Public Pinewood Derby - Cub Scout Pack 473 (Bloomington, Minnesota)

What is the Pinewood Derby?
Boys get a block of wood from a pine tree from which they will make a car to be raced at our annual
Pack 473 Pinewood Derby (January). The basic supplies are provided for those who join our pack and there are plenty of helpers to get you started in December at Den meetings. It's all about the pride in building something and the fun of racing. Of course there are prizes and the opportunity to race for District and Council prizes too -- but in our Pack it's about learning, sportsmanship and a lot of FUN for everyone. The creativity of the boys is always outstanding!

Boys will have access to the tools (and supervising adults) to help them bring their ideas to reality.
You don't need to go out and buy kits, paints, decals and extra supplies unless you choose to.

And for all those parents who REALLY want to race too, we have a family division.
So let the boys really build their own car even... if the paint isn't perfectly even or it's not exactly how you'd do it.

How can you build a fast pine wood derby car?

Answer: To build a fast pine wood derby car, you need to reduce friction.
Friction is the enemy of speed. Reduce friction, increase speed.

Friction DOWN, Speed UP

Your pine wood derby car moves from the pull of gravity and is slowed down from friction. Friction acts like brakes. Reduce friction and your car goes faster. Increase friction and your car slows down. Friction DOWN, Speed UP It's as simple as that. Finding the sources of friction and finding ways to reduce it is the tricky part. Here are some ways to reduce friction and increase speed.

Lubrication

An easy way to reduce friction in your pine car is to lubricate the two surfaces. Purchase a tube of graphite and sprinkle a little on the axles and in the wheel bore. Spin the wheel so the graphite works in. You will immediately notice a significant improvement in the wheel speed as you turn it after applying graphite.

Derby Axles

Your wheels turn on axles. One of the biggest sources of friction is where the axles and wheel surfaces meet. It is important to make your axles as smooth as possible. Be absolutely sure that the burr under the nail head is filed or sanded off. Once that is sanded off, polish the nail and underside of the head to a mirror like finish.

Derby Wheels

Imperfections in your wheels cause friction in many areas. Sanding your wheels, however, can be tricky. If the wheels are not precision sanded or lathed, you can actually make matters worse! Wheel imperfections can also make your car veer left or right. Once again, lathed wheels will remove mold imperfections so each wheel rolls perfectly straight.

More Weight, More Inertia, More Momentum

Your car moves down the track from the force of gravity. If your car is too light, it will have less inertia in the flat part of the track. Be sure your car weighs as close to 5 oz as possible. Find someone with a scale, purchase an inexpensive scale or weigh your car at the Post Office. Add weights until the car with the wheels and axles is up to 5 oz. Don't wait until race night to get this right! When I managed our pinewood derby race, there was always a scramble just before the race to weigh cars and bring them up to 5 oz.

Making your pine wood car go straight

This can be tricky. Roll your car along a smooth floor like the kitchen. If it veers to the right or left too much, the axles are crooked. Just like steering a car, you need to adjust the steering on your Derby Car. To do this, you must adjust one or more of the axles so the car rolls straight. You can do this by re-drilling the axle holes and re-inserting the axles, or you can gently bend the axles.