So, here is how to build a fast pinewood derby car in 6 steps:.
Step 1: Reduce friction to speed up your car
Your pine wood derby car moves from the force 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. Finding the sources of friction and findingways to reduce it is the secret to a fast car. Here are some ways to reduce friction and increase speed.
Step 2: Lubricate Axles and Wheels
The easiest way to reduce friction is to lubricate the surfaces that cause friction. Lubrication is an essential part of pinewood derby racing. Purchase a tube of dry PRO Graphite with moly and shoot it onto the axle shaft and inside the wheelbore. Spin the wheel so the graphite works in. You will immediately notice a significant improvement in the wheel speed as it turns on the axle after applying graphite.
Another good lubricant, if your rules allow, is Nyoil. Nyoil is a highly refined thin-film oil. Apply only one or two drops to your axles. Nyoil will reduce friction throughout your race because it stays on your axles long after graphite has dropped offin the later heats. See more details on this new lube idea in Graphite and Lubes.
Step 3: Prepare and Polish Axles - Essential for Speed
Your wheels turn on Pinewood Derby Axles. If you are using the Cub Scout BSA Grand Prix car kit, then these axles are nothing more than nails. One of the biggest sources of friction iswhere the axles and wheel surfaces meet. It is important to make your axles as smooth as possible. The burr under the nail head will grind into the plastic wheels severely slowing your car. Be absolutely sure that the burr under the nail headand on the nail shaft is filed off. Once these areas are sanded off, polish the nail shaft and underside of the head to a mirror like finish.
Step 4: Balance and tune your Wheels to Maxiumize Speed
Imperfections in your Pinewood Derby Wheels cause friction in many areas. Sanding your wheels, however, can be tricky. If the wheels are not precision sanded, you can actuallymake matters worse. Turning your wheels on a lathe are the best way to remove imperfections and get a uniform, balanced and finely tuned pinewood derby wheel. The wheel is secured in the lathe and spun at a high speed, then it is sanded orshaved with a tool attachment.
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.
Step 5: Add Weight to Increase Inertia
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 block, along with the wheels and axles, is up to 5 oz. Don't wait until race night to weigh your car! When I manage pinewoodderby races, everyone is always a rushed at the last minute to weigh their cars to add (or subtract) weight. If you wait until the last minute, you may not have time to make your car the optimal weight. Don't wait to add weight!
Step 6: Steer your Car Straight (or into the rail?)
Steering a pinewood derby car is challenging. First, gently roll your car along the a floor that has straight lines, so you can see which way it is steering. If it veers to the right or left more than 2" over 4 to 6 feet, the axles are crooked.Just like steering a car, you need to adjust the steering on your pinewood derby Car. To adjust steering, you must adjust one or more of the axles so the car rolls straight.
Below are 3 ways to steer a pinewood derby car so it rolls straignt, or into the rail if you want to build a rail rider car.
- Re-drill the axle slots or drill new axle holes using the PRO Driller.
- Mark the 12 o'clock position on the axle head and then gently bend the axle about 2 degrees. You can then turn the axle left or right with a needle nose pliers until your car rolls straight. This technique can be tedious andit is very difficult to bend the axle so slightly and then turn it. The axle can be easily scratched or damaged and then they need to be replaced. For these reasons, we don't recommend bending your own axles.
- Purchase pre-bent axles. This not only saves time and eliminates the risk of damaging your axles, they are perfectly bent in the precise spot on the shaft. Pre-bentaxles are available with a 1.5 degree bend for steering your car and 2.5 degrees for canting your axles. These axles have a convenient easy-trun screw driver slot in the axle head so you can easily turn them with a flat blade screwdriver.
Consider making a Rail Rider, whereby your car is deliberately steered gently into the rail to avoid banging back and forth on the center guide rail. But be careful! You must learn How to make a Rail Rider properly,or you can actually make your car slower! Rail riding is a proven technique but it will NOT work if you don't have a center guide rail and it will slow your car if have a wooden track. Read our guide to dertermine if rail riding will workfor you.
