January 19, 1998 Design News
Why engineers seek solid ground
Software gurus rave about the power
of solid modeling to revolutionize design. Does it?And if so, how?
Paul E. Teague, Chief Editor
The #!$@%! part doesn't fit! No one ever utters those
words calmly, especially in the latter stages of a design
project. Instead, engineers often shout them through
bared teeth, the words spraying like shrapnel from an
Like so many of his colleagues in industry, Electroglas
Inc.'s Jim Levante, engineering services manager, was
hearing those words too often.
The Santa Clara, CA company designs and builds wafer-probing
machines that semiconductor manufacturers rely on to
sort and classify integrated circuits. Composed of thousands
of parts, the machines position semiconductors under
contact probes for testing while they are still in wafer
Under Electroglas' former 2-D drafting regimen, engineers
didn't test for machine reliability, accuracy, or part
interferences until after they built a physical prototype.
By then, they had consumed a lot of time and expense
only to discover problems with the design, such as parts
that didn't fit.
That was then. Now, using 3-D solid modeling, the company's
engineers conduct design reviews online. They evaluate
product models early and often, and have the freedom
to make changes without affecting the schedule. The
result, says Levante: "We get a better product,
and save money."
A lot of money, in fact. Solid modeling recently helped
Levante and his engineers save $17,000 in the design
of a manipulator, one of the options that comes with
the company's Horizon wafer probers. The key: the ability
to make sure every part fit the first time.
Within the small world of software developers, there's
a lot of talk about the potential for solid modeling
to revolutionize engineering. And the word has gotten
out: The most recent forecast from Cambridge, MA-based
research firm Daratech shows that the fastest growing
software companies are those with solid modeling products--Parametric
Technology Corporation (Pro/ENGINEER), IBM (CATIA and
SolidWorks), SDRC (I-DEAS), and EDS Unigraphics (Unigraphics
CAD and, soon, Solid Edge, which it will market with
Intergraph under a separate subsidiary).
But, to find out if solid modeling really can improve
the engineering process, you have to study closely the
experience at Electroglas and other companies that have
chucked their 2-D ways and bet the future on solids.
Windows on design. Electroglas is
a great case study to follow because, under Levante's
direction, the company has combined solid modeling CAD
with other Windows-based engineering software for a
total remake of its product-development procedures.
The importance of engineers as owners of that process
has become apparent, says Brian Seitz, Microsoft's worldwide
engineering industry manager, who has worked with Electroglas.
As recently as two years ago, Electroglas did everything
in 2-D. Engineers and designers would create a product
layout, then pass it off to the drafting department,
which documented and detailed the design. "The
drafter, not the engineer, was the most important person
in the review process, because he gave the design team
something to look at," Levante recalls.
Analysis? Engineers were doing it too late in the process,
which cost time and money. Today, everything's different.
Electroglas re-engineered its engineering process around
the use of SolidWorks 97, Windows-based 3-D solid modeling
CAD software from Concord, MA-based SolidWorks Inc.
"We now work much harder to create a capability
spec, then model the product in SolidWorks," Levante
Seeing and believing. Designing in
solids opened up all kinds of possibilities, he says.
For one, it enabled engineers to visualize the product
at each step of the design phase, and long before they
made a physical prototype. And, by using the visualization
software of SolidWorks partner Immersive Design, they
can make a video version of the product so they and
others can evaluate it. "That gives everyone the
chance to see the design intent early, and gets engineers
input from others in the company when we can use it,"
Levante asserts. It has also helped engineers win design
approval, he says.
Using Microsoft's Source Safe, an archiving application,
engineers share the solid modeling data with their colleagues.
Source Safe archives all previous versions of the model,
so engineers can go back to any point in the design
process. Then, still within SolidWorks, they use SRAC's
COSMOS/Works finite element analysis software to optimize
the design by, for example, adding or removing material
to make a part stronger and more cost-effective.
Virtual prototypes precede physical prototypes, which
the engineers develop directly from the solid model
When the product is ready for release, they copy drawings
and bills of materials from Source Safe to Agile Configurator,
which the entire company uses as a product data management
tool. That tool gives them the benefit of global viewing
of drawings and bills of materials, and electronic handling
of engineering change orders.
And, because all the software is Windows-based, engineers
can release drawings to the technical publications department,
which uses MS Word to create operating manuals.
The bottom line: "Solid modeling helps us identify
problems early and get the design right the first time,"
Levante says. And, he adds, SolidWorks doesn't limit
the kind of talent the company can hire. "It's
so easy to learn, we no longer look for people specially
trained in a specific CAD system, we look for the best
people," he says.
The model-drawing connection. For
Joe Slater, head of engineering and new product development
at Kaiser Optical, Ann Arbor, MI, the biggest changes
solid modeling has brought to the engineering process
are model-to-drawing associativity, the ability to make
part and assembly drawings quickly, and the ability
to render images of new design concepts.
The company makes holographic optics for the military
market and for industrial process analysis. Until a
year ago, engineers developed the products using 3-D
wireframe models. They could model anything, but rendering
was limited. Engineers would make 3-D wireframes that
they would send to the design and drafting department,
where others would break the file into individual parts,
add screw holes and other changes, and then make new
drawings. "We never updated the original model,
which often became obsolete," Slater recalls.
To save time and money, the designers didn't do traditional
assembly drawings, which were expensive. They relied,
instead, on the original models for assembly information.
In other words, they depended on engineers remembering
how to put the assemnbly together. Engineering productivity
wasn't a problem, but Slater and his team knew they
couldn't continue like that. The company was growing
too fast. They wanted to move to model-to-drawing associativity.
The key was to control the geometry with the solid model.
Associativity features of the software would automatically
update drawings and assemblies to incorporate changes
in the model. To accomplish that, they chose Solid Edge
CAD software from Intergraph, Huntsville, AL.
Kaiser Optical's products are almost always a collection
of individual parts, and it's not possible to create
new parts outside the context of an assembly, Slater
says. "Wireframe models don't know anything about
holes and other features, and couldn't give us the associativity
between models and drawings that we needed," he
adds. "Wireframes are like lines of spaghetti--you
can't make any sense of them."
††Slater isn't ready yet to say that solid
modeling has improved product quality or engineering
productivity, but he suspects it will. For now, he is
pleasedwith the Solid Edge software and athow quickly
the engineers learned to use it. "Our productivity
was already good, and we've held ground during the switch
to solid modeling, which is good enough," he says.
Design, drafting, and configuration tasks have already
improved, he adds.
Oh, and about the software's visualization capabilities:
"I used to think rendered images were fluff, but
that capability has really helped us communicate design
concepts to management and get approval," Slater
asserts. "In that sense alone, it makes my job
What you see is what you get. Brian
Wagner agrees. As engineering manager at Carlson Tool
and Manufacturing in Cedarburg, WI, he likes the aesthetics
that come with solid modeling. "You see what you'll
get," he says.
Among the things he sees are thin-wall and thick-wall
sections that can cause fill problems in the tooling
designs his engineers develop. The company designs and
builds plastic-injection die-cast permanent molds for
automotive, medical, and consumer products. Customers
often send the company 2-D prints, and Carlson engineers
themselves worked in 2-D. But 18 months ago they began
using EDS Unigraphics version 11 solid modeling software.
(They had used Unigraphics for manufacturing for 13
years. Today, they use a combination of versions 12
and 13 for both design and manufacturing.)
"Now, when we model the customer's 2-D print in
3-D, we see all kinds of potential problems in areas
such as radius, draft, and thick or thin walls,"
Wagner says. Catching those problems early saves time
and money while enabling Carlson engineers to help the
company's customers accomplish their own goals.
That added value was evident recently, when Carlson
helped an overseas automotive customer avoid a fill
problem. The customer had supplied 2-D prints for a
battery cover. "We did a solid model of the part
and showed them thick walls that would not fill properly,"
Wagner recalls. "We told them that when the plastic
shrunk there would be blemishes. We re-modeled the part