All language subtitles for S05E13 - Electrical Panels; Kites; Eyeglass Frames; Toothbrushes (576p AMZN WEB-DL x265 Garshasp)_track4_[eng]

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

Electrical panels...

...Kites...

...Eyeglass frames...

...And toothbrushes.

The technical name for it
Is a residential load center,

But people usually call it
An electrical panel

Or circuit breaker box.

This enclosed metal panel

Is usually built
Into an interior wall

And contains
The circuit breakers

That distribute, protect,
And control

The home's lighting and power.

This load center consists
Of up to 40 circuits.

Each one
Has one or two breakers.

Each breaker powers
Several outlets in the home.

First, a powerful press pounds
A sheet of steel

Into what's called a u-channel.

At nearly 3 feet long,
18 inches wide,

And 4 inches deep,

It's part of what's called
The tub --

The load center's main casing.

A worker then attaches
Steel components made earlier

Called tub ends.

A spot welding machine
Fuses them

To close off
Both ends of the tub.

Workers feed an aluminum strip

That's 330 feet long
And 6 inches wide

Into a stamping press.

The press cuts the strip
Into 20-inch-long segments

Called bus bars.

It bends each bus bar 10 times,

Creating two-inch segments
Called stabs.

The breakers will later
Snap onto these stabs.

Next, a worker inserts
Each bus bar

Into a plastic component
Called a base pan.

The base pan
Insulates the bus bar.

This prevents us
From getting electrocuted.

Another press then inserts
A plastic rivet,

Securing the bus bar
To the base pan.

The worker installs
Two components,

Called neutral bars,
In the base pan.

The neutral bars
Conduct electricity

Between the circuit
And the wall socket.

Next comes the main breaker.

Its maximum capacity
Is 200 amps.

Amps are the units
Of measurement

For electrical current.

If demand exceeds
Maximum capacity, it'll trip,

Meaning it'll turn off
All power in the home.

She makes sure
It's sufficiently tight

So that vibrations caused by
Street traffic won't loosen it.

She also encloses labels
To mark the breaker's pathways

And an envelope
With installation screws.

Next, the worker puts the
Base pan assembly into the tub

And secures the neutral bar
With a copper bonding strap

To ground it
And prevent electrocution.

She adds another component --
One of two grounding bars.

These ground each circuit.

The breakers
Simply snap onto the stabs,

Making them easy to remove
And replace if needed.

Inside the breaker,

Several components interact to
Enable the flow of electricity.

One is the load terminal --

The entry point
For the live current.

A circular machine,
Called robot "A," assembles it

And other breaker parts
Along its 16 workstations.

Another breaker component
Is the bimetal assembly.

It's an alloy of two metals
And a magnet.

It trips the breaker
When there's an overload

Or a short circuit.

Next, robot "A" welds a strip
Of silver, which is conductive,

To what's called
The contact arm.

Robot "A" then positions the arm
For welding

With two-inch-long segments
Of braided copper wire --

Copper because it's conductive
As well as pliable.

The robot fuses the copper wire
To the contact arm

In the bimetal assembly.

The wire will flex with the arm

To touch what's called
The line terminal.

This contact permits
The electrical current to flow.

Next, robot "A" deposits
The welded parts

Into the breaker casings,
Called bases.

This automated production line
Functions 24 hours a day,

Five days a week,

And it produces a breaker
Every three seconds.

Another machine,
Called robot "B,"

Stamps the number of amps
On each breaker handle.

Then it connects a spring

To link the contact arm
To another part,

Called the cradle.

When there's an overload,

The bimetal assembly causes
The cradle to pivot

And trip the breaker.

Robot "B" deposits the spring
And cradle into the base,

Then closes the base
With a cover.

This demonstration shows
How moving the breaker handle

Triggers the mechanism that will
Enable the flow of electricity.

If power demand exceeds

The breaker's maximum capacity
By 35%,

The bimetal assembly trips
The breaker and cuts the power.

They cap off the load center

With a metal cover
Called a trim.

The warning label on it

Provides safety information
And instructions.

The load center is now ready
For installation

By a certified electrician.

Narrator: the earliest
Written record of a kite

Tells the story of
A chinese general in 206 b.C.

Who flew a kite
Over a wicked emperor's palace.

He marked the line to measure
The distance, then reeled it in.

His small army then dug a tunnel
Into the palace courtyard,

Launching a surprise attack
That conquered the emperor.

Today's two-line kite,
As the name implies,

Has two lines to pilot it.

It can fly nearly 130 feet high.

This kite is made mainly
Of a lightweight nylon fabric

That is waterproof
And fade-resistant.

It's less than a few hundredths
Of an inch thick,

So it's reinforced with
Nylon mesh to reduce ripping.

The kite's other components

Include nylon and elastic
Cords and straps;

Fittings made of leather,
Rubber, aluminum, and plastic;

And carbon rods.

The kite maker starts
With a pattern

Made out of pressed wood.

She marks out
A piece of the fabric

And, with a few bricks
To hold the fabric in place,

Cuts diagonally.

In sewing terms, that's called
Cutting on the bias.

This will stretch the fabric
And help it fly.

Next, she cuts more pieces
Of fabric,

This time in a different color.

This kite has eight fabric parts
That fit together like a puzzle

To create
An eight-foot wingspan.

The kite's left and right sides
Are mirror images,

So there are only
Four different shapes to cut.

They range in length
From 9 inches to 4 feet.

From start to finish,

It takes one worker about
Two hours to make this model,

Called the dragonfly.

First, the kite maker sews
The longest part,

Called the belly,
To the other parts.

She double stitches
With heavy-duty nylon thread

To help the kite withstand winds
Up to 23 miles per hour.

She makes tiny incisions
Along the belly's curved edge

So she can fold it and sew in
What's called the tension line.

Tension line
Is a type of nylon cord

She'll sew into all the seams
Of the kite's lower sections.

It'll give the kite
Some structure

And help keep it rigid
While airborne.

The kite maker secures each line
With a knot

Which can later be loosened
Or tightened

To adjust
The kite's overall tension.

The kite maker uses straps

Made of very durable,
Yet flexible, plastic

To line the middle and the edges
Of the wings.

The straps strengthen the kite,

Enabling it to survive crashes
Into trees and rocks.

After all,
What goes up must come down.

Next, the kite maker sews
A piece of leather,

Called a fitting,
Onto the plastic strap.

It's made of leather to protect
The kite's structural joints,

Such as the nose of the kite.

It gets a leather patch,
As well.

The kite maker uses
A serrated saw

To cut the 10 carbon rods
To size.

They're a quarter-inch
In diameter

And range in length
From 7 to 32 inches.

They form the kite's skeleton
And, like bones,

They're the most likely part
Of the kite to break

In an accident.

But if they do break,
It's easy to replace them.

A variety of molded plastic,
Rubber, and aluminum fittings

Serve a dual purpose.

They join the rods together

And keep them from falling
Out of their sleeves.

Now the kite maker attaches
A nylon cord, called a bridle,

To the fitting that joins the
Rods on the wing's leading edge.

The bridle is the kite's rudder,

Steering the kite
To the left or right.

The bridle comes off easily
If you need to replace the rods.

The kite maker now attaches
Tension lines

To two plastic components
Called arrows.

They're located
At the kite's wing tips.

She ties elastic bungee cords
Through the arrows

To hold the tension lines
In place.

This makes all the fabric parts
Taut enough to fly.

Next, she attaches the bridle
To the center rod,

The spine of the kite.

She inserts the rod

Into its protective
Leather pouch at the nose.

She inserts other rods
Into both sides of the wing.

These give the wing its curved,
Aerodynamic shape

And help the kite stay aloft.

Finally, additional rods
Under the wing

Provide more structure
And support.

These rods spread the kite
And help keep it open.

In the mood
For a sky-high experience?

For $250, you can buy
A handmade model like this one

And go fly a kite.

Narrator: eyeglasses don't
Merely correct vision.

They're also
A fashion statement --

So much so that many of today's
Top clothing designers

Produce a line
Of eyeglass frames.

Whether you prefer
Plastic frames or metal ones,

They come in so many different
Colors, sizes, and shapes

That you're guaranteed to find
A pair that suits you.

Metal frames comes
In a multitude of shapes,

From ordinary to extraordinary.

It all starts with
A computerized system

Called a three-axis
Eye winding machine.

A set of rollers pulls
Metal wire from a big spool.

Then,
With software-driven precision,

The machine bends the wire
Into the shape of the frame,

Then cuts the end free.

The lenses will fit into
Precut grooves on the inside.

A small part,
Called the insert,

Connects the two ends
Of the eye frame,

Holding them closed
Around the lens.

To attach the insert,
They put it in a clamp,

Then position the eye frame
Just above it.

They apply a cleaning agent,
Called flux, then filler wire.

An electric current heats
The wire, metal frame,

And insert until they all melt
And fuse together.

Now they do the same to what's
Called the screw hinge --

The piece that attaches the arm
To the eye frame.

Again,
Electrically generated heat

Fuses the hinge to the insert.

This process, similar to
Soldering, is called brazing.

Now for the bridge --

The piece over the nose
That joins the two eye frames.

A small press
Bends a piece of metal

Into the shape of the bridge.

Then a worker aligns it
With the eye frames

In an assembly jig.

This ensures the frames
Are perfectly straight.

Brazing again
Melds everything together.

Next comes the piece above
The bridge, called the brow bar.

An automated machine cuts metal
Wire to pieces the right length,

Then carves grooves on the ends

To enable the brow bar
To fit snugly

Onto the top of the frames.

It then bends each piece
To the right shape.

The brow bar
Now goes into position.

A little flux
To remove any dust or dirt

That might prevent the metal
From fusing properly.

Then they braze the brow bar
To the frame.

Now come little hooks
Called pad arms.

They hold small pads under the
Bridge that cushion your nose.

A worker fuses the pad arms
To the frames

Using the same brazing process
As before.

Now for the arms that attach
To the eye frames on one end

And sit on your ears
On the other.

The industry
Calls these arms temples

Because they're at the level
Of your temples

When you wear the glasses.

After stamping the size
And company name on the inside,

They fuse a hinge to each one

And press a plastic sleeve
On the other end.

They set the arms
Momentarily aside

While they position the lenses
In the groove of the eye frame.

A screw keeps everything tight
And intact.

Now they screw an arm
Onto each hinge.

The arms on most models
Have curled ends

That hook over the ears for a
More secure and comfortable fit.

A special machine,
Called a mechanical cam,

Applies pressure
To bend the plastic sleeves

To a 45-degree angle.

These metal-frame glasses
Are functional and fashionable.

Narrator: the chinese invented
The first toothbrush

Around 1600,

But it wasn't till
About 1780 in england

That it became
A mass-produced item.

Like those that followed,

Its bristles came from the necks
And shoulders of pigs.

In the late 1930s,

Synthetic materials replaced
Natural swine bristles.

These toothbrushes should make
You want to flash

Your pearly whites
In appreciation

If you consider that,
Thousands of years ago,

People used twigs
To clean their teeth.

Today's toothbrush begins
As little plastic pellets.

A vacuum sucks them up
Into an injection mold machine.

The machine melts the pellets
Into a kind of plastic dough,

Then injects it
Into a stainless-steel mold,

Forming 10 toothbrush handles
At once.

The head of each handle
Has up to 56 holes for bristles.

This machine generates
10 handles every 35 seconds.

That works out to 27,000 handles
In 24 hours.

Now they melt
Blue rubber pellets.

They pipe the liquid rubber
Into the mold

With the white
Toothbrush handles,

Then press the rubber
Onto the handles to form a grip.

So now you'll have a toothbrush
You can really hang on to.

No dropping this one
In the sink.

They use a semiclear plastic
To produce another type of grip,

One that's softer
And more pliable.

It's called the gummy brush,

Because the grip really does
Feel a bit like

One of those gummy candies.

These nylon fibers will form
The bristles.

A robotic arm pats them down
So that they sit very evenly.

Then, faster than you can
Blink an eye,

The machine feeds the bristles
Into the holes

In the head
Of the toothbrush handle.

This machine works
At a blurring speed,

Filling 900 holes per minute.

And it operates
With incredible precision.

Here's the bristle-selection
Process in slow motion.

The machine selects
Between 22 and 24 bristles

For each hole in the brush.

With 56 holes per toothbrush,

That adds up to over
1,300 bristles for each brush.

This fully automated system

Works faster
Than any human ever could.

And here's another advantage --

A human hand rarely has to touch
The bristles,

So the process
Is incredibly hygienic.

Wondering what holds
The bristles in place?

Wire.

The machine bends the fibers
In half,

Anchoring them to the brush
With wire in the middle.

Now it's time for a brush cut.

These blades trim the bristles
To about the same length.

Another set of blades sculpts
Different types of edges,

Depending on the toothbrush
Model in production.

These may look
Like spinning tops,

But they're rotating disks
Coated with diamond dust,

A mild abrasive.

They sand the edges
Of the bristles

To produce a particular finish.

For instance, the bristles
Can be straight or zigzagged.

Different finishes

Have different
Tooth-cleaning effects.

You may have noticed
That some bristles are white

And others are blue
Or another color.

This is purely aesthetic --
A nifty color combination

To make the toothbrush
Look smarter.

And, of course,
The machine knows

Exactly which color goes where,

So you end up with
A two-tone brush like this one.

Every so often,

The factory pulls a toothbrush
Off the assembly line

For a spot check.

A robot arm tugs at the bristles

To make sure
They're secure enough.

And if the brush passes
The test,

The rest of the production run
Is cleared for sale.

Then a robotic system packages
The brushes

So that they come right off
The line ready for shipping

And ready to maintain
Toothy smiles everywhere.

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

Captions paid for by
Discovery communications, inc.

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