Some high school students deliver newspapers or wash dishes to save money for college. The teens on the reality-based TV show Design Squad try to outbuild each other.
On our final episode of Season 2 we divided our young cast into two teams, and gave them identical sets of parts for off-road go-karts: front and rear suspension, steering, engine and rear drive train, seats, seat belts, and brakes. The teams had to design the chassis, roll cage, and side impact protection, taking into consideration how their designs would affect handling and vehicle weight.
Purple Team took a modular, design-as-you-go approach, thinking about the chassis, roll cage, and side impact protection separately. They focused on a machine that was easy to get in and out of, because the racers had to stop and pick up flags along the course.
Green Team designed the chassis, roll cage, and side impact protection as an integrated unit. This meant that Green used much less metal and kept the weight low — but they had to be careful with the design to ensure that the overall structure would be strong enough to survive intense off-road battering. Green’s racing crew members were smaller and more willing to bump shoulders during the race, so Green designed a narrower chassis than Purple, which further reduced the kart’s weight. (Any guesses yet as to which team was making better design decisions?)
The teams also considered the wheelbase design. Maneuverability would be key in an off-road course. Purple chose a longer wheelbase because of the improved ergonomics for taller racers. Green chose a shorter wheelbase, which allowed for tighter turns, and which gave them better ground clearance on the bump-ridden course.
On race day, it became clear that Green’s shorter wheelbase, narrower chassis, and lighter weight resulted in a nimble off-road racer. Purple’s longer wheelbase made it more difficult to complete tight turns for quick maneuvers, and their heavier kart took longer to get back to full speed after slowing down for a turn. With all of these factors playing into the outcome of the race, it’s no surprise Green crossed the finish line first.
For videos of the go-kart competition, visit pbskids.org/designsquad.