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The Morel of the
Story—Intricate Details Captured with Laser Scanning and Brought to Life
in Thermoplastic
 Bill
Priedeman, director of materials development at Stratasys, the global
leader in rapid prototyping and direct digital manufacturing systems
based in Eden Prairie, Minnesota, is an avid mushroom hunter. He is
fascinated with interesting shapes in nature, so on a recent morel
foraging expedition he had an intriguing idea which combined his
engineering vocation with his nature-loving avocation: to accurately
recreate a complex, convoluted morel mushroom with a Stratasys FDMTM
(Fused Deposition Modeling)
rapid prototype system directly from 3D CAD files.
Since Priedeman works with a software company in Belgium that develops
art products from CAD models of natural shapes his idea to scan a morel
was perhaps not so off-the-wall. “The natural shapes provide
interesting geometries for art pieces such as jewelry, accessories,
lampshades, even couches. Shapes found in nature are unique. There is
no way to replicate them via conventional CNC machining based
manufacturing processes,” mused Priedeman.
When he pondered how to obtain the most accurate and detailed 3D data of
the mushroom’s shape, he came to Laser Design / GKS Inspection
Services. Laser Design, Inc., has been the leading supplier of
ultra-precise, 3D laser scanning systems and services since 1987. Used
for capturing the 3D shape of objects with complex geometries and
freeform surfaces, Laser Design’s Surveyor line of automated and
portable 3D laser scanning systems are ideal for applications involving
reverse engineering of complex shaped objects be they metal, plastic,
or, in this case, organic.
 So
that is how it happened that one day in May, which is mushroom hunting
season in Minnesota, Priedeman brought a real morel to the Laser Design
demo room to be scanned. The morel’s ridged surface with irregular
crevasses would be a real challenge and test for both the Laser Design
Surveyor DS-2020 system with its high accuracy RPS-120 laser and,
afterwards, the Stratasys FDM system. “Mainly, the idea was to scan and
build a very complex-shaped object, and show the amazing capabilities of
3D laser scanning plus rapid prototyping when they are combined,” said
C. Martin Schuster, President of Laser Design.
Even though the project’s goal, a lifelike replica of a morel, was
daunting, the expert metrologists at GKS Inspection Services, a division
of Laser Design, rose to the task. With over 25 years in the business,
GKS metrologists have experience with all kinds of unusual and custom
projects. First, they stabilized the flexible shape of the mushroom by
inserting a metal rod into the center. This did not affect the
geometry on the outside, but prevented the morel from distorting from the pull
of gravity. They then mounted it on a rotary stage to capture the
geometry all the way around from several angles. The idea is to perform
multiple scans from several orientations to capture as much geometry as
possible. To recreate an accurate model, Priedeman needed high
resolution, high detail, high density STL files.
 The
metrologists knew that the deep inside pockets of the morel would be
challenging to scan. The laser scanning system projects a line of laser
light onto surfaces while cameras continuously triangulate the changing
distance and profile of the laser line as it sweeps along, capturing
tens of thousands of coordinates per second that it “sees” with the
cameras. The system measures fine details and captures complex freeform
geometry so that the object can be exactly replicated.
However, the surfaces deep inside the ridges and pockets are
difficult, if not impossible, for it to see and gather data for.
Because the surface of the morel was so complex and pocketed, the very
large data files still contained over 5000 holes in the surface geometry
after all the scan angles were performed. The GKS metrologists knew
that the Stratasys FDM rapid prototyping system would not be able to
recreate the model using data containing holes. To fill in the missing
sections of data manually would have taken many long hours of massaging
the data. Instead they decided to use the Rapidform XOR software black
box module to automate the process. The software took the huge point
cloud of data and automatically fixed and filled the holes in the STL
file that was auto-generated from the 3D scan data. It created a
continuous surface in a closed STL file which is essential for the FDM
rapid prototyping machine to be able to build the part. If the FDM
system finds an empty space it doesn’t know what to do; it can’t create
empty spaces with its thermoplastic material. This data processing step
insured the success of reproducing the complex shape of the morel.
From start to finish, the scanning process took about 25 minutes total;
10 for performing the multiple scans and 15 for cleaning up the data
with RapidForm XOR software. Priedeman took the data files back to
Stratasys where his technicians created multiple copies of the
completely lifelike morel in a translucent polymer. Rapid prototypes
can be made hollow, so they remain lightweight no matter what size they
are.
Priedeman commented, “Scanning things in nature is an interesting idea.
Laser scanning is a relatively quick and painless way to gather the
complex and detailed data to create the natural shapes accurately and
quickly. This process would allow mass customization in a limited
numbers of lots. Anything, no matter how geometrically complex, can be
recreated. The potential for such a process is unlimited.”
About
Laser Design
Laser Design, Inc. has been the leading supplier of
ultra-precise, 3D laser scanning systems and services since 1987. Used
for capturing the 3D shape of objects with complex geometries and
free-form surfaces, Laser Design’s Surveyor line of automated and
portable scanning systems are ideal for 3D scanning applications
involving inspection and reverse engineering of complex shaped plastic
and metal parts. The company’s patented laser line-probe technology
dramatically reduces scanning time by collecting data substantially
faster and more accurately than conventional metrology technologies.
Laser
Design integrates Geomagic software with its laser scanners to provide
complete solutions for reverse engineering and inspection applications.
Headquartered in Minneapolis, the company also has Regional Technical
Services and Support Centers in Seattle and Detroit, and distributors
throughout Europe and Asia. Laser Design also operates GKS Inspection
Services (www.GKS.com),
an in-house service bureau division offering complete 3D scanning,
reverse engineering, and dimensional inspection services.
For further information, contact C. Martin Schuster, by phone
(952-252-3402), fax (952-884-9653), via email to
sales@laserdesign.com or visit Laser Design’s web site at
http://www.laserdesign.com.
About Stratasys
Stratasys Inc.,
Minneapolis, manufactures office-based rapid prototyping and
manufacturing systems and 3D printers and offers rapid prototyping and
manufacturing parts services. According to Wohlers Report 2007,
Stratasys supplied 41 percent of all systems installed worldwide in
2006, making it the unit market leader, for the fifth consecutive year.
Stratasys patented the rapid prototyping process known as fused
deposition modeling (FDM). The process creates functional models and
end-use parts directly from any 3D CAD program using ABS plastic,
polycarbonate, PPSF, and blends. The company holds over 180 granted or
pending rapid prototyping patents globally.
Stratasys products are
used in the aerospace, defense, automotive, medical, education,
electronic, and consumer product industries. The company's systems are
also used for direct digital manufacturing (DDM) and rapid tooling
applications. For more information on the company, go to www.Stratasys.com; www.RedEyeRPM.com;
or www.DimensionPrinting.com.
Stratasys,
Inc. Contacts
Investor Contact:
Shane Glenn,
952-294-3416,
sglenn@stratasys.com
or Editorial Contact:
Joe Hiemenz, 952-906-2726,
jhiemenz@stratasys.com
Web site:
www.stratasys.com
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