detergent · Start · Unload

Zipper

An enlarged sewn zipper shows how a slider joins nested teeth and how the closed chain resists a staged sideways tug.

Close · Open · Tug

Elevator

Send the car between three floors and watch the drive sheave haul it up on its ropes while the counterweight drops, then overspeed it and see the governor trip the safety gear onto the rails.

Floor 1 · Floor 2 · Floor 3 · Overspeed test

Escalator

Follow a rider upstairs and see how linked steps, roller tracks and a synchronized handrail keep an escalator moving.

Start · Ride up · Reverse direction · Emergency stop · Reset stop

Food truck

Prop the hatch, order a taco and watch the cook sear it on a propane griddle, then look through the walls at the fridges, water tanks, generator and gas line that keep a kitchen on wheels running.

Open the hatch · Order · Grill · Hand out

Hand water pump

Work the handle of a cast-iron village pump and watch a brass plunger, deep in the well, lift water up the rising main one half-litre stroke at a time until it pours into your bucket.

Bucket under spout · Lift handle · Push handle · Keep pumping · Carry bucket away

Photo booth

Close the curtain, drop in four coins and strike four poses as the flash fires, then watch a dye-sub printer feed your strip of photos into the slot.

Pull the curtain · Pay · Spin the seat · Take photos · Take the strip

Toilet booth

Drop a coin and the door slides open on a belt; once you leave, it locks itself, pulls the bowl back to wash it and sprays and dries the floor.

Pay · Step in · Flush · Leave

Traffic light

Press the button and follow the signal down the pole to the roadside cabinet, where relays switch the cars to amber and red and light the bleeping green man.

Press the button · Open / close the cabinet · Signals off / on

Vending machine

Drop in coins and punch a code: the spiral turns once, your snack tips off the end, falls through an infrared beam into the bin, and the change rattles down to the cup.

Insert coin · Type a code · Coin return · Take snack

Arcade cabinet

Drop a quarter, press Start and fly a little ship through falling rocks with the arrow keys and space, then look inside at the CRT, game board, power supply and coin mech that make it run.

Insert coin · Press Start · Start over

Capsule toy machine

Two 100 yen coins lift the lock pawl, one turn of the knob swings the agitator wheel a quarter turn over the gate, and a capsule rolls down the chute to the flap.

Insert coins · Turn the knob · Take capsule · Open it

Claw machine

A token buys 20 seconds on the gantry: steer the claw with the keypad, drop it, and only a prize gripped dead centre survives the trip to the chute and its infrared beam.

Insert coin · Take the prize · Start over

Fishing rod

A bench teaching adaptation of a fishing rod shows how a third-class lever trades force for greater tip travel.

Load · Lift · Compare travel · Reset

Friction-drive toy

An enlarged teaching cutaway shows a hand charging a toy flywheel through the road wheels and right-angle gears, then releasing its stored energy.

Push · Release · Stop

Gumball machine

Drop in a quarter and turn the crank: the coin unlocks the drum, the gears turn the dispensing wheel a quarter turn, and one gumball falls through the floor and rolls down the chute to your hand.

Insert coin · Turn the crank · Take gumball

Wind-up toy

Wind the key of a tin robot, flip its stop lever and watch the mainspring drive a buzzing governor and two crank-driven legs that shuffle it across the table.

Wind the key · Flip the stop lever · Pick it up

Music box

Wind the mainspring and lift the lid: the pinned cylinder plucks a steel comb, an air-brake fly keeps the tempo, and a ballerina pirouettes on a crown-wheel spindle.

Wind the key · Open the lid · Close the lid

Piano action

One grand piano key and its double-escapement action, cut out of the case: the key lifts the wippen, the jack throws the hammer up at the string and slips away, the backcheck catches it, and the damper lifts so the string can ring through the bridge into the soundboard.

Open / close lid · Press / release key · Quick repeat · Sustain pedal

Record player

Lift a record off its sleeve onto the platter, start the belt-drive motor and lower the needle; as it plays the spiral groove pulls the arm inward, and see-through shows the motor, belt, bearing, tonearm pivot, cartridge and preamp.

Record on / off · Start / stop · Drop the needle · Lift the arm

3D printer

Feed filament through a heated nozzle and watch a desktop printer build a chess pawn layer by layer.

Load filament · Heat bed + nozzle · Start print · Remove part

Axe

A teaching adaptation of an axe that turns a downward stroke into sideways forces to split wood.

Swing · Split · Reset

Brace and bit

A scale teaching adaptation shows direct crank leverage, hand-fed cutting and chips escaping along the bit grooves.

Turn · Feed · Withdraw

Chain hoist

A scale teaching adaptation of a differential chain hoist shows how unequal chain take-up lifts a load.

Pull chain · Reverse · Let go

Click pen

A rotating cam alternately latches and releases the spring-loaded ink cartridge with each click.

Click · Hold button · Release button

Combine harvester

A scale teaching adaptation traces finite model wheat through cutting, threshing, separation, tailings return and grain unloading.

Harvest · Separate · Unload · Replace crop

Construction auger

A scale teaching adaptation shows a short auger filling with soil, lifting and emptying between batches that deepen one hole.

Drill · Lift · Empty

Dentist's drill

A miniature air turbine turns a dental bit, staged on a teaching mount over a colored substitute tooth with slowed motion and a lasting cut.

Air · Drill · Stop

Excavator

A scale teaching excavator uses three ram-driven levers to dig a sand tray, swing and empty its bucket.

Dig · Swing · Empty · Reset tray

Hammer

A teaching hand swings a hammer about the wrist to drive a nail, showing the greater travel of the head.

Raise · Strike · Reset

Hand drill

A teaching adaptation of the page 66 hand drill shows bevel gearing, hand-fed cutting and chips travelling along spiral flutes.

Crank · Feed · Withdraw

Lawn mower

A teaching adaptation of the page 39 push mower couples the ground wheel, internal ring and pinion to spiral blades that shear a replaceable grass specimen against a fixed blade.

Push · Stop · Slow view · Replace grass

Mechanical mole

A scale teaching cutaway shows a rotating cutter, horizontal screw spoil transport and tunnel lining, with external feed and ring placement.

Bore · Remove spoil · Line tunnel

Nail extractor

A bench teaching adaptation shows a forked nail extractor magnifying hand effort as its heel rocks against wood.

Grip · Pull · Reset

Nut and bolt

A teaching adaptation of pages 62 and 64 follows preload through a restrained bolt, mating nut and two clearance-hole plates.

Tighten · Loosen · Pull

Pencil sharpener

Turn the crank and two helical cutters orbit the pencil, spinning on a fixed ring gear as they shave a cone point and drop the curls into the drawer.

Insert pencil · Turn the crank · Pull out pencil · Empty drawer

Pliers

Two fixed-pivot levers grip a rod in a teaching fixture, with a hand-position comparison at equal finger effort.

Squeeze · Move hand · Release

Plough

A teaching plough cuts and turns soil in a tray, with a deeper cut increasing an illustrative draft index.

Lower · Pull · Deepen

Potter's wheel

A scale teaching adaptation of a direct-kick potter's wheel stores rotation in its heavy lower disc while external hands shape the clay.

Kick · Shape · Coast

Power drill

An enlarged teaching cutaway shows a corded drill with mechanical two-speed gearing, an external feed hand and bench guide cutting a wood specimen.

Start · Drill · Withdraw · Gear

Scissors

A teaching adaptation of paired levers and wedge-shaped edges that shear paper with more force near the pivot.

Open · Cut · Move paper · Reset

Screw jack

A scale teaching model lifts a miniature car with a direct screw and compares ideal effort with handle travel.

Crank · Reverse · Load

Screwdriver

A bench teaching adaptation compares two fixed handle sizes to show how the same hand force gives different torque and rim travel.

Turn · Reverse · Compare handles

Sewing machine

Thread a sewing machine and follow the moving needle, hook and feed dogs as two threads form a lockstitch seam.

Thread it · Lower the foot · Press the pedal · Stitch length

Spanner

A bench teaching model uses interchangeable open-ended spanners to turn a nut and compare torque at the same hand force.

Turn · Reverse · Compare lengths

Tower crane

A scale teaching model traces separate trolley and hoist ropes and raises its top frame to insert a complete lattice mast section.

Hoist · Lower · Trolley · Climb · Reset

Vice

A teaching adaptation of the page 64 screw vice grips wood with one guided moving plate and an illustrative force overlay.

Close · Tighten · Open

Wheelbarrow

A miniature teaching wheelbarrow shows how a load between wheel and handles reduces the effort needed to lift it.

Load · Lift · Roll

Wood screw

An enlarged teaching model turns one wood screw into a specimen and reveals how its integral thread engages the wood.

Drive · Reverse · Test pull · Fresh specimen

Block and tackle

A bench adaptation of the book’s ten-strand tackle trades a long rope pull for a smaller ideal lifting effort.

Pull · Add load · Lower

Cams and cranks

A principle teaching adaptation compares spring-return cam contact with pinned crank geometry and reverse conversion.

Rotate · Swap cam · Drive slider

Flywheel

A principle teaching adaptation of Rotating Wheels compares stored energy with the same masses mounted near the hub or rim.

Spin · Load · Compare mass · Stop

Gears and belts

A principle teaching rig compares gear and flat-belt ratios, with a crossed-belt teaching adaptation beyond the book diagram.

Drive · Compare ratios · Cross belt

Greek mill

A bench teaching adaptation of the pictured Greek mill waterwheel principle shows water turning a horizontal paddle rotor and its direct vertical axle.

Open water · Reduce flow · Slow view · Reset

Hydroelectric turbine

A teaching adaptation of the page 33 Francis turbine links guided water flow to a runner, generator and external indicator lamp.

Open gate · Reduce flow · Close gate

Levers

An adjustable teaching adaptation compares the force and travel of three lever classes.

Lift · Lower · Move fulcrum · Change class

Pulleys

A teaching adaptation compares a fixed pulley with two strands supporting a movable load, trading rope travel for ideal effort.

Pull · Compare routes · Lower

Rack and pinion

A bench teaching adaptation demonstrates how a pinion moves a rack and how pushing the rack turns the pinion.

Turn · Reverse · Push rack

Screws

A screw principle teaching rig compares travel and ideal force at equal torque using complete interchangeable screw and nut pairs.

Turn · Reverse · Compare pitch

Shadoof

A scale teaching adaptation of the shadoof lever, with a human hand, counterweight assistance and an external water tray reset.

Lower · Fill · Raise · Empty bucket · Refill tray

The inclined plane

A teaching adaptation shows how a ramp trades a longer pull for less force while ideal work equals the load's energy gain.

Raise · Ramp · Steepen

The wheel and axle

A teaching winch adaptation compares wheel radii, shared turns and the trade between effort and travel.

Turn wheel · Drive axle · Compare radii · Lower load

Waterwheel

A bench teaching adaptation of an overshot waterwheel uses finite gravity-fed water to turn a shaft and lift a test mass.

Open flow · Apply load · Reduce flow · Refill

Wedge

Push a sloping wedge under a model door to lift it, then add weight to see the forces increase.

Insert · Pull · Load

Windmill

A scale teaching adaptation combines a turning post mill and geared grindstones, with an external bench blower and grain feed aid.

Wind · Face wind · Feed grain

A4988 stepper driver

Turn the trimpot to set the A4988's current limit, move the MS jumpers between full step and 1/16 microstep, and send 200 STEP pulses to watch a NEMA17 turn a full revolution or one dial tick.

Set current limit · Step mode · Send 200 steps · Reverse direction

Arduino Uno

Plug an Arduino Uno into USB, upload Blink through its bootloader and watch pin 13 flash the onboard L LED and a red LED wired on the breadboard.

Plug in USB · Upload Blink · Wire LED to pin 13 · Press reset

Bluetooth headphones

Charge a flat pair of over-ear headphones, switch them on, pair a phone over Bluetooth and play a song, then look inside at the battery, radio chip, antenna, amplifier and the drivers that move the air.

Charge · Power on / off · Pair the phone · Play / pause

DSLR camera

Photograph an apple with a single-lens reflex: light bounces off the mirror up through the pentaprism to your eye, then the mirror flips up and two shutter curtains sweep a slit of light across the sensor.

Look through the viewfinder · Half-press to focus · Press the shutter · Live view

ESP32-S3 DevKit

Plug an ESP32-S3 DevKit into its UART port, flash a sketch through the USB-UART bridge, join Wi-Fi and set its RGB LED from a phone, then watch everything but the RTC timer power down in deep sleep.

Plug into UART · Upload sketch · Join Wi-Fi · Open web page · Deep sleep

HC-SR04 ultrasonic sensor

An HC-SR04 on a breadboard, read by an Arduino Nano, sends a 40 kHz ping at a wooden block and times the echo to read the distance.

Power on / off · Move block to

Hard disk drive

Power on a 3.5-inch hard drive to spin its platters up to 7200 rpm, then pick a file and watch the voice coil swing the arm across the tracks while the heads fly on air and the bits stream out to the SATA port.

Power on · Read a file · Park heads · Power off

L298N motor driver

Set the direction and PWM duty, enable a DC motor, then reverse or brake it while seeing the L298N H-bridge at work.

Set direction · Enable ENA · PWM duty · Reverse · Brake

LM2596 buck converter

Set a robot's supply voltage and overload a buck converter in an illustrative battery-and-motor teaching model.

Connect / disconnect battery · Set 5.0 V · Set 3.3 V · Try 12 V · Stall / release motor

Laptop

Open the lid and press power to boot it, plug in the charger to fill the battery, then load the CPU and watch the heat pipe carry heat to a blower fan that spins up and pushes hot air out the back.

Open / close lid · Press power · Plug / unplug charger · Heavy load

MPU-6050 IMU

A GY-521 breakout on a tilting cradle, wired to an Arduino Nano over I2C: tilt it and watch the integrated gyro angle drift away while the accelerometer angle jitters, until a complementary filter blends the two into one steady reading.

USB power · Tilt · Tap the desk · Complementary filter

Mechanical keyboard key

Press a giant mechanical key and watch the stem slide down its spring until the leg lets the copper leaf snap onto the gold contact 2 mm in, sending a keystroke and lighting the LED beneath.

Press the key · Hold it down · Type fast · Backlight

Optical mouse

A red LED lights the desk at a low angle, a tiny camera takes thousands of pictures a second, and a chip works out how far each picture has shifted to move the cursor.

Slide the mouse · Compare pictures · Click · Lift the mouse

PCA9685 servo board

Connect an I2C bus and send a 50 Hz servo wave through sixteen PWM outputs, with four attached servos and nominal pulse-to-angle calibration.

Connect I2C wires · Center servo at 90 · Run arm wave

QTR-8RC line sensor

Eight infrared pairs time how fast their capacitors drain over white mat and black tape, and an Arduino turns those times into a line position that steers the robot round the loop.

Power on / off · Line under · Upload P controller

Raspberry Pi 5

Slide in the microSD card and plug in power to watch a Raspberry Pi 5 boot step by step, from the PMIC's power rails through the boot EEPROM, RAM and SD card to Linux waking the RP1 I/O chip.

Insert microSD · Plug in power · Plug in HDMI · Power button

Retro Pentium PC

Power a beige Pentium tower, toggle its preset Turbo display, load two kinds of media and uncover the boards, cooling and drive cables inside.

Power · Turbo · Insert floppy · Insert CD · Side panel

Smart speaker

A smart speaker hears its wake word on its own chip, sends your question as Wi-Fi packets through the router to a server, and plays the answer back through its tweeter and down-firing woofer, while the mute button cuts power to the microphones.

Say the wake word · Ask a question · Play / stop music · Press mute

TB6612FNG motor driver

Snap on the 9V battery and drive two gear motors through the TB6612FNG's H-bridges: forward, reverse, short brake or coast, at four PWM speeds, while see-through lights up the MOSFETs that conduct.

Power on / off · Forward · Reverse · Stop · PWM speed

Wi-Fi router

Cable it to the modem, boot it, join a phone, then follow one packet from the phone's radio through antenna, radio chip, SoC, switch and WAN port out to the internet.

Plug in WAN cable · Power on / off · Connect phone · Send a packet

Bicycle brake

A bench teaching model shows how three levers pull two brake blocks against a spinning bicycle rim.

Spin · Squeeze · Release

Bicycle derailleur gears

Pedal and shift an eight-speed bicycle to follow the chain, derailleur and freehub as the rear wheel changes speed.

Pedal · Shift up · Shift down · Stop pedalling

Bicycle distance counter

An enlarged teaching adaptation turns wheel revolutions into cumulative distance and exposes the decimal carry between numbered drums.

Roll · Run farther · Slow view

Car window winder

A 1998 manual-input teaching adaptation uses a hand crank, cog and quadrant to lift guided glass, with a teaching hand supplying the holding force.

Wind up · Wind down · Slow view

Differential

A bench teaching adaptation shows how an open differential shares drive while external wheel conditions change the two output speeds.

Drive · Turn corner · Hold wheel · Stop

Fork-lift truck

A fixed-fork teaching adaptation shows how rear ballast opposes a front load and prevents forward toppling.

Add load · Compare counterweight · Show moments · Reset specimens

Four-stroke engine

A single-cylinder petrol engine on a test stand that you start with a key and throttle up, with a see-through view of the piston, crank, cam, valves and spark going through intake, compression, power and exhaust.

Turn the key · Throttle · Turn by hand

Gearbox

A hand-driven teaching adaptation of the book gearbox selects constant-mesh dog ratios, direct top gear and a stopped-input reverse idler.

Drive · Stop input · Shift · Reverse

Hydraulic platform

A scale teaching adaptation of the firefighter platform shows paired lower rams pushing and the upper ram pulling to lift a cage.

Stabilize · Raise · Lower

Jet engine

Start a turbofan on its thrust stand, open the throttle and watch the fan and compressors spool up, the fuel light and the load cell read the thrust.

Start · Throttle · Shut down

Mobile crane

A scale teaching adaptation of a mobile crane shows its outriggers, boom-raising ram, telescopic sections and reeved lifting rope.

Stabilize · Extend · Hoist · Lower

Seat belt

An enlarged teaching cutaway shows how a belt-sensitive reel locks on a sharp tug and unlocks when externally slackened.

Slow pull · Sharp tug · Slacken

Speedometer

A bench adaptation separates magnetic speed indication from an eccentric-and-ratchet distance counter.

Drive · Accelerate · Roll distance · Stop

Starter motor

An enlarged teaching rig shows how inertia and relative rotation screw a historical starter pinion into mesh, transfer cranking torque, and withdraw it under an explicit engine input.

Start · Crank · Engine running · Reset teaching rig

Steam locomotive

A red tank engine on its track: stoke the fire, raise steam, open the regulator and watch the pistons, rods and driving wheels push it along.

Shovel coal · Build pressure · Open regulator · Pull the whistle

Steering wheel

An unassisted steering model combines the book diagrams with exchangeable teaching rims to compare hand force at the same column torque and prescribed road resistance.

Turn left · Turn right · Compare wheel sizes

Trolley

A tabletop teaching model of a two-wheel hand trolley lifts a load by pivoting around its axle.

Tip · Roll · Add crate

Windscreen wipers

A bench teaching adaptation shows a crank-driven rack rocking two wipers across wet glass.

Wet · Wipe · Stop

Wright Flyer

Start the Wright Flyer's chain-driven propellers, warp its wings and launch the 120 ft first flight.

Start engine · Warp wings · Launch flight · Reset

Balance

A bench teaching adaptation of the book’s equal-arm balance compares an unknown object with known masses in suspended pans.

Load · Add weight · Compare

Beam scale

A bench teaching adaptation of the book's unequal-arm scale balances a suspended pan by sliding a counterweight.

Load · Slide · Read

Enigma machine

Press a key on a three-rotor Enigma I and follow the current through the plugboard, rotors and reflector to the lamp that lights, while the rotors step one place each time.

Set the rotors · Plug a cable · Press a key · Type ENIGMA

How an LLM works

A GPT-2-sized language machine you can step through: it cuts a sentence into numbered tokens, turns each into a 768-number vector, runs them through 12 attention layers, spins a weighted wheel to pick the next word, and feeds that word back in.

Tokenize · Embed · Run layers · Sample next word · Repeat

Mechanical watch

Wind an automatic watch and watch its mainspring, gears and ticking escapement keep the hands moving.

Wind the crown · Set the hands · Let it run · Swing the wrist

Micrometer

A teaching cutaway uses an enlarged 0.5 mm screw lead and 50 thimble divisions to measure a rigid rod, with a simplified slipping ratchet coupling.

Insert · Turn · Read

Microscope

A school light microscope: switch on the LED, lay an onion-skin slide on the stage, rack the stage up until the cells snap into focus, and click the nosepiece between 4×, 10× and 40× to watch the field of view shrink.

Light on / off · Place slide · Turn focus knob · Objective · Explode

Platform scales

A bench teaching model passes crate weight through three connected levers to a bar balanced by a sliding poise.

Load · Slide · Add load · Reset

Wind turbine

Raise the wind and the blades bite, pitch to hold 2 MW and light the house below; swing the wind and the yaw motors turn the nacelle to face it; a storm feathers the blades and clamps the brake.

Wind · Wind from · Brake / release

A simple circuit

A 6 V battery pack, a knife switch, two bulbs, a resistor dial and two meters on a breadboard show how voltage, current and resistance trade off by Ohm's law in series and parallel circuits.

Close switch · Add bulb in series · Rewire in parallel · Turn dial

Faraday's induction

Move a bar magnet through a copper coil to reverse the galvanometer needle, then compare faster motion and more turns.

Push magnet in · Pull magnet out · Push faster · Add turns

Galileo's drop

A feather and a steel ball fall down a glass tube: in air the feather drifts behind, but once the hand pump empties the tube they land together, and a slow-motion replay against a metre rule shows the distance growing as 1, 4, 9, 16.

Drop · Pump out the air · Let the air in · Slow-motion replay

Gas laws

Load, heat and fill a glass piston chamber to explore an ideal gas; PV/T stays constant for fixed gas amount and rises when the pump adds air.

Push piston down · Release load · Light / extinguish burner · Pump in gas · Reset

Maxwell's electromagnetic wave

Switch on an oscillator and watch crossed electric and magnetic fields ripple from one antenna to another, light its lamp, and vanish at a node of the standing wave.

Transmit · Frequency · Move receiver

Newton's three laws

A spring plunger launches a glider down an air track so you can watch one push give a light glider more acceleration than a loaded one, two gliders trade equal and opposite forces, and friction take over when the air is switched off.

Push · Add a mass · Collide · Friction on / off

Prism and lenses

Turn a glass prism to split white light, then focus a candle through two different lenses on an optical bench.

Choose optic · Rotate prism · Slide candle · Focus screen · Trace rays

Rutherford's gold foil

Fire alpha particles at gold foil and count their flashes in a teaching apparatus with enlarged atoms and oversampled rare scattering.

Fire alphas · Swing microscope · Plum-pudding prediction · Reset counts

Special relativity

A toy train carries an ideal light clock past a platform clock in a slowed teaching model of time dilation and length contraction.

Train speed · Start / pause clocks · Length contraction · Reset

Standing waves

A vibrator shakes a string held taut over a pulley by hanging weights; tune it to the first, second or third harmonic for one, two or three loops, add weight to speed the waves up, and freeze the motion with a strobe.

Start / stop · Frequency · Add weight · Strobe

The Cavendish experiment

Weigh the pull between lead balls: swing the big ones beside a beam hung on a hair-thin tungsten wire, watch a light spot creep along a scale over minutes, and work out G from where it settles and how slowly it swings.

Release / lock beam · Swing the big balls · Time-lapse

The atom

Fire a photon at a Bohr atom, watch an electron jump up a shell and fall back, and see its exact spectral line light up on the spectroscope.

Element · Fire a photon · Shine white light

The double-slit experiment

Single photons from a dimmed laser land one by one on a photographic strip and still build up interference fringes, until you cover a slit or watch which slit they go through.

Fire photons · Full beam · Cover one slit · Detector at slit

The pendulum

A school pendulum on a wooden stand with a light gate and timer: the period follows the string's length, ignores the bob's mass and grows only slightly with a wider swing.

Start / stop · String length · Swap the bob · Swing angle

The photoelectric effect

A sodium photocathode experiment with ideal narrow-band filters and enlarged, slowed photon and electron overlays reveals threshold energy and stopping voltage.

Lamp on / off · Light colour · Brightness · Retarding voltage · Reset experiment

A battery (Daniell cell)

A bench Daniell cell where zinc gives up electrons that run through a switch, a bulb and a voltmeter to plate copper, while a salt bridge's ions keep both beakers balanced.

Switch on / off · Fast time · Swap metal · Lift / replace bridge · Fresh strips

A chemical reaction

Spark a sealed jar of methane and oxygen and watch every C-H and O=O bond break and the same atoms snap into carbon dioxide and water, giving out 802 kJ/mol of heat.

Spark · Slow motion · Reset gas · Catalyst

Acid-base titration

Titrate 25 mL of 0.1 M hydrochloric acid with sodium hydroxide from a burette: the pH creeps, then leaps at 25 mL as phenolphthalein flips to pink, while see-through shows H+ and OH- pairing into water and the S-shaped curve drawing itself.

Stirrer on / off · Open / close tap · Add a drop · Reset

Distillation

Heat salt water or wine and follow vapour through a water-cooled condenser into a receiving flask.

Heater on / off · Salt water / wine · Cooling water on / off

Electrolysis of water

Split acidified water into twice as much hydrogen as oxygen, sample each gas with a splint, and reverse the electrodes in an accelerated Hofmann voltameter.

Switch on / off · Test hydrogen · Test oxygen · Swap polarity · Vent both tubes

Molecules and bonds

Turn a bench-top molecule kit to compare four molecular shapes, bond angles and polarity, with schematic electron clouds and slowed vibration.

Molecule · Vibrate · Rotate · Polarity arrows

States of matter

Melt ice, boil water and cool it back down while pressure shifts the boiling point and molecules reveal each change of state.

Heat on / off · Cool on / off · Press / release lid · Reset

DNA replication

A model-kit double helix on a stand: a helicase ring unzips it, two polymerases copy each strand with matching A, T, G and C blocks from a tray, and you end up with two identical helices, each one old strand and one new.

Unzip with helicase · Run polymerase · Rewind · New sequence

Photosynthesis

Explore light-driven photosynthesis in a bell jar with an enlarged leaf cutaway and illustrative gas and sugar readouts.

Lamp on / off · Brightness · Lamp colour

The heart

An enlarged teaching heart traces blood through four chambers, the lungs and aorta, with a slowed beat, pacemaker signals and a valve backflow demonstration.

Beat once slowly · Follow blood · Exercise / rest · Hold / release valves

The living cell

An enlarged animal-cell teaching model traces a secreted protein and shows four representative chromosomes through mitosis and cell division.

Organelle labels · Make a protein · Run mitosis · Reset model

The neuron

Poke a neuron's dendrite and watch the spike cross threshold, leap from node to node along its myelinated axon in a wave of sodium in and potassium out, then release glutamate onto a second neuron, unless a weak poke fizzles or CNQX blocks the synapse.

Poke strong · Poke weak · Add blocker · Wash out

A reflecting telescope

A Newtonian reflector on a tripod aimed at a moon on the wall: rack the focuser until the moon sharpens in the eyepiece, swap eyepieces for more magnification, and lift the hatch to see the curved primary and flat secondary fold the light into your eye.

Dust cap off / on · Turn the focuser · Swap eyepiece · Open the tube