Witness Samples Pressure Washers Bee Hives Cast Iron Cookers
today on "how it's made"... Witness samples. Pressure washers. Bee hives. And cast iron cookers. Special coatings applied to optical glass change the way it transmits light, so that it becomes more or less reflective or even electrically conductive. Testing beforehand on little glass discs known as witness samples bears witness to the quality of the coatings. With witness samples, it's all about the optics. They must be flawless on the surface in order for optical coatings to be applied and properly evaluated. A diamond drill cuts solid cylinders out of a block of optical glass. Each one is an inch in diameter. A worker glues the cylinders together to a glass plate. This keeps them in a tight pack so that they can be cut into discs. The worker suspends the cylinder pack above a grid of piano wire. The wire moves back and forth to grind a silicon carbide slurry into the glass cylinders, to cut them at intervals about a tenth of an inch. The sliced cylinders then go into a hot bath for 15 minutes. This dissolves the glue. The glass discs separate, and are released from the base plate. The worker rinses each disc individually to remove any remaining glue. She sets the discs on a cardboard surface to dry. Once loaded into slots, a robot collects the disc using suctioning fingers. The robot inserts a disc into a suctioning clamp, and nudges it to further establish it there. A diamond cutting wheel meets up with the disc held in the clamp, and machines a bevel into the disc. A technician places plastic carriers with disc-size slots on a pad in a polishing machine. The carrier's gear-style teeth intermesh with teeth on the machine's hub and outer frame. She transfers the glass discs to the slots in the carriers. The upper polishing pad descends, and the carriers rotate as the pads buff the discs on both sides. The glass goes from frosty to transparent. She rinses off the polishing compound. Then, for an intensive cleaning, an automated rack system lowers the discs into a series of tubs. In the first one, they undergo another rinse. In the next tub, a special cleaning solution has been added to water-- one that won't leave a soapy residue. Sound waves bubble through this washtub to gently scrub the disc. After another rinse, it's into a dryer. It blows hot air onto the glass samples to dry them without leaving streaks. A worker tests one witness sample from every production run. Both a camera and a laser scan the sample, and a computer analyzes the information. The witness samples are now ready for coating. The technician loads the sample into fixtures in the coating machine. Using a lift, he elevates the fixtures to the top of the coating chamber. He inserts small crucibles of coating material in the base of the coating machine. The materials are metal oxide compounds that make glass less reflective. For demonstration purposes, the chamber remains open, and he sets the fixtures in motion. As they spin, the coating materials will be heated to the point of evaporation, forming a cloud that will condense on the samples at a certain thickness. The technician closes the chamber, and the process begins. An intense electron beam heats the coating materials. Once the coatings have cured to the glass, they can be evaluated. A computerized machine takes measurements to confirm that the reflective properties are correct. The witness sample has done its job, and the coatings are ready for production. Armed with a pressure washer, it's easy to get carried away and go on an outdoor cleaning spree. It can be used to wash down the driveway, clean the siding on the house, remove dirt from the deck, wash the car, and much more. A pressure washer contains an electric motor, which drives a pump that propels water at high pressure down a hose, and out a trigger-operated nozzle. The machine's mechanics and electronics are hidden from view by a two-part plastic cover. The two main parts of the electric motor are the rotor and the stator. To make the stator, this automated station winds 1,640 feet of copper wire-- or, for certain models, aluminum wire-- then inserts the winding into the slots of a steel cylindrical frame. The rotor is also a steel cylinder. It will sit inside the stator, attached at one end to the motor shaft. When the power washer is turned on, the a/c current passing through the stator winding creates a rotating magnetic field. This turns the rotor, driving the motor shaft, which drives the pump. At the next station, a worker prepares the stator's electrical connections, securing them with a cable tie. She contains and protects the copper winding with tape. Then, the stator moves on to receive the rotor. On another assembly line, a worker mates the guide for the motor's three pistons with the aluminum cylinder head and the motor, now in an oil-filled aluminum housing. The motor drives a rubber plate which moves the pistons, which move various internal components that pressurize the water. A worker places a new stator on the carrier to prepare it for motor assembly. Then on the pumpset, he installs a plastic water inlet pipe. He places the bottom section of the motor housing around the new stator that's heading to the motor assembly. The automated handling system removes the completed pumpset and transfers it to another carrier, which transports it to the final assembly line. A worker installs a rubber tube, which keeps water out of the motor. He pulls the stator electrical connections through it, then installs a watertight plastic box containing all the electronics and the power switch. He plugs the power cord into the circuit board inside the box, then screws down the stator's ground wire. A worker connects both power and water. Then a test machine automatically runs the unit through all the functions. Remember that two-part plastic cover? An injection-molding machine makes the parts in separate operations--  a yellow top and a black bottom. The automated handling system extracts the part and places them on a carrier headed to the pad printer. The printer stamps the model name in quick-dry ink on the top cover. Workers will later attach the company name to the front of the machine. The next station takes the top to the final assembly line, where the handling system turns it upside down and places the pumpset inside. At the next stop, a worker installs a guide for the machine's water hose, then positions the bottom cover. An automated machine screws the covers together. Another worker installs a galvanized-steel axle and two rugged plastic wheels. He applies a decal with safety instructions, plastic wheel covers, and a 33-foot-long rubber water hose wound on a plastic reel. The pressure washer then goes off to the packaging area, where it's boxed with the handle, accessories, and detergents. In the product-development stage, a sound engineer tests the prototype at a sound lab to make sure the noise the pressure washer emits isn't too loud and shrill. He runs the machine amid nine microphones, each positioned three feet away in a different direction. To pass the test, the noise must be a low bass-range hum. To operate the pressure washer, the user connects a garden hose to the water-inlet pipe, connects the handle to the machine's hose, turns on the water and power, then pulls the trigger to spray. For centuries, beekeepers used dome baskets called skeps as hives. But to harvest the honey, the skeps had to be destroyed. In the mid-19th century, they came up with a box hive with removable frames. Bees built their honeycombs on the frames, which beekeepers could remove without destroying them. A hive is home for thousands of bees. The queen resides on the bottom level. Worker bees have the run of the house and move around making honey. Construction of this beehive starts with the inner cover of the hive. A worker cuts a piece of pine plywood to the correct dimensions. He places the plywood in a jig, and carves an oblong-shaped hole into it using a hand-held router. This hole will provide both ventilation and an upper exit point for the bees. For the body of the hive, he uses cypress wood because it's resistant to insect damage and rot. With a table saw, the worker trims one edge of the wall panel, taking it from rough to smooth. He cuts a little more off the other side of the panel to make it the correct width. This gives this side a clean edge, too. A circular saw automatically carves a drawer pull into the panel. This pull is known as a handhold. There will be handholds on all sides of the hive box for easy access. The panel, front-side down now, rides a conveyer to the next operation. Numerous saws cut long grooves along the bottom and the sides of the panel. This creates joints that will fit the hive panels tightly together. A worker stacks the panels to await the next stage of assembly. Meanwhile, at another station, the next worker notches pieces of wood to make a part called the entrance reducer. It's the doorway to the hive. It will allow the bees to enter, but keep intruders like mice out. He makes a wide entranceway on one side and a narrower one on the other. A worker then cuts tongue-and-groove joints in wood that will be used for the bottom and the cover of the beehive. Moving to the beehive stand, he cuts a 45-degree angle on both sides of a piece of wood. This part will serve as a landing strip for the bees. A team slices a sheet of galvanized steel to the desired length. Using a press brake, a worker bends the edges of the sheet against a die. This forms a cover that will fit over the roof of the hive. At another station, a worker pipes glue along the inside groove of the roof frame. He arranges the tongue-and-groove boards in a tight interlock and inserts them in the glued groove of the frame. He applies pressure to further entrench them, and drives nails into the wood frame to secure the boards. He fits the metal cladding over the wood roof. It's been made to fit like a glove, so it takes a bit of maneuvering. He now joins four of the panels to make a box. And thanks to the grooved joints, the corners fit together neatly. He glues them, and then secures the joints with nails. This assembly will be the brood box that houses the queen bee. He now builds the frame for the inner cover of the hive ceiling. He applies glue to the frame. He inserts the cover and pounds it to drive it further into place. It's now time for the final assembly. They install the floor on the stand and position the entranceway piece at the front. The brood box is next. They hang frames with starter honeycomb beeswax on the inner ledges. They place a wire mesh excluder over the brood box to keep the queen bee out of the upper chamber. The smaller worker bees will be able to move through it to deposit honey on more honeycomb frames. They stack the inner cover on top, followed by the metal-clad roof. This empty hive will soon be a-buzz with activity and honey. humans have been cooking over fire with iron implements since, well, the iron age. Today, most outdoor cooking requires some type of appliance. And because of iron's superior ability to retain and diffuse heat evenly, a cast-iron cooker is sure to get everyone fired up. This cast-iron cooker may look like an ordinary barbecue, but it does so much more than grill. It also slow-smokes, caramelizes, sears, and even bakes. To produce the cast iron, the company buys scrap pieces of new steel from steel mills and from factories that use steel to make their products. Manufacturers heat the steel in a pre-heat furnace. This evaporates any residual moisture and speeds up melting in the main furnace. The main furnace operator adds a powdered chemical that solidifies the impurities so that he can scoop them out. He also adds carbon, silicon, and other alloys to transform the steel into iron. The molds are made of a sand, clay, finely ground coal, and water mix compressed at high pressure. The molten iron causes the moisture in the mold to evaporate. The resulting steam escapes through vent holes at the top. This machine lowers the top half of the mold over the bottom half. The furnace empties the molten iron into a ladle, which contains additional alloys. A worker positions the ladle over an opening at the top of the mold and pours in the molten iron. After about two hours, he breaks the sand mold and extracts the casting. Workers use a sledgehammer to break off excess metal. The cast-iron parts are still encrusted in sand, so workers load them into a shot-blasting machine. Shot blasting is like sandblasting, except instead of sand, the machine pummels the surface with tiny steel balls. The shot-blasting cycle thoroughly cleans the surface. The surface is still quite rough, however. So workers refine it with hand tools, hammering off any remaining excess metal and grinding the surface smooth. The top half of the cooker has a handle on the front and half a hinge on the back. The bottom half has the other half of the hinge. A worker drills a hole through each hinge half for the shaft that will connect them. He drills holes in the fire box that will let in air to feed the fire. Using a template and laser cutter, he cuts an opening in the bottom for the ventilation-draft door. He drills mounting holes around the vent, and installs the draft door. Its perforated hole cover lets air in. Its solid sliding door shuts it out. The air intake feeding the fire regulates cooking temperature. The cooker sits in a hand-crafted steel cart. A welder places the parts for the cart's frame in an assembly fixture, which positions them correctly. After welding the frame, he files down the welds so that they'll be virtually invisible once the frame is painted. This computer-guided lathe machines the cart's cast-iron wheels to the final dimensions. The sand molds used to cast the wheels were designed using century-old patterns for cast-iron pulleys. Once workers have mounted the two wheels, the cart goes off to be painted. Then, a worker installs shelves made of either stainless steel, hardwood, or composite decking planks. Workers bolt the bottom half of the cooker to the cart. Then they lower in the fire box, which holds the fuel for cooking. The recommended fuel is hardwood lump charcoal. Next, a worker mounts the cooker's temperature gauge. Then he installs the top vent. It consists of two cast-iron discs which rotate to let in more air or less air. Having adjustable ventilation at both the top and bottom of the cooker enables more precise temperature control. They position the top of the cooker over the bottom, and mate the two hinge halves with the steel shaft and two stainless-steel springs. Fiber gaskets ensure good seal when the cooker is closed over the cast-iron grates. Those grates are reversible, with one side higher than the other, providing a choice of cooking heights above the fire.