For their first major design project, freshman
mechanical engineers at Johns Hopkins had to
think low-tech. The students were assigned to design, build
and race model cars that could not use
conventional motors — or even a single battery. Each
vehicle could be powered only by two mousetraps
and six rubber bands.
Last week, in a hallway of the Computational Science
and Engineering Building on the Homewood
campus, 20 student teams put their motley car creations to
the test. Many of the vehicles boasted
bodies made of wood slabs, wheels made of DVDs and other
parts made of balsa and foam board. The
challenge for each car: traverse an 11-foot-long curved
course while maneuvering around two soda
bottles filled with sand. The requirements to win: accuracy
and speed. The prize: bragging rights and a
good grade.
When the checkered flag descended, the winners were
Michael Rizzoni, Nick Salzman and Alex
Strachen, the three students who built and raced a vehicle
called Awesom-O. Supervising the event
was course instructor Allison Okamura, an associate
professor of mechanical
engineering. The
competition, she said, was more than an entertaining
exercise. While working on their cars, the
students learned about design approaches, potential and
kinetic energy, friction, prototyping methods
and other topics relevant to mechanical engineering.
One of the key challenges was designing the
self-propelled vehicles to turn their wheels and
travel around the two slalom course obstacles. Some
students, including the winners, solved this
problem by mounting rods atop their vehicles. The rods
bumped the obstacles and forced the front
wheels to steer the cars around the bottles. Yet another
solution was a special mechanism designed to
switch the steering angle depending on how far the vehicle
traveled.
The best-designed vehicles veered around these
obstacles and cruised over the finish line.
Other entries performed less successfully, running out of
power just inches from the starting line or
slamming into one of the obstacles.
In an added nonengineering twist, the cars were
required to use a pen, paintbrush or other
implement to mark a pattern on the white paper covering the
hallway floor. These machine-made
markings will be included in the exhibition We're Not Alone
at the Mattin Center March 23 to April 12,
part of the Art on Purpose project called Everyone an
Artist? Exploring the Meaning of Being an
Artist.
To watch a video from the event, go to:
www.jhu.edu/news/audio-video/cars.html.
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