The pinewood derby is an annual racing event held by the Boy Scouts of America where Cub Scouts, with the help of an adult, build their own model cars from a block of wood and race them on a track. The goal is to build the fastest car that will win the race down the track. Building a fast pinewood derby car takes some careful planning, expert craftsmanship and aerodynamic design. Follow these tips to learn how to build a quick, streamlined car that has the best chance of crossing the finish line first.
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Choose the Right Design
The design of your pinewood derby car can have a major impact on its speed. Here are some design factors to consider:
Shape
An aerodynamic shape like a wedge or teardrop can help reduce wind resistance as the car moves forward. Avoid flat sides or right angles that can cause drag. Taper and round off the front and back of the car.
Weight
The maximum weight for a car is 5 ounces, but building it lighter can increase speed. Aim for 3-4 ounces by hollowing out areas like the underside. Just be careful not to compromise structural integrity.
Wheel Position
Placing the wheels closer to the rear skews the weight distribution and creates less friction by lifting the front. This allows the rear wheels to propel the car farther.
Center of Gravity
A lower center of gravity where the car’s weight is concentrated can improve stability and prevent tipping. Keep heavier elements like weights and decorations low.
| Design | Benefits |
|---|---|
| Aerodynamic shape | Reduces wind resistance and drag |
| Lightweight | Increases speed and acceleration |
| Rear-weighted | Puts more power behind rear wheels |
| Low center of gravity | Improves stability and prevents tipping |
Prepare the Wheels and Axles
The stock wheels and axles that come in the pinewood derby kit create a lot of friction. To reduce friction, upgrade to high-performance wheels and polish the axles:
Wheels
– Look for aftermarket wheels made of lightweight plastic or aluminum rather than wood. Graphite wheels can also increase speed.
– Ensure wheels have a rounded tread and no flat spots. Conical or cylindrical shapes work best.
– Check that wheels align perfectly perpendicular to the axles to prevent wobbling.
Axles
– Polish axles with fine grit sandpaper to remove any imperfections that cause friction.
– Apply a thin coat of graphite lubricant to axles before inserting into wheels.
– Make sure axles are positioned parallel to reduce wheel vibration.
Proper wheel alignment, reduced friction, and no wobble are keys to a fast car. Investing in quality wheels and polishing the axles helps maximize performance.
Add Weight Strategically
Though you want your car to be as light as possible, strategically placed weights can improve speed. Here are some tips:
– Add up to 5 ounces of weight on the rear underside of the car, behind the rear axle.
– Use dense materials like lead or tungsten weights available at hobby stores. Avoid heavy materials like steel that add too much weight.
– Secure weights with glue or screws so they don’t shift during the race.
– Experiment with weight placement to find the right balance of speed versus stability.
Adding just a few extra ounces to the rear gives it more momentum while keeping the car light. Carefully position weights to optimize speed.
Apply a Smooth Paint Job
The paint job on your pinewood derby car should be flawlessly smooth to prevent air resistance:
– Sand the wood body thoroughly with fine grit sandpaper to remove any roughness.
– Fill imperfections with wood putty and sand again for an ultra-smooth surface.
– Spray paint using light coats of high gloss paint to create the slickest surface.
– Avoid paint that feels gritty or bumpy when dry. Wet sand and reapply if needed.
– Consider polish like car wax as a final step to make the paint as slippery as possible.
Take the time to perfectly prep and paint the car body. This reduces drag for maximum speed. The glossier the paint, the faster it will go!
Tune the Car’s Setup
Finely tuning the wheels and axles of your assembled pinewood derby car can shave off valuable seconds:
Wheel Alignment
– Check that all 4 wheels make full contact with the track surface.
– Verify wheels are perfectly perpendicular to the axles.
– Make minor adjustments by adding paper shims between the axles and car body.
Reduced Friction
– Confirm axles spin freely within the wheels with minimal friction.
– Re-polish axles and lubricate again if needed.
– Consider lubricating wheel treads lightly with graphite powder.
Neutral Position
– The front of the car should sit exactly level when placed on a flat surface.
– Add weight strategically if the front naturally pitches up or down.
With fine tuning, you can dial in the optimal wheel setup for low friction and alignment. This allows the car to roll straight and true.
Race Day Tips and Strategy
Follow these final tips to get the best performance on pinewood derby race day:
– Carefully pack and transport your car to prevent any damage en route.
– Perform a final wheel alignment, weight placement and lubrication check before the race.
– Use graphite powder sparingly on the wheels and axles right before each heat.
– Stagger your breathing as you place the car on the track to avoid moving it even slightly.
– Release the car gently without any downward force once the race starts.
– Stay positive! Have fun and cheer on fellow racers, win or lose. The process is what matters.
With patience and practice, you can fine tune the ultimate pinewood derby car. But remember – building the car with your child and enjoying the experience together is what really counts. Follow this guide for your best shot at pinewood derby glory!
Conclusion
Building a fast pinewood derby car takes precision design, quality construction and care in the details. With an aerodynamic shape, polished axles, lightweight materials and strategic weight placement, you can create a quick, streamlined car that excels on race day. Pay close attention to the wheels and axles, paint job and fine tuning to maximize speed. But above all, make the pinewood derby a fun learning experience to share with your child. That’s the most rewarding victory of all.