Mid-range CAD muscles in

Newton, MA--The glamour, glitz, and flashy promises of high-end CAD systems are enough to entice most any company. Without a doubt, their powerful analysis and conceptualization capabilities enable engineers to create previously unimaginable designs. But take a closer look at many engineering companies and you'll discover something unexpected: In spite of the functionality offered by high-end systems, much of the actual design work is being done in mid-range CAD.

Companies from the smallest machine shops to the largest corporations are using self-described mid-range products such as Micro Cadam, Cadra, AutoCAD, MicroStation, Cadkey, and Pro/JR. It's an issue of functionality and cost, says John Sunderland, director of industry marketing at MICROCADAM, Los Angeles. Mid-range systems have a lot of functionality and cost less, he says.

That's why "mid-range systems are evolving into an across-the-board solution," says Ralph Mayer, VP of technical marketing at Adra Systems, Inc., Chelmsford, MA. Many engineers say they are also easier to use than their bigger cousins. And, their developers claim they have most of the functionality of high-end systems.

So what is mid-range? The industry has yet to clearly define that. Criteria for mid-range products can include everything from capabilities for 3-D solid modeling to 2-D drafting and detailing to a data management system and extensive user support. MICROCADAM's Sunderland says they should also run on multiple platforms. For example, the company's recently released version of HELIX runs on Windows NT, AIX, and HP-UX operating systems.

There are a few key points, however, on which industry moguls do agree. The "must haves" for a good mid-range package:

Ease of use. Whether through a simple menuing system or intuitive design capabilities, the system should be easy enough for anyone to use, from the most experienced engineers down to more casual users.

The lower price is a major draw for many users. A mid-range package ranges anywhere in price from $5,000 to $10,000, while most high-end systems cost upwards of $20,000 per seat. There are exceptions of course. SolidEdge from Intergraph (Huntsville, AL) and SolidWorks 95 from SolidWorks Corp. (Concord, MA) claim full functionality, yet their price falls into the mid-range level.

Still, "most high-end packages don't do the 80% of the work required in product design. They only do high-end tasks," says Sunderland.

He cites basic 2-D design capabilities as an example. "When an engineer is ordered mid-way through a design cycle to finish a project, s/he needs to do drafting, detailing, and documentation. There is a huge amount of data that has little to do with the actual high-end design of the product," he says. Using a mid-range package that offers a combination of 2-D functionality and 3-D modeling can save the engineer valuable time.

And being easy to use doesn't hurt either. "The efficient interaction of a mid-range system not only saves a company time and money, it puts the engineer in a productive frame of mind. That's where the complexity of high-end systems takes it toll," says Mayer.

Rest assured, high-end CAD has a definite place in the design arena, especially in specialized applications, such as in the automotive and aerospace industries, say industry analysts. But, oftentimes, mid-range systems complement the more robust products, enabling engineers to implement the concepts they work out with more expensive CAD packages.

"Mid-range systems are not displacing low- or high-end systems. Rather, companies are adopting a policy of peaceful coexistence, often finding uses for mid-range systems plus the low- or high-end systems they already have in place," says Mayer. "The mid-range product may not excel in any one specific category, but it provides the depth of applications to go from concept to reality."

Donald Lydic, plastic injection mold designer at Designers and Draftsmen Inc., Richmond Heights, OH, agrees. Though Lydic has access to a combination of high-end and mid-range packages, he turns to the mid-range systems for the majority of his design work. Take his recent development of a mold for an electrical center lower housing for Delphi Packard Electric Systems, for example.

Delphi, Warren, OH, created a 3-D solid model of the part in a high-end product. Once Lydic loaded the part into his high-end system, he made small alterations to improve the product's moldability.

His first design challenge: The original part had walls too thin to accommodate the sizeable pins needed to eject the part from the mold. To solve the problem, he added ejector bosses and lifters around the outer perimeter.

Lydic overbuilt the lock areas to accommodate plastic shrinkage, ensuring the final parts would fit together properly. He also made section views of critical areas that would need detailed design instructions. Once finished, he used IGES to transfer the file into Cadra where he performed the bulk of his design work.

The first step was to "shrink up" or enlarge the entire part to compensate for shrinkage that occurs in the molding process. He then divided the part into mold sections. Lydic also addressed problem areas of the part where gas might get trapped during the injection process, preventing the part from filling completely. He added vents that allow the gas to escape without allowing the plastic to escape as well.

Finally, Lydic made "figures" of various views and sections of the product to provide detailed instructions on building those specific pieces. The final files were forwarded to the tool shop building the mold.

The whole truth. Lydic admits he could have designed the mold in a high-end package, but says he chose Cadra because of its speed. "High-end packages take a lot longer to process information. If you change a feature it may take 20 minutes to regenerate itself throughout all sections of your file. There's not a lot of productivity. In 2-D, I can produce for 10 hours a day with minimal slow down time."

And quick turn-around is the name of the game when it comes to product design. Says Lydic, "There's not a lot of time to do something in 3-D when I can do it in half the time, if not better, in 2-D."

"The mid-range is growing up and getting more and more capable over time. The danger for high-end vendors is that the mid-range will push them to become specialists. The mid-range is going to nibble away at a greater bulk of what the high-end can do," says Peter Brooks, director of the mechanical engineering product organization at Bentley Systems, Inc., Exton, PA.

No matter what the future holds, one thing is certain, mid-range CAD has become the workhorse of the '90s.