All language subtitles for S09E03 - Wooden Bowls; Chainsaws; Stackable Potato Chips; Jet Compressor Blades (1080p AMZN WEB-DL x265 Garshasp)_track4_[eng]

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

Wooden bowls...

Chain saws...

Stackable potato chips...

And jet compressor blades.

There was a time when bowl
Making was a cherished trade

Passed down through generations
Of woodworkers.

But today, with so much
Mass-produced tableware,

Handcrafted wooden bowls
Have become a specialty item,

And this centuries-old
Traditional craft

Is practically a lost art.

Each of these exquisite bowls
Is made

From a solid piece
Of hardwood --

Beech, maple, walnut, or cherry.

Logs arrive at the bowl mill
Fresh from the forest,

So they're still very damp,
And that's an advantage

Because the moisture lubricates
The cutting tools.

The first step is to divide
The log into blocks

With a chain-saw operator

Measuring and inspecting
As he goes.

Defects such as knots
Or scarring

Dictate the length
Of each block.

Any cracks or other flaws
Are marked with a red crayon.

Next, a rip-saw operator uses
Different-size bowl patterns

To determine the best way
To cut the block.

The goal is to get the biggest
Bowl-size pieces possible

Without including
Any defective wood.

Each bowl-sized piece
Is called a bowl blank.

This block is large enough
To yield three blanks,

Each of which will produce
A 17-inch bowl

And a series of progressively
Smaller bowls

That nest inside it.

The blank is mounted
Onto a woodworking lathe.

From this point on,
Production is entirely dependent

On the lathe operator's skill.

As the block spins,
He carves out the bowls

Using a series
Of specialized knives

Designed and forged
At this very mill.

First he uses this curved knife

To shear off the outer portion
Of wood.

It takes great expertise to know
Exactly how to angle the tool

And when to pull it out
And release the wood shavings

And prevent a jam.

After two or three minutes,

The exterior bark shell
Has been sheared off.

The bare wood that's left

Represents the outside
Of the largest bowl

That he'll mill from this blank.

With a finer blade,
He sculpts the wood

To just the right thickness
And smoothes the surface.

Now he switches
To a smaller curved knife

And cuts into the wood.

This forms the inside
Of the largest bowl

And the outside
Of the next smaller one.

The lathe worker repeats the
Smoothing and cutting process

With progressively
Smaller knives,

Making bowl after bowl
At a rate of about one a minute.

This one bowl blank produces
Four nested bowls,

The smallest measuring
About nine inches in diameter.

The bowls are steamed for about
Four hours to draw out the sap

And hydrate the pores
Of the wood uniformly.

Once a bowl is dry --
About a month later --

Workers even out the top rim
On a sanding table.

Then, using a belt sander,

They smooth the outside
And inside surfaces.

A motorized saw shaves off
The bottom of the bowl,

Giving it a flat base
On which to sit

And a place to inscribe
The company name.

Businesses can order
Custom-made bowls

Featuring their company logo.

Artists burn the design
Into the wood or paint it on.

The bowls now go for a bath
In food-safe mineral oil.

This nourishes the wood,
Preventing dryness and cracks.

Oiling also brings out

The natural beauty
Of the wood grain,

And because all raw wood
Is unique,

No two bowls are ever alike.

Up next...

High-tech production
At a chain-saw factory.

Narrator: it's loud,
It's powerful,

And it rules the forest.

The chain saw has revolutionized
The logging industry

By replacing simple muscle power
With mechanical might.

The chain saw can fell a tree

And quickly turn logs
Into lumber.

Production begins
With the plastic housing.

Three aluminum inserts
Must be molded into the housing

To provide solid anchors
For other parts.

A robot picks up the inserts
One at a time

And delivers them
To an injection molding machine.

Then it places the inserts
Into a mold

At the front of the machine.

The machine injects
Melted plastic into the mold

To make the chain saw's
Engine cover.

During the molding process,

The metal inserts become
Integrated into the housing.

It takes just seconds to
Transform these plastic pellets

Into a chain-saw engine cover.

The robot carries each engine
Cover to an automated cutter

That removes any unwanted bits
Of plastic.

The scraps drop
Into a bin below.

The hot covers cool
For about 10 minutes.

Then the robot moves them
To the next station.

There's one more piece
Of plastic housing --

The fuel tank.

The sonic welder melts and fuses
It to the engine cover

Using high-frequency vibration.

Now it's time to move on
To the engine

And install a spring system
For the starter cord.

The two-stroke engine
Slides into the plastic casing.

And a spark plug
Is popped into place.

After the crankshaft
Is lubricated,

The chain saw's automatic
Oiling system is installed.

The carburetor is attached,

Along with
A pull-cord starter system.

This saw gets an air filter.

Then the chain bar's stud bolts
Are dipped in adhesive

And screwed into the inserts
Molded into the plastic housing.

The rear handle goes on...

Along with
A safety-release trigger.

The front handle
Is screwed into place.

And the oil line
Gets a filter attachment

That lubricates
The bar and chain.

That will strain out
Any impurities.

Next, workers install bearings

And the crankshaft
Clutch system.

The clutch is the link between
The engine and chain.

When it's engaged,

The chain will move
Around the cutting bar.

The engine is now ready for a
Test run at typical speed --

8,000 rpm.

Technicians adjust
The carburetor

So that it mixes the right
Amount of gas and air

And check the exhaust
To make sure

It doesn't exceed
Pollution standards.

Workers attach
The company's logo

And other
Operational information.

Then the brake system
Goes into place.

Finally, the metal bar
And chain blade

Are packed
In a protective sleeve.

Once the saw's chain blade
Is installed,

The owner has a power tool
With teeth for almost any job.

When we return...

Get the skinny
On stackable chips.

Narrator: it's a snack
That's made to stack.

Unlike other chips that come
In irregular shapes and sizes,

These chips
Have a uniform concave shape

That allows them
To tightly interlock

And fit neatly
In a tubular container.

The process
For making these tubes

Starts with big rolls
Of plain brown paper

And foil-backed paper
That help keep the chips fresh.

The streams of paper
Travel across rollers

That apply a coat of glue.

The paper layers
Then twist around the mandrel

That's turned by a big belt.

The belt also presses
The glued layers together.

Next, the label paper
Gets a coat of glue.

This helps it stick to the paper
On the mandrel.

A camera photographs the white
Edging on the label paper,

Then relays its location
To a set of circular knives.

They make a precise cut
Just below the white edging.

Cued by the camera, the carriage
Then moves the knives

Into position for the next cut.

You the tubes then head into
A turning station...

A box with a pathway inside that
Flips the tubes right side up.

Hot metal heads curl the tops
To accommodate lids.

A roller pulls foil-backed paper
Into a cutter

That punches out the lid shapes.

Little vacuums take the lids to
The tubes and heat-seal them on.

Plastic lids
Go over the paper ones.

The lidded tubes
Are now turned upside down,

Ready to be stacked with chips.

The chip recipe is 1/3 water
To 2/3 potato flakes

With a little cornstarch
Mixed in.

A conveyor delivers the mix to
An auger, which disperses it.

Then it sets out
On the production line.

Using four tons of pressure,

The mix is rolled
Into one long potato sheet.

A rotary cutter then punches out
Oval shapes.

A device pulls away
The scrap dough,

Leaving flat, uncooked chips.

This scrap dough goes back into
The chip-making process,

While the potato chips
Head for the fryer.

As they travel
Through the fryer,

Rolling molds give the chips
Their uniformly concave shape,

Making them
More easily stackable.

The chips spend 11 seconds
In hot oil, crisping.

Then they travel under blowers
To get rid of excess oil.

The chips
Get a coat of seasoning,

Then do a backflip off one
Conveyor and onto another,

Falling into neat piles.

A worker inspects
The rows of chips.

Then it's onto another conveyor

That shakes them up
To loosen the stack.

They travel over scales to be
Portioned out for packaging.

Automated spoons shove the chips
Into the open ends of the tubes.

Guides tap the tops of the tubes

To nudge the chips
Into position.

Grippers then lower the stacks
Of tubes to a station,

Where spinning heads
Force metal bottoms onto them.

Now they're ready for shipping.

It takes about 20 minutes to
Make a tube of stackable chips,

But it takes less time
To polish them off.

Up next, jet compressor blades
That really make the cut.

Narrator: compressor blades
Are key components

In a jet's engine.

Thousands of them whirl
Inside the engine,

Rotating 400 times per second

And whipping air
Into small hurricanes.

Large compressor blades
Made of titanium

Compress the air in front of
An engine's turbo chamber.

In the back of the chamber,

Smaller blades made of nickel
Alloy compress it even more.

The air heats up
To more than 1,000 degrees,

Then combines with jet fuel,
Creating a powerful mix

That explodes
Out the back of the engine.

The blades start off
As metal pellets called slugs.

A ceramic layer prevents
Their surfaces from oxidizing

When exposed to intense heat.

The slugs are heated for 15
Minutes in an 1,800-degree oven.

Meanwhile,
A robot sprays lubricant

On two dies inside a press.

The robot retrieves the slugs
And loads them in the first die.

The press applies over 1,000
Tons of pressure

To preform the metal.

The robot then transfers
The slugs to the second die,

Where they take the initial
Shape of the blade.

The blades are dipped in water
To cool.

Another robot cleans the metal
Burrs off the edges.

The blade is now an airfoil.

Robots will shape
The rounded base of the blade,

Called the dovetail, later.

The airfoil has gone from this
To this.

After a new ceramic layer
Is applied,

The blade is heated again.

Each heating and cooling cycle
Tempers the metal,

Making it more resilient.

Almost 1,800 tons of pressure

Gives the airfoil
Its final shape.

A trimmer
Shaves off the excess metal.

The searing heat
Has turned

The protective ceramic layer
Into glass.

That will come off later.

It's taken an hour
To shape the blade's airfoil.

The dovetail,
That nub on the right, is next.

But first, this measuring
Machine inspects the airfoil.

If any measurement is off

By just half the thickness
Of a human hair,

The blade doesn't make the cut.

This casting machine will encase
The airfoil in a matrix,

A coating that protects
The airfoil

During work on the dovetail.

The matrix is molded
From liquid tin and bismuth.

It solidifies into a metal cast
Around the airfoil.

The future dovetail sticks out
At the end.

The cast is then loaded into
What is called a broach machine.

Its series of teeth carve the
Dovetail into its final shape.

Now the cast can come off.

A worker loads it
Onto the removal machine,

And a hydraulic cylinder hits
The cast at its weakest point,

Breaking it in half.

The finished airfoil
Emerges unscathed.

A dot-matrix machine

Punches identification numbers
Onto the blade.

Next, the blades are submerged
In a fluid

That penetrates any flaws
In the metal.

This inspection is critical

Because even the tiniest nick
Can spell disaster

When a jet's engines
Are working at full speed.

Inspectors examine the blades
Under a black light.

This one's perfect,

But spots of fluorescence
On this one

Indicate microscopic cracks
And weaknesses.

This one gets rejected.

The dovetail gets two strips
Of rubber silicone

That ensure an airtight seal

When the dovetail slides
Into the slot

On the compressor drum.

A final check, and the blades
Are now ready for takeoff.

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

Captions paid for by
Discovery communications

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