Cadalyst - May 2008 - (Page 13)

techtrends joint identifications, schematics, and as-built assemblies (figure 2). Burchett was certain that only an accurate solid model would enable Técnico to provide the Navy with the best set of engineering drawings. With a degree in mechanical engineering, Burchett was skilled in parametric 3D CAD modeling with packages such as Pro/ENGINEER and SolidWorks. He realized AutoCAD might not be the first choice for a large-scale, solid-modeling project for most users. But the NDSTC’s workflow was standardized on AutoCAD, and the management wanted Técnico to deliver the documents in the same format. Because AutoCAD is not parametric, Burchett couldn’t expect the software to automatically adjust the sizes and shapes of the associated valves and pipes whenever he modified the geometry of a chamber or a panel. To be efficient, he had to meticulously plan out his layering systems. “The layering system is absolutely the key,” he said. “From the engineering standpoint, it’s crucial that you can layer up or layer down to anything you want, to be able to nest files and cross-reference them in a sequence.” To document the complex network of pipes, Burchett took advantage of AutoCAD’s Sweep command. “With this command, I can simply turn a three-dimensional polyline into a pipe,” he pointed out. “I connected the line segments then entered the diameter of the pipe — say, a quarter of an inch — and had the software execute a Sweep along the path.” Another feature upon which Burchett relied was the Flatshot command. “This gave me the opportunity to use the 3D assembly model to create stunning 2D views that would otherwise be impossible to produce in a traditional 2D CAD program. “Flatshot was a tremendous leap, a great progress in producing 2D drawings from a 3D solid model, but it still requires cleanup,” he added. “In the automatically produced drawings, lots of unwanted entities still show up.” Burchett said he hopes the upcoming AutoCAD 2009 might address this problem. Figure 2. Técnico’s solid model, built in AutoCAD 2008, represents the as-built condition of the Hyperbaric Diving Simulation Facility. Swimming in Solids Burchett’s model of the dive simulator was the foundation for Técnico’s refurbishing of one of the three DSFs operated by the Navy. At the end of the project, the chosen facility became fully automated. “In the past, to operate the system, an operator would have to crank up the valves manually,” said Burchett. “No more of that. Now it’s computerized. Dive profiles are loaded into the computer, and the system is controlled from a console [also part of the 3D model].” U.S. Navy’s Delanoy pointed out, “In the past, it could sometimes take one or two days for one of my technicians [to get repair and routine maintenance information], going through reams of technical documentation to find the answer we need. Our quality-assurance program requires development of very detailed Re-Entry Control work packages for everything we do. So we always have to prove how we did the job, the parts we used, all the assembly specifications, and so on. With this info now embedded in the interactive drawings, we can now just point and click [see figure 3].” For maintenance work, the solid model offered additional intelligence that could not have been derived from 2D drawMay 2008 cadalyst www.cadalyst.com Figure 3. A simple click or a zoom reveals the make and model of an assembly component, eliminating the need for technicians to search through archival drawings for this information. ings. “For example, you can unfold the pipes and easily get the total length,” Burchett said. “You can perform volumetric studies or finite-element analyses. You can better understand the pipe intersections and the weld joints.” The dive training center is responsible for training all divers in the U.S. Armed Forces, the Department of Defense, and state and local law enforcement. Every year, roughly 1,500 to 1,800 students receive their dive qualifications from the facility, now maintained and automated using Burchett’s AutoCAD 2008 model. Cadalyst contributing editor Kenneth Wong explores innovative uses of technology and its implications. Reach him at kenneth.wong at cadalyst.com. 13 http://www.cadalyst.com

Table of Contents Feed for the Digital Edition of Cadalyst - May 2008

Cadalyst - May 2008 Contents Editor's Window Cad Central A Solid Job in AutoCAD Today’s Power — Quad-Core Workstations Performance — Tomorrow’s Possibilities Reverse Engineering an Antique Italian Treasure Trends in Reverse Engineering NextEngine 3D Scanner — Reverse-Engineering Tool Setting CAD Standards Fight for Your Hardware Rights The Jack and Jill of Ergonomics Technology for Civil Infrastructure Cad Cartoon Issue Indexes Shortcuts and Solutions

Cadalyst - May 2008

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