How It's Made (2001–…): Season 2, Episode 13 - Ball Bearings/Electrical Wires/Lost Wax Process Casting/Automated Machines - full transcript
Find out how ball bearings, electrical wires, wax casting and automated machines are made.
Narrator:
TODAY ON "HOW IT'S MADE"...
BALL BEARINGS...
ELECTRICAL WIRES...
LOST WAX CASTING...
AND AUTOMATED MACHINES.
WITH ALL THE HIGH-TECH HOOPLA
THESE DAYS,
THE LOWLY BALL BEARING
GETS FORGOTTEN.
BUT MANY MACHINE PARTS
NEED BALL BEARINGS TO ROTATE.
THEY'RE IN HOUSEHOLD APPLIANCES,
INDUSTRIAL MACHINES,
AND CAR ENGINE PARTS
SUCH AS ALTERNATORS AND FANS.
THIS IS WHAT'S CALLED
A DEEP GROOVE RADIAL
BALL BEARING.
IT HAS STEEL BALLS THAT MOVE
INSIDE TRACKS CALLED RACEWAYS.
THE RACEWAYS ARE CARVED INTO
A SET OF HEAVY-DUTY STEEL RINGS.
THE BALLS ARE MADE
OF THE SAME TYPE OF STEEL.
THEY FIRST PREPARE
TO SHAPE THE RINGS
TO THE RIGHT THICKNESS.
THEY INSERT THE INNER RING
INTO THE OUTER RING.
THE SET THEN PASSES
THROUGH A GRINDER
THAT ALTERS THE WIDTH
TO THE CORRECT THICKNESS.
A GAUGE CHECKS THE WIDTH
OF EACH RING AS IT EXITS.
NOW THEY SEPARATE
THE INNER AND OUTER RINGS
IN ORDER TO GRIND
THEIR OUTER CIRCUMFERENCE
ON SEPARATE MACHINES.
THE OUTER RING
ENTERS THE GRINDER,
WHICH SHAPES ITS OUTER SURFACE
TO A PRECISE ROUNDNESS
AND DIAMETER.
A WATER-BASED LIQUID
KEEPS THE RING FROM OVERHEATING,
WHICH WOULD CAUSE WARPING.
THE RING EXITS THE GRINDER
THROUGH A GAUGE
THAT CHECKS THE DIAMETER.
NEXT, THE OUTER RING'S RACEWAY
GOES FOR GRINDING.
ABRASIVE STONE WHEELS
WITH AN OIL COOLANT
SHAPE THE SURFACE TO PRECISELY
THE CORRECT ROUNDNESS AND SIZE.
THE INNER RING AND RACEWAY
GO THROUGH A SIMILAR MACHINE.
NOW THE RINGS GO FOR POLISHING.
AN ABRASIVE STONE
LUBRICATED WITH OIL
POLISHES THE STEEL SURFACE
UNTIL YOU CAN SEE A REFLECTION.
HERE'S THE BEFORE AND AFTER.
NEXT STOP -- WASHING.
THEY COAT THE RINGS
WITH THICK OIL
AND A FINE STONE GRIT.
THEY CLEAN THE RACEWAYS
WITH KEROSENE.
ELSEWHERE IN THE PLANT,
THEY CLASSIFY THE STEEL BALLS
ACCORDING TO SIZE.
THESE BALLS STARTED OUT
AS STEEL WIRE.
A MACHINE CUT THEM INTO PIECES
AND A DIE PUNCHED THEM
INTO ROUGH BALLS.
THOSE ROUGH BALLS
GO INTO A GRINDER,
WHICH REMOVES THE BUMPS.
THEN OTHER MACHINES
ROUND THEM OUT
AND GIVE THEM A MIRROR FINISH.
THIS ENTIRE PROCESS
TAKES A FEW DAYS.
THE BALLS GO THROUGH A FURNACE
TO HARDEN.
THEN THEY GET A BATH
IN CLEANING SOLVENT.
AFTER SEVERAL QUALITY CHECKS,
THE FINISHED BALLS
GO INTO HOPPERS.
THE HOPPERS LOAD ONTO
THE AUTOMATIC ASSEMBLY MACHINE.
THE BALL FEEDER SENDS THE BALLS
THROUGH TUBES
TO A BALL PUSHER THAT FEEDS
THE CORRECT QUANTITY OF BALLS
INTO THE RACEWAYS
OF THE NOW-REASSEMBLED
INNER AND OUTER RINGS.
A BALL DIVIDER POSITIONS
THE BALLS EVENLY
AROUND THE RACEWAYS.
NEXT COMES THE BALL CAGE,
A METAL CAGE THAT RETAINS
THE BALLS IN POSITION
AROUND THE RACEWAYS.
THE FIRST MACHINE
INSTALLS HALF OF THE CAGE,
THE HALF WITH RIVET HOLES.
THE NEXT MACHINE
CAREFULLY POSITIONS
THE OTHER HALF OF THE CAGE,
THE HALF WITH RIVETS.
THE MACHINE TEST-SPINS
THE BEARING,
THEN RIVETS THE TWO HALVES
OF THE BALL CAGE TOGETHER.
THE BEARING
IS NOW FULLY ASSEMBLED.
NOW IT GOES INTO A SOLVENT BATH,
THEN TO A SERIES OF AUTOMATED
QUALITY-CONTROL TESTS.
THIS NOISE-VIBRATION TESTER
MAKES SURE THE BALL BEARING
OPERATES QUIETLY.
SOME TYPES OF BEARINGS
ARE LUBRICATED WITH GREASE.
A MACHINE SQUIRTS GREASE EVENLY
INTO THE BEARINGS' RACEWAYS,
THEN INSERTS A RUBBER SEAL
TO CONTAIN THE GREASE.
A FINAL QUALITY-CONTROL TEST --
AN AUTOMATED SCALE
TOSSES OUT ANY BUM BEARINGS
THAT AREN'T THE REQUIRED WEIGHT.
THE GOOD ONES MOVE ON
TO THE LASER,
WHICH MARKS THEM
WITH INFORMATION
SUCH AS THE PART NUMBER
AND THE TRADEMARK.
Narrator: WHAT IS
GENETICALLY MODIFIED FOOD?
SCIENTISTS MANIPULATE
THE GENES IN CROP SEEDS
TO INCREASE YIELD
OR TO MAKE THE CROP
MORE RESISTANT
TO DISEASE OR INSECTS.
THERE'S A WORLDWIDE DEBATE
OVER WHETHER THIS MANIPULATION
OF NATURE POSES A RISK
TO OUR HEALTH
OR TO THE ENVIRONMENT.
WE'RE SO USED TO THEM
THAT WE BARELY NOTICE
THAT ELECTRICAL WIRES
ARE ALL AROUND US.
THEY'RE IN AERIAL
AND UNDERGROUND CABLES
RUNNING ALONG OUR STREETS
AND TO OUR HOMES.
THEY'RE BEHIND OUR WALLS
AND INSIDE
OUR ELECTRICAL APPLIANCES.
TO MAKE COLOR-CODED
ELECTRICAL WIRES,
THEY USE WHAT'S CALLED ROD,
MADE OF EITHER SOLID COPPER
OR SOLID ALUMINUM.
THEY FEED THE ROD INTO A MACHINE
THAT DRAWS IT OUT
THROUGH A SERIES OF LUBRICATED
PULLEYS AND DIES --
STRETCHING, LENGTHENING,
AND THINNING IT OUT...
...AND EVENTUALLY WINDING IT
ONTO A LARGE BOBBIN.
WHAT WAS ONCE A ROD
4/10 OF AN INCH IN DIAMETER
IS NOW JUST 8/100 OF AN INCH,
THE WIDTH OF ABOUT
A DOZEN HUMAN HAIRS.
THEY LOAD THE BOBBIN
ONTO WHAT'S CALLED
A STRANDING MACHINE.
THEY COLD-WELD THE END
OF ONE BOBBIN TO ANOTHER,
GUARANTEEING
AN UNINTERRUPTED FLOW
ONCE THEY START UP THE MACHINE.
AT HIGH SPEED,
THE STRANDING MACHINE
TWISTS SEVEN WIRES TOGETHER,
FORMING AN ELECTRICAL CONDUCTOR,
ALSO CALLED A BEAR CONDUCTOR.
THIS IS A LOW-VOLTAGE
CONDUCTOR --
UNDER 1,000 VOLTS --
THE KIND YOU FIND IN THE CABLES
THAT RUN ELECTRICITY
TO YOUR HOME.
BEAR CONDUCTORS
NEED TO BE INSULATED
SO THE PEOPLE HANDLING THEM
WON'T GET AN ELECTRIC SHOCK.
A PLASTIC EXTRUSION MACHINE
COATS THE CONDUCTOR
WITH POLYETHYLENE OR PVC.
THIS INSULATES THE CONDUCTOR.
THIS IS WHAT THE POLYETHYLENE
LOOKS LIKE IN ITS RAW FORM.
AS THE CONDUCTOR EXITS
THE MACHINE
WITH ITS NEW INSULATION,
A PRECISION LASER
GAUGES THE DIAMETER
TO MAKE SURE THE INSULATION
IS UNIFORM
AND THE RIGHT DIMENSION.
THE EXTRUSION PROCESS
HAS HEATED UP THE CONDUCTOR,
SO IT HAS TO BE COOLED DOWN
WITH WATER.
SOMETIMES TWO OR MORE CONDUCTORS
ARE TWISTED TOGETHER.
WHEN THAT'S THE CASE,
A PRINTING MACHINE APPLIES
A WHITE STRIPE
TO IDENTIFY WHICH IS WHICH.
THE CLIENT WHO'S ORDERED
THE CONDUCTORS
SPECIFIES THE COLORS
OF INSULATION.
IT CHOOSES THEM BASED ON
HOW IT WANTS TO COLOR-CODE
ITS ELECTRICAL WIRING.
SEVERAL CONDUCTORS
ARE OFTEN GROUPED TOGETHER
TO FORM A CABLE.
THE PLANT PERFORMS
A VOLTAGE TEST,
IMMERSING THE CABLES IN WATER
TO MAKE SURE
THEY DON'T SHORT-CIRCUIT.
THESE MEDIUM-VOLTAGE CABLES
CAN CARRY
FROM 1,000 TO 46,000 VOLTS
OF ELECTRICITY.
THEY'RE THE TYPE USED
FOR UNDERGROUND POWER LINES.
THEY'RE INSULATED THE SAME WAY
LOW-VOLTAGE CABLES ARE.
THE PLANT PRINTS THE DATE
OF MANUFACTURE, THE VOLTAGE,
AND ANY OTHER INFORMATION
THE CLIENT HAS REQUESTED.
THE CABLE GOES ONTO
A REEL TO BE TESTED
BEFORE IT'S SHIPPED OUT
TO ITS DESTINATION.
IN THE MIDDLE OF THE CABLE,
SURROUNDED BY
COPPER GROUNDING WIRES
AND A HOST OF OTHER COMPONENTS
IS THE HEART
OF THE ELECTRICAL CABLE --
THE BEAR CONDUCTOR.
Narrator: MANY MACHINE PARTS
ARE SIMPLY STAMPED OR MACHINED
OUT OF SOLID METAL,
BUT PARTS WITH COMPLEX SHAPES
OR THIN WALLS
CAN'T BE MADE THAT WAY.
THEY HAVE TO BE CAST
USING A TECHNIQUE CALLED
"LOST WAX PROCESS CASTING."
IT TAKES ANYWHERE FROM A WEEK
TO A MONTH
TO MANUFACTURE
A CAST-METAL PART,
DEPENDING ON ITS COMPLEXITY.
THE FIRST STEP IS TO INJECT WAX
INTO AN ALUMINUM DIE,
WHICH IS ESSENTIALLY A MOLD
WHOSE CAVITY IS IN THE SHAPE
OF THE PART.
THIS CREATES A WAX MODEL
SLIGHTLY LARGER THAN
THE FINISHED PART WILL BE.
THEY'LL USE THIS WAX MODEL
TO MAKE A MOLD
OUT OF A CERAMIC MATERIAL.
THE MOLD HAS TO BE LARGER
THAN THE FINISHED PART
BECAUSE METAL SHRINKS
AS IT COOLS.
ONCE THE WAX MODEL IS READY,
THEY STAMP ON A CODE
TO TELL THE FOUNDRY WORKERS
WHAT TYPE OF METAL TO USE
WHEN THEY CAST THE PART.
NEXT, USING A HOT IRON,
THEY ATTACH WAX COMPONENTS
TO CREATE WHAT'S CALLED
A METAL DELIVERY SYSTEM --
CHANNELS THAT WILL FUNNEL
THE MOLTEN METAL
INTO THE MOLD'S CAVITY.
NEXT, THEY DIP THIS WAX ASSEMBLY
INTO A CERAMIC SOLUTION
CALLED "SLURRY."
THEY DO THIS BY HAND
TO PREVENT IMPERFECTIONS
THAT WOULD CAUSE DEFECTS
IN THE CASTING.
TO STRENGTHEN THE SLURRY,
THEY COAT IT
IN A FINE ZIRCONIUM SAND,
THEN LET IT DRY.
A ROBOT THEN KEEPS REPEATING
THE PROCESS WITH COARSER SAND
UNTIL THE CERAMIC SHELL
SURROUNDING THE WAX ASSEMBLY
IS ABOUT 3/10 OF AN INCH THICK.
THIS TAKES FIVE DAYS.
NOW THE CERAMIC-COVERED
WAX ASSEMBLY
IS READY FOR WHAT THEY CALL
THE DEWAX.
WORKERS PLACE IT IN A HOT-STEAM
CHAMBER CALLED AN AUTOCLAVE
FOR 5 TO 10 MINUTES.
THIS MELTS THE WAX
RIGHT OUT OF THE SHELL,
CREATING A CERAMIC MOLD
WHOSE CAVITY IS IN THE SHAPE
OF THE PART.
ONCE THE MOLD HAS DRIED OUT,
WORKERS CAN BEGIN
TO CAST THE PART.
FIRST THEY PUT THE COLD MOLD
INTO AN OVEN
AND HEAT IT UP
FOR TWO TO THREE HOURS.
THIS PREVENTS THE MOLD
FROM CRACKING FROM SHOCK
WHEN IT COMES INTO CONTACT
WITH MOLTEN METAL
THAT'S CLOSE TO 2,200 DEGREES
FAHRENHEIT.
THEY POUR THE METAL
INTO THE MOLD'S CAVITY,
THEN LET IT COOL
AND HARDEN AT ROOM TEMPERATURE.
IT TAKES TWO HOURS FOR ALUMINUM,
FOUR TO FIVE HOURS FOR STEEL.
ONCE THE METAL HAS COOLED
AND SOLIDIFIED,
THEY BREAK OFF THE CERAMIC MOLD
USING A VIBRATING HAMMER.
THIS TAKES ABOUT FIVE MINUTES.
THEY SAW OFF
THE METAL DELIVERY SYSTEM...
...THEN GRIND
THE SURFACE SMOOTH.
THE FINAL STEP IS TO MAKE SURE
THE PART CAME TO
THE EXACT DIMENSIONS
SPECIFIED
IN THE TECHNICAL DRAWING.
THIS IS CALLED "SIZING."
STEEL PARTS HAVE TO BE HEATED UP
IN AN OVEN FOR SIZING.
ALUMINUM PARTS ARE SIZED COLD.
TECHNICIANS USE A SERIES
OF TOOLS AND PRESSES
TO MEASURE THE PART.
IF IT DOESN'T MEET
SPECIFICATIONS,
IT'S EITHER REWORKED
OR SIMPLY DISCARDED.
THEY USE SOPHISTICATED EQUIPMENT
SUCH AS THIS OPTICAL COMPARATOR
TO CHECK THE ANGLES AND RADIUSES
AND THIS COORDINATE MEASURING
MACHINE TO VERIFY DIMENSIONS.
LOST WAX PROCESS CASTING
IS USED TO MAKE METAL PARTS
FOR ALL TYPES OF MACHINES
AND EQUIPMENT,
EVERYTHING FROM MILITARY WEAPONS
TO SNOWMOBILES.
Narrator:
SINCE THE INDUSTRIAL REVOLUTION,
MANUFACTURING HAS BECOME
INCREASINGLY AUTOMATED.
IT'S ABOUT TIME
"HOW IT'S MADE" PAID TRIBUTE
TO THAT MARVELOUS FEAT
OF ENGINEERING,
THE AUTOMATED MACHINE.
UNTIL THE 1780s,
GOODS WERE MADE ONE BY ONE
IN A HOME OR WORKSHOP.
THEN CAME
THE INDUSTRIAL REVOLUTION,
THE MASS PRODUCTION OF PRODUCTS
IN HUGE FACTORIES.
INDUSTRY'S NEXT REVOLUTION
WAS AUTOMATION,
MADE POSSIBLE
BY COMPUTER TECHNOLOGY.
BY THE 1970s,
TWO CENTURIES AFTER THE START
OF THE INDUSTRIAL REVOLUTION,
ROBOTS BEGAN REPLACING HUMANS
ON THE PRODUCTION LINES.
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"...
BALL BEARINGS...
ELECTRICAL WIRES...
LOST WAX CASTING...
AND AUTOMATED MACHINES.
WITH ALL THE HIGH-TECH HOOPLA
THESE DAYS,
THE LOWLY BALL BEARING
GETS FORGOTTEN.
BUT MANY MACHINE PARTS
NEED BALL BEARINGS TO ROTATE.
THEY'RE IN HOUSEHOLD APPLIANCES,
INDUSTRIAL MACHINES,
AND CAR ENGINE PARTS
SUCH AS ALTERNATORS AND FANS.
THIS IS WHAT'S CALLED
A DEEP GROOVE RADIAL
BALL BEARING.
IT HAS STEEL BALLS THAT MOVE
INSIDE TRACKS CALLED RACEWAYS.
THE RACEWAYS ARE CARVED INTO
A SET OF HEAVY-DUTY STEEL RINGS.
THE BALLS ARE MADE
OF THE SAME TYPE OF STEEL.
THEY FIRST PREPARE
TO SHAPE THE RINGS
TO THE RIGHT THICKNESS.
THEY INSERT THE INNER RING
INTO THE OUTER RING.
THE SET THEN PASSES
THROUGH A GRINDER
THAT ALTERS THE WIDTH
TO THE CORRECT THICKNESS.
A GAUGE CHECKS THE WIDTH
OF EACH RING AS IT EXITS.
NOW THEY SEPARATE
THE INNER AND OUTER RINGS
IN ORDER TO GRIND
THEIR OUTER CIRCUMFERENCE
ON SEPARATE MACHINES.
THE OUTER RING
ENTERS THE GRINDER,
WHICH SHAPES ITS OUTER SURFACE
TO A PRECISE ROUNDNESS
AND DIAMETER.
A WATER-BASED LIQUID
KEEPS THE RING FROM OVERHEATING,
WHICH WOULD CAUSE WARPING.
THE RING EXITS THE GRINDER
THROUGH A GAUGE
THAT CHECKS THE DIAMETER.
NEXT, THE OUTER RING'S RACEWAY
GOES FOR GRINDING.
ABRASIVE STONE WHEELS
WITH AN OIL COOLANT
SHAPE THE SURFACE TO PRECISELY
THE CORRECT ROUNDNESS AND SIZE.
THE INNER RING AND RACEWAY
GO THROUGH A SIMILAR MACHINE.
NOW THE RINGS GO FOR POLISHING.
AN ABRASIVE STONE
LUBRICATED WITH OIL
POLISHES THE STEEL SURFACE
UNTIL YOU CAN SEE A REFLECTION.
HERE'S THE BEFORE AND AFTER.
NEXT STOP -- WASHING.
THEY COAT THE RINGS
WITH THICK OIL
AND A FINE STONE GRIT.
THEY CLEAN THE RACEWAYS
WITH KEROSENE.
ELSEWHERE IN THE PLANT,
THEY CLASSIFY THE STEEL BALLS
ACCORDING TO SIZE.
THESE BALLS STARTED OUT
AS STEEL WIRE.
A MACHINE CUT THEM INTO PIECES
AND A DIE PUNCHED THEM
INTO ROUGH BALLS.
THOSE ROUGH BALLS
GO INTO A GRINDER,
WHICH REMOVES THE BUMPS.
THEN OTHER MACHINES
ROUND THEM OUT
AND GIVE THEM A MIRROR FINISH.
THIS ENTIRE PROCESS
TAKES A FEW DAYS.
THE BALLS GO THROUGH A FURNACE
TO HARDEN.
THEN THEY GET A BATH
IN CLEANING SOLVENT.
AFTER SEVERAL QUALITY CHECKS,
THE FINISHED BALLS
GO INTO HOPPERS.
THE HOPPERS LOAD ONTO
THE AUTOMATIC ASSEMBLY MACHINE.
THE BALL FEEDER SENDS THE BALLS
THROUGH TUBES
TO A BALL PUSHER THAT FEEDS
THE CORRECT QUANTITY OF BALLS
INTO THE RACEWAYS
OF THE NOW-REASSEMBLED
INNER AND OUTER RINGS.
A BALL DIVIDER POSITIONS
THE BALLS EVENLY
AROUND THE RACEWAYS.
NEXT COMES THE BALL CAGE,
A METAL CAGE THAT RETAINS
THE BALLS IN POSITION
AROUND THE RACEWAYS.
THE FIRST MACHINE
INSTALLS HALF OF THE CAGE,
THE HALF WITH RIVET HOLES.
THE NEXT MACHINE
CAREFULLY POSITIONS
THE OTHER HALF OF THE CAGE,
THE HALF WITH RIVETS.
THE MACHINE TEST-SPINS
THE BEARING,
THEN RIVETS THE TWO HALVES
OF THE BALL CAGE TOGETHER.
THE BEARING
IS NOW FULLY ASSEMBLED.
NOW IT GOES INTO A SOLVENT BATH,
THEN TO A SERIES OF AUTOMATED
QUALITY-CONTROL TESTS.
THIS NOISE-VIBRATION TESTER
MAKES SURE THE BALL BEARING
OPERATES QUIETLY.
SOME TYPES OF BEARINGS
ARE LUBRICATED WITH GREASE.
A MACHINE SQUIRTS GREASE EVENLY
INTO THE BEARINGS' RACEWAYS,
THEN INSERTS A RUBBER SEAL
TO CONTAIN THE GREASE.
A FINAL QUALITY-CONTROL TEST --
AN AUTOMATED SCALE
TOSSES OUT ANY BUM BEARINGS
THAT AREN'T THE REQUIRED WEIGHT.
THE GOOD ONES MOVE ON
TO THE LASER,
WHICH MARKS THEM
WITH INFORMATION
SUCH AS THE PART NUMBER
AND THE TRADEMARK.
Narrator: WHAT IS
GENETICALLY MODIFIED FOOD?
SCIENTISTS MANIPULATE
THE GENES IN CROP SEEDS
TO INCREASE YIELD
OR TO MAKE THE CROP
MORE RESISTANT
TO DISEASE OR INSECTS.
THERE'S A WORLDWIDE DEBATE
OVER WHETHER THIS MANIPULATION
OF NATURE POSES A RISK
TO OUR HEALTH
OR TO THE ENVIRONMENT.
WE'RE SO USED TO THEM
THAT WE BARELY NOTICE
THAT ELECTRICAL WIRES
ARE ALL AROUND US.
THEY'RE IN AERIAL
AND UNDERGROUND CABLES
RUNNING ALONG OUR STREETS
AND TO OUR HOMES.
THEY'RE BEHIND OUR WALLS
AND INSIDE
OUR ELECTRICAL APPLIANCES.
TO MAKE COLOR-CODED
ELECTRICAL WIRES,
THEY USE WHAT'S CALLED ROD,
MADE OF EITHER SOLID COPPER
OR SOLID ALUMINUM.
THEY FEED THE ROD INTO A MACHINE
THAT DRAWS IT OUT
THROUGH A SERIES OF LUBRICATED
PULLEYS AND DIES --
STRETCHING, LENGTHENING,
AND THINNING IT OUT...
...AND EVENTUALLY WINDING IT
ONTO A LARGE BOBBIN.
WHAT WAS ONCE A ROD
4/10 OF AN INCH IN DIAMETER
IS NOW JUST 8/100 OF AN INCH,
THE WIDTH OF ABOUT
A DOZEN HUMAN HAIRS.
THEY LOAD THE BOBBIN
ONTO WHAT'S CALLED
A STRANDING MACHINE.
THEY COLD-WELD THE END
OF ONE BOBBIN TO ANOTHER,
GUARANTEEING
AN UNINTERRUPTED FLOW
ONCE THEY START UP THE MACHINE.
AT HIGH SPEED,
THE STRANDING MACHINE
TWISTS SEVEN WIRES TOGETHER,
FORMING AN ELECTRICAL CONDUCTOR,
ALSO CALLED A BEAR CONDUCTOR.
THIS IS A LOW-VOLTAGE
CONDUCTOR --
UNDER 1,000 VOLTS --
THE KIND YOU FIND IN THE CABLES
THAT RUN ELECTRICITY
TO YOUR HOME.
BEAR CONDUCTORS
NEED TO BE INSULATED
SO THE PEOPLE HANDLING THEM
WON'T GET AN ELECTRIC SHOCK.
A PLASTIC EXTRUSION MACHINE
COATS THE CONDUCTOR
WITH POLYETHYLENE OR PVC.
THIS INSULATES THE CONDUCTOR.
THIS IS WHAT THE POLYETHYLENE
LOOKS LIKE IN ITS RAW FORM.
AS THE CONDUCTOR EXITS
THE MACHINE
WITH ITS NEW INSULATION,
A PRECISION LASER
GAUGES THE DIAMETER
TO MAKE SURE THE INSULATION
IS UNIFORM
AND THE RIGHT DIMENSION.
THE EXTRUSION PROCESS
HAS HEATED UP THE CONDUCTOR,
SO IT HAS TO BE COOLED DOWN
WITH WATER.
SOMETIMES TWO OR MORE CONDUCTORS
ARE TWISTED TOGETHER.
WHEN THAT'S THE CASE,
A PRINTING MACHINE APPLIES
A WHITE STRIPE
TO IDENTIFY WHICH IS WHICH.
THE CLIENT WHO'S ORDERED
THE CONDUCTORS
SPECIFIES THE COLORS
OF INSULATION.
IT CHOOSES THEM BASED ON
HOW IT WANTS TO COLOR-CODE
ITS ELECTRICAL WIRING.
SEVERAL CONDUCTORS
ARE OFTEN GROUPED TOGETHER
TO FORM A CABLE.
THE PLANT PERFORMS
A VOLTAGE TEST,
IMMERSING THE CABLES IN WATER
TO MAKE SURE
THEY DON'T SHORT-CIRCUIT.
THESE MEDIUM-VOLTAGE CABLES
CAN CARRY
FROM 1,000 TO 46,000 VOLTS
OF ELECTRICITY.
THEY'RE THE TYPE USED
FOR UNDERGROUND POWER LINES.
THEY'RE INSULATED THE SAME WAY
LOW-VOLTAGE CABLES ARE.
THE PLANT PRINTS THE DATE
OF MANUFACTURE, THE VOLTAGE,
AND ANY OTHER INFORMATION
THE CLIENT HAS REQUESTED.
THE CABLE GOES ONTO
A REEL TO BE TESTED
BEFORE IT'S SHIPPED OUT
TO ITS DESTINATION.
IN THE MIDDLE OF THE CABLE,
SURROUNDED BY
COPPER GROUNDING WIRES
AND A HOST OF OTHER COMPONENTS
IS THE HEART
OF THE ELECTRICAL CABLE --
THE BEAR CONDUCTOR.
Narrator: MANY MACHINE PARTS
ARE SIMPLY STAMPED OR MACHINED
OUT OF SOLID METAL,
BUT PARTS WITH COMPLEX SHAPES
OR THIN WALLS
CAN'T BE MADE THAT WAY.
THEY HAVE TO BE CAST
USING A TECHNIQUE CALLED
"LOST WAX PROCESS CASTING."
IT TAKES ANYWHERE FROM A WEEK
TO A MONTH
TO MANUFACTURE
A CAST-METAL PART,
DEPENDING ON ITS COMPLEXITY.
THE FIRST STEP IS TO INJECT WAX
INTO AN ALUMINUM DIE,
WHICH IS ESSENTIALLY A MOLD
WHOSE CAVITY IS IN THE SHAPE
OF THE PART.
THIS CREATES A WAX MODEL
SLIGHTLY LARGER THAN
THE FINISHED PART WILL BE.
THEY'LL USE THIS WAX MODEL
TO MAKE A MOLD
OUT OF A CERAMIC MATERIAL.
THE MOLD HAS TO BE LARGER
THAN THE FINISHED PART
BECAUSE METAL SHRINKS
AS IT COOLS.
ONCE THE WAX MODEL IS READY,
THEY STAMP ON A CODE
TO TELL THE FOUNDRY WORKERS
WHAT TYPE OF METAL TO USE
WHEN THEY CAST THE PART.
NEXT, USING A HOT IRON,
THEY ATTACH WAX COMPONENTS
TO CREATE WHAT'S CALLED
A METAL DELIVERY SYSTEM --
CHANNELS THAT WILL FUNNEL
THE MOLTEN METAL
INTO THE MOLD'S CAVITY.
NEXT, THEY DIP THIS WAX ASSEMBLY
INTO A CERAMIC SOLUTION
CALLED "SLURRY."
THEY DO THIS BY HAND
TO PREVENT IMPERFECTIONS
THAT WOULD CAUSE DEFECTS
IN THE CASTING.
TO STRENGTHEN THE SLURRY,
THEY COAT IT
IN A FINE ZIRCONIUM SAND,
THEN LET IT DRY.
A ROBOT THEN KEEPS REPEATING
THE PROCESS WITH COARSER SAND
UNTIL THE CERAMIC SHELL
SURROUNDING THE WAX ASSEMBLY
IS ABOUT 3/10 OF AN INCH THICK.
THIS TAKES FIVE DAYS.
NOW THE CERAMIC-COVERED
WAX ASSEMBLY
IS READY FOR WHAT THEY CALL
THE DEWAX.
WORKERS PLACE IT IN A HOT-STEAM
CHAMBER CALLED AN AUTOCLAVE
FOR 5 TO 10 MINUTES.
THIS MELTS THE WAX
RIGHT OUT OF THE SHELL,
CREATING A CERAMIC MOLD
WHOSE CAVITY IS IN THE SHAPE
OF THE PART.
ONCE THE MOLD HAS DRIED OUT,
WORKERS CAN BEGIN
TO CAST THE PART.
FIRST THEY PUT THE COLD MOLD
INTO AN OVEN
AND HEAT IT UP
FOR TWO TO THREE HOURS.
THIS PREVENTS THE MOLD
FROM CRACKING FROM SHOCK
WHEN IT COMES INTO CONTACT
WITH MOLTEN METAL
THAT'S CLOSE TO 2,200 DEGREES
FAHRENHEIT.
THEY POUR THE METAL
INTO THE MOLD'S CAVITY,
THEN LET IT COOL
AND HARDEN AT ROOM TEMPERATURE.
IT TAKES TWO HOURS FOR ALUMINUM,
FOUR TO FIVE HOURS FOR STEEL.
ONCE THE METAL HAS COOLED
AND SOLIDIFIED,
THEY BREAK OFF THE CERAMIC MOLD
USING A VIBRATING HAMMER.
THIS TAKES ABOUT FIVE MINUTES.
THEY SAW OFF
THE METAL DELIVERY SYSTEM...
...THEN GRIND
THE SURFACE SMOOTH.
THE FINAL STEP IS TO MAKE SURE
THE PART CAME TO
THE EXACT DIMENSIONS
SPECIFIED
IN THE TECHNICAL DRAWING.
THIS IS CALLED "SIZING."
STEEL PARTS HAVE TO BE HEATED UP
IN AN OVEN FOR SIZING.
ALUMINUM PARTS ARE SIZED COLD.
TECHNICIANS USE A SERIES
OF TOOLS AND PRESSES
TO MEASURE THE PART.
IF IT DOESN'T MEET
SPECIFICATIONS,
IT'S EITHER REWORKED
OR SIMPLY DISCARDED.
THEY USE SOPHISTICATED EQUIPMENT
SUCH AS THIS OPTICAL COMPARATOR
TO CHECK THE ANGLES AND RADIUSES
AND THIS COORDINATE MEASURING
MACHINE TO VERIFY DIMENSIONS.
LOST WAX PROCESS CASTING
IS USED TO MAKE METAL PARTS
FOR ALL TYPES OF MACHINES
AND EQUIPMENT,
EVERYTHING FROM MILITARY WEAPONS
TO SNOWMOBILES.
Narrator:
SINCE THE INDUSTRIAL REVOLUTION,
MANUFACTURING HAS BECOME
INCREASINGLY AUTOMATED.
IT'S ABOUT TIME
"HOW IT'S MADE" PAID TRIBUTE
TO THAT MARVELOUS FEAT
OF ENGINEERING,
THE AUTOMATED MACHINE.
UNTIL THE 1780s,
GOODS WERE MADE ONE BY ONE
IN A HOME OR WORKSHOP.
THEN CAME
THE INDUSTRIAL REVOLUTION,
THE MASS PRODUCTION OF PRODUCTS
IN HUGE FACTORIES.
INDUSTRY'S NEXT REVOLUTION
WAS AUTOMATION,
MADE POSSIBLE
BY COMPUTER TECHNOLOGY.
BY THE 1970s,
TWO CENTURIES AFTER THE START
OF THE INDUSTRIAL REVOLUTION,
ROBOTS BEGAN REPLACING HUMANS
ON THE PRODUCTION LINES.
CAPTIONS PAID FOR BY
DISCOVERY COMMUNICATIONS, INC.
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