Though they usually do their work with automated, high- tech machines and advanced software, the technicians at 3-Dimensional Services in Rochester Hills, MI, like to think
of themselves as craftsmen. This was evident recently when they were
asked to pitch in and help on a project designed to honor outstanding
law enforcement officers.
The project was the brainchild of the folks at the Desert Snow
Training Program. This program has provided the law enforcement
community with top quality interdiction training since 1989. Together
with its partners at the Black Asphalt networking site they have helped
officers apprehend and remove thousands of criminals from our streets
Desert Snow’s history and mission is represented by its symbol, a
knight riding a horse into battle. This is a bronze sculpture that is felt to
epitomize the program’s essence. During its annual conventions, Desert
Snow honors many individual law enforcement officers for their work.
Since the knight sculpture symbolizes the qualities which the organization honors, it was decided to present it to the most outstanding honor-ees during these annual ceremonies.
The problem, though, is that the sculpture is one of a kind and rath-er large, so Desert Snow would need multiple smaller replicas. It was
decided to reverse engineer the sculpture to make a new cast for creating
multiple smaller bronze copies of the original, and so they called on
Applications 3D is a Rochester Hills, MI, firm that provides expert
services in 3D scanning, reverse engineering, inspection and quality
control, CAD and product design and development. “We were asked to
provide the 3D scanning, reverse engineering and 3D Development for
this project,” says Raminder Bhatia, President of Applications 3D.
The 3D scanning was done using Applications 3D’s advanced
Steinbichler Comet 5 white light scanning system. This high resolution
digitizing machine facilitated the collection of tens of millions of highly
accurate x,y,z points on the surface of the sculpture. These points were
then meshed together into a triangular polygon model.
Since there was a lot of intricate detail in the sculpture, and some of
the required areas were hidden from the scanner’s access, the resulting
polygon model needed to be digitally modeled.
This digital shape modeling was done in the state-of-the-art Geomagic
Studio software. Geomagic is a leading provider of 3D software for creating digital models of physical objects for reverse engineering, product
design, inspection and analysis.
“In Studio, the scanned
polygon model was first
optimized, decimating the
points on the flatter areas,
while keeping a larger num-
ber of points on the sharper,
more featured areas,” notes
Bhatia. “During this process,
other abnormalities in the
data were also repaired, and
the model was scaled down
in size to the smaller required size.” Any missing data was filled in using
curvature continuity methods, so that the missing areas were represented
as close to the original as possible. The result was an extremely accurate
STL model. This is a triangular mesh model that is stored in an “ *.stl”
format from which it can be converted into a 3D CAD model.
The next step was the creation of the actual physical model to be
used as a pattern for making the bronze production cast of the sculpture.
The challenge at this stage was to accurately build all the finer details in
the model. At this point, Applications 3D partnered with 3-Dimensional
Services, an industry leader in rapid prototyping and 3D printing.
3-Dimensional Services, a member of the 3-Dimensional Services
Group, Rochester Hills, MI, specializes in design, engineering and analysis, in-house tool construction, and complete build of first-off prototype
parts and low to medium volume production runs. Their use of advanced
process methods and manufacturing technologies, plus the expertise of
their staff, mean that prototype parts – not just models – are typically
provided up to 70 percent faster than conventionally equipped prototype
shops are able to offer.
Technology plus craftsmanship
“The actual pattern was made by using the finished STL model to 3D
print a physical SLA (stereolithography apparatus) model,” says Scott
Duffie, Senior Sales Engineer for 3-Dimensional Services. The company
used one of its two SLA 500 machines on this job. An SLA’s laser beam
cures light sensitive polymers into the shape of the part.
“Since this was a highly complicated and intricate task,” continues
Duffie, “the advanced techniques and years of skill and experience of
our people came in handy during this process.” He points to the fact that
the physical model was built by 3-Dimensional Services in a day and a
half – the sort of quick and accurate work the firm has built its reputation on.
Next, however, came another and often unnoticed, aspect of the firm’s
talents. “Clean up, which was largely hand sanding, took about four
days. This required an eye for details and a steady hand. That’s because
there is a lot of fine detail on the piece, as well as shaded or partially
hidden areas, so you can’t just stand there and sand away as if it were
an everyday home improvement project. I refer to it as artisan work.
Fortunately our people take as much pride in their craftsmanship as they
do in their technical expertise, so we were able to provide the fine and
uniform finish the piece required,” says Duffie.
It was this SLA model that was then used by the bronze cast maker as
a pattern to make the tool for pro-
ducing the smaller sized sculptures
for the award ceremony. “Thanks
to the work of Applications 3D and
3-Dimensional Services, we were
able to provide these illustrious law
enforcement officers with a worthy
symbol of appreciation for their
outstanding service,” says Dave
Frye, Director of Training for Desert
Rapid Prototyping Helps Honor
Outstanding Law Enforcement