Egad, a CADD!
Computer Aided Design & Drafting
Based on a Presentation by Dick Gebhard
by Chuck Umeda 01/05
Dick Gebhard, President of Assembly Technology, Inc., is a
man of many talents. An engineer by training, he now owns a company involved in
and selling CADD. To designers, draftsmen and engineers, CADD is essential,
replacing the traditional drafting table and T-square with the power of the
modern computer. Dick’s presentation held the usually talkative attendees’
attention with amazed silence for the most part. He showed that learning and
using CADD is much easier now for the non-techies. The company Dick represents,
Solid Edge, provides CDs with an actual functioning version of their Origin.
Dick graciously provided each attendee a free “Origin” CD. This was done for
the Phoenix Chapter as well as for Tucson. It was an evening of mutual
education, because Dick learned that inventors don’t all look like Einsteins
and we learned that using CADD is a skill we can all acquire.
Dick gave a brief history of how CADD developed. In the
‘70s, CADD drawings were 2-D, transitioning from the drafting table to the
computer workstation. These were the traditional engineering drawings often
called “blueprints” that showed a product from the top or “plan” view,
from the front and from the side. For complex items there are auxiliary views
and cut-aways for clarification. There could be many sheets of parts drawings,
sub-assemblies, modules and finally, the completed assembly. Each part of an
assembly had its own drawing and frequently designed by different individuals.
If a hole on a part were made larger, every other sheet where that part appeared
would have to be searched out and the change made. It does not take much
imagination to realize that one sheet could be overlooked. All too often, when
the parts were built to the drawings and the parts were put together to make up
the assembly, something wouldn’t fit like it should or holes for the bolts
wouldn’t line up. This meant redesign and added frustration as deadlines were
missed.
Even by the ‘80s though CADD software improved, one still
couldn’t make a drawing of a mold for a Mattel toy as can by done now. The
design and development cycle for a new product would easily take two years.
Engineers built the prototypes, because the product often existed in their mind
and not on a piece of paper. Once a prototype was built, the Engineering
Department felt their job was done and threw the project to Manufacturing who
had to figure out how to produce it profitably. Now, these groups work together
right from the beginning where each can contribute what they know and do best.
The engineer’s creativity is meshed with manufacturing’s knowledge of
producibility. By working together, a product goes from concept to finished
design in a few months.
In the ‘80s, toys were mundane. Designers made clay
models to visualize what they imagined. Engineering drawings were made from the
models. A mold would be made for the toy, but the moldmaker was limited to
simpler shapes. The finished toy would be the result of compromises.
Even in the ‘90s, CADD software was hard to learn, hard
to use and expensive. The computer workstations needed were also expensive. But
things have changed. Today’s designer sits at a PC and creates intricate
shapes using CADD. When the design is completed, an electronic model is sent to
the moldmaker, who can use it directly to make a mold for a toy that has the
intricacy the designer had in mind. Using the power of a modern CADD system, the
user designs a 3-D parametric model,
which is based on geometric relationships . The designer can create the complete
assembly in addition to the parts that go into it. CADD software is also smart.
If a hole is changed on one part, the software automatically makes changes on
all the electronic “sheets” where that part appears. From the model, the
comprising parts are derived, so everything fits together.
The point is that the CADD software is more intuitive in
use, easier to learn and runs on inexpensive PCs. The software allows the user
flexibility to try out ideas on the screen. If it’s good, keep the feature; if
it’s not good, simply erase it! If it’s too small, just make it bigger. That
hole’s in the wrong place? No problem; move it. It’s all done on the screen
and the changes are seen immediately.
Dick demonstrated the power of the Solid Edge software by
creating several different items. Start with a basic geometric shape. Add
rounded corners if desired and more depth if needed. It could be hollowed out to
make a mold. Do you want to see it from a different angle, just turn it around
on the screen. Admittedly, Dick uses the software with confident ease gained
through experience. But it can be learned even by people who don’t have an
engineering background. In fact, classes at Pima Community College may be
offered on Solid Edge CADD if there is sufficient interest. It is very likely
that a similar thing is being offered in the Phoenix area as well. Those
interested may contact the community college or Dick for more information.
Solid Edge offers various CADD packages. Origin
is a fully functioning package with some limitations. There are full-featured
packages available as well through Assembly Technology.
Assembly Technology
Dick Gebhard, President
7529 N. 23rd Street
Phoenix, AZ 85020
Tel: 602-870-0010
e-mail: reg@assytech.com
web site: www.assytech.com