05x02 - Wood Burning Stoves/Orthoses/Ballet Slippers/Buses

[bunniefuu]

Narrator:
today on "how it's made"...

Wood-burning stoves...

...orthoses...

...ballet slippers...

...and buses.

Wood-burning stoves

Do more than create
a cozy ambience.

They're also powerful enough
to heat an entire house.

More and more people
are installing a woodstove

As an additional heat source
in their home.

It's economical,
and the new low-emission models

Are more
environmentally friendly.

Every woodstove
has a fire baffle --

A stainless-steel barrier
above the burning wood

That shields the top
from the intense heat.

The baffle also slows down the
smoke exiting by the chimney,

Which reduces the upward draft
that the rising heat creates.

Production begins
with large steel sheets

That are 1/4 of an inch thick.

A computer-guided laser
cuts out pieces

That workers will shape into
the various parts of the stove.

The laser slices through
the metal quickly

And with extreme precision.

And because it cuts
with intense light

Rather than punching force,

The pieces
have neat, smooth edges.

Workers use a strong magnet
to lift and transfer the pieces

To the next production area.

The largest piece
becomes the surround --

The part that forms the sides
and back of the woodstove.

Workers use a machine called
a press brake to shape it.

A computer guides
this large hydraulic press

To bend the flat steel
in exactly the right spots.

Now they position the surround
in an assembly jig

To keep it steady
during welding.

After welding the front
of the stove to the surround,

They weld the air intake,

Which allows oxygen to enter
the stove to feed the fire.

Next they weld the top --
the fire baffle --

And air channels near the top,

Which are also designed
to feed the fire with oxygen.

The quality of welding
in a woodstove is critical

Because the joints have to be
able to withstand extreme heat.

Now they weld the bottom
of the stove.

It has a hole in the middle

Through which you sweep
the embers to an ash pan below.

Now they weld the flue collar,

The steel ring that attaches
the stove to the flue pipe

That leads to the chimney.

Workers now bolt the stove
to a pedestal.

The pedestal
is also made of welded steel.

Meanwhile, the door takes shape.

They glue a fiberglass rope to
the perimeter of the doorframe

Using a silicone-based glue

That's resistant
to extreme temperatures.

This cord prevents air from
seeping in through the door

And fueling the fire
out of control.

After installing
the locking door handle,

They weld the door hinges.

The stove's interior,
where the wood burns,

Is known
as the combustion chamber.

They line it with bricks

To protect the walls from
warping in the intense heat.

Bricks do deteriorate over time,
but it's easy to replace them.

The last steel part they install
is the cap for the ash pan.

Now an automated conveyer

Transfers the stove
to the paint station,

Where a robotic arm sprays on
a coat of heat-resistant paint.

Once the paint air-dries,

A worker removes the door
to install its glass panel.

This isn't your
run-of-the-mill window glass.

It contains ceramic,
which enables it

To withstand temperatures up to
almost 2,000 degrees fahrenheit.

With the glass panel in place,

Workers can apply
decorative features

And information stickers.

Then they put the door back on
and lock it shut.

They rivet on
the company logo...

...then install a fan
in the back.

The fan blows out the heat
that the stove generates.

When the wood-burning stove
leaves the factory,

Its coat of paint is dry,
but not yet cured.

The heat cures it

When you fire up your stove
for the first time.

Narrator: orthoses are devices
such as arch supports and braces

That address
a joint or muscle problem

In the back or extremities.

An orthosis can provide
artificial support,

Prevent or correct a deformity,

Or improve how a weak
or painful area functions.

You can buy an orthosis off the
shelf or have one custom-made.

Producing a custom-made orthosis

Starts with a thorough
examination.

A certified professional,
called an orthotist,

Analyzes the problem area --

In the case of this patient,
the feet.

After a few manual manipulations
to test the range of motion

And pinpoint weakness or pain,

The orthotist
uses various instruments

To measure the angles of
the different parts of the feet.

Then it's on
to specialized devices

That analyze foot position
and movement

During standing and walking

And how body weight
is distributed onto the feet.

In this scan,
the red areas show

That more weight is landing on
the left foot than on the right.

Next, a 3-d impression
in foam.

It goes to the production
department,

Where technicians fill it
with plaster.

Once it dries, they extract
an exact model of both feet.

Now they can construct
the orthosis piece by piece.

Most of the components

Are made of different types
of polyurethane,

A lightweight thermoplastic.

Each type is designed
to produce a specific effect

At a different phase
of the patient's footstep.

For example, the blue base
is made of rigid polyurethane

That holds the foot
in the correct position.

At the front, dense, black
polyurethane helps propulsion

And reduces stress
on that side of the foot.

They cover the assembled
orthosis with a sheet of glue

And put it in a vacuum press.

The press applies heat
to activate the adhesive.

It sucks out the air
between the components

And compresses them
tightly together.

When the orthosis comes out,

They place it on the model
of the corresponding foot.

Then it goes into
a different vacuum press

To mold it to the shape.

They add made-to-measure
corrective parts

With latex foam.

Then, using hypoallergenic glue,

Line the orthosis
with a soft polyurethane.

All that's left to do now
is buff the orthosis.

This smoothes all the surfaces.

To ensure the orthosis
fits correctly,

The patient redoes the key tests
while wearing it.

Remember that scan
showing red areas?

They're gone now

Because the patient's feet now
bear his body weight equally.

This patient has arrived

With a doctor's prescription
for a knee brace.

The orthotist
analyzes his mobility,

Flection, and balance,

Then sends the technical
specifications

To the production
department.

There, technicians make a model
of the leg.

They begin by positioning
the leg at a 12-degree angle

And wrapping it
in plaster bandages.

While waiting for
the fast-set plaster to harden,

The patient chooses
a decorative pattern

For the outside
of the brace.

The hardened cast
serves as a mold.

Technicians pour in plaster, let
it harden, then remove the cast.

After smoothing the surface,
they draw technical markings,

Then install the lightweight
aluminum joints

That will enable the orthosis
to bend.

Now they run a sheet of plastic
through an oven.

This is high-memory plastic,
meaning that when you form it,

It remembers the shape
and maintains it.

The design the patient chose
comes printed on transfer paper.

They use a laser thermometer

To ensure the plastic
is at the perfect temperature

For the pigments
to penetrate properly.

They carefully position the hot
decorative plastic on the model.

Using a vacuum bag,

They remove the air and
press the plastic on tightly.

The plastic sets in about two
minutes, maintaining the form.

They cut the required shape,

Line the inside,
and sand the edges smooth.

Finally, they attach straps to
fasten the orthosis to the leg.

The orthotist checks the fit
on the patient,

Then runs various tests
to make sure the orthosis

Is doing exactly
what it's designed to do.

Narrator: ever wonder
how ballerinas manage to dance

On the tips of their toes?

It takes years of training,
remarkable skill,

And special ballet slippers.

These toe shoes are handmade

In what's truly
a manufacturing pas de deux --

A graceful pairing
of traditional methods

And modern materials.

They sew the toe shoe's exterior
with three pieces of satin.

They cut those pieces using a
press equipped with a metal die.

It slices through
enough fabric at a time

To make four pairs of shoes.

They also cut a pure cotton
lining for each piece

To protect the dancer's feet
from irritation.

This v-shaped piece
is called the vamp.

It'll become the front half
of the shoe.

The seamstress extends the "v"

By attaching
the two other satin pieces,

Called the quarter panels.

They'll form the back half
of the shoe.

She sews the ends of the "v"
together, making a heel seam,

Which she reinforces
with a rayon ribbon.

Then she feeds the same type of
ribbon through a special machine

That folds it in half
over a drawstring.

She stitches it to
the top perimeter of the shoe.

This encased drawstring
will enable the dancer

To pull the shoe
tightly around her foot.

Now they put the satin upper
onto a wooden form

To check the sizing.

It's absolutely critical

That the height of the vamp
be correct

To within 1/8 of an inch.

If it's even slightly off,

The top of the shoe
will cut into the dancer's foot.

The shoemaker nails
the cotton lining to an insole

On the bottom of the form.

The insole is made
of rigid cardboard for support,

Imbued with plastic
for flexibility.

After trimming off the excess,

He glues the lining
onto the insole,

Making neat little pleats.

Once the glue dries,
he removes the nail

And trims the excess pleating

To eliminate any bumps
that would irritate the foot.

Now they sculpt the toe box,

The hard encasing
inside the tip of the shoe.

It's made of papier-mâché,

Only instead of paper and paste,
they use fabric and paste.

Then they soften up a piece
of resin-coated cotton in water

And apply it on top.

Next they saturate two pieces
of burlap with paste

And apply them, one after
the other, over the cotton.

The paste is made of flour,
water, starches,

And a
rubber-and-plastic-based resin

That hardens
to a semi-flexible state.

That's key, because the toe box
has to be stiff enough

To bear the dancer's
full weight,

Yet flexible enough so that
the ballerina can move fluidly.

Now the final layer of fabric --
a piece of pure cotton.

They wrap the toe box in plastic
to keep the hammer clean

As they square off the front,

Creating what's known
as the platform.

Then they press the toe box
onto a piece of marble

To make it completely flat.

They verify that the platform
is perfectly square.

If not, the ballerina
will topple over.

After letting the toe box
dry for 24 hours,

They glue the lining over it
with contact cement.

They trim off the excess, then
glue the satin over the lining,

Forming delicate pleats.

They use lighter glue this time,

Because contact cement
would stain the fabric.

They apply a foam filler to
even out the shoe's underside,

Then coat it
with high-strength vinyl glue.

They apply the same glue
to a sole,

Then leave both to air dry.



They put them on a heater
set to 200 degrees fahrenheit.

This reactivates the dried glue
in about half a minute.

They apply the sole

Then put the shoe in a press for


Now they can remove the shoe
from the form.

The sole is made of suede,

A material that has
just the right amount of grip.

It's nonslip,

Yet still enables the dancer to
glide smoothly across the floor.

The last step is to glue in
a white suede sockliner.

It cushions the ballerina's foot

And keeps it
from slipping forward

When she's dancing on her toes.

Narrator: a city's fleet
of public transit vehicles

Might include standard buses,
low-floor buses, or both.

Low-floor buses have
a special kneeling feature.

When they pull up
to the bus stop,

They can mechanically lower
themselves to curb height

To make boarding easier
for children, senior citizens,

And handicapped people.

This low-floor bus
is 40 feet long

And can carry
more than 80 passengers.

To build the bus's
internal structure,

Workers put stainless-steel bars
into a press.

It applies between


Bending them
to the required shape.

Workers assemble the structural
pieces on a support frame

Called an assembly jig.

They use
an electronic inspection arm

To verify their work.

Once they've assembled
the roof structure

And the side structures, they
bring them together for welding.

Everything goes
on a rotating jig.

It turns like
a giant rotisserie,

Giving workers easy access

To whatever part of the bus
they need to weld.

When the welding is finished,
they turn the bus right side up.

They put the structure
on a dolly

And release it from the jig

So that they can move it
down the production line.

Meanwhile,
the stainless-steel structure

For the floor of the bus
takes shape.

Once that's complete, it's back
onto the rotating assembly jig

To weld it
to the rest of the structure.

This bus factory
uses stainless steel

Because it stands up well
to corrosion.

Transit systems need to keep
these buses running full-time

For up to 20 years.

Less rusting means

Fewer expensive
and time-consuming repairs.

Workers now move
the completed structure

To another part of the factory

Where they spray the underframe
and lower section

With a black,
anti-abrasion coating.

This protects against
the noise and damage

That stones
and other road debris cause

When they hit the bottom
of the bus.

Next, workers apply
high-strength glue

To the floor structure
and lay down a subfloor.

Then they drive in screws
for reinforcement.

Now they turn
the bus upside down

To install four tanks of
compressed air under the roof.

Three are for the brake systems,

The fourth for the doors
and other mechanisms.

Melamine ceiling panels

Hide everything
that's under the roof.

Next, the engine's radiator
goes in at the rear of the bus.

Then workers turn the bus
right side up again

And lay down a waterproof
vinyl floor covering

That's specially designed

To withstand
heavy-duty transit use.

They cover the sides and roof
with fiberglass panels.

To prevent corrosion,

Workers use glue
rather than screws or rivets.

Then they attach
the fiberglass front of the bus

To the rest.

The bus's low-emission
diesel engine

Arrives at the factory
already assembled.

Workers attach it
to the transmission

And drive shaft
in the engine compartment.

Buses without air-conditioning

Have sliding windows
that open widely.

On air-conditioned buses,
just a small top section opens.

The upholstery
on the molded fiberglass seats

Is a velour-like fabric
woven onto a strong canvas,

Then glued onto
a fiberglass insert.

This construction
makes it impossible

For vandals to slash the seat
with a knife.

Workers install
the driver's seat,

The steering wheel,
and all the controls,

Including the toggle switch that
activates the kneeling feature.

This bus also has a ramp
for wheelchairs.

A safety system
locks the accelerator pedal

And applies the brakes

To prevent the bus from moving

When the ramp or kneeling
feature are in operation.

The finished bus

Undergoes a half-hour
water-infiltration test

With all of the systems running.

This ensures there are no leaks.

At every phase of production,

The factory does
a quality-control inspection,

Checking everything from
mechanical safety to finishings,

Right down
to the tiniest of details.

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