Pneumatic Impact Wrenches Cultured Marble Sinks Plantain Chips NASCAR Stock Cars
A pneumatic impact wrench is a power tool that tightens and untightens nuts, bolts, and other fasteners. You hook it up to the air hose coming off a compressor. The anvil at the tip turns at high speed to tighten until snug, then switches to a hammering action, called impacting, to tighten even more. You've probably seen a pneumatic impact wrench in action at your local garage. It's standard equipment for removing and installing wheels. Air pressure runs through the tool's motor, spinning a rotor within. That rotates the tool's anvil, which turns the wheel nut. At the manufacturing plant, they machine the rotor from a bar of steel mounted on a lathe. It takes about a minute and a half for the computer-guided precision tools to carve out the basic shape. The next machine carves teeth on one end of the rotor, creating what's called a hobbed edge. Now a computer-guided mill cuts eight slots. This shaping of the steel generates a lot of heat, so coolant flows throughout all these machining phases to prevent the equipment from overheating. Next, they temper the rotors for 10 hours in a 1,700-degree-fahrenheit furnace. This hardens and strengthens the steel, but to fortify it further, they pump in carbon from a propane burner. The carbon impregnates each rotor to a depth of . 7 millimeters. Once the rotor cools, a computer-controlled grinder shapes it to the final specifications. Then a machine with nylon bristles smoothes the surface. This completes the transformation from steel bar to rotor. Meanwhile, the tool's magnesium housing has been getting a bright coat of paint. The housing has two parts-- the main section and a back cap. Both go into an oven where the paint bakes for a half-hour at almost 400 degrees fahrenheit. Now assembly begins with the trigger and the stem of the main section and then, with this tool, what's called the tipper valve. When you push the trigger, it tips, letting in air. This spring keeps the tipper valve closed when you're not pushing the trigger. And this bushing is where you attach the air hose coming from the compressor. Next, they install the reversing valve. It slots into the housing just above the trigger. When you press the trigger, the anvil rotates clockwise to tighten the fastener, but when you activate the reversing valve, it sends the air into different chambers, turning the tool counter-clockwise to remove the fastener. They glue a rubber pad to the top of the housing to cushion your grip on the tool. A laser engraves manufacturing information on the back cap. To assemble the motor, they start with a back cap and press in a bearing on which the rotor will spin. Next, a plate to enclose one end of the rotor and an alignment pin to position the plate for enclosing the other end. And finally, the rotor itself. Into each of the rotors' slots goes a vein made of resin-imbued fabric. These veins work like the blades on a windmill. The air entering the tool turns them, which spins the rotor. After slipping a steel cylinder over the rotor, they enclose it with a second plate, then a larger plate with a ball bearing. Now some oil to lubricate what they call the impact mechanism. This component contains the tool's anvil, as well as the parts that produce the hammering action. Finally, a press seals the main section of the housing to the back cap. Every pneumatic impact wrench this factory produces goes through extensive testing in both free speed-- that's when the tool spins like an ordinary drill-- and in impact mode. So, if you've got a nut or other fastener to drive, take one of these babies for a spin. Natural marble has a modern alternative-- a composite material known as cultured marble. It consists of ground marble or limestone mixed with liquid plastic. Less expensive than natural marble and easier to work with than stone, cultured marble is often used to create unique bathroom and kitchen fixtures. This vanity top and pedestal sink are both made of cultured marble, cast in fiberglass molds. To make a vanity top, a worker centers a sink-bowl mold on a counter mold... Then places a drainpipe attachment over the sink mold's exit drain. He marks with a grease pencil where the faucet openings will be. Then, he masks off areas to protect and places a bees'-wax seal all along the bowl's edge where it meets the counter. He sprays the molds with protective gel that will give the vanity top a shiny protective finish. Finally, he places cardboard tubes over the faucet-hole marks. The molds are now ready for casting. A machine equipped with a mixing pot automatically measures out the resin workers pour into these molds. Raw pigments like sterling silver, sandbar, wild rose, white titanium, and fawn beige gives the resin its color. A worker sifts them in measured amounts into the resin as it's mixing. Next, he adds a catalyst to the resin... Then some granulated limestone to thicken it. The catalyst sets off the chemical reaction that causes the resin mix, known as matrix, to harden. From this moment on, he needs to be swift. He has only 15 minutes to mix, color, and pour this batch of matrix into the molds before it hardens. He adds more white pigment to the base color, using a paddle to mix it along the surface. Then he takes the wild rose pigment, mixes in some resin, and again works it into the surface to streak it with color, an effect known as veining, that mimics the look of marble. He scoops out some of the surface mix and pours it onto the mold. As the matrix pulls, the rose-colored veining in the surface mix is visible. Now he pours out the rest of the matrix. He casts the sink and counter in a single piece so there won't be any grout lines around the bowl. A pneumatic tool vibrates the molds, bringing tiny air bubbles to the surface-- the vanity's underside. Air trapped in the matrix can cause it to break or mar the finish. A worker lays down a temporary plastic hat over the bowl. He weighs it down to hold it in place as he pours matrix inside the hat to cast a bowl that's as thick as the base-- about . 8 inches. He lets the matrix set for 30 minutes, then removes the hat from the bowl. Next, he drops down the mold's backsplash and puts a hole in the drain. He shoots in bursts of compressed air while a co-worker carefully wedges under the backsplash to part the mold, revealing the vanity's marbled surface. To make sure the vanity lies level on its cabinet, a worker grinds down the underside, then the drain area. Next, he sands down the backsplash and the sides, working at an angle with a hand sander to dull any sharp edges. He removes the drain mold and buffs the surface to a mirror finish. Finally, he knocks out the faucet holes. Here's a finished vanity with a variety of integrated sink bowls on display. Cultured marble truly is a versatile material that offers endless possibilities. Many of us take time out to enjoy a tasty snack like plantain chips, but we know we should put limits when treating ourselves to a good thing. The trick is to learn as much as we can about the snacks we're eating so we can choose a treat that's right for us. Seeing how plantain chips are made can help us make an informed choice. This looks like a banana, but it's actually a plantain-- a staple food in many parts of the world. In tropical countries like costa rica, it's made into a popular snack called plantain chips. The cycle from fruit to snack begins here. A worker cleans off the root of an offspring from a mature plantain tree. He prepares the root for planting as if it were a seed. In time, this seed will grow into a mature plantain tree. After about nine months, the plantain is ready to harvest. When a worker picks the fruit, they wrap it in plastic to protect it against insects and disease. Each mature tree yields only one bushel of fruit its entire life. Once he harvests the mature tree, it's the tree's offspring that yield more fruit and continue the life cycle. The worker then rinses the plantain in treated water that helps wash off sap and kill any possible fungus. Local workers then load the cases of plantains onto their boat for a full day's trip to the processing plant. Their hard work is valued by the company which is proud to support the local economy. At the plant, a worker puts the plantain into boiling water for about a minute. Boiling the fruit changes its color, but more importantly, it greatly reduces the amount of sap the fruit releases, which makes handling and peeling the otherwise sticky skin possible. The various lengths and widths of plantain prohibit peeling it by machine. Workers at this costa rican plant cut more than 50,000 pounds of plantain every day, all by hand. Each one is then cut into slices of a specific thickness for chips. To do this, workers push the fruit one at a time into a cutting machine. The slices of plantain fall through the machine into a deep-fry oven below. A rotating grill and conveyor system helps ensure uniform cooking of the slices in natural palm oil as they travel on an uninterrupted 30-foot journey. After cooling, the worker removes any under- or overcooked chips. The chips then travel into a tumbler that adds salt or other seasonings or flavors, depending on the product. The chips then exit the tumbler and are ready for packaging. The packaging machine gently funnels the chips into separate chutes as it calculates the exact amount it needs to fill each bag. Once filled, the packaging machine then cuts and seals the individual bags, then sends them for distribution across the world. Plantain chips also come in strips. They're trans-fat free and come in a variety of formats that make a handy treat. Nascar is one of the most popular spectator sports in north america. The national association for stock car auto racing holds a series of 36 races a year, mostly at oval or d-shaped tracks on which the cars make only left turns. They're built from scratch following nascar's strict technical rules. Nascar's stock cars are based on certain american-made road cars. The frame is made out of steel tubing. The hood, roof, and deck lid-- that's like the regular car's trunk cover-- are made out of sheet steel. The workers who assemble the body are called body hangers. They position all the parts according to a nascar-authorized template. Here they clamp the body panels together. Then, with an aluminum bracket, to the template for shaping. To make the wheel openings on the front fender, they use shrinking jaws, a tool that curves metal by squeezing it. Then they switch to a tool called an english wheel. It rolls the curved metal into a particular shape. The car's front suspension is essentially the same as that of a regular car, except for the angle of the tires, which they manipulate by putting shims on this upper control arm. The right front tire tilts inward and the left front tire tilts outward. That's because these cars race on an oval track in one direction only, so they're making only left turns. Next, they install a brake rotor. Then, a steel spacing plate between the rotor and the wheel. This sets up the specific distance from wheel to wheel that nascar rules require. They load a pair of brake pads into a brake caliper and slide the caliper onto the rotor. The caliper contains different-sized pistons so that it applies the brake pads to the rotor evenly. Now they move onto the car's inner workings. They mount the transmission to an aluminum housing that covers the flywheel, clutch, and other components. Then they install the motor. It's an eight-cylinder, 750-plus horsepower engine. They attach the car's plastic windshield with bolted clips. If air gets into the car, these strong clips will keep the windshield from blowing out. The car's seat core is made of aluminum, padded for comfort. Every nascar driver has his car seat custom-built to his body shape. After bolting in the seat, they install the steering wheel. It has a safety release that lets the driver remove the wheel with a single pull. This enables him to get in and out of the car easily and to remove the wheel quickly if he's injured in a crash. Now, for the finishing touches. First, a large decal of the car's number centered on each door. Every nascar racecar is also plastered with decals advertising its driver's sponsors. Nascar's stock cars have a few key safety features. Fenders allow side-to-side contact between cars without their wheels hooking together. Roof flaps direct air downward, keeping the cars close to the ground. This stops a spinning car from flipping over. A nascar stock car weighs in at more than 3,300 pounds. It travels to the track in the top deck of a trailer. This keeps the bottom level clear as a work space for the driver's mechanical crew.