23x09 - NASCAR Car Bodies, Hurley Sticks, Tube Power Amplifiers, Thermal Coffee Pots

[bunniefuu]

Narrator: the first stock cars
were souped-up family sedans.

But today, they're custom-built
for the racetrack.

Each car body
must match the contours

Of templates set by nascar,

The national association
of stock car auto racing.

On the racetrack,
the shape of a car

Can give it an aerodynamic edge
over the competition,

So in nascar races, car bodies
must have uniform curves.

The regulations put the focus
on driver skill

And make the race a fair one.

They mold some
of the car's body parts

From a carbon fiber
and kevlar material.

First, a technician applies
a release agent to a mold

For the car's front end.

Then he sprays a paint undercoat
into it.

This undercoat will eventually
transfer to the completed panel.

A computerized cutter slices the
carbon fiber and kevlar fabric

Into strips.

It produces 22 pieces,

Each one cut to fit
a different section of the mold.

The technician rolls epoxy resin
onto the fabric

One strip at a time.

Once the strip
has been completely coated,

He transfers it to the mold.

He tucks the fabric
into the contours

And smooths out
any big wrinkles.

He layers the strips three deep
in a crisscross configuration

For structural integrity.

A co-worker covers the carbon
fiber with perforated plastic.

They add layers of absorbent
polyester and thick plastic,

Which they glue
to the edge of the mold.

They insert a fitting
and connect a vacuum,

Which sucks out air
and excess epoxy resin.

The polyester material
soaks up the resin

As it flows through the holes
in the first plastic layer.

This both smooths and compacts
the carbon-fiber layers.

Then it's into a hot oven
to bake for three hours.

This activates the epoxy

And combines the layers of
carbon fiber and kevlar fabric.

An employee removes
the completed stock-car panel

And inspects it.

Then it's over
to a weigh station.

At just under 8 pounds,

The part is lightweight
yet virtually shatterproof.

Meanwhile, at another factory,

Work begins on
the stock-car chassis.

They build it from square steel
tubing that's super strong.

An employee
welds the pieces together

To create a support structure
for the car.

At the next station,

A worker forces narrow steel
tubing against a spiral bit

To carve notches in it.

This tubing
is for the roll cage,

The structure that protects the
driver if there's an accident.

The notches will help
form better joints.

He grinds the rough edges,
creating a smooth surface

To weld the tube
to the rest of the roll cage.

Once complete, the team
transfers the roll cage

To the main frame
of the chassis.

They tack-weld it
before doing the final welds.

The next part
is called the rear clip.

It holds the fuel tank and has
mounts for the rear suspension.

With the car framework
now complete,

A technician scans it
using a digital measuring probe.

The scan confirms that
the dimensions are correct.

They now assemble
the various steel

And carbon-fiber body parts
to the stock-car framework.

They measure
the completed car body

By laying template grids on it.

The biggest one sits
over the center of the car.

They pull a gauge
through the gaps

Between the templates
and the car body.

The gap cannot exceed
the tolerances set by nascar.

They often must tweak the shape
of a body part

To meet regulations.

Once the car has been painted,

They apply headlight decals
where the real ones usually are.

Real headlights
would add too much weight

And pose a safety risk
if they shattered.

It's taken three weeks
of intensive work,

But this stock-car body
is now ready for the mechanics.

Things are about
to pick up speed.

Narrator: the game of hurling
has been played in ireland

For at least 2,000 years.

Players swing a stick
called a hurley

To hit a ball the size
of a hockey puck into a net.

Winning takes skill,
quick reflexes,

And, of course,
the luck of the irish.

Pass the ball
and pass on the tradition.

Hurling is a game that's older

Than the recorded history
of ireland.

In ireland, hurleys are still
made the old-fashioned way --

By hand in small shops.

Ash is the wood of choice.

They use only the part
of the tree near the root

Because the grain flows
in a natural curve there,

Making the stick less likely
to break during play.

The hurley maker
slices the trunk

Into planks
that are one inch thick.

He'll make one hurley
from each plank.

He stacks the planks

And then picks through them
to select one for shaping.

He scrutinizes the curve
of the grain on the boards.

It needs to be suitable

For the size of the hurley
he'll be making.

His selection made,

He places a see-through
plastic pattern on the board.

The transparency allows him
to find the curve of the grain

And position it within the
striking surface of the hurley.

He draws an outline around it
with a pencil.

After a rough cut
and some initial shaping,

He re-pencils the pattern
and cuts it with a band saw.

The striking surface
of the hurley is called the bas.

It's the most substantial part
of the stick.

He sculpts the stick to various
thicknesses with a planer.

He keeps it thick at the bas
and thins it at the stem

To give the stick
some elasticity

When striking the ball.

This will allow the player
to hit the ball farther.

He sands the edges
to make them more even.

He tapers the bas
to the very end,

Creating a sloped surface so the
ball can be picked up easily.

He then switches
to a finer grid abrasive belt

And sands the handle
and the rest of the stick

Until it's super smooth.

Next, he cuts steel banding
to a length

That's a little more than
twice the diameter of the bas.

He loops the band
around the end of the bas

And clamps it snugly to it.

He drives large nails
into the band to puncture it.

He hammers smaller nails
into those holes

And all the way
through the wood.

He clips the protruding nails.

He then flattens the cut ends
to turn the nails into rivets.

He folds the ends
of the looped band together

At the rim of the bas
and nails them to the wood.

Now securely attached,

The steel band
will reinforce the hurley

At its most vulnerable point --
the end of the striking surface.

Not every player
wants their hurley banded.

This is an optional feature.

He now winds rubber tape
just under the handle

For better gripping.

He continues to twist it
partway down the stick

Because players sometimes
grip it there with both hands.

He finishes the wrap at
both ends with electrical tape,

Which has stronger
adhesive backing.

It will prevent unraveling
of the rubber tape.

It's taken about 20 minutes
to craft this hurley stick.

How long it will last
is anyone's guess.

There's no warranty on hurleys,

And it's sure to break
at some point

Because hurling is a rough game.

Some players go through
several hurleys in one season.

It doesn't matter
if you lose a stick

As long as you win the game.

Narrator:
in an audio system,

The amplifier is the component
which makes the sound louder

And sends it to the speakers.

While most amps on the market
are powered by transistors,

Many audiophiles
swear by tube amplifiers,

Which use older
vacuum-tube technology.

[ Guitar notes play ]

Many believe
that tube amplifiers

Produce a warmer,
more natural sound.

This factory makes the amp's
main chassis

From a sheet
of polished stainless steel.

A computer-guided punch press

Cuts openings for the
power switches, control knobs,

And other components.

The press prepares eight chassis
per sheet.

Workers separate them
with a few strikes of a mallet.

Then they place them
one at a time

In a bending machine
called a press break.

Once they position the sheet
with the help of metal guides,

They activate a foot pedal,

Releasing 90 tons of pressure
to bend the edge of the sheet.

Then they remove
the adhesive film

Which has been protecting
the mirror-finish surface

Of the chassis.

They clean off any remaining
adhesive residue with alcohol.

Then they put the chassis
into an offset press.

Using a silk-screen
printing process,

It labels the controls
and connections.

Next are the speaker terminals,

Which connect the speaker wires
to the amp.

These connectors are made
of gold-plated brass,

Which are nonmagnetic metals.

Magnetic ones would react
to the electric current

And cause distortion.

The terminal's circuit board,
installed next,

Carries the amplified signal
from the main circuit board

To the speaker terminals.

They install and connect
the power switch

And the circuit board for
the vacuum-tube illumination.

This indicates
the tube's status.

Meanwhile, this machine
winds strands of copper wire

Around plastic bobbins

To begin making the amp's
output transformers.

Output transformers
match the amp's circuitry

To the electronic specifications
of different types of speakers.

The number of wires,
their different gauges,

And the number of revolutions
around the bobbin

Create this unique
compatibility.

After taping the wires
to prevent unraveling,

They join, then solder the ends
to additional wiring.

They will later connect
to the amp's main board.

A fiberglass sleeve
insulates the connection.

They place the bobbin
in a lamination machine.

Laminations are thin plates
of carbon steel.

The machine stacks them
all around the bobbin.

Then workers put a bolt in each
corner to hold them together.

They place the laminated bobbin
in an aluminum housing

And pour in hot black tar.

This immobilizes the laminations
so they won't rattle

When the amp is amplifying
low frequencies.

Then workers install
the two output transformers

Into the chassis,

Along with a third transformer
to power the amp.

They take the amp's
main circuit board,

Plug in ceramic sockets
for the vacuum tubes...

...and solder the sockets' leads
to the board.

Then, after feeding
the transformer leads,

They mount the main board
in the chassis,

Screwing it to posts
to hold it in place.

Then they connect
the transformer leads.

They plug the vacuum tubes
one by one into the sockets.

The tubes are made of glass
with a heat-resistant base.

The interior contains
a combination of metals

But no air,
hence the term vacuum tube.

The amp has 11 tubes in all --

Seven small ones
to power input signals

From a source
such as a cd player

And four big ones
to power output to the speakers.

Then they attach the chassis'
ventilated bottom cover

Made of painted steel.

They affix decals

To differentiate
the output transformers

From the power transformer.

L.e.d. Lights turn green
when the amp is powered up

And ready to deliver
that warm, natural sound

That many believe
only traditional vacuum tubes

Can produce.

Narrator: people generally like
their coffee either hot or iced,

Hence the need
for the thermal coffee pot.

Pour in hot coffee,
and the pot holds in heat,

Keeping the coffee
at that temperature

For a good half-hour.

The trick to a thermal coffee
pot is in the construction.

Both the body and lid
have a double wall,

Two layers of stainless steel.

Between them is a tiny gap
just 5 to 6 millimeters.

The air in this gap
insulates the inner wall,

Trapping the heat
inside the pot.

They start with
a stainless-steel sheet

Just 1.2 millimeters thick.

The first step is to cut it
into smaller pieces

On a mechanical press.

To make the coffee pot's body,
they cut it into strips,

Then each strip into squares
measuring 8x8 inches.

Then they put each square
in another mechanical press.

It stamps the square
onto a circular die,

Which cuts it into a disk.

They'll now use this disk
to make the outer wall.

They run the disk
through a lubricator

That coats the surface with oil
to aid the next step

On a machine called
a hydraulic deep drawing press.

The machine's molders
draw the flat disk

Into a three-dimensional shape.

This stretches
the stainless-steel fibers

To a very fragile state.

They strengthen the piece

By what's called
thermic normalization,

Heating the metal
to 1,800 degrees fahrenheit,

Then letting it cool
to room temperature.

This process restores
the original molecular structure

Of the stainless steel

So it can be shaped further
without breaking.

But first, they even out
the jagged rim with a trimmer.

Then they return the wall
to the deep drawing press

Outfitted with
a differently shaped molder.

The second drawing tapers
the wall to a more rounded shape

And forms a base to make
the bottom perfectly flat.

Then it's back to the trimmer,

Outfitted with a different tool
this time, to smooth the rim.

They repeat the same steps

To make the coffee pot's
inner wall.

The deep drawing press
pulls the stainless-steel disk

Into a slightly different shape

With a lip protruding
to one side.

They heat the wall
in the induction oven

To restore
the molecular structure

Before shaping the metal
further.

Then they place the wall
in a mold and release a press.

This shapes the protruding lip
into a spout.

Then they transfer the wall
to another press,

Which stamps it with a die,
cutting off excess metal.

They check to make sure
that the inner and outer walls

Fit together properly.

If everything is fine,

They polish both walls
inside and out.

A little polishing paste

Applied with a sisal brush
on the polishing wheel

Has the surfaces glistening
in no time.

The surface is now perfectly
smooth and ready for welding.

The first part they weld

Is the coffee pot's
stainless-steel handle.

They shape it with two strikes
of a press, then polish.

They use a spot welder

To fuse the handle
to the pot's outer wall.

Then they turn the wall
upside down

To stamp the manufacturer's logo
into the bottom.

Now the assembly.

They place the inner wall
on a fixture,

Then the outer wall over it.

A press pushes the inner
to the correct depth.

Then they weld along the rim
of the outer wall,

Fusing it to the inner one.

The coffee pot's lid also
has double walls for insulation.

They weld a hinged lever
to the lid

And the adjoining part of the
hinge to the coffee-pot body.

Then they gently hammer a pin
through the hinge,

Riveting the ends of the pin
so that it can't fall out.

After a thorough cleaning
in a dishwasher,

The coffee pot is ready to use.