Flying Solo by Design
Affordable Software Enables Engineer to Spread his Wings
Many engineers long to escape the nine-to-five grind and apply their talents as
independent consultants. Toronto-based Gary Warburton is one who was able to
capitalize on his specialization – thanks to affordable personal engineering tools
– and fly solo.
Warburton’s highly specialized skills are not common, but are essential to the
handful of companies in the world that require his particular brand of
engineering services. He devises aerospace structural testing systems, having
worked with such aircraft manufacturers as Goodrich, Landing Gear, Bombardier,
Ultimate Biplane, and Diamond.
“In the industry, they call it ground testing, which makes sure that these systems
work on the ground before they get in the air,” explains Warburton. “Sometimes
we’ll make simulations to put massive loads onto the airplane, and see what
happens during various extreme flight conditions which shouldn’t ever exist, but
we still have to prove them out.”
When an aircraft company provides Warburton a test specification, he must
create a test methodology that will deliver accurate performance data. Some
performance data he can obtain from the client, but very often a new test
requires the design of mechanical equipment that replicates the interaction of
physical forces on the airframe.
These tests are essential for any aviation application. “I’ll work on anything from
an Airbus A380, the double-decker jumbo jet built in Europe, down to the light
five-seater aircraft I’m working on now,” says Warburton. He has even taken the
principles of flight down to a smaller scale. Toy company SpinMaster enlisted
Warburton to create a prototype for its line of AirHogs, the extremely popular
remote-control stunt planes.
A Different Kind of Analysis
One thing that had to be scaled back while working independently was the
budget for CAD. CATIA, a complex mechanical CAD package from Dassault
Systemes, is a popular choice for aviation companies, but it ranks among the
most expensive CAD software ever developed for a PC.
“Most of my customers use CATIA, and I am a certified CATIA operator.
Unfortunately, I can’t afford CATIA because the price is a bit exorbitant,” admits
Warburton. “When I went on my own, I started looking for a CAD package and
came across Alibre Design. I started using it probably five or six years ago.
From there, I started building up a sort of independent style of work, rather than
being focused solely on CATIA. Now I work in Alibre Design, and deliver my
data in CATIA-compatible formats.”
Alibre Design is a 3D parametric solid modeler that, even at its most expensive
level, sells for only about 10% of the price of CATIA. The mechanical design
package has formed the centerpiece for Warburton’s workflow for both analysis
and test equipment design.
Warburton imports clients’ CATIA data into Alibre Design through neutral file
formats such as STEP or IGES, or using Adobe’s 3D version of Acrobat to do the
conversions. By exporting STEP files from Alibre Design, he can perform
structural simulations on 3D models within standalone analysis programs.
For finite element analysis, Warburton exports the 3D assembly into Multiframe
or ALGOR. “For the actual kinematics, I’ll use Alibre Motion, which does pretty
good motion simulation,” he says. Alibre Motion, included with Alibre Design
Expert, is capable of both kinematic and dynamic analysis of mechanical
assemblies. Warburton simply establishes the parameters of movement and
Alibre Motion animates the mechanism. By adding in hypothetical load
information into the program, Warburton can calculate reaction forces and
various other physical variables that influence the control surfaces of the
airplane, like mass-moment or simple inertia.
Making the Numbers
To create designs of test machinery for his clients, Warburton relies on Alibre for
the nuts-and-bolts of mechanical engineering. He uses another affordable
modeler, Rhinoceros, when he needs to interface with the complex curves of
airplane surfaces. To share his ideas with clients, Warburton takes advantage of
Adobe’s universal lightweight file format, 3D PDF, which can be read with any
Acrobat viewer. He exports a 3D PDF directly from Alibre Design and emails it to
his clients.
Warburton’s clients send his completed equipment designs to outside fabrication
shops. Once the machine is made, Warburton starts generating performance
data.
“One of the last designs I created was for a wear test machine, used to
determine the wear characteristics of steel and aluminum,” he explains. “I used
Alibre Motion to determine the input torque requirement so that accurate motor
sizing could be completed. This enabled the system to maintain the correct
velocity and simulate an accurate wear profile.”
A New Independence
In recent years, the growth of technology has resulted in engineering tools
making great strides in capability, while at the same time, affordable pricing of
these tools from companies like Alibre has virtually eliminated the barrier of
software cost for individual engineers who want to strike out on their own. Now
engineers have the option of working for one company, or for many.
Warburton works for several clients, but generally focuses on one project at a
time. Typically, the battery of ground tests needed for aircraft development is
an extensive process.
“When you go out on your own, you’re very much dependent on the small jobs
that come through. Now, those small jobs sometimes turn out to be several
years worth of work, as was the case with my last customer. My current
customer might be a couple of years worth, too – I don’t know at this point,”
says Warburton. “When you don’t know how long projects will last, you can’t
always go out and buy something like a CATIA license. Alibre Design has
definitely helped me go out on my own, mainly due to the fact that I could
actually afford it.”
At the end of the day, even for the most advanced analysis and equipment
design there are affordable alternatives to the big-ticket software brands, which
provide comparable functionality for far less money. And the affordable software
that Gary Warburton has based his business on has passed with flying colors.
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A photo-rendered image of a hydraulically actuated CAM Plate.
Model of a new canopy for the 20-300 Ultimate biplane. The aircraft, currently under
construction, will fly within the next year or two. Modeled using a combination of Alibre Design
and Rhinoceros.
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