Choosing the Right CAD Viewer to Achieve Successful Concurrent Engineering in Moldmaking

In the following Q&A, MoldMaking Technology editor Sherry Baranek examines how one software developer has changed the way engineering software is marketed, which helps to promote collaborative engineering in moldmaking.

Why give away software?

"We are offering software for high-end data translation and communication as a free download," says Stuart Watson, director of CAD product development and based at Delcam PLC, in Birmingham, England. "We are offering software to extend concurrent engineering setups, to collaborate more closely with customers. Most any viewer on the market today can read and display 3-D CAD models, but unlike them, this software is targeted specifically at the tooling industry which manufactures complex surfaced products, such as molds, from solid modeler designs of new products."

What are you trying to accomplish?

"If any industry needs concurrent engineering and the capability of bringing more and more people into collaboration on new projects, it's tooling," says Sivitter, vice president of Delcam's North American operations, based in Windsor, Ontario, Canada. "Mold shops and die makers are being asked to produce more tooling for a greater variety of products, take on more of the design work, lower prices and deliver sooner. And this in a business where the pool of talented people is growing much slower than overall demand."

Watson adds, "Collaborative engineering provides the tools to involve more people in the enterprise in the decisions and evaluations of new products. Viewers empower people upward in the supply chain, downward in the service and support organizations, on the shop floor and out in sales or marketing. That means better decision-making. The viewer frees them from having to interrupt and distract overworked CAD operators just to discuss progress on a job with a customer."

What should a viewer for the tooling industries offer?

"Viewers should provide basic functionality for viewing, measuring and sec-tioning models - regardless of where they were created or translated from,* or files imported via IGES and STEP," Watson explains. "For tooling users, the viewer should be able to analyze surfaces for proper draft angles or to determine the proper milling cutter diameter.

"At a minimum, using and sharing the viewer will simplify and accelerate the ways in which files are translated and distributed," he continues. "The viewer also should support drawing mark-up, plotting, dimensioning and features for handling engineering change orders with a low-cost upgrade."

Sivitter adds, "The viewer should run on any Pentium PC - including laptops.** And users should be aware that a viewer is not just a stripped-down CAD system. The term 'viewer' means just that. Users see a model, but they cannot save it to another format. The exporting capability comes with the added-cost options to the translators. Otherwise they too are free.

"It is true," he continues, "that removal of save function limits a viewer's use for practical design work. But even without save, a viewer greatly extends the reach of collaborative development and concurrent engineering." How about accuracy?

"A viewer should handle the true geometry of the model, not just faceted representations of the surfaces such as the tiny triangles in STL*** files," Watson explains. "If a viewer can only see tiny little straight lines, which are actually the edges of hundreds of tiny triangles, its software has to 'guess' at what the geometry means. A circle is inferred, in other words, rather than known. This offers a great potential for error. Furthermore, triangles can only approximate a curved surface, so tolerance inaccuracies are inevitable. A viewer should see not only the real surface geometry but also the relationships among all of its elements. Tolerance inaccuracies in geometry are caused by dissimilar tolerance settings on two CAD systems exchanging a model."

What does the moldmaker get out of this?

"Moldmakers get the software capability they need to keep up with their customers and ahead of their competitors," Sivitter says. "At the end of the day, tooling companies really have just three resources to draw on: faster computers to handle ever-larger computational loads, more powerful software that behaves more intuitively and better project management.

"Although we are software developers, we have come to realize that, in moldmaking, this last resource is actually the most important. In tooling, project management refers less to knowing how many hours and dollars are in a particular job than in ensuring that everyone knows what's going on. Our customers regularly remind us that their success depends on making sure that input is gathered from everyone on a project - and not just on someone's idea of a timely basis, either, but early and often."

How does this help the moldmaker's customers?

"A viewer is the open sesame of concurrent engineering, the magic lantern that lets everyone who needs to, see what is going on," Watson says. "Supplying the viewer along with the file eliminates any need to translate CAD and IGES models before they can be viewed. This helps the moldmaker's customers to be sure that all input and viewpoints are considered.

"Now, with a good viewer, everyone with access to the files can get answers to all of the vital questions," he continues. "What exactly does the product look like? What has and has not been done? What has changed most recently? Are engineer-ing changes being made on top of changes? Can the delivery schedule accommodate any additional features? What still needs to be done? Do we have all of the feedback? At any stage in the project, when a user needs clarification from a customer, the file and the viewer can simply be sent to the customer with a request for feedback."

Notes
* This viewer reads files from CATIA, Parametric Pro/Engineer, CADDS and Unigraphics, products respectively of Dassault Systemes of France, Parametric Technology Corp. (Waltham, MA) and Unigraphics Solutions Inc. (Madison Heights, MO).

** This viewer requires an Intel Corp., Pentium-powered PC with a 128 Mb RAM and Microsoft Corp.'s Windows NT operating system.

*** STL or Stereolithography Tessell-ation Language is a basic standard in the rapid prototyping industry.