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From 2D Drafting to 3D Dynamics
In MMA's early days,
conceptual designs were drafted on drawing boards. The company later
migrated to two-dimensional (2D) computer-aided design (CAD) software to
improve the efficiency of these drafting tasks. Hardware prototypes were
then constructed from these drawings for design testing.
Last year MMA invested in a 3D CAD environment. Now the company’s
engineers use the computer for more than just drafting; they can actually
perform all design and testing tasks electronically, right from initial
concept. MMA’s engineers don’t need to wait for drafting, manufacture,
and physical testing to see if a design concept works. Instead they can
immediately build an assembly and see it in operation, then refine and
optimize the design -- all on the computer, and all before producing a
single drawing or building a single physical prototype.
The critical enabling technology in MMA’s design simulation approach
is Dynamic Designer/Motion software from Mechanical Dynamics, Inc. Dynamic
Designer/Motion is built on the ADAMS® dynamic solution engine, the
world’s most commonly used mechanical system simulation tool.
Single-window integration within the CAD system lets MMA’s engineers
apply Dynamic Designer/Motion’s capabilities without leaving their
familiar CAD environment. A designer can instantly convert a CAD assembly
into a working "virtual prototype" by adding joints, friction, motion,
and forces.
The user then runs the assembly through a battery of realistic 3D
dynamic simulations to test the design’s functionality. Based on the
results of these simulations, the user can progressively tweak the design
and quickly iterate to optimal performance.
Accurate Upfront Insight
According to Brett Lewis, a design engineer for MMA, what Dynamic
Designer/Motion lends more than anything else to the process is
confidence. He says, "We use the software to test each phase of the
model as it is conceived and assembled on the screen. This gives us
confidence that we have a good solution for the customer. Then, seeing the
proposed design in successful simulated operation gives the customer
confidence to commit funds to the machine's production."
Lewis adds, "A project can move forward faster and on budget
because everyone in the design and production team has -- again, the key
word -- confidence in what they are doing. Communication is unambiguous
and at a level such that everyone, including administrative staff and
contractors, understands how the design will work."
According to Lewis, "It's not always obvious, but one of the
greatest impediments to progress can be lack of confidence in a design on
the part of engineering and production, management, and, most importantly,
the customer. Seeing the virtual machine at work in living color on the
screen, and being able to literally put it through its paces before
risking large financial commitments is enough to speed the
sales-to-delivery process by up to 80%."
Another confidence-building advantage of the simulation approach is
that MMA gains an accurate upfront understanding of a proposed machine's
production costs, which helps offer competitive pricing to their customers
while still assuring profits.
Fast Customer Design Review
Using Dynamic Designer/Motion, MMA engineers can automatically check
for interference between parts through the assembly's complete range of
motion. They can then quickly and easily capture animation files, which
can be e-mailed anywhere and viewed on any PC to show how the machine will
look and operate. For example, the MMA design team can send an animation
of a proposed machine for review by a customer in Europe within ten
minutes of completing the Dynamic Designer/Motion simulation.
MMA engineers also use Dynamic Designer/Motion to test machine parts
for forces, stresses, and deformation. This helps assure that parts are
correctly sized, material waste is minimized, and strength requirements
are safely met.
Once the "virtual machine" has been completely designed and
tested on the computer, drawings can be automatically generated directly
from the model's parts, then plotted for distribution. "In this
way," notes Lewis, "we've shifted our main focus from creating a
drawing to creating a design -- a design that we can be sure will
work."
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