Pinewood Derby Racing Stategies
I have listed the following observations based on my experiences participating and organizaing countless pinewood derby races. Some of these ideas were also rumors heard from others. Believe what you want, discard the rest!
When designing your car take into consideration the
- Wheel alignment,
- Axle and wheel lubrication.
- Weight distribution.
- Car design.
- A high gloss finish.
- Polish the axles. First with a 400 grit if you have a really bad spot. Then a 600 grit, and then a jewelers rouge. Finish off with a chrome/metal polish. Reducing friction is the goal here.
- Have only three wheels touching the track. Raise a front one slightly. There is less friction with 3 wheels rolling than 4.
- Do not put the axles in at the top of the groove. Put them in at the middle. This lifts the car of the track a bit more and reduces the chance of rubbing on the center strip.
- Position the axles in at a downward angle (5-10 degrees). The first benefit is only the inside edge of the wheel is in contact with the track. This seems to make the car go straighter with less wobble. The second benefit is that the wheel rides to the outside of the axle and don`t come in contact with the body.
- True the axles, don`t trust the slots! If you have one, use a drill press to ensure all axles are straight. This can also be accomplished by taping the axle in place, rolling the car forward to see if it rolls straight. If it does not roll straight, turn the wooden dowel a quarter turn and try rolling again. When the car rolls straight and true, glue the dowel in place.
- One of the front and two of the back should be measured to be the same height. After pressing in the axles, test the car for crooked wheels...roll it on the floor. If the wheels are on straight, the car should roll 8-10 feet in a fairly straight line. Should the car turn left or right, you need to
tinker with the axle placement without removing them from the car body, until it rolls straight. When they are properly positioned, glue the axles in place.
- Nothing is worse than having the wheel fall off as you cross the finish line. Once you match a wheel and axle together with graphite, keep them together. They wear into each other as a matched set.
- Debur the wheels. Take off the flashing and seam that was produced when the wheel was molded with a 600 grit or better sandpaper. Inside as well as out. Sand any bumps off the wheel the sandpaper. Metal polish will restore the gloss. Be careful not to break any rules your race has regarding wheel modification. (Narrower wheels have less friction and are better, but often disallowed). Don`t sand too much or you`ll create a flat spot. Sand by hand not in the drill. Heat from the high speed of a drill will damage the plastic wheel.
- Lubrication is the key in many designs. Powdered Graphite is one type although there are many other liquid lubricants that may gain an advantage, but some race rules prohibit the use of liquid lubricants.
- Wax the wheels with furniture polish. Make sure the polish does not contain a solvent of any sort.
- The ways to increase potential energy are to raise the center of gravity (weight) higher above the track and increase the weight. Reduce friction where any two moving parts of the car or track touch each other where the car is in contact with the air.
- Have extra axles and wheels on hand. You never know when your car may be the one dropped by your son as he shows off his handiwork.
- Have a derby tool kit handy. It should include superglue, sandpaper, a drill, extra screws for your weights, extra weights, a small screwdriver. You may not use it, but it will make you the most
popular person at the event.
- Transport your car in a shoebox. Dropped cars are unfortunately a too common experience.
- Add LOTS of graphite right before check in.
- Explain to your son that running the car along the floor prior to the race will cause it to lose!
- Don`t pray to win, pray not to cry if you lose!