An increasing number of engineers are making the switch from the ol' reliable—2D software—to the cutting edge—3D solid modeling—which depicts product designs via electronic 3D solid models rather than 2D drawings. And the reasons are obvious. Not only do solids give engineers more design flexibility, they also offer realistic images of products and allow the easy integration of downstream tasks, such as analysis.

What's more, solid modeling supports a decades-long push by the CAD/CAM industry to give manufacturing customers "art-to-part" capabilities—bringing a design from the concept to the tooling stage in a completely digital world. By implementing a purely digital process, manufacturers can foster more effective communication between departments, make better products and enjoy greater profits because of a speedier time to market. And to make "art-to-part" product development work, you need solid modeling.

Aside from enabling "art-to-part," solid modeling offers a dazzling list of benefits, including:

· Interactive 3D design · Accurate and improved visualization · Detail manipulation · Diagnostic tools · Model reuse · Much faster production of prototypes or even, their complete elimination · Design integrity

But while solid modeling provides many advantages, it hasn't caught on fast enough, say some observers. "There should be a stampede from 2D to 3D, not a migration," says engineering consultant Bill Dresselhaus, president of the Dresselhaus Design Group.

Possible reasons for solid modeling's gradual spread are its cost and the perception that it's complicated to use. Fortunately, cost is becoming less of a hurdle, with affordable options such as SolidWorks, Solid Edge, Think 3, Alibre and a new version of Pro/ENGINEER from PTC.

As for solid modeling's other major drawback—its perceived complexity—that still remains a factor. And this lack of user-friendliness is 3D's biggest constraint, says Robert Kross, Autodesk's vice-president of manufacturing. Learning to work with solid modeling and solid modeling itself are indeed lengthy processes, even though downstream activities can be automated to a much greater degree.

In addition, solid modelers may get more design flexibility, but they are constrained by CAD software functionality. This means they are limited by the software's capabilities. Moreover, users may have a hard time utilizing concept models exported from non-CAD design programs.

Another caveat to using solid modeling software is that images of models can give casual observers the mistaken impression that a product is farther along the development process than it actually is. And while the software's computer representations are photorealistic enough to fool the uninitiated, they aren't advanced enough to solve all of the product's ergonomic issues, making prototypes unavoidable.

Exactly how many engineers have converted to solid modeling is unknown, and estimates differ depending on whom you ask. While SolidWorks asserts that about one-third of design engineers rely on 3D solid modeling for mechanical and electromechanical design, Solid Edge VP Bruce Boes cites a Gartner Group study, saying that about 15% of engineers will be depending on solids by 2004.

But whatever the actual percentage may be, one thing is certain—solid models are here to stay. In fact, 3D solids are already usurping 2D's role as the prevalent standard for manufacturing, says Kross from Autodesk. Today's 3D models are useful to manufacturing because they precisely define values that can't necessarily be ascertained from 2D models. They hold non-geometric information such as tolerances, making drawings unnecessary in some cases.

Jack Beeckman, manager of CAD support for Liebert Corp., a division of Emerson, notes, "Manufacturing companies are relying on models, not drawings, to get the better designs they want, so engineers should control whole intelligent assets in the modeling environment, not just the drawings."

Engineers who are reluctant to drop 2D should ask themselves what their objective is—to make a drawing or a product—says Kross from Autodesk. Since producing a product is obviously the main intent, and 3D is much better than 2D in doing this, the choice to upgrade is straightforward, he believes.

Also on solid modeling's side is the success that users have enjoyed. From industrial to consumer products, there has been a trend toward more artful product designs with a growing number of functional benefits, such as ever-smaller sizes, enhanced ergonomics, improved fluid flow and less stress. This is because many engineers have been able to bolster the visual appeal and function of products through their use of midrange to high-end CAD systems with sophisticated shape description capabilities, which of course include solid modeling.

Indeed, the transition to solid modeling is just a matter of time. For one thing, its many advantages overshadow its limitations. And it appears poised to dethrone 2D in manufacturing because not only is it a linchpin to "art-to-part" product development, but it also upholds a product-centric approach.

Sources: Solid Footing For CAD
Paul E. Teague
Design News, April 7, 2003
http://www.manufacturing.net/dn

Today's Solid Modelers—Key to Art-to-Part Success
Mark Huxley and Steven Weisberg
Cadalyst, Jan. 2003
http://www.cadalyst.com/features/0103arttopart/0103arttopart.htm