Original subtitles

--Captions by VITAC-- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

Narrator: TODAY ON "HOW IT'S MADE,"

BELTS...

...3-D METAL PRINTERS...

...DETECTABLE WARNING PANELS...

...AND MODEL STIRLING ENGINES.

BELTS HAVE BEEN WORN WITH DIFFERENT TYPES OF GARMENTS

SINCE THE INVENTION OF CLOTHES.

MADE TO CINCH YOUR WAISTLINE, THIS ACCESSORY IS WORN WITH

PANTS, SHIRTS, ROBES, OR DRESSES,

MAKING A FASHIONABLE ADDITION TO ANY OUTFIT.

DURABLE AND FLEXIBLE, LEATHER IS THE CLASSIC MATERIAL

USED FOR BELT MAKING.

THIS PRODUCTION FACILITY MANUFACTURES STYLISH,

HIGH QUALITY BELTS AT TOP SPEED.

A DESIGNER CREATES A BELT PATTERN ON HER COMPUTER

AND SENDS THE DESIGN ELECTRONICALLY

TO THE IN-HOUSE LASER ETCHING MACHINE.

A CRAFTSMAN PLACES A COWHIDE ON A LARGE TABLE.

HE EXAMINES THE HIDE FOR ANY FLAWS

AND CAREFULLY MARKS EACH ONE.

THE COWHIDES ARE MADE FROM MEAT INDUSTRY BYPRODUCTS,

AND MOST ARE SOURCED FROM ITALY.

A DEVICE SCANS THE SHAPE OF THE HIDE

AND THE CRAFTSMAN DIGITALLY MARKS THE LOCATION OF THE FLAWS.

A SPECIALIZED CUTTING MACHINE USES THE MARKED INFORMATION

TO CREATE AN EFFICIENT SERIES OF CUTS.

THIS PROCESS RESULTS IN A HIGH QUALITY PRODUCT

WITH MINIMAL WASTE.

ANOTHER TECHNICIAN SORTS THE VARIOUS BELT LENGTHS

INTO CONTAINERS,

PREPARING THEM FOR THE NEXT STEP.

THE CUTTING MACHINE IS CAPABLE OF SLICING

UP TO 2,400 BELTS PER DAY.

THE CUTTING MACHINE CREATES STRAIGHT, SHARP-EDGED STRIPS.

THE TECHNICIAN FEEDS THE BELTS INTO A MACHINE

THAT BEVELS THE EDGES AT THE RATE OF 6,000 PER DAY.

AT THE NEXT STATION, A SERIES OF SMALL SUCTION DEVICES

QUICKLY LIFT AND PLACE EACH BELT ON A CONVEYOR SYSTEM.

A STAMPING MACHINE ACCURATELY CUTS THE SHAPE

OF THE BELT TIP AND THE HOLES FOR THE PRONG.

THE CRAFTSMAN STACKS A GROUP OF BELTS AND PACKS THEM

TIGHTLY TOGETHER, THEN HE DYES THE EDGES WITH INK

AND SANDS THEM DOWN.

THESE STEPS COMPLEMENT THE EDGE DYEING MACHINE PROCESS,

WHICH CAN ADD COLOR TO THE BELT EDGES.

THEN THE BELTS ARE TRANSFERRED TO A DRYING MACHINE.

THE EDGES MUST BE COMPLETELY DRY

BEFORE THEY MOVE TO THE NEXT STEP.

POWERED BY WORLD WAR II JEEP ENGINES,

A ROTATING WOODEN DRUM TUMBLES THE BELTS,

WHILE SIMULTANEOUSLY BURNISHING THE LEATHER.

THIS TYPE OF MACHINERY COMES FROM

ITALY'S FAMOUS LEATHER WORKING REGION.

THIS IMPORTED MACHINE, FROM MILAN,

RAPIDLY PUNCHES OUT THE PATTERN OF PERFORATIONS,

WHICH MAKE UP THE BELT'S SIGNATURE DESIGN ELEMENTS.

SINCE THE MACHINE'S DIE IS LESS THAN 20 INCHES LONG,

THE COMPLEX PATTERN ALONG THE BELT CAN'T BE STAMPED AT ONCE.

INSTEAD, THE MACHINE PUNCHES OUT A SECTION AT A TIME

RESULTING IN A PRODUCTION RATE OF 1,400 BELTS PER DAY.

A LASER ETCHING MACHINE BURNS A SECOND PATTERN

INTO THE LEATHER SURFACE.

THIS PATTERN WAS CREATED BY THE DESIGNER

PRIOR TO PRODUCTION.

AT THE NEXT STATION, A CRAFTSWOMAN FILLS THE HOLES

OF A SPECIALLY CRAFTED TWO-PART METAL DIE

WITH NAIL HEADS.

THE NAIL HEADS ARE MADE OF ZINC WITH A BRASS FINISH.

USING A PRESS, AN OPERATOR PLACES THE DIE

IN A WAITING REPOSITORY.

SHE REMOVES THE TOP HALF,

ENSURING THAT ALL OF THE HOLES ARE FILLED WITH NAIL HEADS.

THEN SHE TURNS THE BELT AROUND AND PLACES IT OVER THE DIE

BEFORE SLIDING THE BELT INSIDE THE PRESS.

THE PRESS AFFIXES THE NAIL HEADS TO THE LEATHER.

BEFORE ATTACHING THE BUCKLE,

THE BELTS GO THROUGH A PROCESS CALLED SKIVING.

THIS DEVICE SHAVES OFF A SECTION OF THE LEATHER

SO THAT WHEN IT'S FOLDED OVER, IT WON'T BE TOO THICK.

A LOOP IS ATTACHED ON TO THE END OF THE BELT,

FOLLOWED BY A BUCKLE.

THE CRAFTSWOMAN USES THE LOOP TO TEMPORARILY HOLD

THE BUCKLE AND TAG IN PLACE.

THE TAG CONTAINS THE BELT'S SIZE, PRICE,

AND BRAND INFORMATION.

ANOTHER CRAFTSWOMAN SEWS THE BELT BUCKLE AND TAG IN PLACE,

USING 69 WEIGHT THREAD AND A BAR TACKING STITCH.

THIS FACILITY MANUFACTURES NEARLY 10,000 BELTS PER DAY.

THIS INTRICATE LEATHER FASHION ACCESSORY

MIGHT BE A CINCH TO WEAR, BUT NOT TO MAKE.

Narrator: 3-D PRINTERS GENERATE METAL PARTS FOR SPACECRAFT,

CARS, AND MEDICAL DEVICES, TO NAME A FEW.

3-D PRINTING TECHNOLOGY ALLOWS FOR THE PRODUCTION

OF COMPLEX DESIGN STRUCTURES WHICH CAN'T BE ACHIEVED

USING TRADITIONAL MANUFACTURING METHODS.

THE 3-D METAL PRINTER COULD TRULY BREAK THE MOLD.

THANKS TO ADVANCEMENTS IN TECHNOLOGY,

IT'S NOW POSSIBLE TO PRINT METAL PARTS.

THIS 3-D PRINTER MELTS AND LAYERS METAL POWDER

AND A PART MATERIALIZES.

THIS PART WILL BECOME A ROCKET NOZZLE HEAT EXCHANGER.

AT THE CORE OF THE 3-D METAL PRINTER IS THE DEPOSITION HEAD,

WHICH FEEDS AND MELTS THE THE METAL POWDER.

SO FAR THE DESIGNING PROCESS HAS TAKEN HUNDREDS OF HOURS.

TOOLS GUIDED BY THE DESIGN SOFTWARE TRANSFORM

A BRASS CYLINDER INTO THE NOZZLE CONE.

THE PROFILE OF THE NOZZLE CONE CAN VARY SLIGHTLY,

DEPENDING ON THE PARTS THE 3-D METAL PRINTER

WILL BE USED TO PRODUCE.

NEXT THE POWDER INLET COMPONENT IS ADDED.

METAL POWDER WILL FLOW THROUGH THIS PART

TO A MIXING CHAMBER AND, EVENTUALLY, THE NOZZLE CONE.

COMPUTERIZED TOOLS CUT ANGLED CHANNELS,

DELIVERING DIFFERENT METAL POWDERS

TO THE MIXING CHAMBER WITH AN ANGULAR VELOCITY,

CREATING A VORTEX TO HELP BLEND THE POWDERS.

THE PART HAS BEEN NICKEL PLATED AND FASTENERS ARE INSTALLED.

THE TECHNICIAN ALIGNS THE LASER DELIVERY CHANNEL

TO THE POWDER INLET PART, AND SCREWS THEM TOGETHER.

THE LASER WILL MELT THE METAL POWDER

AS IT FLOWS THROUGH THE INLET.

SHE INSTALLS LATCHES ON THE RIM OF THE POWDER INLET PART

AND TIGHTLY TORQUES THE SCREWS THAT HOLD THEM IN PLACE.

USING THE LATCHES, SHE LOCKS THE MIXING CHAMBER TO THE INLET.

THE LATCHES WILL HELP MAKE FURTHER ASSEMBLY AND DISASSEMBLY

OF THE 3-D METAL PRINTER HEAD A SNAP.

NEXT, A LASER NOZZLE IS SCREWED ONTO THE MIXING CHAMBER.

THEN, THE TECHNICIAN PLACES THE MAIN NOZZLE CONE

OVER THE LASER NOZZLE

AND CONNECTS THE THREADED RIM TO THE MIXING CHAMBER.

THE DEPOSITION HEAD IS NOW COMPLETE.

NEXT, ANOTHER THE TECHNICIAN MOUNTS THE LASER SYSTEM

TO A VERTICAL AXIS IN THE PRINTER HOUSING.

HE RUNS COOLANT LINES FOR THE LASER

AND ATTACHES THE DEPOSITION HEAD,

SCREWING IT IN PLACE WITH A THREADED BRASS COLLAR.

THE LASER SYSTEM AND DEPOSITION HEAD ARE NOW INTEGRATED.

FIRST, THE POWDER FEEDER IS ASSEMBLED WITH

A SUBSTANTIAL BASE TO ACCOMMODATE A FEED DRIVE SYSTEM.

THE TECHNICIAN INSTALLS THE FEEDER SHAFT

IN THE UPPER HALF OF THE BASE.

THEN, HE SCREWS A DISC TO THE SHAFT.

THE DISC WILL SPIN TO MOVE THE METAL POWDER

INTO THE PRINTER HEAD SYSTEM.

HE SLIDES A SPRING ON TO THE SHAFT

WHICH HELPS MAINTAIN ITS POSITION.

THEN, HE CONNECTS THE UPPER HALF OF THE BASE TO THE BOTTOM HALF.

HE INSTALLS AN INLET FOR CARRIER GAS

THAT WILL BE USED TO MOVE THE POWDER THROUGH TUBING

TO THE PRINTER HEAD.

HE ASSEMBLES WINDOWS TO A LID.

THEY'LL PROVIDE A VIEW OF THE METAL POWDER

SWIRLING IN THE FEEDER DISC,

SO THAT ANY PROBLEMS CAN BE IDENTIFIED.

HE PRESS FITS THE HOPPER CONE INTO A RIDGED HOLE IN THE LID.

HE ATTACHES THE HOPPER TO THE CONE.

HE CLAMPS THE FEEDER MOTOR TO THE HOPPER USING LONG SCREWS,

WHICH SEALS THE HOPPER AND TURNS IT INTO A PRESSURE VESSEL.

THE RESULTING PRESSURE WILL HELP FORCE THE POWDER

THROUGH TUBING TO THE DEPOSITION HEAD.

HE INSTALLS THE LID AND HOPPER ASSEMBLY ON THE BASE.

ONCE ASSEMBLY IS COMPLETE,

THE TECHNICIAN SETS THE BASE ON A MOUNT,

SLIDING PROTRUDING PINS INTO CORRESPONDING HOLES IN THE LID.

THIS COMPLETES THE POWDER FEEDER.

THE POWDER FEEDER NOW READY TO SUPPLY THE RAW MATERIAL

FOR 3-D PRINTING.

AN OPERATOR CONNECTS IT TO THE PRINTER

AND POURS METAL POWDER INTO THE HOPPER.

THE SYSTEM DELIVERS THE POWDER TO THE PRINTER HEAD.

THE DISPENSING AND MELTING OF THE METAL POWDER,

AS WELL AS THE LAYERING,

ARE ALL CONTROLLED BY A COMPUTER GENERATED PROGRAM.

THIS 3-D PRINTER CAN MANUFACTURE A PART IN A FEW HOURS,

SO YOU CAN SIT BACK AND WATCH IT MATERIALIZE.

Narrator: DETECTABLE WARNING PANELS ARE CAUTIONARY SIGNALS

FOR THE VISUALLY IMPAIRED.

THEIR SPECIFIC PATTERN OF DOMED BUMPS

ARE DETECTABLE BY TOUCH OR WITH WALKING AID EQUIPMENT.

THEY ALSO SERVE AS WARNING SYSTEMS

AT INTERSECTIONS OR ON TRANSIT PLATFORMS,

ALERTING ALL PEOPLE TO PROCEED WITH CAUTION.

FOR THE VISUALLY IMPAIRED,

THESE LITTLE BUMPS ON THE ROAD AREN'T A PROBLEM.

THEY'RE A SOLUTION.

EMBEDDED IN SURFACES AT INTERSECTIONS,

DETECTABLE WARNING PANELS HELP PEOPLE

FIND THEIR WAY THROUGH TOUCH.

MAKING A FIBERGLASS POLYMER VERSION OF THE PANELS

STARTS WITH A CAREFULLY CALCULATED FORMULA.

TECHNICIANS ADD PIGMENT TO RESIN PASTE

KEEPING A CLOSE EYE ON THE SCALE

TO CONFIRM THE AMOUNTS ARE CORRECT.

NEXT, A CHEMICAL THICKENER IS ADDED,

THIS INGREDIENT WILL INCREASE THE VISCOSITY

TO A SYRUPY CONSISTENCY.

THEN THE INGREDIENTS ARE BLENDED TOGETHER.

THE AGITATION FROM THE BLENDER CAUSES THE MIXTURE TO HEAT,

STARTING A CHEMICAL REACTION

WHICH WILL EVENTUALLY CAUSE SOLIDIFICATION.

AS THE MIXTURE THICKENS, IT TURNS A VIVID COLOR

THAT PEOPLE WITH COMPROMISED VISION CAN STILL PERCEIVE.

THE TECHNICIAN GAUGES THE TEMPERATURE

TO CONFIRM THAT THE CHEMICAL REACTION ISN'T TOO ADVANCED.

THEN, THE MIX IS SET ASIDE,

SO TECHNICIANS CAN PREPARE OTHER INGREDIENTS.

RAMS PUNCH THE BAG OF MINERAL FILLERS TO BREAK UP ANY CLUMPS

AS THEY FLOW INTO A HOPPER.

STEARIC ACID IS ADDED TO CUT THE THICKENING.

A COMPUTER DISPENSES THE MINERAL FILLER AND RESIN

INTO A LARGE MIXING TANK.

AN OPERATOR ADDS AN INHIBITOR

TO DELAY THE CHEMICAL REACTION AS THE MIXING BLADE

BLENDS THE INGREDIENTS INTO A PASTE.

ZINC STEARATE IS ADDED TO THE MIXTURE,

WHICH WILL ALLOW THE COMPLETED PANEL TO RELEASE FROM THE MOLD.

GLASS BUNDLES, KNOWN AS ROVINGS, THEN UNWIND.

A BLADE CHOPS THEM INTO TOOTHPICK SIZED PIECES.

THE PIGMENT MIXTURE,

WHICH HAS BEEN BLENDED INTO THE RESIN PASTE,

FLOWS ON TO A PLASTIC LINER.

SHARDS OF GLASS FALL DOWN ON TO THE YELLOW RESIN MIXTURE.

AS THE MACHINE PULLS THE MIXTURE FORWARD,

THE LINER TAKES THE GLASS-ENCRUSTED RESIN

TO THE NEXT STAGE.

MORE RESIN AND A TOP PLASTIC LINER,

CREATE AN ENCASING WITH THE GLASS IN THE MIDDLE.

ROLLERS SQUEEZE THE ENCASING TOGETHER,

FORCING THE RESIN TO FLOW AROUND THE GLASS SHARDS.

THE MATERIAL IS COMPACTED TO THE DESIRED THICKNESS.

THEN, THE GLASS AND RESIN MATERIAL

CURES FOR 24 HOURS.

THIS ALLOWS THE MATERIALS TO THICKEN,

SO IT CAN BE CUT INTO PANELS.

A CIRCULAR CUTTING WHEEL MOVES ON A CARRIAGE ACROSS THE MAT

SLICING IT TO LENGTH.

THE MATS ARE RETRIEVED FROM THE MACHINE AND STACKED.

THE PLASTIC LINERS ON BOTH SIDES ARE STILL INTACT.

NEXT, THE MATERIAL IS WEIGHED TO CONFIRM THE SPECIFIED AMOUNT.

IF MORE IS NEEDED,

A TECHNICIAN WILL ADJUST ACCORDINGLY.

HE THEN PEELS OFF THE LINERS.

THE GLASS AND RESIN MATERIAL ARE TRANSFERRED TO A HEATED MOLD.

THE MOLD APPLIES 500 TONS OF HOT PRESSURE.

THE MATERIAL LIQUEFIES AND FLOWS INTO THE CREVASSES OF THE MOLD,

FORCING AIR OUT.

AS THE BUMPY PANELS TAKE SHAPE,

A CHEMICAL REACTION CAUSES THE MATERIAL TO SOLIDIFY.

A WORKER TRIMS THE FRESHLY MOLDED PANELS

TO GIVE THEM A CLEANER LINE.

AND SANDS THE EDGES SMOOTH.

HE CLAMPS THE PANEL TO A FIXTURE AT BOTH ENDS.

THE CLAMPS KEEP THE PANEL IN POSITION

AND PREVENT IT FROM BENDING.

AS MOUNTING HOLES ARE DRILLED INTO THE PANEL.

THE TECHNICIAN USES AN AIR GUN TO

BLOW OFF DRILLING RESIDUE AND DUST.

THIS DETECTABLE WARNING PANEL IS NOW READY FOR INSTALLATION.

TWO CRAFTSMEN PIPE ADHESIVE INTO CHANNELS

AT THE BACK OF THE PANEL.

THE PANEL IS INSTALLED IN A RECESSED PART OF THE CURB

AND SCREWED INTO ANCHORS IN THE CONCRETE.

FOR PEOPLE WITH LIMITED VISION

TRYING TO NAVIGATE THEIR WAY AROUND,

THESE TACTILE PANELS WILL MAKE A DIFFERENCE THEY CAN FEEL.

Narrator: A STIRLING ENGINE PRODUCES POWER

BY CIRCULATING HOT AND COLD AIR, OR OTHER TYPES OF GAS,

AT DIFFERENT TEMPERATURES.

HEATING EXPANDS THE GAS, WHILE COOLING CONTRACTS IT.

THESE ALTERNATING REACTIONS MOVE UP TO FOUR PISTONS AT A TIME,

DRIVING THE MACHINE AND THE PULLEYS ATTACHED TO THE ENGINE.

THIS GERMAN COMPANY MANUFACTURES MODEL STIRLING ENGINES

AND ACCESSORIES, LIKE THIS MARBLE TOWER.

THE ENGINE PARTS MOVE BY A CLOSED LOOP OF AIR

THAT CIRCULATES INSIDE THE ENGINE,

EXPANDING AND CONTRACTING AS IT REPEATEDLY HEATS AND COOLS.

A SPECIALIST DESIGNS THE ENGINES

AND PRODUCES DIGITAL RENDERINGS FOR EACH COMPONENT.

THE DIMENSIONS MUST BE ACCURATE

WITHIN 1/1,000 OF A MILLIMETER.

A COMPUTER GUIDED TURRET MACHINE SHAPES THE ENGINE'S

COOLING CYLINDER OUT OF A SOLID PIECE OF BRASS.

HEAT ESCAPES BRASS QUICKLY, MAKING IT IDEAL FOR A COMPONENT

TO RAPIDLY REDUCE ITS HOT AIR TEMPERATURE.

THE COOLED AIR CONTRACTS, PRODUCING A VACUUM

THAT DRAWS THE ENGINE'S WORKING PISTON DOWNWARD.

WHEN REHEATED, THE AIR EXPANDS, PUSHING THE PISTON UP.

THIS REPETITIVE MOTION DRIVES THE CRANKSHAFT.

THE COOLING CYLINDER HAS FINS TO HELP DIFFUSE HEAT,

A HOLE ON TOP FOR THE WORKING PISTON

AND ANOTHER HOLE ON THE SIDE FOR THE DISPLACE PISTON.

AFTER CLEANING THE CYLINDER WITH COMPRESSED AIR,

A TECHNICIAN PERFORMS A QUALITY CONTROL CHECK.

FIRST, HE INSERTS MULTIPLE TEST PINS INTO THE HOLE

FOR THE WORKING PISTON UNTIL ONE IS THE RIGHT FIT.

THIS TELLS HIM THE DIAMETER MEASUREMENT.

USING A DIGITAL CALIPER, THE TECHNICIAN MEASURES A SERIES

OF ALUMINUM WORKING PISTONS UNTIL HE FINDS THE ONE

THAT'S THE CORRECT SIZE FOR THE HOLE'S DIAMETER.

HE INSERTS THE PISTON INTO THE CYLINDER,

THEN HOLDS THE CYLINDER UPSIDE DOWN.

IF THE PISTON FALLS OUT SLOWLY, IT'S THE RIGHT SIZE.

THE FIT MUST BE PRECISE TO PREVENT THE CIRCULATING AIR

FROM LEAKING OUT OF THE CYLINDER.

IN THE ASSEMBLY AREA,

ANOTHER TECHNICIAN SUPERGLUES A CRANKSHAFT BALL BEARING

INTO EACH OF THE ENGINE'S STAINLESS STEEL SIDE FRAMES.

SHE GLUES THE DISPLACE AXLE TO THE DISPLACE PISTON.

THE PART SHOULD FIT LOOSELY IN THE COOLING CYLINDER

TO ALLOW THE AIR TO FLOW AROUND IT,

WHILE MOVING BACK AND FORTH

BETWEEN THE ENGINE'S HEATING AND COOLING ZONES.

SHE INSERTS THE DISPLACE PISTON INTO THE SIDE HOLE

OF THE COOLING CYLINDER.

THEN THE HEATING CYLINDER IS MOUNTED OVER THE PISTON.

THE HEATING CYLINDER DRAWS HEAT GENERATED BY THE FLAME

INTO THE ENGINE.

SHE ATTACHES IT TO THE COOLING CYLINDER WITH FOUR SCREWS.

A CONNECTING ROD IS ATTACHED TO THE WORKING PISTON

AND THE PISTON IS INSERTED INTO THE COOLING CYLINDER.

NEXT, THE TECHNICIAN MOUNTS ONE OF THE SIDE FRAMES

TO THE CYLINDER,

ATTACHES A ROCKER ARM TO THE SIDE FRAME,

THEN PUTS ONE END OF THE CRANKSHAFT

THROUGH THE SIDE FRAME'S BALL BEARING.

SHE ATTACHES THE SECOND SIDE FRAME,

BY INSERTING THE OTHER END OF THE CRANKSHAFT

THROUGH ITS BALL BEARING.

SHE MOUNTS WHAT HAS BEEN ASSEMBLED SO FAR

ON TO A WOODEN BASE PLATE, THEN SHE CONNECTS ONE END

OF THE ROCKER ARM TO THE WORKING PISTON'S CONNECTING ROD.

THE OTHER END OF THE ROCKER ARM IS JOINED

TO THE CRANKSHAFT CONNECTING ROD,

WHICH IS CONNECTED AT A 90-DEGREE ANGLE

TO BOTH THE ROCKER ARM AND THE CRANKSHAFT.

ON EACH END OF THE CRANKSHAFT,

A HEAVY BRASS FLYWHEEL IS MOUNTED.

THE FLYWHEELS INCREASE THE MOMENTUM OF THE ENGINE.

TO POWER AN ACCESSORY WITH THE STIRLING ENGINE,

ONE END OF A DRIVE BELT IS RUN AROUND A PULLEY

ON THE ACCESSORY, AND THE OTHER END OF THE BELT

AROUND A PLASTIC DRIVE WHEEL.

THE FINISHING TOUCH IS AN ENGRAVED BRASS

IDENTIFICATION PLATE.

HERE'S HOW THIS ENGINE WORKS.

FIRST, THE BURNER CASE IS FILLED WITH DENATURED ALCOHOL

AND THE WICK IS ATTACHED.

THE BURNER CASE IS PLACED UNDER THE HEATING CYLINDER,

LIGHT THE WICK, AND LET THE ENGINE PREHEAT

FOR 10 TO 15 SECONDS,

THEN TURN A FLYWHEEL TO KICKSTART THE ENGINE.

THE FLAME HEATS THE AIR INSIDE THE HEATING CYLINDER.

THE HOT AIR EXPANDS INTO THE COOLING CYLINDER,

CAUSING THE CYLINDER TO COOL AND CONTRACT.

THIS MOVES THE WORKING PISTON UP AND DOWN,

TURNING THE ENGINE'S CRANKSHAFT.