Here are some friendly hints for building a Pinewood Derby car!
We like to see a good clean event, where every scout can win at least one race. The races are made up from several heats. We have a four lane track and each car runs on every lane once. The computer will average out the four times and make up the fastest car. That means the car finishing first, may not be the fastest car. It's all based on time, so your scout may have a hard time understanding they are racing the clock, not the other cars.
Words to live by...
There are other awards to win besides the fastest car. On raceday, we will give out awards for the fastest looking, coolest car, best paint job, and most original design. Our scouts vote on the winner before the race. The winners of those awards have a car they can be proud of...even if they lose every race.
Some may disagree, but the car is more of a model than a race car. The car will only race once and spend more time on a display stand. Because of that, it's important that your scout is proud of their design, almost as much as speed. If you have a limited amount of time building your car, consider a large effort in apperance. Or, be creative on your design.
At the end of the race the most important lesson for our scout is to display good sportsmanship. That goes for all winners as well as losers. The value to our event is spending time together while building a car.
Worth its weight in gold...
The best tips for building a fast car is all in the weight, wheels, axels, and alignment.
Weight: The weight should be as close to 5oz (142 grams) as possible. The cars are propelled by gravity and released to free-fall down the track. The heavier you make the car, the faster it will fall with more force. Everyone has their opinion about weight placement. However, more people agree that the car should balance perfectly just in front of the rear wheels. Depending on your design, that means weight maybe added to the front or back.
Wheels: The wheels need to spin smoothly and not skip along the track surface. The intent for sanding the wheels is to remove imperfections caused through manufacturing. If you open the box and look carefully at the wheels, you'll see a spot where the wheel was removed from the plastic mold. The scout shop and hobby stores sell a tool used for sanding wheels. The bit installs into your drill, so you can slowly spin the wheel on sandpaper. Be careful not to over sand causing the wheel to be damaged or disqualify your car from racing. Polish the wheel using fine grit sandpaper in steps, perferred in this order: 400, 600, 800, 1000, 1500, then 2000 grit sandpapers. Finish by reducing wheel friction by rubbing dry graphite into plastic wheel. Repeat steps for all four wheels
Axels: You can repeat the same step used in sanding and polishing the wheels for the axels. Just like the wheels, there are manufacturing imperfections on the nail. If you look closely at the nail, you will see excess metal under the head of the nail and grooves from the stamping process. Place the pointed end of the nail into your drill, and spin the nail allowing you to sand and polish spots that make contact with the wheel. Finish the process with working graphite into contact points. Place the wheel on the nail and spin. You should be able to count at least 20 seconds before the wheel stops rotating. Continue to work graphite in all contact points until the wheel spins for more than 20 seconds.
Alignment: Last but not least, alignment... This could be the most critical stage to car building. The fastest path between two points, is a straight line. The car is fastest if it rolls straight!! Trying to align the wheels so they don't create unnecessary friction while rolling straight, is the hardest part in building the car. Your goal is to install the axels into the car so if you push the car, it will roll straight. Good Luck!!
BE CAREFUL!!! The design of your car must pass OUR Pack 1720 rules and inspection process. Some hints and car building ideas will disqualify your car from the race. Please download OUR PACK Rules and PWD Race Inspection Forms to verify if your car will qualify for the race. Please contact a Pinewood Derby Chair Member, to answer any questions
Here are some helpful links, if you want more information:
Official BSA Website!!
