Friday, May 4, 2007

The Last Pinewood Derby

Nathan is my only son, and what a fantastic boy he is. Nathan had his 10th birthday at the end of March, at which time he became a Webelos Scout. He was quite excited to move up another notch on the ladder of life. In Cub Scouting, Spring always means Pinewood Derby. With Google on his side, Tom armed himself with ideas for making the cars fast, and helped with cutting, wheel assembly, and weighting. Nathan decided on the design, and did all sanding and painting. Nathan's cars are perhaps not as fancy as some, but what they lack in aesthetics, they more than made up for in speed.

Before our foray into the world of Pinewood Derby Engineering, I hadn't given any thought to what made a car fast. Obviously, friction is bad. Anything that reduces friction makes the car go faster. What surprised me were the number of speed-em-up strategies that could be applied to a simple creation made from a block of pine, four wire nails, and plastic wheels. Here are a few:
  • Sanding the wheel axles (wire brads) to remove tiny burrs that catch on the tires and increase friction.
  • Applying powdered graphite to the space between axle and tire.
  • Inserting axles at 90 degree angle to car body, to ensure straight tracking. Tracking must be tested to make sure that it followed a straight line, to prevent rubbing against the side of the track, which produces friction, which slows down the car. Adjust axles as needed.
  • Angling one front wheel slightly upward so that it doesn't touch the track. Three wheels in contact with the track produce less friction than four wheels. (I personally am not convinced of this, since the same amount of weight will be distributed among three wheels, thus increasing friction on each wheel, thus net friction will be unchanged. However, since I was not consulted for my expert opinion, I kept my mouth shut).
  • Weight distribution is also important. The farther back on the car the weight is placed, the faster it will go. I could explain why this is so, but it would require diagrams and several paragraphs, and since it is too early in the morning for that much effort, you'll just have to take my word for it. If you desire more details, please email my Pinewood Derby Engineer husband at

Nathan's first derby car (left), painted black with flames on the hood, sported vaulted nuts to provide the needed weight. It took second place in the pack -- not bad for the youngest Cub Scout in the pack! Nathan was proud, dad was pleased, and the car and trophy were displayed proudly on his dresser for many months.

2006 produced a red car of similar shape, with coiled lead fishing weights attached in front of a flared spoiler. This car also took second place overall in the pack, and fastest car in the Bear Den.

For 2007, Tom and Nathan decided to go a new direction with the car design in one last effort to produce a champion car. As mentioned above, weight distribution is very important. In order to put maximum weight at the back of the car, the pine block was cut very thin. A drill press was used to create 90 degree holes for the axles. The flat shape inspired the skateboard motif, and yes, that is C3PO hanging ten with the help of a little hot glue. A stack of weights was added to bring the creation up to the allotted 5 ounces, and wallah! -- a champion was born.

Kinda gnarly looking, isn't it? This car finally earned Nathan the title Pinewood Derby Champion... at least is would have, except that for some reason, this year, the Cubmaster decided to award prizes within dens only, rather than an overall champion. So while Nathan was officially only the Webelos champion, his car beat the Wolf and Bear champions, so I'm claiming Pack Champion as well. And nobody can stop me. So there.

Here is the proud boy holding his winning droid skateboard.

Could he get any cuter? I sure love this kid.


  1. I think that you can claim all of the above. let someone just try to stop you...i'd pay money to see it so keep me posted. nathan is a cutie and you can tell him that this nelson household is proud of him as well :)

  2. That car is awesome! Who knew C3PO could race a car?

  3. first, i want to know who this person "peacekeeper" is, and also christina,
    C3PO had to bend over because he was to tall to fit through the finish line, so he wasn't realy driving. also, if I could have done it without breaking the rules, I could have streched his arm out so the other cars would give him a boost.

  4. That is the coolest pinewood derby car that I have ever seen!!! Way to go!!!

  5. Yeah, that is a pretty sweet car. By the way... did you ever get your 5 bags of doritoes, Nathan?

  6. what five bags of doretos? Oh, those ones. no i didn't get them.

  7. aunt jessica, that is a weird name for you.