Horseshoes Dishwashers Graphite Fly Rods Pizza
Today on "how it's made"... Horseshoes... Dishwashers... Graphite fly rods... And frozen pizzas. Horses first wore leather and metal shoes around 500 a.d. to protect their hooves from wear and tear. Today, depending on the animal's vocation, horseshoes are usually made of steel, aluminum, or plastic. A farrier is someone who makes the horseshoes and carefully applies them. A horse's hoof has a hard outer wall like a fingernail, only much thicker. The farrier attaches the horseshoe to this wall with heat and lead nails. The horse feels no pain because the nails don't reach the sensitive tissues inside. Horses get new shoes about every five weeks. After removing the old ones, the farrier uses a file to trim the wall's growth since the last change--  about 1/3 of an inch. He measures the hoof's contour, marks the measurement on a steel bar, and cuts it to size with a rotary saw. Steel is the material of choice because it's affordable and durable. Next, he heats the bar until the middle's white-hot. He brushes off any dirt, then dips the bar in water to cool it. Then he hammers the ends to redistribute the metal toward the middle. This widens and thickens the part of the horseshoe that gets the most wear, since the front of the hoof hits the ground first and hardest. After reheating the bar, he hammers it again, this time with no cooldown. For larger shoes, two farriers take turns hammering so that it goes faster, and they can shape the steel while it's still hot and pliable. Using a drafting compass, the farrier gauges where two grooves for nails will go. He reheats the bar, then holds a sharp-ended tool against it, while another farrier drives it in with a hammer. The nails won't protrude when they're embedded in the grooves. These areas will also fill with dirt to give the horse traction. The farriers round the sharp edges of the horseshoe so the animal won't cut itself when it's lying down. They make the nail holes by first driving this tool into the grooves. Then they use another tool to perforate the steel, hammering it into the shoe over an opening in the anvil that lets the tool pierce through. The farrier then repeats these steps on the other side. It takes 2 farriers about 15 minutes to make a pair of horseshoes. The first farrier heats one shoe, while the second hammers the other. Like the hooves, the front and back shoes are differently shaped. The front pair are rounder, the back ones, more oval, because the horse's hind hooves have evolved to dig into the ground for traction. The farriers also hammer part of both curves, flattening the edges into raised sides called clips. These help the shoe fit onto the hoof. For larger workhorses like clydesdales, the farriers bend the ends downward to give the feet more traction. It's not uncommon for a 2,000-pound horse to have to pull twice its weight. Now time for the fitting. After heating the shoe, but not as much this time, the farrier uses it to melt the outer part of the wall. This makes an imprint on the horseshoe that later helps him place it properly on the hoof. Horses first wear shoes at about 3 years old, the age when they start working or competing. The farrier fine-tunes the fitting with a metal filing tool, curving the edges further to make them even safer for the horse. Next, he shines the steel with a metal brush. The shine will quickly fade once the horse takes its first steps. Depending on the foot size, the finished shoe can measure anywhere from 2.5 to 9 inches across. Now, to attach the shoe, the farrier first files the hoof to remove any dust or sharp edges. He slips on the shoe, then gently hammers as many as three nails into each side. The nails are about 2 inches long. They're made of lead--  a metal that's easy to bend-- and that's he'll do after hammering them through the wall. He clips off the ends and bends the rest in towards the wall. Then he uses other tools to gouge small crevices in which to bury the ends. This makes it easy to straighten out the nails and yank off the shoe when it's time. He also hammers the hoof against a template to stabilize the shoe. Next, he files the hoof so that it meets the angle of the shoe. And, finally, the horse is ready to stroll. So whether you've got a pony or a stallion, make sure the shoe fits. When it comes to horse footwear, function, not fashion, dictates. In 1886, an american woman invented the automatic dishwasher. Josephine cochran built a motorized wheel with wire compartments for dishes, turning inside a copper tank filled with soapy boiling water. It was a hit with restaurants and hotels, but it wasn't until the 1950s that affordable dishwashers for home kitchens came on the market. Building a dishwasher starts with a watertight container called the tub. Some high-end models have stainless-steel tubs. The rest have tubs made of molded plastic, usually polypropylene. Workers screw two pairs of plastic wheels to each side of the tub. They'll support the sliders on which the upper dish rack moves. The lower dish rack rolls along the bottom of the tub. This steel frame helps solidify the tub. They affix a steel plate at the bottom to shield the plastic from heat of the motor. Then they attach steel legs to the frame. Here, they install a rubber reservoir called the sump. It collects the water that flows to the bottom of the tub. They screw in a two-part ring to hold the sump in place. The heating element is a ceramic-insulated iron cable. This filter traps food particles washing off the dishes. After fitting an o-ring seal to make the sump leakproof, they secure the heating element by screwing ceramic insulators to the protruding connectors. Now for the polypropylene wash arms. This model has one at the bottom, with a tower that juts out for a larger spray span, and a second wash arm at the top. The motor pumps clean water directly to the bottom wash arm and, through this flexible hose, to the top wash arm. Once they connect the hose, they spin the wash arm to make sure there's no obstruction. Meanwhile, workers connect key components to the dishwasher's circuit board. This metal box is the timer. It controls the wash and dry cycles. For example, it activates this green cam lever to trigger the white lever to open the detergent dispenser at the right moment in the wash cycle. The detergent dispenser is located on a plastic panel that will line the dishwasher's door. They call this panel the inner door. This seal will prevent water from leaking out and also provide some soundproofing. A press runs over the inner door, driving in the seal evenly all around. Now they screw the inner door to the outer door. The assembled door hooks onto hinges at the base of the tub. This machine presses the hook and hinge together so that the door doesn't come unhinged. The dishwasher's motor is relatively quiet because it uses an inherently low-noise induction drive design. The white machine attached to the motor is a food disposer. It grinds up food particles so that they don't clog the drain. The last technical step is to connect the various wires. Before applying the finishing touches, workers conduct a seal test. They flush each tub with water to check for leaks. In this portable dishwasher, workers install cement blocks as a counterweight so that the washer won't tip forward when you open the door. And because a portable usually sits in full view, it also needs sides and a top. The top is decorative laminate on medium-density fiberboard. They screw it to what's called the wrapper, a three-sided panel made of painted steel that covers the sides and back-- a clean look to go with your clean dishes. Fishing may not be rocket science, but the graphite fly rod certainly is. Graphite is a space-age material-- lightweight, flexible, and strong. The very qualities that make it useful in space also come in handy at the river or lake. It explains why graphite fly rods are now popular in the fishing world. To make one, they start with a sheet of graphite. They cut out shapes, following precise measurements. One mistake here, and the performance of the rod will be compromised. This will be a three-piece rod, with a butt piece, midsection, and tip. They place a shape on a tapered steel mandrel... And peel away the paper backing. This machine rolls the graphite shape around the mandrel. They make all three sections of the fishing rod the same way. A graphite strip at the end reinforces it all. The graphite remains on the mandrel for the next step. They wind polypropylene tape around the graphite to squeeze out any air pockets between the layers. Then it's into the oven to cook at 257 degrees fahrenheit for an hour and a half. The tape won't melt, but resins in the graphite will, baking the rolled layers together. Afterwards, they remove the shrink tape and pull the graphite blank off the steel mandrel. Then the rod blanks go for a dip in a special finish, which turns it a deep blue. They bake on the finish for a half-hour at 257 degrees fahrenheit. Afterwards, they measure the rod sections and cut them to size so they all fit together. Bending without snapping is the graphite rod's strong point. They hot-glue the stainless-steel tip to the end. Then they piece together the retainer for the fishing reel. This locknut will allow the reel to be tightened. The plug will keep everything from sliding off. They glue cork rings together to make a handle. Then they shape it with a chisel and sandpaper. The line guides go on next. They keep things from getting into a tangle. They wind thread around it to secure it to the rod, one foot at a time. A final step ensures the handiwork doesn't unravel. They place the rod in a rotating jig and brush three coats of glossy epoxy onto the thread wrap. This not only protects it but gives it a nice finish. Now they slide a metal foot into a groove on the reel retainer, and it's ready for the reel to be attached. But before you can cast your line, there is some information that needs to go on the rod, like the brand name and serial number. A final inspection, and it's almost time to test the waters. The reel snaps into place, and it's easily adjusted with the locknut. The rest is a matter of luck and the right bait. Millions of pizzas travel daily from the frozen-food section of the supermarket to the family dinner table. Thick or thin crust, meat or vegetarian, their convenience makes them a staple in the freezer. But how do they end up tasting so fresh when they start out so frozen? Making frozen pizzas requires a maze of machines. To make the dough for the crust, they combine flour, salt, sugar, water, yeast, and oil in a large mixer... And they throw in a bit of cornmeal for flavor. The mixer turns the ingredients for about four minutes. This is one powerful machine. A truck transmission drives the steel bars that knead the dough. The dough rises for about half an hour. Then they feed it into a chunking machine, which divides the big blob into smaller pieces. The chunks travel to a sheeting machine that rolls them into a flat sheet one-inch thick. A light dusting of flour keeps the dough from sticking to the machinery. A series of rollers called quick reducers gives the dough an even consistency. A flour brush massages the dough, ensuring a smooth surface. Next, stainless-steel spikes pierce the dough with holes about a quarter-inch deep. These holes will stop air pockets from forming in the dough. A large plastic roller with several round forms cuts the circular shape of the pizza crust. The machine automatically separates the leftover dough. The factory remixes it with fresh dough for the next batch. A conveyor takes the dough circles to their next destination--  the oven. They bake for two minutes between 390 and 600 degrees fahrenheit. Six chambers inside the oven automatically control the temperature pattern to ensure that each one bakes evenly. Next stop-- the tomato sauce. A tank pumps a steady supply of sauce into a reservoir, drenching a roller turning inside. A plastic board then scrapes the sauce onto the crusts passing below. The excess sauce drips down, replenishing the reservoir. Mounds of preshedded mozzarella are ready to be added. A cheese-applicator machine controls the output so that the mozzarella forms an even layer. Large hoppers load heaps of pepperoni, sausage, and other meat toppings into a meat applicator. As with the tomato sauce and cheese, the meat toppings cascade down on the pizza crusts. The pizza is now ready for inspection. Workers take samples off the line and weigh the crust, sauce, cheese, and meat to ensure the equipment dispensed the right amount of each. Next, the pizzas enter a spiral freezer called a blast cell, where they spend about 20 minutes at minus-25 degrees fahrenheit. An overwrapping machine applies a clear layer of plastic around each pizza, automatically cutting the wrap to fit. A vision-control system takes a picture of every pizza, verifying the size, diameter, and checking for any imperfections. The machine automatically rejects any less-than-perfect pizzas by air-blasting them into a separate tub. Finally, an arm pushes each pizza into a waiting box. All that's left now is to heat it up and dig in.