It’s that time of year when a young scout’s thoughts turn to… Pinewood Derby racing. This annual event challenges scouts to design and build a race car from a block of wood, four plastic tires and four nails. They can go for a car that is quickest on the track, one that looks the best and/or is the most original, or a little of both.
Pinewood Derby racing began on May 15, 1953 in Manhattan Beach, California. Don Murphy was a pack Cub master. His son was too young to compete in the popular Soap Box Derby so he came up with pinewood derby racing as an alternative. The miniature cars use gravity, the same power source as the full-size Soap Box Derby racers, but were much easier to build. Pinewood Derby racing was immediately popular and was adopted the same year by the Boy Scouts as an official activity.
Pinewood derby racing is about learning to do your best, enjoying quality time with a parent, project planning, being creative, problem solving and sportsmanship. Each scout starts with the same basic kit and can carve and decorate the car as he chooses. Cars can vary from basic wedge shapes to whimsical objects to replicas of real vehicles.
The two main forces that affect pinewood Derby racing success are gravity and friction. Gravity is good; it is the force that propels them down the track. Friction and wind resistance are the problem; they create drag and slow the car. Racers strive to reduce any sources of friction and air drag and maximize the potential energy in their car.
Here’s some basic design hints:
- Use an aerodynamic shape; wind resistance is a minor but not insignificant factor. Plus the car will look cool.
- Leave room in the back to add weight; you want to be as close to the race maximum of 5 ounces as possible and you want the weight near the back for a longer gravity pull.
- Cut out the basic profile and then use sandpaper or rasps to perfect the final shape. Sand with progressively finer sandpaper grits up to 180 or 220 to get a nice smooth finish.
- Finish with spray paint, model paint, poster paint, markers, colored tape, decals or whatever you choose. A final coat of clear spray lacquer will yield a nice shiny look.
- Polish the wheels and axles to be sure all the surfaces are smooth. White toothpaste on a pipe cleaner works well for inside of the hubs.
- Assemble car and test to be sure it rolls straight. Usually you can correct problems by turning the front axles about ¼ turn at a time until the car rolls straight.
- Lubricate the hubs and axles liberally with graphite and roll the car gently to ‘break in’ the graphite.
The building Pinewood Derby building process should be as much fun as the actual event. Prepare the best car you can and then go racing.
Remember: ‘Gravity is your friend. Friction is your enemy.’
