The derby

When I was growing up I was never involved in the scouting program. So I never had the chance to master the art of the Pinewood Derby. Now that I have kids I don’t want them to miss out on this fun chance to learn cool things and to build and race a Pinewood Derby car. This is Garrett’s second year, meaning my second chance at making a car that can do decently.

As any good Dad would do, I researched the physics and dynamics of the race. What aspects of the car could I improvise and create better. My conclusion was that the friction of 4 wheels was the major cause of drag to the car. To fix it was to remove a wheel. I looked online for this common solution and found many people saying to raise one of the wheels so it doesn’t touch the track but none saying to remove the entire wheel. So my engineering mind went to work to figure out a cool solution. The problem though is that I’m not a mechanical engineer so I never studied in depth dynamics. So my limited exposure would have to do to conceive, design, and build a 3 wheeled car!



I presented Garrett with two options for the pinewood derby, 1) build a regular car and improve on what we learned last year or 2) build an experimental 3-wheeled car that may go faster or may just fly off the track! Without a moments pause Garrett said very excitedly “let’s do the 3-wheeled one!”

I actually did some calculations in my design to try and alter the center of gravity and position the weights to not only keep the car on three wheels but to have the weights positioned to improve the performance and hopefully speed down the track. The finished car was balanced and tested in our home. The result of the testing was that it went straight. The true test came when we went to the derby!



Let me just say that there are some serious Dad’s out there with real intent on winning. Garrett and I had a goal to win but our winning would come if the car stayed on the track and did decent. Plus I must add that even though I did the design work I let Garrett do cut, sand, and paint the car. I tried to get him involved with the whole process to make it his car. I must say that the cars at this derby seemed to be professionally manufactured by Dads intent on breaking land speed records. I mention that just because we had different goals with the race. When we submitted the car for weighing the leader said “I can tell whose Dad is an engineer!” It was kind of funny and Garrett looked at me and said he knows you’re an engineer!



The night of the race, the true test. Garrett was in the second group to race. I was so nervous. I must say running a 3-wheeled car down a track and having your son look at you in hopes we did it right is some pressure. I held my breath as it went down the track! It went smoothly down with no problems…3rd place. Four heats in total before the semifinals and the car made it in 3rd place each time and then 2nd a couple times. Success! The car stayed on the track and did very decently and I count it a win for us. We had a great time through the process and look forward to next year and who knows what kind of crazy ideas we come up with.

-- John