Gut Strings
Absinthe
Belt Buckles
Lever Locks

The instruments in the violin family have a distinct sound created in large part by the type of strings they have.

While there are strings made of synthetic materials or metals on the market, traditional strings are made of a specific part of a certain animal.

Stay tuned for the details.

Playing an instrument in the violin family takes guts-- literally.

That's because the instrument's four strings are made of sheep intestines.

The two thinner, higher note strings are made of plain gut.

The two thicker, lower note strings have a gut core wrapped in silver wire, then silk thread wound around the extremities.

The intestines, each roughly 65 feet long, come from local slaughterhouses and arrive already emptied, cleaned, and salted.

The first step is to soak them in cold water for one to two days.

This starts a controlled, very smelly decomposition which helps loosen up the intestines' components.

Next, using a half piece of wood cane, the string maker scrapes off the outer layers of fat and mucosa membranes.

Then, five times a day for a week, he softens the gut in an alkaline potash bath and pulls it against a handmade copper thimble.

This gently scrapes away the waste remnants until the gut is a tube of pure, transparent muscle, at which point he slices it with a splitting horn into two gut ribbons of differing widths.

The thinner, right one for making violin strings, the thicker, left one for making cello and double bass strings.

During the scraping phase, guts sometimes break apart.

Rather than discard these pieces, the string maker knots them together to produce full-length strands.

The string maker's assistants cut the gut ribbons into 23-foot lengths and bleach them for four days.

This prevents the gut from turning brown.

Then they count out the number of strands required to produce the various size strings-- from six to make the thinnest violin string all the way up to 120 to make the thickest double bass string.

They tie the ends in a loop and hook them up to a twisting machine, then turn the machine's crank and tightly twist the gut ribbons together to form one strong, single string.

Then, since the guts have begun to dry out a bit, they rehydrate the string to restore a consistent level of moisture.

Then they twist it again and transfer it, along with additional strings, to a drying frame.

There's no set drying time.

They monitor each string individually around the clock.

As a string dries, it shrinks in diameter but grows in length, creating slack.

So, they repeatedly remove and retwist until it dries completely, at which point it stabilizes.

This drying and retwisting process can take up to seven days.

The string is ready when it's hard and stiff and slightly yellowed.

At that stage, they rub it with horsehair-- the traditional equivalent of coarse sandpaper.

It makes the string smooth and even throughout.

Next, they fine-polish the string with abrasive, dried grass in a cloth that's been moistened with olive oil.

Some string makers use almond oil and pumice or powdered glass as the abrasive.

They sever the strings from the drying frame and cut them to standard lengths.

These strings will be for a child-size violin, so they're 100 centimeters long.

To produce the correct sounds, the instrument's two lower-note strings must be considerably thicker than the others.

The problem is this thickness in gut alone would produce a dull sound, so they wrap the string in sterling silver wire-- silver being seven times denser than gut.

This gives the string the right sound and a loud, brilliant tone with minimal thickness.

Next, for decoration, they wrap the top and bottom of these gut-core strings with silk thread.

On a violin string, the silk runs about a centimeter long on each end.

On a longer cello string, like this one, about 5 centimeters.

The finished string is ready to be inserted into its retail packaging.

There are less expensive synthetic strings on the market, however, particularly for early music, many musicians prefer the sound and feel of traditional gut strings-- made by hand today just as they were centuries ago.

Absinthe is a strong alcoholic drink with a colorful history.

During the late 1800s and early 1900s, drinking this anise-flavored spirit was the rage among european bohemians.

Conservatives of the day saw it as dangerous and immoral and succeeded in getting absinthe banned in several countries.

The traditional way to drink absinthe is to pour one part into a glass, straddle a specially designed slotted spoon holding a sugar cube over the glass, then, very slowly, drip three to five parts ice water directly onto the cube, dissolving the sugar into the diluting spirit.

This transforms the drink from clear to cloudy and draws out the subtle flavors and aromas of the herbal ingredients.

You can do this with a single glass or several using a traditional absinthe fountain-- a large mounted glass vessel which dispenses the ice water through multiple spigots.

This 180-year-old french distillery makes both white and green versions of absinthe.

Each is made from a different combination aromatic plants.

However, for both, the primary ingredients are green anise and grand wormwood.

Both also contain fennel.

The white absinthe has more of it.

And only green absinthe contains additional plants, such as petty wormwood, hyssop, mint, and chamomile.

The distillery workers pour the recipe ingredients into a copper still.

They pump in highly concentrated alcohol made from white grapes.

The plants soak in this alcohol base overnight, gradually imbuing the alcohol with their respective flavors and aromas.

This process is called maceration.

The next day, distillation begins.

They heat the still with pressurized steam.

After about 45 minutes, the spirit reaches the boiling point, and a floating gauge monitoring its alcohol level slowly rises and flows out the neck of the still.

However, what comes out during the first 10 minutes or so has to be discarded.

It's white, oily, and has a 90% alcohol level.

What follows is the good stuff-- crystal clear, with an average alcohol level of 78% to 80%.

This streams steadily out of the still for about three to five hours, followed by a weak tail-end flow that they discard like the first flow.

Then they dilute this distilled spirit with water to reduce the final alcohol level of this white absinthe to 60%.

To make green absinthe, before that final dilution, they pump the white absinthe through a burlap bag containing a specific plant-- the identity of which the distillery won't divulge.

They let the plant soak in the absinthe for a specific length of time.

This draws out the plant's chlorophyll, which colors the spirit bright green.

Then they dilute with water to obtain the target alcohol level of 62%, slightly higher than white absinthe.

That extra bit of alcohol helps preserve the chlorophyll.

In the distillery's in-house laboratory, quality-control technicians test a sample from each batch to verify the alcohol content.

Absinthe contains about 20% more alcohol than most spirits.

The lab monitors the level of thujone, a chemical compound in wormwood, the drink's second key ingredient.

Thujone content is regulated to varying degrees in many countries.

The european union permits up to 35 parts per million, for example, while canada, no more than 7 parts per million.

The distillery, therefore, bottles several versions of absinthe, tailoring the wormwood portion of the recipe to the export destination.

White absinthe has a strong anise taste, well balanced with wormwood, whereas green absinthe, containing more plants, has a more complex flavor.

While white is typically bottled in clear glass, green is always bottled in dark-colored glass.

That's because chlorophyll, the plant pigment that produces the green color, is highly sensitive to light.

Without dark glass shielding it from exposure, the green absinthe inside would turn yellow and eventually brown.

This would have no effect whatsoever on the taste, however, the potent drink known in 19th-century france as la fée verte, the green fairy, would lose some of its magic.

There are reports of archaeologists finding evidence of belts and buckles dating back to the 6th and 7th centuries in britain.

Decorative belt buckles appear to have been worn for the first time as symbols of status in the 1500s throughout regional spain.

Today, hand-engraved belt buckles are prized not only as fashion accessories but as inspired examples of workmanship and art.

The buckle maker welds small stainless steel rods together to form the back of the buckle.

After placing them in a welding fixture, he precision-welds them.

Using another fixture, the buckle maker adds a center pin to the back of the buckle.

After precision-welding it into place, he melts the tip of the stainless steel pin into a smooth ball.

This locating pin centers the belt in the buckle.

The buckle maker uses a jeweler's saw to cut the shape of the buckle from heavy gauge solid sterling silver.

He stamps the company logo into the back of the buckle.

Using pure silver, he solders the welded rods onto the back of the buckle, along with a stainless steel keeper tongue.

He uses a jeweler's saw to cut out initials, using the font, material, and size selected by the customer.

The buckle maker uses a soldering gun to apply solder to the back of the letters, which are made of gold fill, a thin layer of gold on top of brass.

He carefully positions the initials on the sterling silver buckle, which has been covered with flux for the soldering phase to come.

Too much solder on the back of the letters, and it could flow out onto the buckle surface.

Heating the belt buckle causes the solder on the back of the letters to attach firmly to the sterling silver surface.

The attachment process happens very quickly.

With a polishing compound and cloth polishing wheel, he gives the buckle a brilliant shine.

The buckle maker hand-engraves the buckle using assorted engraving tools.

He uses a shading tool to add depth to lines.

He follows guidelines drawn in felt pen.

The pattern engraved is chosen by the customer.

The belt maker rolls out a piece of tan strap leather.

Using a gauge knife, he cuts the width of leather needed to make the belt chosen by the customer.

The belt maker uses a variety of tools to cut and shape the leather.

He cuts the tip of the belt.

He places the leather in room-temperature water for about five minutes.

When bubbles stop rising, the leather is saturated.

After the leather has dried, he transfers a pattern from the design strip to the leather.

Stamping tools allow him to stamp intricate designs.

Using a swivel knife, he cuts to a depth of between a quarter to a third of the way through the leather.

The initial pattern has been carved.

With a beveler, he deepens and shapes the carved lines.

He chooses a bar backgrounder to create leaf in the background.

With a swivel knife, he makes the final decorative cuts.

The belt maker applies dye to the background sections of the carved leather, completing the most intricate part of his work.

He stamps in the maker's mark.

Using a piece of sheepskin, he applies an oil finish to the belt.

A thin paste highlights the cuts and gives the belt an antique finish.

A final tanned coat waterproofs the belt and helps protect it.

He makes holes in the belt.

The belt has a bend in it where the buckle will be attached.

With chicago screws, he attaches the buckle firmly to the belt.

Ideally, the belt and buckle complement each other.

Strong and stylish, meticulously handcrafted belt buckles and belts have managed to make a clear fashion statement out of belt-tightening.

The lever lock was invented in the late 18th century by an englishman.

At the time, the ward lock, with its simple, concentric plate mechanism, was the main kind of lock in use.

It was medieval technology and fairly easy to pick.

The lever lock took security to a whole new level.

More than two centuries after their invention, lever locks are still on security duty.

The mechanism hasn't changed much, except instead of two levers, there can be many inside.

They fall into slots, locking the bolt until a key lifts the levers.

This lever mechanism is very rugged.

It will continue to function even if dirt or moisture infiltrates the lock.

It's why many armed forces will only use this kind of lock.

To make the two halves of the lock body, they uncoil a narrow band of heavy steel.

Rollers straighten it.

Then a punch press shapes and cuts out the part.

Four punches produce a fully formed part.

The front half includes the side flange, the keyhole, a post, and rivet holes.

The parts tumble with wood chips, and the friction removes unwanted bits called burrs.

The chips also absorb residual oil from punch pressing.

They punch out the lock levers and other parts.

They plate all 23 parts with yellow zinc.

Next, rivets funnel into a network of tubing.

They tumble four at a time into an assembly device.

There are different-sized rivets to fit different-sized holes.

The delivery system pushes the rivets up through holes in the assembly device.

A factory worker places the back of a lock body on the rivets, and a hydraulic press squeezes them into place.

He keeps a stash of rivets at the workbench in the event that the tubing doesn't deliver.

The back of the lock body is now ready to receive the lock mechanism.

There are 240 different lever combinations.

The next worker determines which one to use.

She places the bolt lever in the casing and slides all the other levers onto a rivet.

There are a total of six levers in this particular padlock.

Some locks have more, some have fewer.

The more levers there are, the tougher the lock is to pick.

She wraps a metal spring around a rivet...

And then hinges the shackle to a third post.

She sets the back half aside and assembles the keyhole cover to the front part of the lock.

She winds a spring around a post and places the cover over it.

The spring will allow the cover to be swung open and shut.

A rivet secures the keyhole cover.

She now brings the two lock body halves together, so the rivets from the back protrude through the front.

She flattens the rivets to hold the parts together.

The next part is the clevis.

It's a u-shaped attachment for a chain to make the lock easier to hang onto when not in lockdown mode.

Another worker now categorizes the locks in separate boxes, according to the key code.

He leaves a key code i.d. card in each box.

When transferring a lock for painting, that i.d. card goes with it.

This system prevents mix-ups, so that later they'll be able to make keys to match.

They spray the locks military green and give them four coats for corrosion resistance.

It's time to rev up the key cutter.

There are 240 key profiles to match the 240 lever lock combinations.

The operator sets the blades in the desired sequence and carves the keys to give them the right geometry.

With the correct profile, the key lifts and lowers the levers in the lock to open and close it.

A standard padlock comes with two keys.

If the owner loses them both, the lock will usually need to be replaced.

That's because the keycode is never written on the lock body to avoid tipping off thieves.

The technician confirms that both keys work, and this lever padlock is now ready to thwart criminals and safeguard possessions.


Surfboards
Stickers
Sandwich Cookies
Concrete Roofing Tiles

Surfing is an ancient polynesian pastime, first documented by europeans in the 18th century.

In the 1920s, the sport spread from hawaii to the beaches of california.

Back then, surfboards were made of solid wood.

Today, they're made of lightweight synthetic materials.

Serious surfers have their boards custom-made and engineered for the types of waves they'll be riding.

At the board's core is a piece of polyurethane foam with a wooden strip down the center.

The factory's shaping specialist inspects the board and checks the foam for defects.

If all is well, he cuts the board to the right length.

Then he chooses a board shape template from his library and traces it.

Then he saws along his pencil line.

Using a planer, he refines this starting shape to the customer's specifications.

When he finishes, he checks to make sure everything's symmetrical.

Next, he shapes the edges.

With a power sander, he flattens and smoothes out the surface then follows with a fine sanding by hand.

Before releasing the foam core to the next department, he checks the dimensions-- thickness, contours, and the smoothness.

A lamination specialist preps the board to receive its first layer of fiberglass.

He masks the top, called the deck, to shield it from the resin he'll now apply to the bottom.

He lays down the first fiberglass cloth, leaving a 3-inch overlap along the perimeter.

Next, he spreads polyester resin that's tinted to whatever color the customer ordered all over the fiberglass cloth.

He folds the overlap onto the deck...

Then grinds the corners flat.

He flips the board deck-side up and trims the overlap.

Next, he covers the deck in two layers of fiberglass.

In between them, he pours clear polyester resin then positions company logos printed on rice paper.

The resin soaks the paper, embedding the logo.

Then another layer of resin-coated fiberglass.

Once that dries, he applies yet another coat of resin on both sides of the board.

Using a router and template, he cuts a hole for the box that'll hold the surfboard's fin.

He fills the hole with black resin then inserts the fin box.

Now a sanding specialist takes over.

He grinds the box flush, which opens its fin slot.

Then he gives the board an overall sanding to smooth the surface.

Next stop is the paint room.

The painter uses masking tape and an acrylic paint pen to decorate the surfboard with black pin lines.

Once they dry, he masks the board and air-brushes in a white pin line.

Once dry, he applies a finishing coat of resin over the entire board.

Now a polishing specialist steps in.

After a fine sanding, he buffs the entire board with polishing compound, producing a slick high-gloss finish.

The factory ships the board to the surfboard shop, where the customer chooses a fin from the many models available.

The fin screws into the fin box, and, dude, the board is ready to go.

Stickers have long been used in merchandising.

But in 1979, they took a crafty turn with the introduction of decorative stickers.

Sticker art soon became a popular hobby, allowing anyone to engage in a little creative embellishment.

Stickers can be used to accent greeting cards, photo albums, or add a certain flourish to any project.

Every sticker begins with a work of art.

The artist transfers the image to a computer and manipulates it until the desired effect is achieved.

Next, a sheet of photopolymer goes onto an exposure machine.

The technician places a negative of the art on top of the photopolymer sheet.

He pulls plastic over the two and closes the machine's lid.

Inside, a vacuum pulls the negative to the photopolymer.

Intense ultraviolet light transfers the art to the photopolymer in seconds.

He makes several photopolymer printing plates, each one a variation of the original artwork.

They will be used to layer pattern and color.

Before they can print, they have to make the art stand out from the background.

This machine removes material surrounding the transferred images using a special chemical and a heavy-duty brush.

Because the images were hardened during the exposure, they withstand the chemicals and abrasion.

The process leaves the images slightly raised against a clear backdrop and ready for the printing press.

They wrap the printing plates around cylinders.

The press operator examines the seam under a magnifying glass to confirm that the edges are perfectly aligned.

He loads the cylinder into the printing press.

Then he pours yellow ink into a reservoir below.

And it's time to roll the printing press.

Rollers transfer the ink to the printing cylinder, and it prints the art onto adhesive-backed sticker paper.

They use a different printing plate for each color to create variations in the design.

As a result, each of these hearts ends up looking different.

It's all about layering color and pattern to give the sticker artists plenty of options.

Next, the press operator prepares a cutting cylinder.

It cuts around the designs, but only penetrates the top layer of the sticker paper.

Rollers pull off the surrounding material.

They wind it up for recycling offsite.

Only the stickers remain on the backing, but they aren't ready for the scrapbook just yet.

First it's over to another press, which hot-stamps foil to the designs.

This process is carefully choreographed.

A sensor on the press detects the hearts which are to be given the metallic finish.

Those get shiny swirls, glossy ribbons, or other trimmings while others are left untouched.

The next machine cuts the stickers into sheets.

Then it's over to a packaging machine where an operator loads the sheets into a hopper.

Wheels with little grippers collect the sheets and drop them in piles of two onto a backer car.

The packaging machine then wraps plastic film around the stickers and seals the package with a static charge.

A hot knife then cuts and seals it at both ends.

When it comes to other designs, there's no shortage of choices, giving sticker artists of all ages plenty of ways to express themselves.

Early in the 20th century, an american biscuit company introduced a cookie sandwich.

It was two chocolate cookies with rich vanilla icing at the center.

This sandwich cookie created an instant sensation, and almost a century later, it hasn't lost its appeal.

People still crave this sugary fusion of crunch and cream.

Dipping the sandwich cookie in milk is a tasty tradition, and whoever started it must have been one smart cookie.

Sandwich cookies start with pure granulated sugar.

This worker heaves bags of it into a mixer as he prepares to whip up the batter for the wafers.

He adds two kinds of cocoa.

The combination will give the wafers the desired taste and color.

A premix of salt and other ingredients follows.

A specially formulated canola-oil mixture will transform these dry ingredients into a batter as huge beaters blend everything together.

They add water, and the batter starts to look like a bubbling chocolate soup.

They add dry ice, which chills the batter as it evaporates.

The lower temperature is key as they add flour to thicken the batter into a dough.

The dough will turn out less crumbly than it would have been if it had been kept at room temperature.

A premix of leavening ingredients goes in next.

One final mix, and this chocolate dough is ready to go.

The worker shovels it onto a grate, which protects his fingers as he presses the dough down into a molding machine.

This machine shapes the dough into cookie wafers while pressing intricate designs and the brand name onto them.

It churns out an impressive 5,000 chocolate wafers an hour.

The freshly molded cookie wafers now move from the silicon conveyer to a steel one.

It takes the wafers into a gas oven, where they travel in a continuous loop for several minutes to receive an even baking.

After that, fans cool the wafers to the desired crispiness.

The chocolate wafers then move to another conveyor, which feeds into a series of chutes.

Then the wafers travel over ramps designed to make them fall into a certain position.

One row lands plain-side up, and the next lands with the embossed side up.

This correctly orients them to be sandwiched around a cream filling.

It's a high-speed operation, as a cylindrical pump deposits the vanilla cream on the plain side of the wafers.

The cream-coated wafers head over to the next station.

Here, machinery moves the top wafers onto the cream-coated ones.

The cookies move up for the count.

Mechanical fingers separate them into bunches of 11.

Then grippers swing into action to move each little bunch forward.

They release the cookies neatly into plastic trays.

The trays full of sandwich cookies move on to the wrapping station.

Here, metallic film unwinds and wraps around the trays.

Hot jaws move in to seal the package at both ends.

Finally, they're shipped to retailers.

But once these sandwich cookies are in the pantry, it might be tough to keep them under wraps.

In moderate climates, tile roofs are the norm.

The tiles are typically rounded and terra-cotta in color, characteristic of mediterranean architecture and made of clay or concrete.

Today, concrete roofing tiles come in a wide variety of colors and styles from traditional to contemporary.

While concrete roofing tiles can emulate wood or asphalt shingles, they have a far longer life span-- more than 50 years.

The tile-making process begins with smooth sand from natural sand deposits combined with sharp, jagged sand made from pulverized rock.

The factory regrinds any concrete tiles that failed quality control and adds them to the mix, as well.

Technicians analyze the composition of the mix, measure the moisture, and assess the silt content.

Too much silt will weaken the concrete.

They measure silt by shaking the sand in a test tube.

Heavier particles settle to the bottom, water at the top, and silt in between.

The amount of silt must not exceed 10%.

The sand mix runs through a vibrating screen, which filters out large objects, such as rocks and sticks.

To make concrete, you mix sand with cement.

The cement-truck driver hooks up a hose to blow its contents into a huge silo.

From the silo, the conveyor system metes out a specific amount of cement into the sand.

It's critical to get the ratio just right.

Roof tiles come in a choice of colors.

They tint the concrete a specific shade by pumping in natural iron-oxide pigments and water.

A cement screw mixes everything until it's evenly blended.

The concrete is now ready to be molded into roof tiles.

This machine sprays the aluminum molds with vegetable oil, which will make it easy to extract the finished tiles.

The concrete drops into an extrusion machine, which squeezes it out in a continuous sheet onto the passing molds.

Knives descend, cutting the sheet to tile lengths.

This is what the process looks like in slow motion.

Real-time production moves at a rate of 110 tiles per minute.

The tiles now run past rollers that finish the edges nicely.

Then an ink-jet printer applies product information along with the date and time.

The next stop is a giant oven.

The factory meticulously controls the temperature and humidity inside so that the concrete dries and cures properly.

The tiles come out of the oven, depending on their size, 5 to 24 hours later.

An automated separator extracts each tile from its mold.

The conveyor then sends the empty molds back to be refilled with wet concrete.

Nozzles spray sealer onto the top of the tiles.

This will force moisture and calcium to exit thorough the bottom, preventing discoloration on the tile's surface.

Workers do a final visual check, removing any tiles with cracks or other flaws.

Automated equipment stacks and straps 36 to 39 tiles into a group called a sleeve.

The factory subjects random samples to rigorous quality-control testing for strength...

Permeability...

Even hail.

To pass this test, the tile must be left unscathed by a 2-inch ice ball flying at 35 yards per second.

This fire-safety test ensures that heat or flames can't penetrate the tile.

Roofs made of concrete tiles can even withstand winds of up to 150 miles per hour, making them ideal for regions prone to hurricanes.


Carpets
Drinking Water
Laser Eye Surgery
Acoustic Guitars

Today on "how it's made," carpets, drinking water, laser-eye surgery, and acoustic guitars.

People use the words "rug" and "carpet" interchangeably, but they're not the same thing.

A rug covers just part of the floor.

A carpet goes wall to wall.

Today most carpets on the market are made of synthetic materials.

The first step is to make the carpet yarn.

They start by feeding bales of nylon or polyester fiber into the opening and blending machine.

The carding machine then untangles the individual fibers, lining them up in neat rows, then gathering them into wider bands.

The bands go into cans.

From the cans, they go into a machine called a drawing frame...

Which draws out five threads to make one rough, loose thread.

That thread goes onto spools.

Then they twist threads from two spools to make a stronger and thicker thread.

Next they twist two of those threads together to form a two-ply yarn.

To ensure the two plies don't untwist, the yarn goes through a heat-setting machine at almost 270 degrees fahrenheit.

The continuous heat permanently sets it, much the way a curling iron sets hair.

After 45 seconds of heat-setting, the yarn is rewound on spools.

Those spools then go to the tufting department, where the carpet-making begins.

A standard 144-inch-wide carpet is made from 1,440 spools of yarn.

Each spool feeds into a plastic tube, which feeds into the tufting machine, where the 1,440 lines of yarn feed 1,440 tufting needles.

The needles stitch the yarn into a canvas backing made of polypropylene.

With slow motion, you can see the yarn being hooked on the canvas then cut underneath into carpet pile.

Up to 12 needles work each inch of canvas.

The result is a pile carpet in the standard 12-foot width.

Next they dye it.

For multicolored carpets, they use a machine called a chromojet.

It works much the way a computer ink-jet printer does, forcing streams of dye in different colors into the carpet fibers.

The more complicated and colorful the design, the more often the machine passes over the carpet.

For solid-color dyeing, there's a mixer in each dye reservoir to keep the color even.

They soak the carpet for four hours in a hot bath of dye and water heated to 212 degrees fahrenheit.

Another method uses heat and air pressure in an autoclave.

What the bath method does in four hours, this method does in just 30 minutes and with more carpets at a time.

Once the dyeing is finished, they apply a water-based glue to a polypropylene backing then put the backing over the original canvas backing, locking the carpet fibers in place.

Then it's on to what's called the marriage roll, a roller press that marries the two backings together.

After a quick run through an oven to make the water and the glue evaporate, they cut the finished carpet into rolls.

A standard roll is 100 feet long.

Researchers have invented a pollution-free car that runs on hydrogen.

The research team modified the standard car engine to burn hydrogen instead of gasoline.

Now they have to figure out how to prevent the hydrogen tank from blowing up in a collision.

Drinking water that's fresh, clean, and crystal-clear is something many of us take for granted.

We might not give it a second thought, but between the source and our tap, a lot happens to make that water fit to drink.

Our water may come from mother nature, but it's far from pristine.

It starts its journey to the treatment plant through a water-intake pipe.

On the wall of that pipe, about 6 1/2 feet down, is a 6-inch hole.

Covering that hole is a metal grill designed to keep out large debris, such as tree branches.

The water flows to the pumping station, where it goes through a preliminary screening.

A giant revolving screen removes fish, garbage, and grass.

Once they remove the debris, a low-pressure pump moves the water into the treatment plant.

The untreated water, called raw water, is dirty and smelly.

They first add a powerful form of the chemical element carbon called activated carbon.

It absorbs contaminants such as solvents and pesticides.

That rids the water of bad taste and odor.

From there, the water then goes through a series of mixing tanks.

The first tank holds a chemical called aluminum sulfate.

It acts as a coagulant, a substance that thickens liquid into globs.

In the raw water, the aluminum sulfate forms tiny, sticky globs called flocks.

Bacteria, mud, and other impurities stick to those flocks.

Then the flock-filled water moves on to the second mixing tank.

The second tank holds a chemical called polymer, which is essential to the next step of the process, called sedimentation.

Five pipes inject the water with superfine particles of sand, called microsand.

The polymer coats the sand, making it sticky.

The grains of sand then stick to the flocks in the raw water, weighing them down even more.

The water then flows into a settling tank, where the flocks, because they're heavier, settle to the bottom.

You can see the result in this demonstration.

The water is finally clear, but it's far from drinkable because it's still full of bacteria, viruses, and other organic matter.

So, on to the next step--  filtration.

The water flows onto the top of the filter then trickles downward, passing through a layer of anthracite, a type of coal, then through a layer of sand.

This filters out any remaining particles, which then flow to the middle.

But the water is still teeming with bacteria and viruses, so it has to be disinfected.

They add 1.9 milligrams of chlorine for every 4 cups of water, enough to kill off those germs and bugs.

Then they add a mineral called silicate to prevent calcium buildup from blocking our water pipes.

The treatment plant sends water samples to a government inspector, who continuously monitors the water supply to ensure it meets safety standards.

The amount of chlorine remaining in our drinking water is 20 millionths of an ounce per liter.

The chlorine gas the plant uses is highly toxic.

Should any leak out, emergency teams would have to evacuate a 6-mile radius.

So the plant stores the drums of chlorine in a high-security area.

It's taken about 45 minutes to turn raw water into treated water.

Now these electric motors will pump it through underground pipes, right to your tap.

Short-sightedness, far-sightedness, and astigmatism are all due to light not focusing precisely onto the retina.

Surgeons can correct this by using a laser to reshape the curvature of the front surface of the eye, called the cornea.

The surgeon operates on one eye at a time.

He cleans the eye, the lid, and the lashes with antiseptic...

And administers anesthetic drops to freeze the eye and lid.

He opens the lid wide with a speculum then rinses the eye with a saline solution.

Everything's frozen, so the patient doesn't feel a thing.

Next-- antibiotic drops to prevent infection.

Before every operation, the surgeon tests the equipment.

He fires the laser on a metal plate to test its energy level.

The surgeon administers a few more anesthetic drops...

Then inspects the microkeratome, the device he'll use to lift a very thin layer from the outer surface of the eye.

He also measures the patient's cornea using an ultrasonic instrument.

The cornea must be a minimum thickness for it to be safely reshaped.

The surgeon uses the speculum again to prop the lid open.

Then he begins the operation.

He marks the eye with sterile ink, reference marks he'll use later.

Next he positions a metal ring around the cornea.

The ring is attached to a suction pump so it clings to the eye.

Like holding a tomato steady while you slice it, it holds the eye steady while the surgeon cuts the tissue.

The surgeon lubricates the eye with sterile water then mops up the excess water with a small, absorbent sponge.

Then he takes the microkeratome and slips it into grooves in the metal suction ring.

In a matter of seconds, the device moves across the eye, cutting open a flap of tissue, the same way a carpenter's plane shaves a layer of wood.

The surgeon uses a sterile sponge ring to keep tears from contaminating the cornea.

He folds back the flap of tissue, exposing the cornea.

He mops up the excess liquid...

Then starts up the laser.

Meanwhile, a tiny sponge keeps the flap moist.

The laser, an invisible light, fires in pulses--  50 pulses per second.

Each pulse vaporizes an area of corneal tissue 100 thousandths of an inch thick.

The laser has been computer-programmed beforehand so it knows exactly how to reshape the cornea to give most patients 20/20 vision.

In less than a minute, it's done.

The surgeon removes the sponge and then using those little ink marks he made earlier as reference points, folds the flap back to its original position.

If the flap isn't precisely where it was before, the patient will have distorted vision.

Using a syringe that flushes the area with sterile water, the surgeon carefully smoothes the flap the same way you'd smooth out a tablecloth.

Then he removes the sponge ring.

Within 45 seconds, the negative pressure inside the cornea sucks the flap back on.

The flap literally seals itself.

With a sponge, the surgeon dabs up any excess water.

He applies antibiotic drops as a preventive measure then inspects the microkeratome again before moving on to the other eye.

He takes the speculum off, tapes the eye closed, then performs the same operation on the other eye.

When that's done, the surgeon uses a high-powered microscope to make sure the flaps are wrinkle-free.

The patient wears protection shields until the next morning then overnight for a week.

The best guitars come from trees about 800 years old, trees with enough rings in their trucks to provide wood with a tight and straight grain, wood flexible enough to vibrate, yet strong enough to withstand the pull of the guitar strings.

The guitar traveled from north africa to europe with the moors, who invaded spain in the 8th century.

In time, the guitar became the signature instrument of spanish flamenco music and the trademark of the singing cowboy.

In the 1930s, the acoustic guitar debuted as a jazz instrument.

By the 1960s, as the electric guitar took over rock 'n' roll, the acoustic guitar remained a staple of the folk-music scene.

They use spruce or cedar because those woods are lightweight and vibrate well.

Using a 30-ton press that works like a cookie cutter, they punch out the shape of the guitar.

The size of the sound hole affects how the guitar will sound-- the larger the hole, the more treble, the smaller the hole, the more bass.

Then they glue on a wood inlay decoration called a rosette.

Next they make the sides of the guitar.

They first immerse wood pieces in boiling water for about 15 seconds...

Then place them in a heated press to make the curve.

The press applies heat from both the top and the bottom for about a minute.

Then they connect the two sides with blocks of wood made of either mahogany or poplar.

One is glued and clamped at the bottom, the other at the top.

Then they glue on and clamp a wooden lining which will connect the sides to the top and back.

Those little cuts give it flexibility around the curves.

Then with a hand router, they carefully notch the lining to receive four wooden braces to support the back of the guitar.

Strategically placed braces help the top of the guitar withstand the tension of the strings.

They also equalize sound frequencies by controlling vibration differently at different spots.

After a vacuum press makes the bracing adhere evenly, they glue on the top and bottom.

The body of the guitar is now assembled.

It goes into a press, then a drying rack for several hours.

Next they glue on a plastic binding to protect the guitar's edges.

Then comes a fine sanding.

Next a machine with a special sensor measures the precise angle at which the body and neck of the guitar will later be attached.

The angle is critical for sound quality.

It drills the holes and sands the pieces accordingly.

Next they apply lacquer-- four to eight coats, depending on the finish.

The fingerboard is made of rosewood or ebony.

The metal frets separate the halftones on the musical scale.

An adjustable rod goes inside the neck.

This lets the neck adapt to the different tensions that different types of strings require.

They glue the fingerboard on the neck...

Then vacuum-press it to make sure it adheres evenly.

Next they install the machine heads on which the strings will be wound.

The rod in the neck slips into a groove on the body.

The neck is then bolted and clamped until the glue dries.

Next they glue on the bridge, securing it with temporary screws and a clamp.

Then they glue on the headstock nut, a hard, plastic piece that spaces the strings evenly.

Next comes the saddle, then the bridge pins, which lock the strings in the bridge.

Finally they string the guitar using an electric winder.

Because of all the glue-drying time, it takes three weeks to make a guitar.

The wood will become suppler the more the guitar is played, so as the guitar ages, the better it will sound.


Today on "how it's made"...

Drill bits...

Photo booths...

And stamps.

Drill bits are attachments you fasten to drilling tools.

A taper-point drill narrows to a point so the threads of the screw grab the wood.

A countersink makes the top of the hole the same diameter as the screw head so that the head lies flush or below the surface.

A plug cutter removes a round piece of wood with which you plug the hole afterward to hide the sunken screw.

Countersinks and plug cutters start out as steel bars.

To make a countersink, this computer-guided tooling machine uses what's called a center drill to pierce a starting hole, then switches to its main drill, which bores right through.

Next, it uses what's called a rough turning tool to shape the countersink's angled nose, then its body.

The machine now switches to a milling cutter.

This tool shapes the countersink's four blades.

A cross-drilling tool bores a hole for the two screws that'll hold the countersink to the drill.

A tap cuts threads into the hole.

Next, a tool called a dovetail cutter sharpens the blades.

Then, finally, a cutoff blade removes the tool.

The same machine makes plug cutters.

Its center drill makes a starting hole, but this time, the main drill doesn't bore right through.

It stops at the depth that the plug cutter is designed to cut.

Just as before, the rough turning tool shapes the body, and the milling cutter sculpts the four blades.

Some plug cutters on the market have fewer blades.

This company makes four so the cutter will clear the wood chips more efficiently when it tunnels into the wood.

After the dovetail cutter sharpens the blades, a tool called a boring bar refines the hole in the center, making it the proper size.

Another turning tool now forms the shank, the stem of the plug cutter that you insert into the power tool.

Then the cutoff blade slices the tool off.

Now for some manual touch-ups.

First, they grind the plug cutter against an abrasive wheel to remove excess metal from the cutoff.

Then they do what's called side-chipping, grinding the sides of each blade to a particular shape that'll clear the wood chips.

Here's how the plug cutter looks before and after grinding off the excess and before and after side-chipping.

And now for making the drills to which the countersinks attach.

It all starts with a tapered piece of steel because this will become a taper-point drill.

Straight drills begin with a straight piece.

A mechanical arm inserts this drill blank, as it's called, into a computer-guided grinder.

The machine has two wheels made of boron nitrite granules, a natural material that's tough and abrasive.

The first wheel shapes the smooth blank into lengthwise spirals called flutes.

A second wheel then grinds sharp cutting edges on the flutes and shapes the tip of the drill to a point.

Back to the countersinks now.

The steel is still relatively malleable, so a worker runs each one through a stamping machine that imprints the size of the tool and the company name.

Whereas the drills are made of a different type of steel that's already hard enough, the countersinks and plug cutters must undergo a heat-treating process to harden-- about 20 minutes in a fiery oven along with a secret recipe of chemicals.

The intense heat--  1,750 degrees fahrenheit-- transforms those chemicals into gases which then permeate and harden the steel.

After cooling in warm water and oil for about 15 minutes, workers submerge the tools in an industrial-strength cleaning solution that removes all the oil grit, then a bath in acid to remove soot from the oven.

Then, finally, 20 minutes in a blackening solution, the ingredients of which are, again, a closely guarded company secret.

This last step is purely cosmetic.

So, how do the three drill bits we've seen all work together?

First, you use the plug cutter to make the plug.

Then you pop out the plug with a screwdriver.

Next, mounting the countersink, that black tool, onto the taper-point drill.

You drill a hole for the screw.

Then you drive the screw into the hole, sinking it below the surface.

Then you cap the hole with a plug.

These tools come in an extensive range of sizes and grades for both amateur and professional woodworkers and for industrial machines.

Photo booths were first introduced in the 1920s in the united states.

Today, the small, private cabins still enable us to be kooky in several snapshots or one large picture.

The booths are quaint reminders of our pop culture, but they use the latest technology to make portraits worth treasuring.

This model simulates a painting or a drawing based on the photo it takes of you.

To customize the preassembled cabin, a worker applies stickers to the outside.

These advertise local businesses or the booth's eventual location, such as a shopping mall or amusement park.

Inside, there are five shelves for equipment.

Two layers of plexiglass glued together will act as safety glass, protecting the equipment from vandals.

It fits over an opening in the wall that divides the seating area from the camera and a tv monitor.

The worker installs a metal plate in another opening.

It will cover the coin acceptor and give the booth operator access to the money people pay to have their photo taken.

The coin acceptor attaches to brackets on the back of the door.

They'll program it to accept tokens or specific currencies.

A black-and-white photo usually costs $3.

Color is $5.

This 15-watt bulb provides some light for your photo.

It goes in a panel that fits into the wall.

Next, a motorized tripod to hold the camera.

In this model, they use a digital camera with an 8-millimeter lens.

"up" and "down" buttons on the control panel adjust the camera angle.

A computerized voice from a speaker will prompt you to make selections.

A fan attaches to the ceiling to vent the cabin and keep the equipment from overheating.

And two 40-watt florescent lights will provide most of the frontal lighting for the subject.

Another 15-watt light behind a frosted panel provides some diffuse light.

The booth's power panel has connections for up to 19 pieces of equipment.

Here, a worker plugs in the camera...

Then a tv monitor...

And an ink-jet printer.

Software will process the photos, and the printer will print them on photo-quality paper.

A plexiglass window protects the 15-inch monitor that's used for viewing and making selections.

Two other monitors fit in windowed panels on the outside of the cabin.

The monitors all connect to the computer and show the same images at the same time, including what stage of development your picture is at.

They install a dispenser that sells optional cardboard frames for your portrait.

Money from these sales falls through a slot into a metal coin box inside the cabin.

The dispenser holds up to 100 cardboard frames, each large enough to hold one portrait measuring 8 by 11 inches.

If the dispenser is out, a sign reading "out of frames" drops into the tray.

For security, the two doors enclosing the equipment each have two key locks, one at the top and one at the bottom.

The worker installs four signs on the cabin roof.

They're plexiglass boxes with vinyl posters and florescent lights.

The cabin's curtain lets you make goofy faces in private, but is short enough to let people know you're in there.

Inside the cabin, the control panel helps you guide the camera.

You press "up" or "down" to adjust the camera angle.

Then you choose one of three photos the camera has captured.

The computer bases its portrait on this photo.

You can tell it to make a caricature, a simulated work of art, or four small portraits in different artistic media.

You can choose an oil painting, a pencil sketch, or a drawing in charcoal or pastel.

Now you've got a masterpiece starring you.

The world's first postage stamp was introduced in england in 1840 as part of a major reform of the postal system.

Until then, the letter recipient had to pay the postage.

This first stamp was called the penny black because it cost one penny and featured queen victoria's profile on a black background.

Today's postage stamps feature all types of illustrations.

A graphic artist produces a design concept, working the computer cursor like a paintbrush on canvas.

The concept goes to the postal service's design authority for approval.

Once approved, the design goes to the printing company.

The printer produces one type of stamp using two different types of printing presses, one of which requires an engraved printing plate.

The company's master engraver draws his artistic interpretation of the concept using photographs of real subjects for inspiration.

Then he paints his drawing in watercolors.

The shading is key because it indicates where the engraving will have depth.

This helps him envision the end product.

Once he's happy with the result, he scans the image into a computer and shrinks the digitized image to the actual stamp size.

Then he lays a sheet of clear acetate over the reduction.

With a tool called a point, he etches the main elements into the sheet.

This etching process is known as scribing.

Now he tapes the scribed sheet onto a piece of soft steel.

He lifts the sheet and coats the metal surface with beeswax.

Then he lays the sheet down again and, rubbing with a burnishing tool, transfers the scribed image to the wax coating.

Now, under a microscope that magnifies the image seven times, he etches the design using what's called a pointing-in tool.

Then he sharpens another tool called a lozenge graver.

With that, he deepens the etched lines of the design's focal point.

This adds depth, which will make the deer appear almost three-dimensional on the finished stamp.

Once complete, the engraving will be copied multiple times onto a plastic master plate.

Workers coat the plastic with silver so that it will conduct electricity, then submerge it into a bath containing baskets of nickel.

They run an electrical current in both the bath and plate.

This dissolves the nickel and draws it onto the plate in a thorough and even coat.

With a nipping tool, workers remove the excess nickel along the perimeter, then extract their nickel printing plate.

Then they plate the nickel plate in chrome.

Now it's ready to go on to the intaglio printing press, a specialized machine used to print only select elements on certain types of stamps.

We will explain why later.

This machine, meanwhile, produces the templates for carving what are called chablons, the rollers on the intaglio press that transfer ink to the printing plates.

Here, the machine traces a pattern for one of the stamp's intaglio elements, guiding a router on the other end to reproduce it in half the size in thick plastic.

At another machine, meanwhile, a worker makes the chablons.

He takes several ingredients-- what they are is a closely guarded company secret-- and pours them into a roller forming machine.

The mix heats to about 350 degrees fahrenheit, and over about an hour and a half, it thickens and hardens.

Now an automated router machine with multiple heads goes to work.

Following the plastic template, the heads carve away at the rubber, leaving behind a raised design in the shape of the elements the intaglio press will print.

It's this raised area that transfers the ink to the printing plate.

Why do they print some parts of a stamp using one type of press and other parts of it using another type?

Simple.

Off-set printing presses are widely available, so if the entire stamp will be printed using that technology, counterfeiters would have it easy.

Intaglio printing presses, on the other hand, are harder to come by, making fake stamps harder to produce.

The sheets first run through the offset press.

It prints one color at a time, making a separate printing plate for each color.

The plate is wrapped around a cylinder.

As it revolves, the plate transfers or offsets the ink image to a rubber cylinder rotating against it.

As that cylinder turns, it transfers the image to the paper passing underneath.

A postal-service official inspects the press output.

Using a magnifying glass, she scrutinizes the color and print quality, circling any problem areas for the press operator to investigate and correct.

Now the offset printed sheets move on to the intaglio press.

The intaglio's chablon rollers spread ink over the printing plate the factory produced from the engraving.

The ink fills the recessed lines of the image.

The press runs the plate against the paper sheets, transferring the image.

Intaglio printing leaves the ink slightly raised above the surface of the paper.

This gives the image height, a third dimension.

Once again, the inspector checks the result.

It's up to the press operator to correct any error.

The cause can be as complicated as a printing plate problem or as simple as a speck of dirt in the machine.

The printing now done, a worker loads the stamp sheets into a computer-guided perforating machine.

Grippers pull the sheets forward one section at a time.

Down comes a die with rows of steel pins, each just a fraction of an inch in diameter.

They punch through the sheet, framing each stamp with tiny holes spaced less than 1/16 of an inch apart.

The machine knows just where to punch these perforations by reading the line of florescent ink that runs along the borders of each stamp.

This ink, called tagging, is visible only under ultraviolet light.

Tagging also plays a role later on.

The automated machines that process mail at the sorting plants are programmed to scan for tagging.

They reject all envelopes without it.

Those letters are either missing a stamp or bear counterfeit postage.

After stacking the perforated sheets, workers trim them down to the finished size, usually sheets of 10 called panes.

Their trimming machine is appropriately called the guillotine, but unlike the head-chopping version, this one slices with a sideways shearing action.

That puts less wear on the blade.

The machine holds the stack in place with more than 8,800 pounds of pressure so that it doesn't budge under the weight of the blade.

The blade rings in at almost 71 pounds.

Now it's time to group the panes into manageable-sized packs for post offices and other stamp retailers.

This machine is called a vacuumatic counter because it uses suction to draw the panes across a paddle wheel which counts them.

This stack adds up to 503 panes, so the worker removes three to make an even 500.

The counter inserts a tab between every 50.

Some stamps go through what's called bursting, the process of manually separating pairs of stamps for different post office product lines such as gift sets.

Some burst stamps go onto first day cover envelopes, one popular collector's item.

An automated pad picks up the stamps and runs them against a wet roller that activates the adhesive on the back.

After a worker positions an envelope against the guide bar, the pad places the stamps in a precise spot and applies even pressure over them so that they'll lay flat and adhere securely.

Many stamps are still the old lick-and-stick type printed on paper that's coated with a moisture-activated adhesive on the back side.

However, the most commonly issued stamps, known as definitives, are printed on what's called pressure-sensitive paper.

That's a technical term for peel-and-stick-- no water or saliva required.


Wood Slat Baskets
Bells
Gyroscopic Stabilizers

Today on "how it's made"...

Traditional wood slat baskets are containers used to carry and gather food during a harvest.

They're also used in retail settings to display produce, providing the consumer with a farm-fresh marketing aesthetic.

Since the 1800, farmers have used wood slat baskets to hold and transport food.

Today, they still come in handy at harvest time.

Wood slat baskets are made out of american sweet gum trees.

First, the freshly cut logs are sprayed with water so they don't dry out and decay.

One at a time, spiked rollers grab the logs and turn them, as knives shave off all the bark.

The de-barked log rolls down a conveyor to be cut to the specified length.

The wood spins on a lathe as a blade cuts into the wood, producing long, thin sheets.

Technicians pull the sheets forward and stack them.

The sheets move through rollers.

The rollers feed the stack to a long guillotine-type blade which chops them into slats.

Once all of the slats have been cut, the slats are stacked and checked for quality.

Technicians use these patterns to configure the wood slats and form a web.

The technician distributes the slats in a specific order, which will add strength when the web is formed into a basket.

He uses a staple gun to place staples into the center of the web to hold it together.

At another station, workers evaluate and grade narrower strips of wood that will be formed into bands to hold the baskets together.

Then, using a basket machine, technicians form the web into a basket.

The machine wraps bands around the basket and staples them to reinforce the shape.

In seconds, the basket takes shape.

Once it's complete, the baskets are removed from the machine and placed on a conveyor belt.

At another station, technicians build a basket with a base made of solid wood.

This base will provide the basket with additional strength.

Workers arrange slats to build the basket.

Automated staplers secure the slats to the solid-wood base.

Bands are attached to hold the basket together.

A technician places the rim of the basket into a machine that drives thick wire into the basket.

The machine's formers bend the wire into a handle and cut the ends.

The technician turns the basket over for a matching handle on the opposite side.

The baskets now take a slow trip through a dryer.

This step removes the majority of the moisture in the wood.

Once complete, the produce baskets slide down a steel slope.

A technician evaluates their quality and stacks them accordingly.

Next, the lids are constructed.

Technicians place wood slats in the slots of a conveyor.

This positions them to be formed into squares, known as mats.

The conveyor takes them forward, and a device creates staples from wire, punching them into the mats to secure the arrangement.

Meanwhile, a worker prepares the lids' hoops.

First, he steams gum wood strips, which makes the wood pliable.

Then he tucks one end of the wood into the revolving wheel of the machine, which shapes the wood into a hoop.

The ends are then secured with staples.

An assembler fits the hoop around a circular platform...

And places the mat on top.

The platform rotates as a stapler attaches the hoop to the slats.

The mat must now be trimmed flush to the hoop so that it will fit more neatly on the rim of the basket.

To do so, another assembler places the corners of the mat under a semi-circular blade, chopping off the excess wood.

The wood slat lid is now ready to be put on the basket.

A device bends wire into a loop that will be used to fasten the lid to the basket.

This factory can make up to 6,000 wood slat baskets a day.

That's a lot of empty baskets to fill.

For thousands of years, we've used bells to make noise.

The concept behind them is simple.

A clapper or hammer strikes the bell wall creating vibrations that disturb the air.

The disturbance causes the ringing sound.

It's not high tech, but it can be high-pitched.

Every bell has a distinctive ring.

From the festive jingle of sleigh bells, to the clang of the boxing bell that marks the beginning of a fight.

Even the cow bell has a sound that's not quite like any other.

The bell's shape and the material it's made from affect the ring's pitch.

To make a cow bell, an assembler uses two flared steel components to form a cone.

He inserts a handle between the two parts at the top...

And welds the seams of the bell shell to hold the two parts together.

Then he welds the handle to the cow bell body.

The handle contains a small loop that extends inside the bell body to hold the clapper.

This strip of steel is about to be transformed into sleigh bells.

An upper die forces the steel strip into dies on a rotating platter.

The dies form the metal into a shape that resembles an open flower.

Ball bearings funnel into a shoot.

The ball bearings land in the open flowers on the platter.

The upper die closes the petals of the flower creating a round sleigh bell.

The rattle of the interior ball bearing will create the sound.

A device pops the bell out of the die and the sleigh bells fall into a bin.

Once the sleigh bells are plated with nickel, they are ready for rattling.

At another station, a boxing bell begins to takes shape.

An assembler transfers the bell to a punch that cuts a hole in the center.

The punch forces it on to a form that contours the area around the hole.

Oil keeps the metal lubricated as it's forming.

The gongs tumble around in a machine with vibrating ceramic stones, detergent, and water.

The stones scrub off the oil and rub off rough edges.

After about 10 minutes, the gongs emerge smooth and clean.

They land in the tub of ground corn cobs.

The corn absorbs residual water as it pulsates in this vibratory machine.

A technician places the gongs in an oven.

This heat treatment rearranges the crystalline structures of the steel and hardens it.

Making the steel more resilient will also make the gong sound more resonant when struck.

The gongs are sprayed with a powder coating.

When baked on, the powder particles will form a protective skin on the metal and provide the gongs with a uniform finish.

A powder coat is sprayed on the bell's baseplate, and an adhesive-backed company logo is applied to the back.

Posts have been installed on the front for assembling the other parts.

A brass lever for operating the bell hammer and the mechanism that will swing it, called a dog.

The assembler rivets the dog to the lever and hooks one end of a spring to the mechanism.

He fastens another spring to the hammer and then hooks the end to the baseplate.

He installs the hammer on one of the posts.

Using a push nut, he secures the hammer to the post.

He hooks the lever spring on the baseplate and slides the lever onto a post just under the hammer.

Another push nut locks the lever in place.

The assembler pulls the lever, examining the movement, adjusting accordingly.

He now adds the gong, aligning the center hole to the threaded post in the middle of the backplate.

He screws on a fastener to hold the gong in place.

He pulls the lever to confirm that the hammer hits the gong and makes a noise.

Finally this boxing bell is now ready for the ring.

at the turn of the 20th century, gigantic gyroscopes were used to stabilize ships.

Even though they were effective, the devices were large and heavy.

Today, gyroscopes are smaller, lighter, and are highly effective stabilizers.

The boat on the left has a gyroscopic stabilizer that counteracts wave action.

Different boats require different sized gyroscopes.

This complex device includes a flywheel and a hydraulic brake which controls its movement.

A large hammer forge has pounded the flywheels into this shape.

The process begins on a cnc lathe that shapes this aircraft quality alloyed steel to perimeters with very small tolerances-- roughly one third the diameter of a hair strand.

The shafts, or bearing journals, are put into a machine which form the axis on which the flywheel will spin.

A diamond wheel grinds the journal to the specified size and shape.

Once complete, the flywheel is balanced.

A state of the art balancing machine i.d.s exactly which spots need adjustment.

Highly trained technicians carefully grind off small quantities of steel in the identified spots before putting the object through more tests.

With tolerances of just a fraction of an ounce, even a tiny particle of dust can throw off the flywheel's balance.

A probe locates this aluminum cast hemisphere so that a machine can begin processing it.

The hemisphere will form one half of the enclosure that will house the flywheel.

It must be precision machined so that it can form a perfect airtight seal.

Made of aluminum to decrease overall weight, the airtight enclosure is one of the crucial elements of this gyroscope.

Once it's completely sealed, all the air will be vacuumed out and helium will be pumped in.

Because helium is so much lighter than air, the flywheel will be able to spin much faster due to radically diminished friction.

Machining with horizontal and vertical cnc tools and a vertical grinder brings the bearing housing within reach of the required parameters.

A technician attaches the vacuum valves which will allow air to be removed from the enclosure.

Then he installs some of the sensors that carefully monitor the gyroscope's status.

He applies a specified torque to tighten the component in place.

A generous amount of grease is applied to the large o-ring that fits perfectly into a groove in the lip of one hemisphere.

The o-ring will ensure a vacuum tight seal when the two hemispheres of the enclosure come together.

These heavy duty eye bolts form an attachment point for lifting, which helps move the gyroscope in and out of position.

Once everything has been put together, the technician connects the flywheel to the enclosure.

He begins bolting an inner and outer set of retainer rings in place.

These rings will support the flywheel assembly.

Faster spinning in its vacuum containment will allow the gyroscope to achieve the same stabilizing effect as a much larger, heavier flywheel spinning at a slower speed.

The technician joins the sub-assembly to the second hemisphere, carefully lifting and lowering it into place before bolting the enclosure securely together.

But the gyroscope stabilizer isn't done yet.

It still needs to be mounted to a specialized foundation assembly.

Early attempts to use gyroscopes for stabilizing boats weren't successful because the gyroscopes were too big and heavy.

But thanks to some state of the art technical innovations, a new breed of lighter, smaller gyroscopes can easily keep a boat deck steady, even in rough weather.

A technician uses a specialized device to measure three important factors of the flywheel's performance.

Concentricity, eccentricity, and clearance.

This means he's checking to see if the component is spinning smoothly and consistently without any wobbling.

He spins the flywheel slowly on its axis, evaluating the meter accordingly.

The gimbal shaft will allow the sphere to tilt back and forth, stabilizing the boat.

A technician installs a set of steel dowel pins that will hold the brake cylinders in place.

He uses a press to install the spherical bearing and urethane that will permit the sphere to shift its axial rotation and absorb vibration.

With the bearing and protector in place, he mounts the gimbal shaft securely to the gyroscope enclosure.

A total of 10 heavy duty bolts are tightened to the specified torque value.

Next, the technician installs the cover and bolts it in place, sealing the enclosure and fully rounding out its exterior.

Once the valve is installed, he checks for leaks by spraying helium outside of the enclosure.

This meter will register the presence of helium if the lightweight gas sneaks in through any cracks.

This magnetically mounted sensor will allow the technician to conduct final trim balance, ensuring a vibration-free operation.

It's vital to keep vibration to a minimum to make sure that the gyroscope provides a smooth, stable boat ride.

Now it's time to attach the cooling components.

When the flywheel spins at 9,000 rpms, it generates heat.

Sea water mixed with glycol is used to keep it cool.

The enclosure will sit in a framework known as the foundation, which is made of cast aluminum.

Once the gimbal shafts are set within their lower housings, which are situated on either side of the foundation, a technician installs the upper housings and bolts them securely in place.

This aluminum section of the foundation will support the hydraulic brake arm, a key component of the gyroscope's function.

The brake support piece also doubles as a support structure for the heat exchanger, which is an important element of the gyroscope's cooling system.

The technician installs the brake arm cylinder.

This helps the gyro perform in all weather and at all speeds.

He installs the hydraulic lines for the brake system.

They manage the flow of hydraulic fluid to and from the cylinders.

The solenoids that make up the major elements of this assembly dictate braking pressure to the hydraulic cylinder.

The drive box controls the brake, the start up, and speed of the flywheel and the angle sensors, which detect the roll rate and angle of the boat.

The drive box receives data from the rest of the gyroscope.

This wiring harness serves as the conduit of information to and from the components of the unit.

Once assembled, the technician installs the remaining support arm on the other side of the gyroscope.

Before the assembled gyroscope gets its aluminum cover piece, it must undergo a thorough factory assessment test.

The test ensures that it's fully functioning and meets all design parameters.

There is no question that gyroscopic stabilizers help maintain level heads on deck.


Custom Knee Braces
Ductless Air Conditioners
Window Film
Motorcycle Exhaust Systems

If you suffer from osteoarthritis of the knee, your doctor might prescribe a knee brace.

Osteoarthritis is when the cartilage cushioning the knee joint wears out, causing bone to painfully rub on bone.

A brace relieves some of that pain by realigning the leg to shift weight off the knee joint.

This dual-action knee brace rotates the foot, which moves the thighbone, the femur, off the most painful area of the shinbone, the tibia.

It also creates what's called a distraction, pulling the femur and tibia slightly apart to further reduce stress on the joint.

The brace is custom-made for each patient.

An orthotist takes the measurements by passing a sophisticated 3-d scanner approximately 12 inches above and below the knee.

The scanner translates the data into a 3-d computer image with highly specialized medical-device software, then processes that image into anatomical blueprints for a 3-d model.

The computer then reads the plans and guides this carving machine to create the model from a block of high-density foam.

The carving process takes about 10 minutes.

The finished model is an exact replica of the patient's leg, which technicians now use to construct a brace that fits the patient perfectly.

After wrapping the model in plastic film to protect the surface and marking the main anatomical landmarks of the knee, they lay a thick foam band over the tibia and begin marking where they'll install the two articulation hinges, which rotate the foot and distract the femur and tibia.

This template is for the lateral hinge, the primary rotator.

It's situated on the outside of the leg.

Next, taking an aluminum bar and bending it on special tools, the technicians form the brace's tibial crossbar, the band that crosses the shin and holds the two hinges.

The foam band takes up the space of a silicone lining that will go under the tibial crossbar-- critical cushioning to prevent pressure points that can cause skin irritation.

Once the cross bar fits perfectly, they reapply the template and mark where rivets will attach the lateral hinge.

Then, using the same metal bending tools they used to shape the crossbar, they contour the hinge to follow the shape of the leg.

They attach the lateral hinge to the tibial crossbar with copper rivets.

Copper is a soft metal, so they can compact it to produce a solid joint, which won't loosen up over time with repeated use.

At the other end of the crossbar, they affix the medial hinge, which produces the distraction.

When the knee is extended, this hinge lengthens the brace by approximately 3/4 of an inch, pulling the tibia and femur slightly apart to eliminate pain.

It's time to mold the plastic shell, the upper part of the brace that fits onto the thigh.

First, they soften a foam sheet in a low-temperature oven and wrap it around the model.

This takes up the space of the fabric lining that will go under the plastic.

After covering the foam in a cotton heat barrier, they soften a plastic sheet in the oven, wrap it around the model, staple the ends together, then coat the surface in talc, which prevents their gloves from sticking when they apply pressure.

Once the plastic cools, they trace the shell's shape and cut it out.

Then, they wrap it in a protective vinyl finish, heating the material so that it becomes sticky and adheres to the plastic.

They also wrap the tibial crossbar in vinyl.

Then they apply a strip of velcro to the underside, where they'll later adhere padding.

They install a cover over each hinge to protect the mechanism.

Then they cut a fabric lining for the upper part of the brace.

It adheres to the plastic with velcro so that it's removable for washing or for replacement when worn out.

The brace applies the greatest amount of pressure at the tibial crossbar, so they line the crossbar with silicone padding for comfort.

The pad attaches to the velcro strip.

The brace fastens to the leg with three adjustable straps and works only when the knee is extended, which is when osteoarthritic pain hits the most.

The ductless air conditioner, invented in japan in the 1970s, transforms homes into cool spaces.

This system consists of an outside condenser and refrigerant lines that run to a fan in the wall.

In homes without ductwork, it provides cooling without renovations.

No central air?

Ductless air conditioners, also known as mini-splits, are a cool option.

To manufacture the condenser, they start with copper tubing.

It will be used to make the coils that cool and condense the refrigerant.

A machine unwinds six reels of tubing simultaneously and pulls them between rollers.

They iron out the kinks.

Little rotating knives cut the tubing to the correct length.

The cut tubes exit into a device that bends them around a mandrill.

This creates hairpin bends in the center of each tube, and they end up looking like big copper bobby pins.

Next, a sheet of aluminum feeds into a progressive die.

A press moves up and down to drive the metal into the die.

With each stroke, the aluminum is shaped into a part known as a fin.

They'll use a hundred or more fins in one air conditioner coil.

The fins fall out of the press into neat stacks.

A worker slides metal rods into the stacks to maintain the alignment of the fins and adds a steel end plate.

She now inserts the hairpin copper tubing following a precise pattern.

The fins will act as a kind of web for the tubes.

They're an important part of the coil, allowing heat from the refrigerant gas to be dissipated more quickly.

Next, a press drives mandrills into the tubes, expanding them so they'll fit tighter to the fins.

The coil has really taken shape.

At the next station, they load it into a hydraulic bending machine.

It bends one section of the coil around a metal form.

This gives the coil a more curved profile on one side so it will fit in the condensing unit later.

They close the open end of the copper tubes with u-bend connectors.

They brace the connectors to the tubes for a leakproof fit.

This ductless air conditioner coil is now complete.

They're ready to test it for leaks.

A technician pumps compressed air into the unit to simulate refrigerant.

By using compressed air, they're playing it safe, because unlike refrigerant, it won't damage the environment if they're actually is a leak.

Once the coil is full of compressed air, he immerses the part in water.

Air bubbling out would indicate a leak that needs fixing.

A worker keeps a close watch on each coil as it floats by for signs of trouble.

They're now ready to assemble the entire condenser.

The team screws the compressor to the base.

They install the coil and attach a motor and fans to cool the refrigerant.

The next part is the filter dryer.

It contains chemicals to remove moisture and filter out contaminants.

They install the wiring and control panel for the compressor and fan motor.

The team connects the pump to the coil to suction out air and create a vacuum inside, creating a perfect environment for the refrigerant gas.

He closes the service valves and sends the ductless air-conditioning unit down the production line to be charged with refrigerant.

After that, all that's left is the packaging and the installation.

On a hot day, all the consumer needs to do is grab the remote control and activate the ductless air conditioner for some cool air.

Developed in the 1960s, window film is a product with transparent benefits.

Applied to the windows of vehicles and buildings, this tinted film lets light in while shutting out some of the sun's harmful rays.

And depending on the darkness of the tint, it also provides a measure of privacy.

Tinted window film allows drivers to see things in a different light, one that can be a lot less harsh.

Not only does the tinting mean less squinting, it also reduces the amount of heat that permeates the vehicle's cabin.

This film will also hold glass together if it shatters.

Because dark tints can make it hard for the driver to see the road or to be seen, the use of window film is regulated in many jurisdictions.

The laws vary depending on the region, so the factory makes different window films for different markets and applications.

There are numerous formulations for the tinted coatings.

It all starts with the acrylic adhesive that will hold the layers of plastic film together.

The adhesive will also serve as the base for the tint and other additives.

The technician thins the adhesive with solvent, which will make it easier to blend in the other ingredients.

Those ingredients include chemicals to absorb ultraviolet rays...

Initiators to make the mix cure faster...

And finally the colorant.

It's carbon-based, and as a result, it's highly soluble and disperses well.

Achieving the right shade of colorant is truly an exact science, one that started beforehand in the lab.

A technician mixed up test batches combining one or more dyes with the adhesive base until satisfied with the results.

Once the adhesive has been mixed, they add a chemical catalyst to activate it.

They're now ready for the plastic film.

There are various grades and thicknesses.

The type used depends on the type of window film being manufactured.

The plastic film unwinds over rollers into the coating machine.

At the same time, the tinted adhesive flows into a pan in the machine.

A roller soaks up the adhesive and applies it to the plastic.

The coated film travels over a narrow cylinder with fine grooves etched into it, and the excess formulation collects in the grooves and drips back into the tank.

This gets rid of the excess and ensures an even application.

The film then moves through a long dryer, and the heat causes the coating to cure.

The film exits under a glare of blue u.v. light.

The light activates the initiator chemicals in the adhesive to further cure the coating.

Next, a second plastic film unwinds and meets up with the coated one.

They travel between rollers that apply heat and pressure to laminate the two films together.

A computerized system checks for defects, and a worker does a double check as the film passes in front of a bright light.

After a third film, mounting adhesive, and release liner have been applied to the product, a technician tests a sample.

She pulls it off a piece of glass, and a sensor measures the amount of force it takes.

The test confirms the window film grips the glass adequately.

The production run gets the green light, so next blades trim the sides and cut it to width.

The width of the film can be customized to the job.

At the end of the cutting line, a worker slides a plastic core onto a cylinder.

He sticks the end of the window film onto that core.

He activates the cylinder, and it revolves to wind the film up onto the core.

Sold in rolls, the film will later be cut for an exact fit to various windows by an installer.

Window film comes in a range of colors with a variety of characteristics.

The choice is up to the customer.

But no matter what, window film is sure to change one's view of things.

Motorcycle racers typically replace their bike's standard exhaust system with a high-performance one, which emits exhaust gases faster, clearing the way for new fuel and air to enter the engine's combustion chamber, generating more power and better traction, which produces greater speed on the racetrack.

This high-performance, aftermarket exhaust system isn't any louder than your standard exhaust system, yet it delivers up to 30% more power due to its more efficient design.

Rather than steel construction, it's made primarily of titanium, which is more durable and weighs half as much.

The exhaust system has two main components-- the muffler, which dampens sound, and the header, which routes exhaust gases from the engine to the muffler.

The header's tubing is made from a super-thin strip of titanium that's six inches wide.

It enters a forming machine, in which 14 stations of rollers apply tons of pressure to progressively curve the edge of the strip upward until they meet at the top.

The formed tube, two inches in diameter, then enters a chamber.

Inside, a welder heats the top until the edges fuse together into a solid seam.

After the 330-yard-long tube exits the welding chamber, a powerful, carbide guillotine blade chops it into several shorter tubes.

Then, workers mount each of those shorter tubes onto a computer-guided machine, which bends it to the shape required for several exhaust systems.

Workers then separate each system's tubing with a circular saw.

Like the guillotine before, the saw has a carbide blade.

An ordinary steel blade isn't hard enough to saw through titanium.

A welder assembles the tubes to the other header components, among them the collar and flange, which connect the header to the engine...

And the bulbous resonance chamber, also made of titanium.

It does a pre-muffler sound dampening.

Once the parts are welded and inspected, the header is finished.

They begin assembling the muffler by joining the two halves of its resonance chamber.

The parts must fit with a tight seal to prevent exhaust gases from leaking out.

They set the resonance chamber on a welding fixture, take a ring made of perforated titanium, and weld it to the chamber opening.

This ring allows a specific amount of gases to enter the resonance chamber at a time.

Next, they weld a sound-absorption tube to the resonance chamber.

They wrap the sound-absorption tube in a fiberglass blanket.

The muffler's housing is made of a titanium sheet which a machine shapes into a cannister.

At each edge, they peel back the film protecting the surface from scratches, then, with an automated welder, join the edges with a strong seam.

Then they remove the protective film entirely and electrically charge the cannister in a mild chemical solution for about a minute.

This anodizing, as it's called, changes the color of the titanium and hardens the surface, making it more durable.

After attaching an aluminum mounting bracket to the cannister, they insert the sound-absorption tube, then secure the cannister to the resonance chamber with screws.

They apply the manufacturer's sticker, and the muffler portion of the exhaust system is finished.

To install the exhaust system, you bolt the header to the motor, which is toward the front of the motorcycle, then mount the muffler to the other end of the header.

The muffler bolts to the bike chassis via a bracket on the cannister.

Now the bike is ready to hit the racetrack.