Custom Shoe Trees Clay Targets Squeeze Chutes Composite Boat Propellers
Today on "how it's made"... Custom shoe trees... Clay targets... Squeeze chutes... And composite boat propellers. Shoe trees are a device placed inside leather shoes to preserve their shape. They also absorb foot perspiration by wicking away leather-damaging moisture from the inside of the shoe. Shoe trees are a worthwhile investment because they extend the life of footwear. Shoe trees can be purchased at any price. Some are mass produced and inexpensive, while others can be handcrafted and custom ordered like these from a small workshop in france. The customer can select their preference of tree style as well as the type of wood and color. A craftsman uses a model in the customer's size and marks its length on a piece of wood. Using a band saw, the craftsman cuts the wood to the marked length. He saws one side flat to be able to lie the piece on its side. Then he traces the general shape of the model and saws along his previously marked lines to remove excess wood. Once complete, the block is roughly shaped like the model. Next, the block is mounted on one side of a pantograph, a milling machine that copies the form of one object to shape another. He mounts the model on the other side of the pantograph. Once the machine is turned on, both model and block begin rotating. The machine's tools, a tracer and a cutter, are linked. As the tracer runs across the model, the cutter moves in identical carving motions across the block. By the time the tracer finishes, the block is an exact copy except for those extra inches on the ends for mounting the block to the machine. The craftsman takes the copy off the pantograph and uses the sanding belt to remove any excess wood. He repeats the process to make a second copy. The craftsman measures and marks where he'll drill a hole on each piece of wood. For this style, he drills a hole right through the wood. Next, he measures the front of the customer's shoe and measures the length of each shoe tree. He does this to ensure that he has the correct dimensions. If the shoe tree is longer, he marks how much wood he needs to remove. Then he uses a template to create the top opening and traces the design on to the wood. With the band saw, the craftsman cuts along the marked line. The top opening is now complete. He drills holes in the bottom of each shoe tree to hollow it out. The drill bit is replaced with a different tool, to carve out the remaining wood in the cavity. With another tool, he smoothes the the surface of the bottom and top openings. With a band saw, he slices the shoe tree in half to create a hinged style. On each piece, he makes markings for the hinge, which will connect the two parts and cuts out a notch. After drilling holes for the hinge screws, he files the notch smooth and attaches the polished brass hinge. To ensure there are no rough edges, the craftsman sands the shoe tree. Depending on the style, the craftsman may apply a stained wood finish or a coating of liquid wax. Finally, the shoes are ready to be shipped back to the customer with the custom shoe trees rooted firmly inside. Clay targets are made to be destroyed the very first time they're used. Manufactured in multiple colors, these inverted saucers are used as practice targets and can be launched by hand or through automated machines. Also referred to as clay pigeons, these targets are not actually made of clay. They're made with pitch, a ceramic-type material, or resin. Since the 1920s, this french company has been producing clay saucers for both target practice and competitions, including the olympics. The founder invented the first automated target molding machine in 1947. Pitch targets are made from petroleum pitch, a substance derived from crude oil, and calcium carbonate, commonly known as talc. Talc is the filler while petroleum pitch is the binding agent, which solidifies into a hard, brittle material. The talc arrives at the factory heated at 176 degrees fahrenheit. A technician transfers the talc from the truck to a heated storage silo. A screw conveyor moves the talc from the silo to the blender tank, mixing it with the pitch. The petroleum pitch arrives to the factory heated to 392 degrees. The pitch is transferred to a heated storage silo and pumped into a blender. Every 10 seconds, 22 pounds of petroleum pitch and 64 pounds of talc are released into the blender. The materials cool as soon as they leave the heated silos. A gas boiler reheats the ingredients in 509-degree oil. The hot oil circulates in pipes around the blender, heating the pitch talc mixture to about 390 degrees. This process changes the consistency to a paste. The paste flows from the blender to the automatic molding machine. This valve cuts the flow at regular intervals to time the injections into the target-shaped molds. The machine compresses the paste while cooling it with water so that it solidifies. A transfer distance moves the targets on to a conveyer belt one at a time. As they move to the next conveyer belt, the molds are flipped right-side up. Even though the molds are still hot, they've remained soft and pliable. As the targets continue to cool and harden, a separating device lines them up for the conveyer belts that go to the paint chambers. The paint is made primarily of carbonate and biodegradable powdered pigment. A technician pours a pre-measured amount of water... And a bag of pigment into a mixer. The mixer combines the ingredients together. Once the water and pigment have blended together, a pre-measured amount of carbonate is added to the mixer, along with a binding and thickening agent. After additional blending, the paint is ready. The targets move from the conveyer belt onto spinning holders, which carry the targets through the paint chamber. Inside, a sprayer coats the spinning targets with paint. The targets exit the chamber wet and cooled. Another separator divides the targets on to two conveyer belts, which carry them through a hot-air tunnel for 30 seconds to dry the paint. The conveyer belt feeds the targets to a machine, which piles them in stacks. Clay pigeons can be manufactured in several sizes. Olympic regulation size is the largest, containing a width of four inches. A smaller target is used for training purposes and contains a width under four inches. Regardless of their size, all targets are engineered to remain stable in flight while following the intended trajectory. And, finally, shatter when shot. The average cow weighs up to 2,000 pounds. During medical procedures, due to its size, a device called the squeeze chute is used to hold a cow steady. The walls of this stall immobilize the animal, allowing a veterinarian access to administer treatment. A squeeze chute holds an animal still for medical and other procedures so that no one gets hurt. The key to the design is a front gate that closes around the animal's head and a cage-like structure with a squeeze wall that contains the rest of the body. Production starts with a big coil of steel. As it unwinds, rollers straighten the steel and the blade cuts it into sheets. The sheets move to a laser-cutting station. The laser cuts out the same part multiple times, producing many parts from one sheet. The part that's produced is a component of the side exit gate. The steel is formed into tubing. An operator loads the tubing into a bending machine. The machine wraps the tubing around dies, shaping it into one of the chute's access hoops. The machine cuts the ends of the hoop and ejects it. An automated system transfers the hoops to a rack. A technician arranges the hoops on the upper half of one of the chute's side frames. The jig serves as a template for the placement of the hoops. The bottom of the hoops are welded to hinges on the frame. These clips are for opening or locking the hoops. He welds one to the top of each access hoop. The operator can reach through the hoops to gain access to the animal. The hoops can also be opened if needed. Another technician assembles a panel to the bottom of the second side frame. He welds clips to the top so the panel can be opened for access to the lower part of the animal. He hinges the panel to the base of the frame. Next, an operator uses a machine to bend steel tubing against a circular form. After the first bend, the operator repositions the tubing so the machine can make the second bend in the specified location. The tailgate frame has taken shape. With the frame and a jig, a technician installs vertical bars and diagonal linkages and welds a metal shield to the lower half. This part keeps the cow's hooves safely inside. Meanwhile, holes have been drilled in both ends of the chute floor. They'll be used to move one wall inward to tightly contain the animal. Then the chute's skeleton is constructed. Using a hoist, a technician transfers the tailgate to the structure. The technician guides the top on to the squeeze chute framework and welds the structure together. Next, he attaches the squeeze wall to the structure. He opens the tailgate to test the clearance and assembles a steel panel to the lower half of the squeeze wall. He mounts the other side panel with the exit gate to the structure. He places hinges into the tailgate frame and welds the panel to the frame at the top. To verify the side gate is operating smoothly, the technician pulls the lever. Then he opens the tail gate to check its clearance. He moves the squeeze side to various settings, making adjustments if needed to ensure that the squeeze wall is properly aligned at each notch. Next, the entire structure is dipped in a paint vat, providing the structure with even coverage. The head gate has been especially contoured to hold the animal's head in position. Then a worker slides rubber grippers on to the operating handles. This squeeze chute is now ready to assist veterinarians and ranchers with a safe way to lock an animal into position. Until nearly 30 years ago, boat propellers were normally made of steel or aluminum. Today, developers have since tested the waters with composite propellers. Made from nylon resin and fiberglass, composite propellers are light weight and don't corrode. And, in certain models, broken blades can even be replaced. Composite propellers provide boaters with another way to move on the water. These props are the latest way to convert rotational motion into thrust. Production starts with a computer design. This one is for a houseboat propeller. The design will drive the machinery that manufactures the molds. Pellets that are half fiberglass, half resin are placed in a dryer to remove moisture. An operator takes a sample of the dried pellets. First, he weighs the pellets. Then he heats them to evaporate any additional moisture. The change in weight indicates how much moisture has been removed. These two-part metal molds form the pellets into propeller blades. This process takes just a minute and a half to complete. A technician starts a molding machine that melts the pellets. A large feed screw forces the molten material into the mold. The composite material solidifies, and the operator removes the newly formed propeller blade. The process leaves a piece of unwanted material known as the sprue. The sprue is composite material that hardened as it flowed into the mold. Once cut, it falls into a bin to be recycled into the next composite propeller. The trim propeller is now a functional part. Next, composite material is molded around an aluminum core to create the hub. A band saw cuts an extruded bar of aluminum to size. Each piece will serve as one core. Using a tool with a sharp-curved blade, the technician trims the rough bits left behind by the saw. These rough bits are known as burrs, so this process is known as deburring. Once the edges are smooth, the technician attaches clips to the three wings. These clips will be used to center the core in the mold. The technician slides the core into the mold. The clips hold it in a precise position. Then the machine is activated. The machine allows molten fiberglass and resin material to flow into the mold cavity and encapsulate the aluminum core. It also forms channels for the insertion of the propeller blades. A computerized milling machine moves the hub into position for trimming. A drill cuts into the center to widen the hole. The next operation called broaching will carve teeth into the hole, which will help connect the hub to the motor shaft. A machine pulls a spiraling tool called a broach through the center hole of the hub. The tool carves through the composite layer and into the aluminum core to cut the teeth. Here's a close-up look at those teeth. Now it's time for all the parts to come together. An assembler slides the blades into grooves in the hub. The grooves help hold the blades in place. Using a hammer, the assembler makes sure the blades are connected accordingly. Finally, a part called a rear cap is attached. For an inside look, the propeller has been cut open. The cut-out reveals how the composite material has become one with the aluminum core. And now a test. The technician attaches a chain to a blade. Using a hydraulic ram, he applies pressure. He measures the breaking point. At 1 1/2 tons of force, it's significant. This composite boat propeller has taken about 20 minutes to produce. Once attached to the motor shaft, it should last for years. Now this boat is ready to provide boaters with a ton of fun while out on the water.