How It's Made (2001–…): Season 6, Episode 13 - Amphibious Vehicles/Putters/Model Ships/Drumheads - full transcript
Narrator:
TODAY ON "HOW IT'S MADE"...
AMPHIBIOUS VEHICLES...
...PUTTERS...
...MODEL SHIPS...
...AND DRUMHEADS.
A VEHICLE IS AMPHIBIOUS
WHEN IT TRAVELS ON LAND
AND WATER.
THIS ONE'S USED MAINLY
BY HUNTERS AND FISHERMEN,
BUT ALSO BY UTILITY COMPANIES
AND THE MILITARY.
WIDE, RUGGED TIRES EASILY TREK
THROUGH MUD, SNOW, AND BUSHES.
WHEN THE VEHICLE'S IN THE WATER,
THE TIRES' DEEP TREADS
ALSO FUNCTION AS PADDLES.
THIS EIGHT-WHEEL MODEL
CAN CARRY SIX PEOPLE ON LAND
AND FOUR IN THE WATER.
BUOYANCY REQUIRES
A LIGHTER LOAD.
THEY BEGIN PRODUCTION BY WELDING
8 STEEL SECTIONS TOGETHER
TO MAKE THE DRIVER'S SEAT,
THEN 12 OTHER PARTS
FOR THE VEHICLE'S MAIN FRAME.
THIS FRAME WILL LATER HOUSE
THE SEAT, A GAS TANK,
THE BATTERY, AND A STORAGE BOX.
NEXT, A WORKER ASSEMBLES
WHAT'S CALLED THE AXLE HUB.
A ROBOTIC PRESS
PUNCHES FIVE BOLTS
THROUGH THE COMPONENTS
TO FUSE THEM.
THIS DESIGN
KEEPS THE HUB LIGHTWEIGHT
AND STRENGTHENS THE AXLE
FOR DRIVING ON ROUGH TERRAIN.
NEXT, A WORKER INSERTS
WHAT'S CALLED THE AXLE SHAFT
THROUGH THE HUB.
A ROBOTIC WELDING MACHINE
THEN FUSES THE SHAFT
TO ONE SIDE OF THE HUB.
AFTER HE FLIPS IT,
THE MACHINE WELDS THE SHAFT
TO THE HUB'S OTHER SIDE.
THIS COMPANY USES A ROBOT
FOR THIS IMPORTANT STEP
BECAUSE IT'S FASTER
AND MORE PRECISE.
HERE, A WORKER REVEALS
SOME OF THE VEHICLE'S SECRETS
TO FUNCTIONING IN WATER.
EACH AXLE'S BEARING HAS
RUBBER AND STEEL COLLARS
CALLED FLANGES.
THEY FORM A WATERPROOF SEAL
OVER THE AXLE.
THE WORKER GREASES THESE FLANGES
TO LUBRICATE THEM
AND TO KEEP DUST AND WATER
FROM INFILTRATING.
HE INSERTS ONE OF 16 GASKETS
BETWEEN THE FLANGES.
THEY'RE MADE OF CORK
TO KEEP MOISTURE OUT
AND GREASE FROM ESCAPING.
AFTER ADDING ANOTHER FLANGE
AND A GASKET,
HE APPLIES A LIQUID COMPOUND
TO RUSTPROOF THE STEEL SHAFT.
HERE, A COMPUTER-GUIDED
CUTTING TOOL
CARVES TEETH ON A STEEL RING
TO CREATE ONE OF THE VEHICLE'S
17 GEARS.
LUBRICANT COOLS THE HEAT
THIS GENERATES
SO THAT THE MACHINE DOESN'T
OVERHEAT AND BREAK DOWN.
WHEN THE CUTTING'S COMPLETE,
ROBOTIC ARMS REMOVE THE GEAR
AND REPLACE IT
WITH A NEW, UNSHAPED RING.
THE GEARS RANGE FROM
ABOUT THE SIZE OF A COIN
TO THE SIZE OF A DINNER PLATE.
HERE'S HOW THE SHIFT LEVER
CHANGES THE GEARS
FROM NEUTRAL TO LOW TO HIGH
AND INTO REVERSE.
AND HERE'S HOW THE CLUTCH
WILL TRANSFER POWER,
VIA A COMPONENT CALLED
THE INPUT SHAFT,
INTO THE TRANSMISSION.
A WORKER HOOKS UP
THE TRANSMISSION TO THE ENGINE,
THEN HE SLIDES TWO CLUTCHES
ONTO THE INPUT SHAFT.
HE ATTACHES EACH ONE
WITH A BOLT AND TWO WASHERS,
THEN CONNECTS THE ENGINE
TO THE TRANSMISSION
WITH A RUBBER DRIVE BELT,
ENCIRCLING THE CLUTCHES.
TWO BRAKE CALIPERS CONNECT
THE BRAKE SYSTEM
TO THE TRANSMISSION.
NOW HE TESTS THE DRIVE BELT,
CLUTCH SYSTEM,
ENGINE ROTATIONS, BRAKES,
AND STEERING.
THE WHEELS DON'T TURN.
THE DRIVER STEERS THE VEHICLE
BY SLOWING OR BRAKING
EITHER SET OF WHEELS
AND SKIDDING TO ONE SIDE.
TO MAKE THE VEHICLE'S
LOWER BODY,
THEY TAKE A SHEET
OF POLYETHYLENE,
A HEAVY-DUTY PLASTIC,
AND HEAT IT IN AN OVEN.
AFTER 4 1/2 MINUTES
AT 450 DEGREES FAHRENHEIT,
THE SHEET EMERGES,
SOFTENED BY THE HEAT.
AN ALUMINUM MOLD DROPS DOWN,
AND A VACUUM-FORMING MACHINE
STRETCHES THE PLASTIC AROUND IT,
SUCKING OUT THE AIR
FROM BETWEEN THE TWO.
AFTER THE PLASTIC COOLS
FOR 4 1/2 MINUTES,
THE MACHINE LIFTS THE MOLD,
LEAVING A CAVITY ABOUT THE SIZE
OF A LARGE BATHTUB.
TWO WORKERS THEN MOVE THE LOWER
BODY TO AN ASSEMBLY LINE.
THEY INSERT THE VEHICLE'S
MAIN FRAME, NOW PAINTED BLACK.
THEN, ON THE OUTSIDE,
THEY MOUNT FOUR EXTENSIONS
THAT WILL CARRY THE VEHICLE'S
TWO FRONT AND TWO REAR AXLES.
THESE WILL ENABLE THE AXLES
TO WITHSTAND GREATER PUNISHMENT.
THEY INSTALL EIGHT DRIVE CHAINS
ONTO SPROCKETS
ON THE AXLE SHAFTS,
THEN TWO MORE
LINKING THE TRANSMISSION
TO THE COMPONENTS
THAT PROPEL THE VEHICLE --
WHAT'S CALLED THE DRIVE SYSTEM.
A WORKER THEN ATTACHED AN END
PLATE TO COMPLETE THE LINK.
WORKERS LOWER THE 26-HORSEPOWER
ENGINE INTO THE CARRIAGE
AND ATTACH IT WITH THREE BOLTS.
NEXT, THE POLYETHYLENE UPPER
BODY, AND THEN THE WHEELS.
THEY TEST THE DRIVE CHAINS
FOR TENSION
AND SPROCKETS FOR VIBRATIONS.
THE WHEELS ARE TWICE AS WIDE
AS MOST CAR WHEELS
BUT 10 TIMES SOFTER,
TO CUSHION THE RIDE.
ON LAND, THIS $16,000 VEHICLE
TRAVELS UP TO 21 MILES PER HOUR.
TOP SPEED IN THE WATER
IS ONLY 3 MILES AN HOUR.
BUT, HEY,
IT'S EASIER THAN SWIMMING.
Narrator: GOLF PLAYERS
IN 17th-CENTURY SCOTLAND
WERE THE FIRST
TO HONE THEIR GAME
BY USING DIFFERENTLY SHAPED
CLUBS FOR SPECIFIC TASKS.
TODAY, YOU USE
WHAT'S CALLED A PUTTER
TO GENTLY ROLL THE BALL
INTO THE HOLE
USING THE FEWEST NUMBER
OF STROKES.
THE CLUB'S HIGH-TECH,
STREAMLINED DESIGN
IS CRUCIAL TO ANY GOLFER'S
PUTTING STRATEGY.
THIS COMPANY USES
A ROBOTIC TESTER
TO SPOT-CHECK ITS PUTTERS
FOR QUALITY.
THE CLUB PASSES IF THE BALLS
ROLL ALONG A STRAIGHT LINE
INTO THE HOLE.
THAT MEANS THE PUTTER'S STRIKING
WITH JUST THE RIGHT IMPACT.
PRODUCTION BEGINS
WITH BARS OF ALUMINUM,
A METAL THAT'S LIGHTWEIGHT
AND EASY TO SCULPT.
A BAND SAW SLICES THEM
INTO 4 1/2-INCH-LONG PIECES.
EACH PIECE WILL BECOME
A PUTTER HEAD,
THE PART OF THE CLUB
THAT HITS THE BALL.
A COMPUTER-GUIDED CUTTING TOOL
SCULPTS THE HEADS
BY SHAVING AWAY
UP TO A THIRD OF THE ALUMINUM.
THE MACHINE FIRST MILLS ONE SIDE
OF THE HEAD INTO TINY STEPS.
ANOTHER CUTTING TOOL
THEN SHAPES THIS AREA
INTO A SMOOTH CURVE.
THE PROCESS TAKES 10 MINUTES.
THEN THE FOUR-SIDED
PLATFORM REVOLVES,
AND THE CUTTER BEGINS WORKING
ON THE NEXT PUTTER HEAD.
ANOTHER MILLING MACHINE CARVES
BLOCKS OF COPPER-NICKEL ALLOY
INTO WHAT'S CALLED THE INSERT.
THIS PART WILL FIT INTO A CAVITY
IN THE PUTTER HEAD,
MAKING THE AREA THAT STRIKES
THE BALL FIRM YET RESONANT.
IT'S WHY THE GOLFER FEELS
THE IMPACT
REVERBERATE THROUGH
THE PUTTER --
WHAT'S KNOWN AS FEEDBACK.
THIS DEVICE PERFORMS
RANDOM QUALITY CHECKS
OF THE INSERT CAVITIES
IN THE PUTTER HEADS.
A VISE HOLDS THE HEAD
AS THE PROBE GAUGES THE CAVITY'S
WIDTH AND DEPTH.
NEXT, THESE CHUNKS OF COPPER
GO INTO A CHEMICAL BATH
WITH PUTTER-HEAD MODELS
MADE OF DIFFERENT METALS.
THE MATERIAL FROM WHICH
A PUTTER HEAD'S MADE
DETERMINES THE WEIGHT
AND FEEL OF THE CLUB.
THIS 10-MINUTE BATH REMOVES
ANY CONTAMINANTS
FROM THE SURFACE OF THE METALS
AND COATS THE HEADS IN COPPER.
THIS ENSURES THAT THE PLATING
THEY'RE GOING TO GET WILL STICK.
AFTER THAT, THE HEADS ARE PLATED
IN A DIFFERENT METAL.
THIS DETERMINES
HOW THE CLUB LOOKS.
FOR THIS,
CHUNKS OF MAT-FINISHED NICKEL
GO INTO A SECOND CHEMICAL BATH.
THEY'LL PROVIDE ONE OF THIS
COMPANY'S FOUR FINISHES,
RANGING FROM MAT TO SHINY.
DURING THIS 15-MINUTE STEP,
A MECHANICAL ARM
OCCASIONALLY SHIFTS THE RACK
TO DISPERSE THE CHEMICALS
AND THOROUGHLY PLATE THE HEADS.
TO FIT THE INSERT,
A WORKER FIRST POSITIONS
THE HEAD IN A VISE.
HE APPLIES FOUR DROPS
OF EPOXY GLUE
INSIDE THE RIM
OF THE INSERT CAVITY.
THIS PROVIDES
ADDITIONAL BONDING
ONCE THEY FORCE THE INSET
ALL THE WAY IN.
AFTER PLACING THE INSERT
IN THE CAVITY BY HAND,
A WORKER USES A PRESS
TO FORCE IT INSIDE.
THEY COVER THE PRESS WITH PAPER
SO IT WON'T SCRATCH THE INSERT,
WHICH MUST BE FLUSH
WITH THE SURFACE OF THE HEAD.
ANY AIR UNDER THE INSERT ESCAPES
THROUGH A HOLE UNDERNEATH,
WHERE THEY'LL INSERT
THE CLUB SHAFT.
A WORKER FIRST APPLIES GLUE
INSIDE THE HOLE,
THEN HE INSERTS THE SHAFT
AND SECURES IT TO A TEMPLATE
WITH RUBBER BANDS.
THE SHAFT IS MADE
OF STAINLESS STEEL.
THEY USUALLY COME
IN STANDARD LENGTHS
OF 33, 34, AND 35 INCHES.
THEY'RE SET AT THE ANGLE MOST
PLAYERS PREFER -- 18 DEGREES.
THE NEXT STEP IS
TO MOUNT A HANDGRIP
AT THE TOP OF THE SHAFT.
FIRST, A WORKER WRAPS THE TOP
IN DOUBLE-SIDED TAPE.
THEN HE POURS WATER
OVER THE TAPE
TO DILUTE THE GLUE
ON ITS SURFACE.
THIS WILL ENABLE THE GRIP
TO SLIDE ON MORE EASILY.
HE POURS WATER
INSIDE THE GRIP, AS WELL.
THE GRIP IS A RUBBER SLEEVE
THAT'S JUST UNDER
10 INCHES LONG.
ONCE LUBRICATED,
IT SHIMMIES OVER THE SHAFT
FOR A SNUG FIT THAT LASTS
UP TO THREE YEARS.
HE LINES UP THE FLAT PART
OF THE GRIP AT A 90-DEGREE ANGLE
WITH THE FLAT PART
OF THE PUTTER HEAD.
THIS HELPS THE PLAYER
STRIKE THE BALL PROPERLY.
NEXT, A WORKER COLORS
THE CLUB'S ENGRAVED LOGO.
USING A TINY NOZZLE, SHE APPLIES
MINUTE AMOUNTS OF EPOXY PAINT
INSIDE THE GROVES OF THE DESIGN.
SHE CONTROLS THE AMOUNT OF PAINT
WITH A FOOT PEDAL
THAT RELEASED PRESSURIZED AIR
INTO THE NOZZLE.
THIS COMPANY MAKES PUTTER HEADS
IN SOME FAIRLY LUXURIOUS
MATERIALS,
INCLUDING BERYLLIUM COPPER.
THAT'S ONE FOR PLAYERS WANTING
A CLUB WITH A SOFTER FEEL
AND WHO DON'T MIND PAYING
UP TO $500 TO GET IT.
Narrator: MODEL SHIPS ARE MADE
FOR NAVAL GAZING.
THEY'RE REPRESENTATIONS
OF REAL SHIPS.
SOME ARE BUILT
METICULOUSLY TO SCALE
WITH EXTREME ATTENTION
TO DETAIL
AND ARE TRULY MUSEUM PIECES.
YOU CAN BUY MODEL SHIPS
PREASSEMBLED OR IN KITS.
BUT BE CAREFUL.
THESE ARE TRULY DELICATE
WORKS OF ART.
THE PORTLAND STEAMER
SANK IN THE ATLANTIC IN 1898,
ALL LIVES LOST.
BUT ITS IMAGE SURVIVES
IN MODELS.
TO MAKE A MODEL
LIKE THE PORTLAND,
THE WORKER SELECTS SOME WOODEN
PIECES FROM A STOCK ROOM.
MODEL SHIPS ARE ACTUALLY MADE
OF THOUSANDS OF PARTS,
BIG AND SMALL.
THESE ARE JUST A FEW,
AND SOME ARE TO BE CUT DOWN.
A COMPUTER GUIDES A LASER BEAM
AS IT CARVES THE LARGER, FLAT
PIECES OF WOOD INTO MANY PARTS.
THEY'LL BE COMPONENTS
FOR THE SHIP'S DECKHOUSE.
NEXT, A WORKER SHAPES A HULL,
OR MAIN BODY,
USING A MACHINE CALLED
A DUPLICATING CARVER.
HOLDING THE MACHINE'S STYLUS
ON THE LEFT,
HE TRACES AROUND A MASTER SHAPE.
THIS MOTION GUIDES TWO ROUTERS
ON THE RIGHT
AS THEY CHISEL INTO BASSWOOD,
MAKING EXACT COPIES
OF THE MASTER HULL.
TO MAKE RESIN PARTS,
THEY MIX POLYURETHANE
WITH SOME PLASTICIZER
AND POUR IT INTO A MOLD.
A CHEMICAL REACTION
CAUSES IT TO HARDEN.
THIS TAKE UP TO A HALF-HOUR,
AND THEN THEY PULL A NEWLY
SHAPED LIFEBOAT OUT OF THE MOLD.
NEXT, A WORKER CLEANS UP
ANOTHER MOLD.
IT'S TO BE USED TO SHAPE
CAST-METAL ANCHORS.
HE PLACES THE MOLD
IN A CENTRIFUGE
AND POURS A MELTED MIX OF TIN,
ANTIMONY, AND COPPER INTO IT.
THE CENTRIFUGE SPINS,
AND THIS CAUSES THE METAL
TO FILL THE CAVITIES IN THE MOLD
AND SOLIDIFY.
HE OPENS THE MOLD
AND FINDS THE ANCHORS
FORMED LIKE SPOKES
AROUND THE HUB.
IT'S ANCHORS AWAY
AS HE SNIPS THEM FREE.
NOW A WORKER SANDS SMOOTH
THE BOTTOM OF THE HULL.
THEN HE POSITIONS THE FIRST
OF THE SHIP'S FIVE DECKS.
HE GLUES WOODEN SPACERS
BETWEEN THE DECKS.
A SPECIAL GLUE THAT DRIES
IN ABOUT 10 SECONDS
ALLOWS HIM TO WORK QUICKLY
AS HE BUILDS THE TIERS.
NEXT, HE SUBMERGES A DECKHOUSE
SIDEPIECE IN WATER
TO SOFTEN THE WOOD.
HE CUTS THE LITTLE TABS
TO FREE OTHER DECKHOUSE PARTS
FROM A MATRIX.
AFTER THAT, HE CARVES OUT
THE CENTER OF TWO OF THE PIECES.
THEN HE GLUES A BLOCK
BETWEEN THEM
AND APPLIES MORE GLUE
TO THE EDGES.
HE BENDS THE DECKHOUSE SIDE,
WHICH IS NOW WET AND SUPPLE,
AROUND THE STRUCTURE.
THE MOISTURE CAUSES
A CHEMICAL REACTION IN THE GLUE
WHICH STRENGTHENS IT.
AFTER HE POSITIONS
THE DECKHOUSE STARBOARD SIDE,
HE STICKS A STRIP
OF CLEAR ACETATE
TO THE BACK
OF A BAND OF WINDOWS.
THE ACETATE SIMULATES GLASS.
HE PAINTS THE FRONT
OF THE WINDOWED WALL WHITE
AND THEN TURNS IT AROUND
TO PAINT RED CURTAINS
ON THE ACETATE.
OTHER DETAILING HAS BEEN
LASER-ETCHED INTO THE WOOD.
HE GLUES THE WALL OF WINDOWS
BETWEEN DECK TIERS,
AND THE LOOK IS AUTHENTIC.
HE POSITIONS PADDLE WHEELS
ON EACH SIDE.
THESE HAVE 57 WOOD PADDLES
HELD IN PLACE BY BRASS RADIALS.
REMEMBER THE ANCHORS CAST
IN THE CENTRIFUGE MOLD EARLIER?
HE NOW POSITIONS SOME
ON THE SHIP DECK.
THEN HE PREPARES THE LIFEBOATS.
THE LARGER PLASTIC ONE
GOES ON THE UPPER DECK.
THIS GOLDEN EAGLE
IS THE FINISHING TOUCH.
HERE, ANOTHER WORKER RIGS UP
A FOUR-MASTED SCHOONER.
USING SURGICAL CLAMPS,
HE PINS THE ROPES DOWN
SO THEY DON'T GET IN THE WAY.
THEN HE MEASURES
A PIECE OF DECKING
TO MAKE THE TOP
OF THE DECKHOUSE.
HE GLUES IT TO A BASE...
AND THEN POSITIONS IT
ON THE SHIP.
NEXT, A JEWELER'S LATHE
SPINS A PIECE OF BRASS
AS A WORKER
MANIPULATES A CUTTER,
MILLING PARTS
FOR THE SHIP'S BELL.
ONCE IT'S MOUNTED,
THIS SHIP MODEL IS READY
FOR EVERYONE TO ADMIRE.
Narrator: A DRUM'S PLAYING
SURFACE IS CALLED THE DRUMHEAD.
IT'S THE PART OF THE INSTRUMENT
THAT VIBRATES, CREATING SOUND.
SOME DRUMHEADS ARE STILL MADE
THE TRADITIONAL WAY,
FROM ANIMAL SKIN.
BUT A NATURAL SKIN IS
VERY SUSCEPTIBLE
TO TEMPERATURE
AND HUMIDITY CHANGES,
SO MOST DRUMMERS TODAY
PREFER HEADS
MADE OF MODERN,
SYNTHETIC MATERIALS.
THE DRUMHEAD SURFACE IS
OFTEN CALLED THE SKIN
BECAUSE, TRADITIONALLY,
IT WAS MADE OF CALFSKIN.
THIS SYNTHETIC SKIN IS
A FLEXIBLE PLASTIC FILM
CALLED POLYETHYLENE
TEREPHTHALATE,
THE SAME POLYESTER-BASED PLASTIC
THEY USE TO MAKE
SOFT-DRINK BOTTLES.
WORKERS LOAD SEVERAL SHEETS
OF IT INTO A PRESS
THAT APPLIES 75 TONS OF FORCE
ONTO SHARP, CIRCLE-SHAPED DIES,
PUSHING THEM UPWARD
THROUGH THE FILM SHEETS.
THE DIE-CUT FILM CIRCLES
BECOME THE SKINS.
A SKIN COULD BE MADE UP
OF JUST ONE FILM CIRCLE
OR SEVERAL TAPED TOGETHER.
WORKERS ASSEMBLE THE LAYERS
USING A VACUUM TURNTABLE.
THE SUCTION KEEPS
THE BOTTOM FILM STEADY
WHILE THEY APPLY TAPE
TO ITS OUTSIDE EDGE
AND THEN ADHERE
ANOTHER FILM ON TOP.
EACH LAYER IS CALLED A PLY.
THE MORE PLIES A SKIN HAS,
THE MORE BASS FREQUENCIES
IT'LL PRODUCE.
NOW THE SKINS GO ONTO
A COMPUTER-GUIDED DRILL PRESS.
THE MACHINE DRILLS TINY HOLES
ALL ALONG THEIR PERIMETER,
ABOUT 1/8 OF AN INCH IN.
THE HOLES ARE ROUGHLY
THE SIZE OF A NAILHEAD.
THEY'RE SPACED
ABOUT 1/4 INCH APART.
THE NEXT MACHINE HEATS THE EDGE
OF EACH FILM TO SOFTEN IT,
THEN APPLIES PRESSURE
TO MOLD IT TO SHAPE.
THE SKIN COMES OUT
WITH A FLUTED EDGE,
LIKE WHAT YOU SEE
ON A PAPER CUP.
THIS SHAPE KEEPS
THE TENSION EVEN
WHEN THE MUSICIAN TIGHTENS
THE SKIN TO TUNE THE DRUM.
MEANWHILE,
THIS ROLL-FORMING MACHINE
USES A SERIES
OF PRESSURE ROLLERS
TO GRADUALLY SHAPE
AN ALUMINUM STRIP INTO A HOOP.
THE HOOP WILL HOLD THE SKIN
TIGHTLY OVER THE DRUM'S BODY,
CALLED THE DRUM SHELL,
CREATING THE TENSION YOU NEED
TO PRODUCE SOUND.
THIS MACHINE
ALSO IMPRINTS TINY DIMPLES
ONTO ONE SIDE OF THE STRIP.
WHEN THE FACTORY LATER GLUES
TOGETHER THE SKIN AND HOOP,
THIS ROUGH TEXTURE
WILL IMPROVE THE BOND.
NOW THE MACHINE FOLDS THE EDGES
OF THE STRIP INWARD
TO CREATE A CHANNEL
ON THE INSIDE OF THE HOOP.
THAT'S WHERE THE GLUE WILL GO.
ONCE THE MACHINE FINISHES
FORMING THE HOOP,
A SMALL, BUILT-IN CIRCULAR SAW
CUTS THE END.
A WORKER THEN LOADS EACH HOOP
ONTO A ROTATION SOLDERING JIG,
POSITIONING THE ENDS TOGETHER.
THE REST IS ALL AUTOMATED.
A GLOB OF SILVER SOLDER
ON THE JOINT...
THEN NATURAL-GAS TORCHES
FUSE THE HOOP CLOSED.
AFTER WATER COOLS OFF
THE HOT METAL...
THE JIG EJECTS
THE FINISHED HOOP.
DRUMHEAD HOOPS CAN BE
AS SMALL AS 6 INCHES
OR AS LARGE AS 40 INCHES
IN DIAMETER.
FINALLY, IT'S TIME TO FIT
THE SKIN INTO THE HOOP.
THIS IS THE TRICKY PART,
BECAUSE THE FILM MUST BE
PERFECTLY LEVEL AND CENTERED.
OTHERWISE, WHEN YOU TIGHTEN
THE SKIN TO TUNE THE DRUM,
THE SHORT SIDE WOULD TIGHTEN
BEFORE THE REST,
AND THAT UNEVEN TENSION
WOULD THROW THE TUNING OFF.
SO THEY DO THIS
CRITICAL ASSEMBLY STEP
ON A SPECIALLY DESIGNED TABLE,
PLACING THE SKINS
ON CIRCULAR VACUUM FIXTURES
THAT ARE PERFECTLY LEVEL.
AS SUCTION HOLDS
EACH ONE STEADY,
A ROBOTIC ARM RUNS GLUE
IN THE HOOP'S CHANNEL
ALL THE WAY AROUND.
THE GLUE DRAINS DOWNWARD
THROUGH THE TINY HOLES
ALONG THE SKIN'S PERIMETER,
THEN DRIES, ANCHORING THE SKIN
SECURELY IN THE HOOP.
SOME DRUMHEADS GO ON
TO GET A TEXTURED COATING.
BY ADDING WEIGHT,
THE COATING MUFFLES
THE HIGHER SOUND FREQUENCIES,
ENHANCING THE LOWER ONES.
THIS PRODUCES
A WARMER, DEEPER TONE.
IT ALSO PRODUCES
THAT SWOOSHING SOUND
WHEN JAZZ DRUMMERS
PLAY SOFTLY WITH BRUSHES.
ONCE THE COATING DRIES,
A PAD-PRINTING MACHINE
STAMPS ON THE COMPANY NAME.
ONLY ABOUT 30% OF DRUMHEADS
ON THE MARKET ARE COATED.
THE REST ARE WHAT'S KNOWN
AS CLEAR HEADS.
AND THAT'S
HOW DRUMHEADS ARE MADE.
CAPTIONS PAID FOR BY
DISCOVERY COMMUNICATIONS, INC.
IF YOU HAVE ANY COMMENTS
ABOUT THE SHOW,
OR IF YOU'D LIKE TO SUGGEST
TOPICS FOR FUTURE SHOWS,
DROP US A LINE AT...
TODAY ON "HOW IT'S MADE"...
AMPHIBIOUS VEHICLES...
...PUTTERS...
...MODEL SHIPS...
...AND DRUMHEADS.
A VEHICLE IS AMPHIBIOUS
WHEN IT TRAVELS ON LAND
AND WATER.
THIS ONE'S USED MAINLY
BY HUNTERS AND FISHERMEN,
BUT ALSO BY UTILITY COMPANIES
AND THE MILITARY.
WIDE, RUGGED TIRES EASILY TREK
THROUGH MUD, SNOW, AND BUSHES.
WHEN THE VEHICLE'S IN THE WATER,
THE TIRES' DEEP TREADS
ALSO FUNCTION AS PADDLES.
THIS EIGHT-WHEEL MODEL
CAN CARRY SIX PEOPLE ON LAND
AND FOUR IN THE WATER.
BUOYANCY REQUIRES
A LIGHTER LOAD.
THEY BEGIN PRODUCTION BY WELDING
8 STEEL SECTIONS TOGETHER
TO MAKE THE DRIVER'S SEAT,
THEN 12 OTHER PARTS
FOR THE VEHICLE'S MAIN FRAME.
THIS FRAME WILL LATER HOUSE
THE SEAT, A GAS TANK,
THE BATTERY, AND A STORAGE BOX.
NEXT, A WORKER ASSEMBLES
WHAT'S CALLED THE AXLE HUB.
A ROBOTIC PRESS
PUNCHES FIVE BOLTS
THROUGH THE COMPONENTS
TO FUSE THEM.
THIS DESIGN
KEEPS THE HUB LIGHTWEIGHT
AND STRENGTHENS THE AXLE
FOR DRIVING ON ROUGH TERRAIN.
NEXT, A WORKER INSERTS
WHAT'S CALLED THE AXLE SHAFT
THROUGH THE HUB.
A ROBOTIC WELDING MACHINE
THEN FUSES THE SHAFT
TO ONE SIDE OF THE HUB.
AFTER HE FLIPS IT,
THE MACHINE WELDS THE SHAFT
TO THE HUB'S OTHER SIDE.
THIS COMPANY USES A ROBOT
FOR THIS IMPORTANT STEP
BECAUSE IT'S FASTER
AND MORE PRECISE.
HERE, A WORKER REVEALS
SOME OF THE VEHICLE'S SECRETS
TO FUNCTIONING IN WATER.
EACH AXLE'S BEARING HAS
RUBBER AND STEEL COLLARS
CALLED FLANGES.
THEY FORM A WATERPROOF SEAL
OVER THE AXLE.
THE WORKER GREASES THESE FLANGES
TO LUBRICATE THEM
AND TO KEEP DUST AND WATER
FROM INFILTRATING.
HE INSERTS ONE OF 16 GASKETS
BETWEEN THE FLANGES.
THEY'RE MADE OF CORK
TO KEEP MOISTURE OUT
AND GREASE FROM ESCAPING.
AFTER ADDING ANOTHER FLANGE
AND A GASKET,
HE APPLIES A LIQUID COMPOUND
TO RUSTPROOF THE STEEL SHAFT.
HERE, A COMPUTER-GUIDED
CUTTING TOOL
CARVES TEETH ON A STEEL RING
TO CREATE ONE OF THE VEHICLE'S
17 GEARS.
LUBRICANT COOLS THE HEAT
THIS GENERATES
SO THAT THE MACHINE DOESN'T
OVERHEAT AND BREAK DOWN.
WHEN THE CUTTING'S COMPLETE,
ROBOTIC ARMS REMOVE THE GEAR
AND REPLACE IT
WITH A NEW, UNSHAPED RING.
THE GEARS RANGE FROM
ABOUT THE SIZE OF A COIN
TO THE SIZE OF A DINNER PLATE.
HERE'S HOW THE SHIFT LEVER
CHANGES THE GEARS
FROM NEUTRAL TO LOW TO HIGH
AND INTO REVERSE.
AND HERE'S HOW THE CLUTCH
WILL TRANSFER POWER,
VIA A COMPONENT CALLED
THE INPUT SHAFT,
INTO THE TRANSMISSION.
A WORKER HOOKS UP
THE TRANSMISSION TO THE ENGINE,
THEN HE SLIDES TWO CLUTCHES
ONTO THE INPUT SHAFT.
HE ATTACHES EACH ONE
WITH A BOLT AND TWO WASHERS,
THEN CONNECTS THE ENGINE
TO THE TRANSMISSION
WITH A RUBBER DRIVE BELT,
ENCIRCLING THE CLUTCHES.
TWO BRAKE CALIPERS CONNECT
THE BRAKE SYSTEM
TO THE TRANSMISSION.
NOW HE TESTS THE DRIVE BELT,
CLUTCH SYSTEM,
ENGINE ROTATIONS, BRAKES,
AND STEERING.
THE WHEELS DON'T TURN.
THE DRIVER STEERS THE VEHICLE
BY SLOWING OR BRAKING
EITHER SET OF WHEELS
AND SKIDDING TO ONE SIDE.
TO MAKE THE VEHICLE'S
LOWER BODY,
THEY TAKE A SHEET
OF POLYETHYLENE,
A HEAVY-DUTY PLASTIC,
AND HEAT IT IN AN OVEN.
AFTER 4 1/2 MINUTES
AT 450 DEGREES FAHRENHEIT,
THE SHEET EMERGES,
SOFTENED BY THE HEAT.
AN ALUMINUM MOLD DROPS DOWN,
AND A VACUUM-FORMING MACHINE
STRETCHES THE PLASTIC AROUND IT,
SUCKING OUT THE AIR
FROM BETWEEN THE TWO.
AFTER THE PLASTIC COOLS
FOR 4 1/2 MINUTES,
THE MACHINE LIFTS THE MOLD,
LEAVING A CAVITY ABOUT THE SIZE
OF A LARGE BATHTUB.
TWO WORKERS THEN MOVE THE LOWER
BODY TO AN ASSEMBLY LINE.
THEY INSERT THE VEHICLE'S
MAIN FRAME, NOW PAINTED BLACK.
THEN, ON THE OUTSIDE,
THEY MOUNT FOUR EXTENSIONS
THAT WILL CARRY THE VEHICLE'S
TWO FRONT AND TWO REAR AXLES.
THESE WILL ENABLE THE AXLES
TO WITHSTAND GREATER PUNISHMENT.
THEY INSTALL EIGHT DRIVE CHAINS
ONTO SPROCKETS
ON THE AXLE SHAFTS,
THEN TWO MORE
LINKING THE TRANSMISSION
TO THE COMPONENTS
THAT PROPEL THE VEHICLE --
WHAT'S CALLED THE DRIVE SYSTEM.
A WORKER THEN ATTACHED AN END
PLATE TO COMPLETE THE LINK.
WORKERS LOWER THE 26-HORSEPOWER
ENGINE INTO THE CARRIAGE
AND ATTACH IT WITH THREE BOLTS.
NEXT, THE POLYETHYLENE UPPER
BODY, AND THEN THE WHEELS.
THEY TEST THE DRIVE CHAINS
FOR TENSION
AND SPROCKETS FOR VIBRATIONS.
THE WHEELS ARE TWICE AS WIDE
AS MOST CAR WHEELS
BUT 10 TIMES SOFTER,
TO CUSHION THE RIDE.
ON LAND, THIS $16,000 VEHICLE
TRAVELS UP TO 21 MILES PER HOUR.
TOP SPEED IN THE WATER
IS ONLY 3 MILES AN HOUR.
BUT, HEY,
IT'S EASIER THAN SWIMMING.
Narrator: GOLF PLAYERS
IN 17th-CENTURY SCOTLAND
WERE THE FIRST
TO HONE THEIR GAME
BY USING DIFFERENTLY SHAPED
CLUBS FOR SPECIFIC TASKS.
TODAY, YOU USE
WHAT'S CALLED A PUTTER
TO GENTLY ROLL THE BALL
INTO THE HOLE
USING THE FEWEST NUMBER
OF STROKES.
THE CLUB'S HIGH-TECH,
STREAMLINED DESIGN
IS CRUCIAL TO ANY GOLFER'S
PUTTING STRATEGY.
THIS COMPANY USES
A ROBOTIC TESTER
TO SPOT-CHECK ITS PUTTERS
FOR QUALITY.
THE CLUB PASSES IF THE BALLS
ROLL ALONG A STRAIGHT LINE
INTO THE HOLE.
THAT MEANS THE PUTTER'S STRIKING
WITH JUST THE RIGHT IMPACT.
PRODUCTION BEGINS
WITH BARS OF ALUMINUM,
A METAL THAT'S LIGHTWEIGHT
AND EASY TO SCULPT.
A BAND SAW SLICES THEM
INTO 4 1/2-INCH-LONG PIECES.
EACH PIECE WILL BECOME
A PUTTER HEAD,
THE PART OF THE CLUB
THAT HITS THE BALL.
A COMPUTER-GUIDED CUTTING TOOL
SCULPTS THE HEADS
BY SHAVING AWAY
UP TO A THIRD OF THE ALUMINUM.
THE MACHINE FIRST MILLS ONE SIDE
OF THE HEAD INTO TINY STEPS.
ANOTHER CUTTING TOOL
THEN SHAPES THIS AREA
INTO A SMOOTH CURVE.
THE PROCESS TAKES 10 MINUTES.
THEN THE FOUR-SIDED
PLATFORM REVOLVES,
AND THE CUTTER BEGINS WORKING
ON THE NEXT PUTTER HEAD.
ANOTHER MILLING MACHINE CARVES
BLOCKS OF COPPER-NICKEL ALLOY
INTO WHAT'S CALLED THE INSERT.
THIS PART WILL FIT INTO A CAVITY
IN THE PUTTER HEAD,
MAKING THE AREA THAT STRIKES
THE BALL FIRM YET RESONANT.
IT'S WHY THE GOLFER FEELS
THE IMPACT
REVERBERATE THROUGH
THE PUTTER --
WHAT'S KNOWN AS FEEDBACK.
THIS DEVICE PERFORMS
RANDOM QUALITY CHECKS
OF THE INSERT CAVITIES
IN THE PUTTER HEADS.
A VISE HOLDS THE HEAD
AS THE PROBE GAUGES THE CAVITY'S
WIDTH AND DEPTH.
NEXT, THESE CHUNKS OF COPPER
GO INTO A CHEMICAL BATH
WITH PUTTER-HEAD MODELS
MADE OF DIFFERENT METALS.
THE MATERIAL FROM WHICH
A PUTTER HEAD'S MADE
DETERMINES THE WEIGHT
AND FEEL OF THE CLUB.
THIS 10-MINUTE BATH REMOVES
ANY CONTAMINANTS
FROM THE SURFACE OF THE METALS
AND COATS THE HEADS IN COPPER.
THIS ENSURES THAT THE PLATING
THEY'RE GOING TO GET WILL STICK.
AFTER THAT, THE HEADS ARE PLATED
IN A DIFFERENT METAL.
THIS DETERMINES
HOW THE CLUB LOOKS.
FOR THIS,
CHUNKS OF MAT-FINISHED NICKEL
GO INTO A SECOND CHEMICAL BATH.
THEY'LL PROVIDE ONE OF THIS
COMPANY'S FOUR FINISHES,
RANGING FROM MAT TO SHINY.
DURING THIS 15-MINUTE STEP,
A MECHANICAL ARM
OCCASIONALLY SHIFTS THE RACK
TO DISPERSE THE CHEMICALS
AND THOROUGHLY PLATE THE HEADS.
TO FIT THE INSERT,
A WORKER FIRST POSITIONS
THE HEAD IN A VISE.
HE APPLIES FOUR DROPS
OF EPOXY GLUE
INSIDE THE RIM
OF THE INSERT CAVITY.
THIS PROVIDES
ADDITIONAL BONDING
ONCE THEY FORCE THE INSET
ALL THE WAY IN.
AFTER PLACING THE INSERT
IN THE CAVITY BY HAND,
A WORKER USES A PRESS
TO FORCE IT INSIDE.
THEY COVER THE PRESS WITH PAPER
SO IT WON'T SCRATCH THE INSERT,
WHICH MUST BE FLUSH
WITH THE SURFACE OF THE HEAD.
ANY AIR UNDER THE INSERT ESCAPES
THROUGH A HOLE UNDERNEATH,
WHERE THEY'LL INSERT
THE CLUB SHAFT.
A WORKER FIRST APPLIES GLUE
INSIDE THE HOLE,
THEN HE INSERTS THE SHAFT
AND SECURES IT TO A TEMPLATE
WITH RUBBER BANDS.
THE SHAFT IS MADE
OF STAINLESS STEEL.
THEY USUALLY COME
IN STANDARD LENGTHS
OF 33, 34, AND 35 INCHES.
THEY'RE SET AT THE ANGLE MOST
PLAYERS PREFER -- 18 DEGREES.
THE NEXT STEP IS
TO MOUNT A HANDGRIP
AT THE TOP OF THE SHAFT.
FIRST, A WORKER WRAPS THE TOP
IN DOUBLE-SIDED TAPE.
THEN HE POURS WATER
OVER THE TAPE
TO DILUTE THE GLUE
ON ITS SURFACE.
THIS WILL ENABLE THE GRIP
TO SLIDE ON MORE EASILY.
HE POURS WATER
INSIDE THE GRIP, AS WELL.
THE GRIP IS A RUBBER SLEEVE
THAT'S JUST UNDER
10 INCHES LONG.
ONCE LUBRICATED,
IT SHIMMIES OVER THE SHAFT
FOR A SNUG FIT THAT LASTS
UP TO THREE YEARS.
HE LINES UP THE FLAT PART
OF THE GRIP AT A 90-DEGREE ANGLE
WITH THE FLAT PART
OF THE PUTTER HEAD.
THIS HELPS THE PLAYER
STRIKE THE BALL PROPERLY.
NEXT, A WORKER COLORS
THE CLUB'S ENGRAVED LOGO.
USING A TINY NOZZLE, SHE APPLIES
MINUTE AMOUNTS OF EPOXY PAINT
INSIDE THE GROVES OF THE DESIGN.
SHE CONTROLS THE AMOUNT OF PAINT
WITH A FOOT PEDAL
THAT RELEASED PRESSURIZED AIR
INTO THE NOZZLE.
THIS COMPANY MAKES PUTTER HEADS
IN SOME FAIRLY LUXURIOUS
MATERIALS,
INCLUDING BERYLLIUM COPPER.
THAT'S ONE FOR PLAYERS WANTING
A CLUB WITH A SOFTER FEEL
AND WHO DON'T MIND PAYING
UP TO $500 TO GET IT.
Narrator: MODEL SHIPS ARE MADE
FOR NAVAL GAZING.
THEY'RE REPRESENTATIONS
OF REAL SHIPS.
SOME ARE BUILT
METICULOUSLY TO SCALE
WITH EXTREME ATTENTION
TO DETAIL
AND ARE TRULY MUSEUM PIECES.
YOU CAN BUY MODEL SHIPS
PREASSEMBLED OR IN KITS.
BUT BE CAREFUL.
THESE ARE TRULY DELICATE
WORKS OF ART.
THE PORTLAND STEAMER
SANK IN THE ATLANTIC IN 1898,
ALL LIVES LOST.
BUT ITS IMAGE SURVIVES
IN MODELS.
TO MAKE A MODEL
LIKE THE PORTLAND,
THE WORKER SELECTS SOME WOODEN
PIECES FROM A STOCK ROOM.
MODEL SHIPS ARE ACTUALLY MADE
OF THOUSANDS OF PARTS,
BIG AND SMALL.
THESE ARE JUST A FEW,
AND SOME ARE TO BE CUT DOWN.
A COMPUTER GUIDES A LASER BEAM
AS IT CARVES THE LARGER, FLAT
PIECES OF WOOD INTO MANY PARTS.
THEY'LL BE COMPONENTS
FOR THE SHIP'S DECKHOUSE.
NEXT, A WORKER SHAPES A HULL,
OR MAIN BODY,
USING A MACHINE CALLED
A DUPLICATING CARVER.
HOLDING THE MACHINE'S STYLUS
ON THE LEFT,
HE TRACES AROUND A MASTER SHAPE.
THIS MOTION GUIDES TWO ROUTERS
ON THE RIGHT
AS THEY CHISEL INTO BASSWOOD,
MAKING EXACT COPIES
OF THE MASTER HULL.
TO MAKE RESIN PARTS,
THEY MIX POLYURETHANE
WITH SOME PLASTICIZER
AND POUR IT INTO A MOLD.
A CHEMICAL REACTION
CAUSES IT TO HARDEN.
THIS TAKE UP TO A HALF-HOUR,
AND THEN THEY PULL A NEWLY
SHAPED LIFEBOAT OUT OF THE MOLD.
NEXT, A WORKER CLEANS UP
ANOTHER MOLD.
IT'S TO BE USED TO SHAPE
CAST-METAL ANCHORS.
HE PLACES THE MOLD
IN A CENTRIFUGE
AND POURS A MELTED MIX OF TIN,
ANTIMONY, AND COPPER INTO IT.
THE CENTRIFUGE SPINS,
AND THIS CAUSES THE METAL
TO FILL THE CAVITIES IN THE MOLD
AND SOLIDIFY.
HE OPENS THE MOLD
AND FINDS THE ANCHORS
FORMED LIKE SPOKES
AROUND THE HUB.
IT'S ANCHORS AWAY
AS HE SNIPS THEM FREE.
NOW A WORKER SANDS SMOOTH
THE BOTTOM OF THE HULL.
THEN HE POSITIONS THE FIRST
OF THE SHIP'S FIVE DECKS.
HE GLUES WOODEN SPACERS
BETWEEN THE DECKS.
A SPECIAL GLUE THAT DRIES
IN ABOUT 10 SECONDS
ALLOWS HIM TO WORK QUICKLY
AS HE BUILDS THE TIERS.
NEXT, HE SUBMERGES A DECKHOUSE
SIDEPIECE IN WATER
TO SOFTEN THE WOOD.
HE CUTS THE LITTLE TABS
TO FREE OTHER DECKHOUSE PARTS
FROM A MATRIX.
AFTER THAT, HE CARVES OUT
THE CENTER OF TWO OF THE PIECES.
THEN HE GLUES A BLOCK
BETWEEN THEM
AND APPLIES MORE GLUE
TO THE EDGES.
HE BENDS THE DECKHOUSE SIDE,
WHICH IS NOW WET AND SUPPLE,
AROUND THE STRUCTURE.
THE MOISTURE CAUSES
A CHEMICAL REACTION IN THE GLUE
WHICH STRENGTHENS IT.
AFTER HE POSITIONS
THE DECKHOUSE STARBOARD SIDE,
HE STICKS A STRIP
OF CLEAR ACETATE
TO THE BACK
OF A BAND OF WINDOWS.
THE ACETATE SIMULATES GLASS.
HE PAINTS THE FRONT
OF THE WINDOWED WALL WHITE
AND THEN TURNS IT AROUND
TO PAINT RED CURTAINS
ON THE ACETATE.
OTHER DETAILING HAS BEEN
LASER-ETCHED INTO THE WOOD.
HE GLUES THE WALL OF WINDOWS
BETWEEN DECK TIERS,
AND THE LOOK IS AUTHENTIC.
HE POSITIONS PADDLE WHEELS
ON EACH SIDE.
THESE HAVE 57 WOOD PADDLES
HELD IN PLACE BY BRASS RADIALS.
REMEMBER THE ANCHORS CAST
IN THE CENTRIFUGE MOLD EARLIER?
HE NOW POSITIONS SOME
ON THE SHIP DECK.
THEN HE PREPARES THE LIFEBOATS.
THE LARGER PLASTIC ONE
GOES ON THE UPPER DECK.
THIS GOLDEN EAGLE
IS THE FINISHING TOUCH.
HERE, ANOTHER WORKER RIGS UP
A FOUR-MASTED SCHOONER.
USING SURGICAL CLAMPS,
HE PINS THE ROPES DOWN
SO THEY DON'T GET IN THE WAY.
THEN HE MEASURES
A PIECE OF DECKING
TO MAKE THE TOP
OF THE DECKHOUSE.
HE GLUES IT TO A BASE...
AND THEN POSITIONS IT
ON THE SHIP.
NEXT, A JEWELER'S LATHE
SPINS A PIECE OF BRASS
AS A WORKER
MANIPULATES A CUTTER,
MILLING PARTS
FOR THE SHIP'S BELL.
ONCE IT'S MOUNTED,
THIS SHIP MODEL IS READY
FOR EVERYONE TO ADMIRE.
Narrator: A DRUM'S PLAYING
SURFACE IS CALLED THE DRUMHEAD.
IT'S THE PART OF THE INSTRUMENT
THAT VIBRATES, CREATING SOUND.
SOME DRUMHEADS ARE STILL MADE
THE TRADITIONAL WAY,
FROM ANIMAL SKIN.
BUT A NATURAL SKIN IS
VERY SUSCEPTIBLE
TO TEMPERATURE
AND HUMIDITY CHANGES,
SO MOST DRUMMERS TODAY
PREFER HEADS
MADE OF MODERN,
SYNTHETIC MATERIALS.
THE DRUMHEAD SURFACE IS
OFTEN CALLED THE SKIN
BECAUSE, TRADITIONALLY,
IT WAS MADE OF CALFSKIN.
THIS SYNTHETIC SKIN IS
A FLEXIBLE PLASTIC FILM
CALLED POLYETHYLENE
TEREPHTHALATE,
THE SAME POLYESTER-BASED PLASTIC
THEY USE TO MAKE
SOFT-DRINK BOTTLES.
WORKERS LOAD SEVERAL SHEETS
OF IT INTO A PRESS
THAT APPLIES 75 TONS OF FORCE
ONTO SHARP, CIRCLE-SHAPED DIES,
PUSHING THEM UPWARD
THROUGH THE FILM SHEETS.
THE DIE-CUT FILM CIRCLES
BECOME THE SKINS.
A SKIN COULD BE MADE UP
OF JUST ONE FILM CIRCLE
OR SEVERAL TAPED TOGETHER.
WORKERS ASSEMBLE THE LAYERS
USING A VACUUM TURNTABLE.
THE SUCTION KEEPS
THE BOTTOM FILM STEADY
WHILE THEY APPLY TAPE
TO ITS OUTSIDE EDGE
AND THEN ADHERE
ANOTHER FILM ON TOP.
EACH LAYER IS CALLED A PLY.
THE MORE PLIES A SKIN HAS,
THE MORE BASS FREQUENCIES
IT'LL PRODUCE.
NOW THE SKINS GO ONTO
A COMPUTER-GUIDED DRILL PRESS.
THE MACHINE DRILLS TINY HOLES
ALL ALONG THEIR PERIMETER,
ABOUT 1/8 OF AN INCH IN.
THE HOLES ARE ROUGHLY
THE SIZE OF A NAILHEAD.
THEY'RE SPACED
ABOUT 1/4 INCH APART.
THE NEXT MACHINE HEATS THE EDGE
OF EACH FILM TO SOFTEN IT,
THEN APPLIES PRESSURE
TO MOLD IT TO SHAPE.
THE SKIN COMES OUT
WITH A FLUTED EDGE,
LIKE WHAT YOU SEE
ON A PAPER CUP.
THIS SHAPE KEEPS
THE TENSION EVEN
WHEN THE MUSICIAN TIGHTENS
THE SKIN TO TUNE THE DRUM.
MEANWHILE,
THIS ROLL-FORMING MACHINE
USES A SERIES
OF PRESSURE ROLLERS
TO GRADUALLY SHAPE
AN ALUMINUM STRIP INTO A HOOP.
THE HOOP WILL HOLD THE SKIN
TIGHTLY OVER THE DRUM'S BODY,
CALLED THE DRUM SHELL,
CREATING THE TENSION YOU NEED
TO PRODUCE SOUND.
THIS MACHINE
ALSO IMPRINTS TINY DIMPLES
ONTO ONE SIDE OF THE STRIP.
WHEN THE FACTORY LATER GLUES
TOGETHER THE SKIN AND HOOP,
THIS ROUGH TEXTURE
WILL IMPROVE THE BOND.
NOW THE MACHINE FOLDS THE EDGES
OF THE STRIP INWARD
TO CREATE A CHANNEL
ON THE INSIDE OF THE HOOP.
THAT'S WHERE THE GLUE WILL GO.
ONCE THE MACHINE FINISHES
FORMING THE HOOP,
A SMALL, BUILT-IN CIRCULAR SAW
CUTS THE END.
A WORKER THEN LOADS EACH HOOP
ONTO A ROTATION SOLDERING JIG,
POSITIONING THE ENDS TOGETHER.
THE REST IS ALL AUTOMATED.
A GLOB OF SILVER SOLDER
ON THE JOINT...
THEN NATURAL-GAS TORCHES
FUSE THE HOOP CLOSED.
AFTER WATER COOLS OFF
THE HOT METAL...
THE JIG EJECTS
THE FINISHED HOOP.
DRUMHEAD HOOPS CAN BE
AS SMALL AS 6 INCHES
OR AS LARGE AS 40 INCHES
IN DIAMETER.
FINALLY, IT'S TIME TO FIT
THE SKIN INTO THE HOOP.
THIS IS THE TRICKY PART,
BECAUSE THE FILM MUST BE
PERFECTLY LEVEL AND CENTERED.
OTHERWISE, WHEN YOU TIGHTEN
THE SKIN TO TUNE THE DRUM,
THE SHORT SIDE WOULD TIGHTEN
BEFORE THE REST,
AND THAT UNEVEN TENSION
WOULD THROW THE TUNING OFF.
SO THEY DO THIS
CRITICAL ASSEMBLY STEP
ON A SPECIALLY DESIGNED TABLE,
PLACING THE SKINS
ON CIRCULAR VACUUM FIXTURES
THAT ARE PERFECTLY LEVEL.
AS SUCTION HOLDS
EACH ONE STEADY,
A ROBOTIC ARM RUNS GLUE
IN THE HOOP'S CHANNEL
ALL THE WAY AROUND.
THE GLUE DRAINS DOWNWARD
THROUGH THE TINY HOLES
ALONG THE SKIN'S PERIMETER,
THEN DRIES, ANCHORING THE SKIN
SECURELY IN THE HOOP.
SOME DRUMHEADS GO ON
TO GET A TEXTURED COATING.
BY ADDING WEIGHT,
THE COATING MUFFLES
THE HIGHER SOUND FREQUENCIES,
ENHANCING THE LOWER ONES.
THIS PRODUCES
A WARMER, DEEPER TONE.
IT ALSO PRODUCES
THAT SWOOSHING SOUND
WHEN JAZZ DRUMMERS
PLAY SOFTLY WITH BRUSHES.
ONCE THE COATING DRIES,
A PAD-PRINTING MACHINE
STAMPS ON THE COMPANY NAME.
ONLY ABOUT 30% OF DRUMHEADS
ON THE MARKET ARE COATED.
THE REST ARE WHAT'S KNOWN
AS CLEAR HEADS.
AND THAT'S
HOW DRUMHEADS ARE MADE.
CAPTIONS PAID FOR BY
DISCOVERY COMMUNICATIONS, INC.
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