22x07 - Sanders, Solid Terrain Models, Stucco, High-Speed Roll-Up Doors

[bunniefuu]

Narrator: most experts
will tell you that the key

To the perfect paint job
or wood-refinishing job

Is to prep the surface properly

Before applying the paint
or wood stain.

That requires sanding
to remove old finishes

And to level uneven areas.

The easiest way to do that
is with a motorized sander.

Professional-caliber sanders
are typically pneumatic,

Meaning you plug them
into an air compressor.

Air-driven tools are more
powerful than tools

Than run on electricity.

This type of sander is called
a straight line,

Because the pad
to which you attach sandpaper

Moves in a straight line
back and forth.

Many of the tool's components
are made of powdered metal,

Then machined
to exact dimensions

On a computer-guided lathe.

Powdered metal is iron powder

That's compacted
with high pressure

And heated in a furnace to bond
the particles into a solid part.

Sometimes they further
strengthen the powdered metal

By infusing it with copper
in the furnace.

Using an induction welder,

Which heats the metal
with an electric current,

They fuse a powdered-metal gear
to each end of a steel shaft

By melting on silver.

This constructs the sander's
timing driveshaft,

The regulating component

That makes each stroke
of the sanding pad

Just under an inch long.

Heating the metal softens it,

So they now cool the timing
driveshaft in oil.

This quenching hardens
the component.

Meanwhile, they coat
a sheet of aluminum rectangles

With industrial-strength
contact adhesive.

Each rectangle is a base
for a rubber sanding pad.

The rectangular pad, which they
coat with the same adhesive,

Is 6 1/2 millimeters thick,
the same dimensions as the base

With identical holes
for the mounting screws.

Once the adhesive becomes tacky,
they mate the base to the pad.

Using a small pneumatic press,

They force out trapped air
to ensure a thorough bond.

Elsewhere in the factory,

They paint
the recessed lettering

Of the polished aluminum plates,
two per sander,

Which bear
the manufacturer's name.

Once all the remaining
components are prepared,

Technicians begin the assembly.

First, the motor's piston.

They place the piston rack
in an arbor press

And push a plastic piece
onto each end.

Then, on each end piece,
they mount a piston ring

Made of a proprietary
wear-resistant material.

They insert
the now-assembled piston

Into the sander's
aluminum motor block.

The ring creates a tight seal
to prevent air leakage.

Next, a technician installs
the timing driveshaft

And the idler gear shaft,

Pressing the gears of both
into the piston rack's teeth.

The powdered-metal counterweight
goes on each side

To balance the piston rack,

Then guides made of that
proprietary material

To align and lubricate
the counterweights.

A second set of anti-wear guides

Goes in the lower part
of the motor block.

These help balance
the sanding pad.

Then the start
of the valve system,

Which controls the entry of
compressed air into the sander.

At the front of the motor block,

They install a paper gasket
to prevent air leakage,

Then seal it
with an aluminum end plate.

Continuing with
the valve system,

They install the components,

Which control the timing of the
pistons' back-and-forth motion.

After sealing the top
with a cap,

They install the air-valve
block, then the handle,

Which contains the inlet

To which the air compressor
connects.

The handle squeeze trigger

Is mounted to the cap
above the handle.

They install the counterweight
for the pad.

Here, you can see the two shafts
the piston rack rotates.

Workers connect them
to an aluminum drive shoe,

Which will move back and forth.

A pair of side rails holds
the drive shoe in place.

Where the air exits the tool,

They install a muffler made
of porous plastic.

Finally, when the technician

Screws the base
to the drive shoe,

The chain is complete.

Compressed air moves the piston,
which rotates the shafts,

Which moves the drive shoe

Holding the rubber pad
with sandpaper.

This pneumatic sander
is ready to level

And smooth a surface
in seconds flat.

Narrator: a solid terrain model,
"stm"; for short,

Is an exact, three-dimensional,
miniature replica

Of a geographic area.

Stms are indispensable tools
for museums, visitor centers,

And for planning everything
from industrial projects

To military operations.

To create a solid terrain model,

The first step is to gather data
via satellites and aircraft.

Two types of data --
color photographs of the surface

Showing the precise location
of vegetation, rock, buildings,

And so on,
and elevation measurements,

Taken with lasers
and other equipment.

A cartographer digitally merges

The black and white elevation
diagrams with the color photos

And adds artwork for roads
and place names.

He produces a 3-d computer model
of the area.

This model will guide
the machines

That manufacture
the physical model

Out of a block
of polyurethane foam.

Foam is a durable material
and lightweight,

Making the model easy
to transport.

A computer-guided cutting
machine first shapes a ledge

Around the block's perimeter.

This is for mounting
the model on a frame.

Then the machine reads the
computer model's elevation files

And carves a miniature replica
of those elevations into foam.

The machine first does
a rough cut.

Then --
and this takes much longer --

It carves the fine details.

Depending on the complexity
of the terrain,

Cutting the elevations
into the foam

Can take just a few hours
or several days.

When the cutting's finished,

The technician cleans off
the foam dust

With compressed air and a brush.

The foam goes into a spray booth

Where it first receives
a coat of primer

To seal the porous surface,

Then multiple layers
of special coatings

To make images printed on
the surface sharp and vibrant.

Once the coating's dry --
that takes about a day --

Technicians put the model into a
custom-designed inkjet printer,

Which reads the computer model's
photograph file.

Just like an ordinary printer,

This printer produces
a multitude of shades

From just four basic colors --

Black, yellow, magenta,
and cyan.

The jets pass just a few
millimeters above the model,

Emitting one microscopic drop
of ink at a time

At precisely
the correct location.

The end result
is a miniature replica

Of what the surface looks like
in real life.

Other workers, meanwhile,

Construct a sturdy frame
for the model

By gluing, clamping,
and nailing together

Four lengths of oak.

This frame will protect
the model from damage

And make it easier
to lift and move.

Once the glue dries, they remove
the clamps, and with a saw,

Trim each corner
to a 45-degree angle.

Then they round the edges
with a sander.

They complete the frame
by protecting the wood

With a coat
of clear polyurethane.

When that dries,

They spread glue
onto the frame's inside edge.

Then they position the model

So that the ledge
along its perimeter

Sits on top of the frame.

After printing,
they spray the model

With clear polyurethane
or lacquer.

The protective finish
allows people

To now touch the model
without damaging it.

Sometimes, an area
they're modeling has buildings,

Bridges, or other structures.

When that's the case,

An engineer designs a computer
model of the object.

Then, guided by this model,

A 3-d printer produces
a physical model out of plastic,

Building the miniature replica

From the bottom up
one thin layer at a time.

These mountaintop castles
in portugal

Are the finishing touch
on this model

That's set to go on display
at the local tourist center.

Solid terrain models are
a creative and valuable tool

For educating people
young and old.

By translating complicated
technical data

Into a unique and
scientifically sound visual aid,

A solid terrain model delivers

A fascinating bird's-eye view
from the ground.

Narrator: stucco is one

Of the oldest construction
materials on the planet.

The earliest formulations

Date back to ancient greece
and mayan mexico.

Stucco has stuck around,

And as an exterior siding,
it's come a long way.

Modern stucco is more attractive
and offers better protection.

Whether cement-
or acrylic-based,

Stucco always starts out
as a sticky paste,

And that's the great thing
about stucco.

In this wet and gooey form,
it can be worked

As it's applied to the exterior
of a building

To achieve a variety
of textures.

It hardens to provide
a tough exterior

That shields the building
against the elements.

To mass-produce cement stucco,

They start with tons
of silica sand.

They unload it into a conveyor
and elevator system,

Which delivers the sand to silos
for storage until needed.

They select sand with various
grades of coarseness

For different stucco finishes.

They mix it with cement, lime,
and other ingredients

To create the stucco base.

A technician demonstrates how
the ingredients come together

Using this research lab mixer.

She blends
all the ingredients dry,

Achieving a consistency that's
similar to cake mix from a box.

Cement stucco
is sold in dry form.

Water will be added to liquefy
the ingredients on the job site.

In this demonstration,
she also adds pigment.

With the stucco pre-colored,

There's no need to paint
the building.

To mass-produce cement stucco,
they use this mega-mixer.

The operator adds three or four
different pigments

To create a custom color
in the dry stucco batch.

Large paddle blades
spiral vigorously.

Usually,
this is a closed operation,

But they've opened it up
for our camera.

After three minutes of mixing,

The dry stucco mix is ready
for scrutiny.

An employee takes a sample

And sends it to the quality
control lab for evaluation.

At the lab, the technician
weighs the stucco mixture

And adds water.

He keeps an eye on the scale

To ensure that the amounts
are proportionate.

He mixes them
and visually checks to confirm

That the pigment and raw
materials are well dispersed.

Acrylic stucco,
on the other hand,

Calls for
an entirely different recipe.

They use calcium carbonate
instead of silica send

And acrylic as a binder
instead of cement.

They mix it with water

And sell it wet in a bucket
instead of dry.

To color it, they use
a computerized tint machine,

Similar to what you find
in a paint store.

They load the machine
with liquid pigments

And enter a color formula
into the computer.

It mixes the pigments
to produce the exact color.

And it releases
the precise amount needed.

They blend the color
into the acrylic stucco,

And the batch ends up
looking like blue mud.

It's now ready to apply
to a home.

No prep required.

They also sell acrylic stucco
with no color at all.

It's called tint base.

The pigments will be added
on the job site,

Where they can be adjusted
if needed.

An airtight seal keeps
the stucco in its viscous state.

Acrylic stucco dries quickly,
like paint,

While cement stucco
takes 28 days to totally cure

Into a more durable finish.

Over on the cement stucco line,

A rotating machine
handles all the packaging.

A suctioning device pulls
a paper bag into position

Under a spout,
which then fills it up.

It takes just 8 seconds
to fill a 90-pound bag.

That works out
to over 1,300 bags per hour,

Enough material for 30 houses.

The machine transfers the bag
to the conveyor belt.

This stucco is now ready
to provide a strong finish

To building projects.

Applied to
a building's exterior,

Stucco can be textured to suit
the homeowner's taste,

And it will harden to provide
the building with a tough skin.

That's why stucco continues to
be part of the urban landscape.

Narrator: an industrial
roll-up door opens and closes

At least three times as fast

As your average
residential garage door.

That means machines and products
can be moved in and out quickly.

These heavy-duty rubber doors

Are also engineered for a good
seal, so they're weathertight.

In many workplaces, doors
are always opening and closing.

A high-speed roll-up door
is designed for heavy traffic.

Coal mines, parking garages,
and large food freezer rooms

Are just a few of the places
you will find them in action.

They start with rubber panels.

Their number and size depends
on the width of the door

Being manufactured.

Workers brush high-strength
epoxy onto the edges

To bind the panels together.

The epoxy will take
a couple of hours to cure,

So there's time to smooth out
the air bubbles

By applying pressure to
the seams with a heavy roller.

After the epoxy cures, they map
out areas with masking tape

To contain glue

For the application
of extruded rubber strips.

The horizontal one
is a stiffener,

And the vertical strips
at the sides are wind blocks.

They'll secure the curtain
to the building

Even in bad weather.

The employee also applies
synthetic fabric to both sides

To prevent wear.

He adds reflective yellow strips
to the front and back

To make the black rubber door
visible at night.

A machine now drills holes
in a steel tube.

This tube is the header

That the rubber curtain
will be rolled up on to.

The holes will be used
to attach the curtain to it.

He tack-welds axles
onto both ends of the tube.

The axles will be attached
to mounting plates,

So these are critical welds.

He measures the axles to confirm

That the assembly is level
and won't wobble.

Satisfied, he welds them
permanently to the steel tube.

Next, he assembles
and welds the side frame

For the rubber curtain.

He assembles a hinge cover
to the front of the frame,

Creating a compartment
for the curtain

That can be opened when needed.

Then it's on to the paint booth.

Here, an employee primes
the frame components

To protect them from rust and
then gives them a coat of paint.

A worker assembles
the bottom beam now.

He bolts an aluminum track
for the rubber edging

To a heavy steel frame.

He screws the box
for the wireless transmitter

That opens and closes the door
to the beam.

Two workers now pull
the rubber edging

Through the aluminum track.

The edging is equipped
with an electric safety wire

To detect movement
and abort a door closing.

This will keep the door
from hitting anyone

Who walks under it.

It's now time to pull
everything together.

The team screws the rubber
curtain to the steel tube,

Making use
of those pre-drilled holes.

They move down and position
the bottom beam on the curtain.

They attach it to the curtain
with numerous nuts and bolts.

They roll up the rubber curtain

To prepare for assembly
to the mounting brackets.

With the attachments,

The curtain now weighs
over 1,100 pounds.

A crane transfers it
to the end mounting plates

And holds it steady

While workers slide
the end brackets onto the axles.

They build a steel support
structure around the brackets

And the rolled-up curtain.

They attach the motor
to one of the axles.

This roll-up door is now ready
for delivery.

Two days in the making,

It's ready
for whatever comes its way.

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