All language subtitles for S04E03 - High-Precision Cutting Tools; Stained Glass; Semi-Trailers; Recorders (576p AMZN WEB-DL x265 Garshasp)_track4_[eng]

Narrator:
Today on "How it's made"...

High-precision cutting tools...

...Stained glass...

...Semi-trailers...

...And recorders.

Industrial cutting tools

Are the metalworking components
Of factory machinery.

They're designed
To form metal into product parts

Or into devices
For making product parts.

High-tech industries use
High-precision cutting tools.

These are the end mills --

Tools specifically designed
For cutting and shaping metal.

They're made from a very durable
Grade of steel

Or from tungsten carbide --

A metal
Even stronger than steel.

Steel bars
In their raw state

Are actually soft enough
To be cut and shaped.

But it takes loads
Of lubrication

To cool the intense heat

That metal-on-metal friction
Generates.

Using a giant band saw,

They cut the bars
Into end-mill-size pieces,

Called blanks.

Workers turn
Each blank individually

On a computer-guided
Metal lathe.

First, they form a point
On one end.

Then they flatten the opposite
End and drill a center hole.

Then they trim the diameter
To the required size.

Next stop -- a computer-guided
Milling machine.

It works on three blanks
At a time,

Carving helix-shaped ridges
Called flutes.

The flutes run almost
The full length of the blank.

Once again,

Lubrication is essential
To prevent overheating.

This milling process transforms
Each blank into a tool.

From this point on,

The shorter, smooth portion
Is called the shank,

The longer, fluted portion,
The cutting end.

Here's the same
Milling process again

But for a different model.

Here are both models
Before and after.

Now they cure the steel

Using a two-step
Heat-treatment process.

The first stage hardens
The metal, using molten salt --

Salt that's been heated
Until it liquefies.

They soak the tools in five
Progressively hotter salt baths,

Whose temperatures range

From 1,200 to 2,200 degrees
Fahrenheit.

The second phase
Of heat treatment

Is a process called induction.

They set each tool
Into a large metal coil.

The coil's internal magnetic
Field generates intense heat,

Which softens the shank,
Making it more flexible.

Now the finishing process.

They run the shank
Against a grinding wheel,

Whose grit is made
Of diamond particles.

This gives it the strength
To erode steel

With a high degree of precision.

They verify the final diameter
Using a digital micrometer.

Then a robotic arm runs
The tools -- one at a time --

Through a high-precision
Automated grinding machine,

This time to finish
The cutting end.

The machine uses
Diamond grinding wheels

To grind the precise
Cutting angles

And finalize the diameter.

More complex tools

Go into this even more
Sophisticated grinding machine.

It, too, uses diamond wheels
And runs robotically.

The end mills are now completed.

This factory makes
High-precision cutting tools,

Primarily for the aerospace
And automotive industries,

Where precision is everything.

So at each stage
Of the production process,

The factory verifies
Measurements

Using various optical
And digital instruments.

This sensing probe conducts
The final quality-control test.

It scans each and every
Finished end mill

To ensure that the surface
Is as smooth as silk.

These high-precision
Cutting tools

Are now ready to be put to work
Machining aluminum, titanium,

And different types of steel.

Narrator:
Around 1,000 a.D.,

Craftsmen began making
Intricate window designs

Using lead --
Rather than wood or plaster --

Between pieces of colored glass.

Before long, the church
Began commissioning

Stained-glass windows
Depicting religious scenes

To adorn the great cathedrals
Of europe.

You can make stained glass
Two ways --

Using copper foil,

A technique developed
About 100 years ago

By the american artist
Louis comfort tiffany,

Or you can use the centuries-old
European lead technique,

Which we're about to see.

First, the artist lays a plate
Of glass over a pattern

And traces the parts
Of the design

That she'll cut from that plate.

Then she scores her trace line
Using a glass cutter.

A quick snap, and the glass
Separates neatly.

She follows the same procedure

With different colors
And textures of glass,

Making all the pieces
Of the design.

By running the cutter
Slightly inside the trace line,

She leaves room
For the strip of lead

That will later hold
The pieces of glass together.

Once she finishes cutting
All the pieces,

She checks them against
The pattern,

Making sure
They'll fit together properly.

Now it's time
To assemble the pieces,

Using the pattern as a guide.

This zinc molding
Will frame the panel,

Its inner groove fitting
Over the edge of the glass.

The artist
Positions this molding

Along the perimeter
Of the pattern.

Then she drills an l-shaped
Wood frame into the worktable

To hold everything in place
During assembly.

A few nails keep the molding
In place.

She'll join the pieces of glass
Using strips of lead,

Called came.

Lead is used because
It's soft enough to bend

To the shape of the pieces.

After straightening out
A long strip of came,

She cuts the various lengths
She needs

To border each piece of glass.

The came is shaped in such a way

That the glass on each side
Just slides right under.

The cutting pliers,
Called nippers,

Are specially designed
To slice through the came

Without deforming it.

Once the artist finishes
Assembling the glass pieces,

She pushes everything gently
Against the wood frame.

This squares the panel

And ensures the pieces
Fit together snugly.

Now she brushes on flux,
A type of acid.

This cleans the lead came

So that the solder
Will adhere well.

Using a soldering iron,

She applies a bead
Of lead-and-tin solder

Wherever two strips
Of lead meet.

Then she uses
A short-bristled brush

To coat the lead in black putty.

This makes the seams watertight

And gives the lead
A darker, aged look.

Finally, she sprinkles
On calcium chloride powder,

Called whiting.

This sets the putty and polishes
The glass and lead to a shine.

After four painstaking hours,
The panel is finished.

More elaborate
Stained-glass works

Feature hand-painted detailing.

The artist first prepares
The design on paper,

Then cuts the pieces of glass
Accordingly.

He paints the design outline
On the pieces in black,

Then fires them in a kiln
To set the paint.

To create shading, he applies
A coat of brown paint

Called grisaille.

Using a dry brush,

He removes it from the parts
He wants to highlight.

Then he fires the glass again.

Now he paints in
The fine details

And fires the glass
For one last time.

The paint contains
Powdered glass,

So the intense heat of the kiln
Bonds it to the glass pieces.

The result is nothing short
Of spectacular.

Narrator: for those of you
Who flunked truck anatomy 101,

Here's a quick review.

The front of the truck,
Where the driver sits,

Is called the cab.

The back that carries
The cargo is the trailer.

A semi-trailer
Is a type of trailer

Whose front end goes
On the same wheels

As the rear end of the cab.

This type of semi-trailer
Is called a van.

It has a closed-in compartment
For transporting cargo

That needs protection
From the elements.

To make the coupler plate --

The part that attaches
The van to the truck cab --

They submerge steel plates
In water

To quell the smoke
That metal-cutting generates.

They use a computer-guided
Plasma cutter.

This powerful torch ejects
Hot gas at high pressure,

Slicing through the metal
With detailed precision.

Elsewhere in the factory,

They take prepainted
Aluminum panels

And rivet them onto aluminum
Or steel support posts...

The same way drywall
Goes onto 2x4s

In house construction.

These thin, lightweight panels

Will be
The van's exterior walls.

Plywood on the reverse side
Makes up the interior walls.

A computerized sensor
Guides the robotic drills

To drive screws
Through the plywood,

Into the support posts
Underneath.

For heated or refrigerated vans,

There's a layer of insulation
In the walls.

The floor is made of either
Laminated hardwood or aluminum

Screwed onto narrow steel beams.

After assembling the walls,
The steel door frame, and doors,

Workers install a steel
Floor plate at the doorway.

This protects the floor
From damage

When truckers load and
Unload their cargo by forklift.

Workers fold aluminum flashing
Over the roof's perimeter

To prevent water infiltration.

Fiberglass roofing like this
Allows daylight into the van.

Aluminum roofing doesn't,

So those vans sometimes
Have electric lighting.

Another type of semi-trailer
Is the flatbed --

An open trailer used mostly
For hauling raw materials,

Such as logs and pipes.

Heavier flatbed models are made
Of thick, higher-grade steel.

Workers cut the bulkier parts

Using what's called
An automatic oxy cutter.

It combines two gases to create
A flame intense enough

To slice right through metal.

Once cut, the parts have to be
Formed to the required shape.

To do that, workers use
What's called a press brake --

A machine that applies up
To 330 tons of pressure --

To bend the steel.

They measure the result

To ensure it meets
Design specifications.

The chassis
Will have two main beams

Running the length
Of the flatbed.

A semiautomatic robot welds
Together the various sections

That make up each beam.

A worker follows behind,

Inspecting the joints
And removing welding residue.

Now they position
Two main beams side by side,

Inserting steel cross members
Through them

To support the floor.

They install the coupler plate
And other components,

Then weld everything together.

Flatbeds come
In extendable versions

Designed to accommodate loads
Of various lengths.

They extend and retract
On steel rollers

Operated by controls
Located inside the truck cab.

With the chassis complete,

They can now work
On the axle assembly.

Semi-trailers
Have an air-brake system.

When the driver
Applies the brakes,

There's a release
Of air pressure

Into the brake chambers,

Triggering the brake shoes

To bear down on the brake drums
And stop the vehicle.

Once the wheels and
Suspension system are in place,

Workers install the axle
Assembly under the trailer.

The average semi-trailer weighs
Between five and seven tons

And can haul up
To five times its weight.

Narrator:
The recorder is a type of flute
That's played vertically.

It consists of a mouthpiece
That works like a whistle,

Connected to a tube
With finger holes.

Mass-produced plastic recorders

Are a staple of elementary
School music programs.

Real musicians, though,
Play finer wooden recorders.

The recorder dates back
To medieval europe,

Though it was likely
Modeled after flutes from asia.

Back then,
Recorders were called flutes.

And, by 1500,

They were among the most popular
Musical instruments.

Around 1750, though,
The new transverse flute

Banished the recorder
To musical oblivion.

It took a 20th-century
Revival of music

From the renaissance
And baroque periods

To bring
The long-forgotten recorder

Some noteworthy attention.

A recorder is composed
Of three hollow sections

Made of a lightweight hardwood,
Such as boxwood.

Crafting one section at a time,

They find a portion free of
Cracks, knots, and other faults,

Then cut away the surrounding
Wood using a band saw.

They measure
The block's diameter

To ensure it's large enough.

Then they carefully mark
And drill through the midpoint

In order to mount the block
On a lathe.

Precision is critical.

The block must be
Perfectly centered

As they round it
Into a cylinder.

Next, they use a large drill
To widen the inside hole,

Known as the bore.

They enlarge it enough to insert
A tool called a reamer.

Then they ream the bore
To the final diameter,

Which varies according
To the size of the recorder.

The bore tapers slightly toward
The bottom of the instrument.

The cylinder, now a tube,
Goes back on a lathe.

The smooth pencil line
Means the bore is straight

And the tube is centered.

They trim the outside to reduce
It to the right diameter,

Checking the measurement
With the help of calipers.

Then it's back onto a lathe
For the final profiling.

This is where the maker
Gets to flaunt his artistry,

Embellishing the tube
With ornamentation

Typical of the baroque period.

It takes about
An hour and a half

To cut and shape
The recorder's three sections --

The head joint,
The middle joint,

And the foot joint.

Now they smooth the surface of
Each joint with fine sandpaper.

Then it's back
To the technical tasks.

Locking the middle
And foot joints in a vise,

They drill the finger holes --

Seven holes down the front

And one in the back
For the thumb.

For the recorder
To play in tune,

They must follow
The precise measurements

Specified
In the technical drawing.

In the head joint, they cut
A flat canal called the windway.

It directs the air that's
Blown into the instrument.

Next, they carve out
A rectangular window

With a sloped opening,
Called the labium.

The labium is what regulates
The recorder's tone --

The sound quality --

So its size and angle
Are critical.

The air the musician
Blows into the mouthpiece

Travels down the windway

And hits the sharp edge
Of the labium.

This creates a whistle effect,

Thanks to a block of wood

Closing off
The top of the instrument.

They use cedar
Because it never rots,

Despite years of hot air
And saliva blowing on it.

They complete the head joint
By beveling the top.

This forms the mouthpiece.

Now they glue a thin layer of
Cork around all the joint ends.

This creates a snug fit
When the instrument's assembled.

They test the recorder's
Tone and tuning,

Making adjustments
To the workings if necessary.

Next, they stain the wood,
Then wax and buff it to a shine.

Recorders have a 2-octave --
Or 16-note -- range,

And they come
In about 15 different sizes.

The longer and wider
The instrument is,

The lower its register.

The shorter and thinner it is,

The higher the sound
It produces.

--captions by vitac--
Www.Vitac.Com

Captions paid for by
Discovery communications, inc.

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