Modern Machine Shop

SEP 2018

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

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MMS SEPTEMBER 2018 92 CAD/CAM tooling and machines capable of simultaneous five-axis contouring. With Mr. Bowman as the team leader, the Flying S staff of "programmer/machinists" was also growing during this time. By 2017, he had 12 individuals with this combined title on board. Most were Vincennes graduates. "We are a small team, and we can pivot quickly. We prefer not to outsource. If there is something to be learned, we prefer to bring the intelligence, the infrastructure and the equipment in house and learn how to do it ourselves," Mr. Bowman says. Each team member writes CNC programs and operates the equipment, so they are familiar with how changes in programming strategies affect manufacturing outcomes. Mr. Bowman explains that, as a group, they are committed to systematically pushing the capabilities of the equipment and software (within safe limits) and sharing what they have learned with one another so that they can support company growth. For example, when a process plan for a part is being devel- oped, details about each operation and their exact sequence are recorded and added to the company's manufacturing database. This data- base includes the toolpath files and related tool libraries generated in Mastercam, as well as setup instructions and operational notes. With combined programming and machining skills, the shopf loor team is especially effec- tive at creating efficient part plans and sticking to them. No time is wasted on guess- work or reinventing procedures. Because CAD/CAM capability is central to the company's growing capacity and manufacturing proficiency, the software must also promote the strategy of safe and sound programming. Mr. Bowman enumerates some of the CAD/CAM tools that have been the most helpful: Optimized Material Removal. The shop team spends substantial time programming and cutting molds used for making carbon-fiber-composite airframe structures for commercial and military customers. These free-form shapes can be very intricate, requiring as many as three to four million lines of code, and they can run unattended on CNC equip- ment for as long as a week at a time. Oftentimes the team is tasked with producing one of these molds every other day. Generating these programs must be an efficient operation, and the resulting programs must remove material efficiently as well, Mr. Bowman explains. For moldmaking, Flying S relies on tool paths incorporating Mastercam's Dynamic Motion technology, which constantly maintains the chip load recommended by the cutting tool vendor for safe, yet optimal, removal rates. Mr. Bowman notes that the programming software facilitates programming by guiding the programmer to input parameters and select options in a straight- forward, almost intuitive, manner. In addition, the tool paths link to one another with smooth transitions so that hand work after machining is minimal. "The tool paths have proven to be so stable that they can be used with confidence for days on end in unattended operation," he says. He also credits his Mastercam reseller, ShopWare, with careful editing of postprocessors to ensure that outputs to each of the five-axis machines are precisely tailored to the variations in machine configuration or control structure that inevitably turn up. "This is another safety factor that minimizes disruptions or unwelcome surprises on the shop f loor," he says. Safe Moves. Mr. Bowman emphasizes that machining strategies should be as efficient as possible, but they must also be safe. Team members rely on both toolpath and machine simulation to protect valuable workpieces and equipment. "Whenever we go to do a large mold, for example, we always use the same tools to rough, and we always use the same feeds and speeds. Even though we might have as many as 12 different guys who would be able to program that particular part, we are always using the same process. Sharing the CAM software's tool libraries has also been a great risk mitigator," he says. The key is to play it safe, but always be ready to move to the next level.

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