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Narrator:
Today on "How it's made"...
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Springs...
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...Pavers...
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...And pianos.
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A spring
Is a flexible metal device
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That returns to
Its original shape or position
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After it's stretched,
Squeezed, or twisted.
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00:00:59,344 --> 00:01:03,517
Springs were first used in
Clocks during the 16th century
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And, starting in the late 1800s,
In chair seats and bedding.
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Today springs pop up all over.
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They're crucial components
Of modern technology.
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Different types of springs
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Include compression,
On the right,
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And extension, on the left.
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00:01:18,758 --> 00:01:20,172
During use,
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These torsion springs
Will twist at one or both ends.
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Workers start
With rolls of steel cord.
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The cord diameters range in size
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Depending on the type of springs
Being made.
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A machine called a dereeler
Unwinds the roll,
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Feeding it to a computer-guided
Forming machine.
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This forming machine forces
The cord through a channel,
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Shapes it into a coil,
And then cuts it into segments.
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Small wheels and a metal shaft
Guide the cord into shape.
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These are torsion springs for
Use in the automotive industry,
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Which relies heavily
On a variety of springs.
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The average car, for example,
Has about 350 of them.
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A cone-shaped yellow sensor
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Detects the correct angle
Of each spring.
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A good reading is required
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So the machine can move
The next spring forward
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Through the channel
To be formed.
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This machine can produce
Up to 2,000 springs per hour,
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Depending on their size.
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Here another larger
Forming machine
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Creates extension springs
That are over 6 inches long.
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A mechanical arm grabs the coil
And chops it into segments
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After it's formed in a channel.
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As the coil emerges,
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Another mechanical arm steadies
It to prevent it from vibrating.
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This keeps
The spring tension constant,
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Enabling the machine
To produce at top speed.
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In slow motion,
You can see how the machine
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Grabs the coil's first ring
And bends it to form a hook.
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This all takes place as the coil
Emerges from the channel.
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A vise then secures the last
Ring on the end of the coil,
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While another arm twists it
To make the spring's other hook.
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Slowed down,
You see how two arms
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Surround the coil
Being held in the vise.
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One arm then grabs the last ring
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While the other arm
Twists it upward.
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This machine
Makes compression springs --
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A model with tapered ends
That's often used in seat belts.
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A metal probe detects the
Correct length of the springs
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After they're formed.
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The machine has four
Rotary shafts called cams.
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A computer ensures each spring
Has the desired specs.
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The springs are also heated
To relax the metal.
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This gives them the ability
To retain their shape
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After flexing.
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Another machine creates longer,
Thicker torsion springs.
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It shapes the cord into a coil
With a shaft
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And then passes it over a tube
To steady it.
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This ensures the spring
Will have the required tension.
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Springs can be as thin
As a human hair
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Or as thick as a broom handle.
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Train wheels, for instance,
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Include some of the industry's
Thickest compression springs.
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This machine
Makes another type of spring,
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Often called wire forms.
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They're flexible steel cords
Curved or bent at an angle.
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These ones, shaped like a "W,"
Are used in ovens.
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Here, a worker places a spring
Into a machine
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That makes its hooks.
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He uses an adaptor
To avoid hurting his fingers.
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He places each one individually
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Because specs for springs
Can vary by minute amounts.
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This company makes some springs
With hooks made of two rings
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Instead of one.
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Clients order them this way
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Because the hooks
Are more durable.
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Custom orders for springs
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Can range from just a few
To many thousand.
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This is another type
Of wire form.
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It'll be used in a firearm.
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A worker assembles it by hand
Because it's so intricate.
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After joining two base pieces,
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He places them into a small die.
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Using a foot pedal,
He controls the die
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To bend the segments
And complete the assembly.
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To check the
Compression spring's tension,
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A worker tests it
With a weight gauge.
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The correct tension varies
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Depending on what
The client wants.
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A 1 1/2-inch long spring,
For example,
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Might need to withstand
5 pounds of tension
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When compressed to 1 inch.
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To test an extension spring,
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Workers just add hooks
To the weight gauge.
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Whether they're extension,
Compression,
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Torsion, or wire form,
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And whether they're inside pens
Or satellites,
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Springs prove that some
Old ideas definitely still work.
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Narrator: you could say that
Interlocking concrete pavers
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Came out of the rubble
Of world war ii.
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In post-war holland,
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There weren't enough clay pavers
To rebuild city streets,
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So the dutch
Began making concrete pavers.
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The germans
Refined the technology
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And exported it
To north america,
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And they found
A quick road to success.
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These pavers are solid,
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And the interlocking design
Disperses weight,
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Easing the load on the road.
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To make these pavers,
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A conveyor belt delivers
Concrete sand to a weigh belt
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That weighs the coarse sand
As it falls onto it.
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The weigh belt
Carries the sand forward,
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While another conveyor belt
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Unloads stone chips
To be weighed.
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These chips are no longer
Than an 1/8 inch.
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The ratio of sand
To stone chips varies
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Depending on the type
Of paver being made.
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The weigh belt transports
The stone chips forward
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Along with the coarse sand.
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Both are en route
To the skip hoist.
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They spill off the conveyor
Into the skip hoist,
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Which is essentially
A bucket on rails.
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Cables pull
The loaded bucket upwards.
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It stops about 30 feet up,
Just above a big concrete mixer.
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A trap door opens and dumps
The sand and stone chips
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Into the mixer.
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Six giant steel paddles mix
And then rotate and mix again,
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While cement
Is added automatically
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Through several nozzles
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On the side
Of this enormous mixing bowl.
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Making pavers
Is a bit like baking cookies.
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Too much or too little liquid
In the batter,
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And it won't bake properly.
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Water is added until
The consistency is just right.
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Nozzles also shoot a pigment
Into the mix to tint it.
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The mixture
Looks dry and crumbly,
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But the recipe gives it
Just enough moisture
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To form the concrete.
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Now a filling wagon
Spreads the mix
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Over a steel mold containing
Up to 50 paver-shaped cavities.
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The mold presshead applies
11 tons of vibrating pressure.
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This pulsating force compacts
The mixture in the paver mold
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And removes any air pockets,
Which could weaken the pavers.
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Hydraulic cylinders
Lift the mold,
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Leaving the pavers
On the press board.
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The press board slides out,
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And the mold once again
Gets filled in
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And makes another
50 paver stones.
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It only takes about 10 seconds
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To mold, compact,
And release a batch of pavers.
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The press boards filled
With pavers slide into a rack.
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A hydraulic chain hoist
Lifts each board
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Into a large holding rack.
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There, a special moving wagon,
Called a finger wagon,
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Picks up all the boards
From the rack
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In just one move.
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The electrical wagon moves
Along a rail to a curing kiln,
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Where it's almost
100 degrees fahrenheit.
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The pavers
Actually generate the heat,
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Due to a chemical reaction
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From the combination
Of cement and water.
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About 12 hours later,
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The finger wagon carts
The pavers out of the kiln.
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They are now 70% cured as
A result of the chemical process
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That binds the cement,
Sand, and gravel,
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Causing the pavers to harden.
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The rest of the curing will
Happen over the next 28 days.
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The pavers
Are now sturdy enough to handle,
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So four steel arms
With rubber pads move in
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And straighten the stones
On the board.
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These alignment arms
Are hydraulically driven.
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They arrange the concrete pavers
So they interlock snugly.
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00:10:12,586 --> 00:10:15,758
Now hydraulic clamp arms
Lift the pavers off the board
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And begin to pile them up.
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They're making a cube of stone.
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This stacking machine
Is called a cuber.
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It packs 9 or 10 layers
Of pavers on top of one another
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To make this cube.
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The cube
Is actually called a bundle.
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It will be strapped
And shipped out to the jobsite.
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These concrete pavers
Will be on the road soon
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Building and rebuilding
Our streets.
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Narrator: piano keys
Were once made out of ivory.
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This sought-after material
Isn't used anymore
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Because it's banned to protect
Elephants who were killed
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For their ivory tusks.
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Pianists now play plastic keys,
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But the techniques involved
In manufacturing a piano
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Haven't changed much and still
Rely on handcraftsmanship,
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Just like a century ago.
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Beautiful music is a triumph,
But so is the piano itself...
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...Made of inner and outer rims,
A soundboard,
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Treble and bass bridges over
Which the strings are stretched,
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00:11:56,000 --> 00:11:58,586
And a heavy cast-iron plate.
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00:12:00,482 --> 00:12:02,068
To make a piano rim,
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00:12:02,068 --> 00:12:05,931
Automated rollers spread glue
Onto sheets of hard rock maple,
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Coating both sides.
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00:12:07,758 --> 00:12:12,482
Then they layer the glue-soaked
Sheets 5 to 8 deep,
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00:12:12,482 --> 00:12:15,068
Depending on the model of piano.
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00:12:15,068 --> 00:12:18,517
Workers feed the wet layers
Of wood to a rim press.
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00:12:18,517 --> 00:12:21,551
An impact wrench,
Powered by compressed air,
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00:12:21,551 --> 00:12:23,620
Turns the clamp screws.
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00:12:23,620 --> 00:12:27,275
The screws bend the wood
Into a piano rim form.
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00:12:27,275 --> 00:12:29,896
They measure the pressure
On the layers
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00:12:29,896 --> 00:12:31,793
With a torque wrench.
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00:12:31,793 --> 00:12:33,896
Steel arms
Reach across the wood,
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00:12:33,896 --> 00:12:36,689
Holding the shape
While the glue dries.
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00:12:36,689 --> 00:12:40,275
After 24 hours, workers loosen
The machine's grip,
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00:12:40,275 --> 00:12:43,034
And the rim
Now holds its contour.
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00:12:43,034 --> 00:12:45,896
Now it's into what's called
The conditioning room
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00:12:45,896 --> 00:12:47,344
For more drying out.
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00:12:47,344 --> 00:12:52,448
The piano rims stay in this
Warm, arid room for 30 days.
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00:12:52,448 --> 00:12:55,655
It's time to make
The bracing structure.
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00:12:57,896 --> 00:13:00,482
They place glued struts
Inside the rim,
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00:13:00,482 --> 00:13:03,655
Then apply pressure
With a clamp.
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00:13:03,655 --> 00:13:06,379
The framework remains
In this embrace for an hour
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00:13:06,379 --> 00:13:08,103
While the glue dries.
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00:13:08,103 --> 00:13:12,103
This piano will have a tension
Resonator for extra support.
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00:13:12,103 --> 00:13:15,931
Steel turnbuckles
Attach to a center hub.
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00:13:15,931 --> 00:13:18,551
A worker tightens
The turnbuckles with a wrench.
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00:13:18,551 --> 00:13:22,137
Then he thumps it to make sure
It's tight and won't rattle.
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00:13:24,034 --> 00:13:26,931
Next, they'll install
The soundboard made of spruce
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00:13:26,931 --> 00:13:28,827
And the two bridges.
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00:13:28,827 --> 00:13:30,689
Strings will straddle
The bridges
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00:13:30,689 --> 00:13:33,310
And transmit vibrations
To the soundboard,
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00:13:33,310 --> 00:13:35,655
Which is the amplifier
Of the piano.
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00:13:38,172 --> 00:13:41,275
A worker glues ribs
Onto the soundboard.
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00:13:41,275 --> 00:13:44,172
He lowers wooden clamps
Over each rib
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00:13:44,172 --> 00:13:47,206
To apply pressure
While the glue dries.
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00:13:47,206 --> 00:13:49,275
That takes about an hour.
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00:13:55,482 --> 00:13:58,172
Next, he thins the ribs
Around the edges
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00:13:58,172 --> 00:14:01,689
With an automated
Stagger-tooth shaper cutter.
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00:14:01,689 --> 00:14:04,344
This will allow the soundboard
To resonate freely
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00:14:04,344 --> 00:14:06,655
When the piano is played.
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00:14:12,448 --> 00:14:16,103
Now they position the soundboard
In a bridge press.
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00:14:17,655 --> 00:14:19,862
Then they place
A bridge-locating fixture
243
00:14:19,862 --> 00:14:21,517
On top of the soundboard.
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00:14:21,517 --> 00:14:23,931
This device holds the bridge
In place
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00:14:23,931 --> 00:14:26,275
While it's glued
To the soundboard.
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00:14:26,275 --> 00:14:29,103
After the two bridges
Are glued down,
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00:14:29,103 --> 00:14:32,344
They lower the soundboard
Onto the piano rim.
248
00:14:32,344 --> 00:14:35,413
Then they hoist
A cast-iron plate onto it.
249
00:14:35,413 --> 00:14:36,827
It's a critical fitting.
250
00:14:36,827 --> 00:14:38,413
If they don't get it right,
251
00:14:38,413 --> 00:14:40,793
The piano
Will never function properly.
252
00:14:40,793 --> 00:14:43,551
Then the plate is removed
For finishing.
253
00:14:45,275 --> 00:14:47,379
A worker cuts notches
In the bridges,
254
00:14:47,379 --> 00:14:49,103
Which are now topped
With a lubricant.
255
00:14:49,103 --> 00:14:51,103
This very sharp chisel
256
00:14:51,103 --> 00:14:53,241
Cuts through the hard maple
Like butter.
257
00:14:53,241 --> 00:14:56,034
Each notch will cradle
Three piano strings,
258
00:14:56,034 --> 00:14:58,827
Giving them the freedom
To vibrate.
259
00:15:05,275 --> 00:15:09,206
Now they roll glue onto
The outside case of the piano,
260
00:15:09,206 --> 00:15:12,379
Which is made
Of rosewood veneer on maple.
261
00:15:12,379 --> 00:15:15,517
They fit it snuggly
Over the rim structure.
262
00:15:17,758 --> 00:15:19,965
A mechanical clamp
Holds it in place for an hour
263
00:15:19,965 --> 00:15:21,758
While it dries.
264
00:15:23,517 --> 00:15:26,482
Then they stand the entire piano
On its side.
265
00:15:26,482 --> 00:15:30,137
Spinning cutters shape the arms
That sit next to the keyboard
266
00:15:30,137 --> 00:15:32,517
Into an elegant curve.
267
00:15:36,068 --> 00:15:38,689
This is called
A vertical stroke sander.
268
00:15:38,689 --> 00:15:41,517
A worker runs it
Along the side of the piano
269
00:15:41,517 --> 00:15:43,413
To smooth out the wood.
270
00:15:46,655 --> 00:15:49,551
After a black polyester paint
Is applied,
271
00:15:49,551 --> 00:15:52,655
They buff it up with
This electrical cloth polisher.
272
00:15:55,275 --> 00:15:58,103
Then they hand-rub
A mirror glaze cream into it
273
00:15:58,103 --> 00:16:00,206
Until you can
Really see yourself
274
00:16:00,206 --> 00:16:03,103
In this half-finished piano.
275
00:16:15,241 --> 00:16:17,310
Narrator: to play a piano,
276
00:16:17,310 --> 00:16:20,862
You need time to practice
And lots of money
277
00:16:20,862 --> 00:16:25,344
Because a grand piano can cost
About the same as a luxury car.
278
00:16:25,344 --> 00:16:29,448
And like a luxury car, when you
Lift the top of a grand piano,
279
00:16:29,448 --> 00:16:33,000
You'll see that a lot
Has gone into its construction.
280
00:16:45,103 --> 00:16:48,517
The bass and treble bridges
Are now fixed to the soundboard
281
00:16:48,517 --> 00:16:50,655
Of this half-finished piano.
282
00:16:50,655 --> 00:16:52,137
Then to add glamour,
283
00:16:52,137 --> 00:16:56,034
They spray gold paint
On the cast-iron plate.
284
00:16:56,034 --> 00:16:58,551
The next step
Involves the pin block,
285
00:16:58,551 --> 00:17:00,862
Which holds all the stress.
286
00:17:00,862 --> 00:17:04,896
It bears 45,000 pounds
Of tension from the strings
287
00:17:04,896 --> 00:17:07,827
And transfers it
To the iron plate.
288
00:17:07,827 --> 00:17:10,068
He drills
Into the maple pin block,
289
00:17:10,068 --> 00:17:12,206
Through holes
In the iron plate over it.
290
00:17:12,206 --> 00:17:14,103
The holes
Are for the tuning pins,
291
00:17:14,103 --> 00:17:16,586
Hence the name -- pin block.
292
00:17:16,586 --> 00:17:20,344
They unfurl pieces
Of steel wire from big coils.
293
00:17:20,344 --> 00:17:22,172
Using a vise grip,
294
00:17:22,172 --> 00:17:26,758
The worker twists the end
Of the wire into a neat loop.
295
00:17:26,758 --> 00:17:28,862
Then he hooks it
Onto a hitch pin
296
00:17:28,862 --> 00:17:31,241
On the back side
Of one of the bridges,
297
00:17:31,241 --> 00:17:34,586
Making sure it runs between
The guide posts over the bridge.
298
00:17:36,103 --> 00:17:39,310
Now he threads the wires through
Another guide called an agrafe.
299
00:17:41,068 --> 00:17:42,724
Using wire cutters,
300
00:17:42,724 --> 00:17:45,965
He snips the wire to
The exact length that he needs.
301
00:17:47,862 --> 00:17:50,517
Then he wraps the wire
On the tuning pin
302
00:17:50,517 --> 00:17:52,862
Using a device
Called a stringing crank.
303
00:17:55,586 --> 00:17:58,068
He taps it into a hole
In the pin block.
304
00:17:58,068 --> 00:18:01,344
Then, using a pneumatic hammer,
305
00:18:01,344 --> 00:18:04,517
He drives the tuning pins
Into the pin block.
306
00:18:04,517 --> 00:18:07,931
Now the string stretches
From above the bridge
307
00:18:07,931 --> 00:18:09,448
To the pin block.
308
00:18:09,448 --> 00:18:13,655
Each string is under a tension
Of up to 425 pounds,
309
00:18:13,655 --> 00:18:16,379
Again, a force
That will be kept in check
310
00:18:16,379 --> 00:18:18,310
By the heavy cast-iron plate.
311
00:18:18,310 --> 00:18:20,965
Now he places
Little felt-covered blocks
312
00:18:20,965 --> 00:18:23,758
Called dampers
Above the strings
313
00:18:23,758 --> 00:18:27,000
To stop them from vibrating
When a note is played.
314
00:18:27,000 --> 00:18:30,620
Using pliers, he makes parallel
Bends in the damper wires,
315
00:18:30,620 --> 00:18:32,379
So they're aligned.
316
00:18:32,379 --> 00:18:34,655
He pounds the key frame,
317
00:18:34,655 --> 00:18:36,517
Checking for gaps
That could cause knocks
318
00:18:36,517 --> 00:18:39,310
Under a pianist's
Vigorous blows.
319
00:18:39,310 --> 00:18:40,862
He smoothes out the gaps,
320
00:18:40,862 --> 00:18:43,586
Shaving off bits of wood
With a strip of sandpaper
321
00:18:43,586 --> 00:18:45,827
Attached to a handle.
322
00:18:45,827 --> 00:18:49,000
Now another worker
Presses the piano keys
323
00:18:49,000 --> 00:18:50,517
In between steel guide pins
324
00:18:50,517 --> 00:18:54,000
That have been installed
In rows on the key frame.
325
00:18:55,586 --> 00:18:58,586
She uses an air cylinder
To push the backcheck
326
00:18:58,586 --> 00:19:00,793
Into the end of a piano key.
327
00:19:00,793 --> 00:19:04,241
The backcheck is a piece of wood
Covered with felt and buckskin
328
00:19:04,241 --> 00:19:06,034
That will catch
The piano's hammer
329
00:19:06,034 --> 00:19:08,034
After it strikes a string.
330
00:19:09,758 --> 00:19:11,758
It's time to make those hammers.
331
00:19:11,758 --> 00:19:16,034
She glues the felt-covered top
Onto a thin piece of hornbeam,
332
00:19:16,034 --> 00:19:18,689
A species of very strong wood.
333
00:19:18,689 --> 00:19:21,068
When a pianist hits a key,
334
00:19:21,068 --> 00:19:23,517
It will catapult the hammer
Into the string,
335
00:19:23,517 --> 00:19:26,482
And that produces a note.
336
00:19:26,482 --> 00:19:30,000
Now she aligns the hammers
To be perfectly parallel,
337
00:19:30,000 --> 00:19:32,517
Using a plastic square
As a guide.
338
00:19:32,517 --> 00:19:34,827
This is called "Squaring it up."
339
00:19:37,068 --> 00:19:40,172
Next, she sands the tail
Of each hammer with a file
340
00:19:40,172 --> 00:19:44,413
So there'll be no sharp edges
To damage the backcheck.
341
00:19:44,413 --> 00:19:46,206
Then she attaches the hammers
342
00:19:46,206 --> 00:19:48,724
To the top of the keyboard
With screws.
343
00:19:48,724 --> 00:19:51,586
Now she places weights
On each key
344
00:19:51,586 --> 00:19:55,896
And then gently taps the rail
To get the hammers moving.
345
00:19:55,896 --> 00:19:58,103
She's testing the amount
Of effort it would take
346
00:19:58,103 --> 00:20:00,551
For a pianist
To push each key down.
347
00:20:00,551 --> 00:20:02,517
This is called "The weigh off."
348
00:20:04,275 --> 00:20:06,896
After she determines
How much weight is needed,
349
00:20:06,896 --> 00:20:09,172
She marks a place
On the side of the key
350
00:20:09,172 --> 00:20:11,517
And drills one or two holes.
351
00:20:11,517 --> 00:20:14,206
She plugs each hole
With a piece of lead.
352
00:20:14,206 --> 00:20:16,034
In a process called swedging,
353
00:20:16,034 --> 00:20:18,206
She pushes a divot into the lead
354
00:20:18,206 --> 00:20:21,275
So it expands
And fits snugly into the key.
355
00:20:21,275 --> 00:20:24,448
The lead will counterbalance
The weight of the hammers
356
00:20:24,448 --> 00:20:28,275
And give the key
The required amount of weight.
357
00:20:28,275 --> 00:20:31,586
Next, this technician
Checks each hammer and each key,
358
00:20:31,586 --> 00:20:33,689
Making subtle
Mechanical adjustments
359
00:20:33,689 --> 00:20:36,896
So they move smoothly
And fluidly.
360
00:20:36,896 --> 00:20:39,379
It's the piano's
First big tune-up.
361
00:20:41,379 --> 00:20:44,517
He fine-tunes the hammer action
By using a let-off tool
362
00:20:44,517 --> 00:20:46,793
To adjust the driving mechanism.
363
00:20:46,793 --> 00:20:50,896
The piano is now ready for
The hands of a skilled pianist
364
00:20:50,896 --> 00:20:54,344
And the ears
Of an appreciative audience.
365
00:20:58,000 --> 00:21:01,000
--captions by vitac--
Www.Vitac.Com
366
00:21:01,000 --> 00:21:04,034
Captions paid for by
Discovery communications, inc.
367
00:21:18,310 --> 00:21:20,689
If you have any comments
About the show
368
00:21:20,689 --> 00:21:22,862
Or if you'd like to suggest
Topics for future shows,
369
00:21:22,862 --> 00:21:25,379
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