Laser Scanner Helps Auto Supplier Cut Inspection Time by
Two-thirds
The
switch from a coordinate measuring machine (CMM) to a laser scanner
recently helped an automotive supplier reduce by two-thirds the time
needed to inspect the company’s first article of foam parts. The
Lexington, Kentucky manufacturer builds a wide range of foam parts, and
inspection of components with a CMM was a tedious and error-prone process
because of the difficulty involved in making contact with the part without
depressing the soft material.
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A
customer gave the company’s quality manager the idea of improving the
speed and accuracy of the inspection process with a laser scanner that
works by projecting laser light onto surfaces while cameras continuously
triangulate the changing distance and profile of the laser as it sweeps
along. “The laser scanner
has reduced the amount of time needed to lay out a first article from
about an hour to under 20 minutes,” said the quality manager.
“Just as important, the accuracy of the measurements has been
substantially improved because this noncontact measurement method
eliminates the danger of depressing the part surface.”
The quality
manager said he saw the potential for overcoming these problems with laser
scanning - a new technology designed to address today’s quality control
and reverse engineering challenges. Laser
scanning systems work by projecting a line of laser light onto surfaces
while cameras continuously triangulate the changing distance and profile
of the laser line as it sweeps along, enabling the object to be accurately
replicated.
Instead
of collecting points one by one, the laser scanner picks up tens of
thousands of points every second. This
means that reverse engineering of the most complicated parts can often
accomplished in an hour or two. Laser
scanning can reverse engineer parts that are so complex that they would be
practically impossible one point at a time. Finally, the software provided with the scanner greatly
simplifies the process of moving from point cloud to computer aided design
(CAD) model, making it possible in minimal time to generate a CAD Model of
the scanned part that faithfully duplicates the original part.
Special, but readily available software can be used to compare
original design geometry to the actual physical part, generating an
overall graduated color error plot that shows in a glance where and by how
much, surfaces deviate from the original design.
This goes far beyond the dimensional checks that can be performed
with touch probes on CMMs.
The quality manager evaluated a number of different laser scanners and
selected the DM1620 from Laser Design, Inc., Minneapolis, Minnesota. This
scanner features a line-range laser sensor that captures up to 14,400
points per second and also digital coordinate output, a Class II rating
for safe and easy-to-see operations and a long standoff design to prevent
crashes. “I really
appreciate the training and service that we got from the people at Laser
Design,” he said. “They
made every possible effort to help us get up and running and were
extremely patient as we got acquainted with this new technology.”
“First
article inspection with a laser scanner is substantially faster than with
a CMM,” he said. “In the
past, our technicians had to move the probe along a line to see where the
part matches while now they can simply paint the part and perform the
comparison on the computer. The
time required to inspect first articles has been substantially reduced
while at the same time improving the accuracy of the process.” |
