Sand Castles, Laser Printers Improve Fuel Economy, Cost and Reliability of Ford Vehicles
While Ford Motor Company's new Beech Daly Technical Center may be the most sophisticated prototyping complex in the industry, the mediums they use may not seem like the stuff of rocket science. Sand castles, laser printers, and candle wax are used to quickly and efficiently build prototype parts used to test every nut and bolt on a new car. Housed in a rather unassuming building in Livonia, Mich., the center is capable of casting, machining, assembling and testing every major powertrain component, faster and more efficiently than ever. Prototype components are used in every stage of vehicle development, with the intent of making the product more reliable, more fuel-efficient, and more affordable for the consumer. The BDTC facility's rapid prototyping brings these benefits to the consumer faster, and more economically than ever. Five years ago, the time required to turn computer-aided design data into a functioning engine prototype could require more than six months. Today, Ford plans to build the first prototype of an all-new engine program from scratch in just 10 weeks. For Ford, this quick reaction time is expected to cut one to two years off of the typical time required to bring a powertrain to market. In addition, rapid prototyping eliminates the expense of tooling previously required to make functional components. This saves up-front costs, and significant costs as the engineering process drives design change. For example, the tooling for a small engine component could cost as little as $10,000. However, if nine design changes are required through the program, the cumulative cost of tooling alone could be $100,000. These cost savings increase exponentially with larger, more complicated components, such as engine blocks, cylinder heads and intake manifolds. "We believe the Beech Daly center is the most advanced prototyping facility in North America," says Todd Kloeb, manager, Engine Manufacturing Development Organization. "Paired with our sister facility in Dutton, England, Ford Motor Company now has the most sophisticated prototyping organization in the world. The center features proprietary technologies, but our advantage is not just in hardware and equipment. Rather, it's how we deploy that technology for significantly faster, cheaper prototype production." The BDTC relies on six techniques to produce prototype components. Two rapid casting techniques produce functional metal components that replicate sand-cast or high-pressure die-cast production components. Four rapid prototype technologies replicate functional plastic components, or non-functional, design-aid replicas. Here, computer data is translated into molds, built out of sequential layers of sand. These molds would humble the most elaborate sand castles, as these precise sand molds are filled with molten metal to make functional prototype pieces, such as an engine block. A pre-mixed layer of sand and activator is first applied to the entire build platform. Next, a printhead squirts a binding mixture onto the layer of sand. The activator and binder harden, creating the sand mold, one layer at a time, from bottom to top. Once the excess sand is removed, the mold can be filled with molten metal to cast the prototype piece. This makes very accurate, very intricate metal prototypes, such as transmission valve bodies. The begins by producing a rapid prototype master directly from CAD data. A silicone mold of the master is then filled with wax to create a pattern. These wax patterns are then dipped in ceramic. However, these ceramic pieces are not meant for display on a kink-knack shelf. After the ceramic hardens, the wax is replaced with molten metal to cast the prototype piece. SLS is used to make functional plastic components. For example, technicians at the center used SLS to develop functional intake and velocity stacks for use on Ford Racing's championship-winning FR500C Mustang. The Selective Laser Sintering process involves the production of a physical model by melting specific sections of powdered material, layer by layer. Like a laserjet office printer, the SLS laser beam scans each layer on the powder bed to fuse the fine particles into a solid area. Another layer of powder is then deposited and the next layer of the part is drawn. The solid sintered material forms the part, while the loose material acts as a support. When the build is finished, the loose material is removed to reveal the prototype piece. (click here for related story) Stereolithography can produce a very accurate, very inexpensive replica of a component in plastic. These are not functional pieces, and are usually used for design aid, or engineering models. For example, SLA replicas of metal castings are used to verify machining patterns and tool paths before the expensive metal components are cut. SLA components are made by curing a photosensitive liquid resin, which forms a solid surface when exposed to an ultraviolet laser. Each layer of the part is scanned onto the resin surface. Once a layer has been scanned, the build platform is lowered below the surface of the resin, and the process is repeated. When the build is complete, the part is raised out of the liquid resin, cleaned, and fully cured.
