Learning how to make a pinewood derby car is a classic project that combines creativity, basic physics, and family fun. This guide provides a clear, step-by-step process to build a car that is not only looks great but performs well on the track.
Crafting a pinewood derby car involves shaping, weighting, and finishing a small block of wood. While the official rules can vary by pack or district, the core principles of building a fast and stable car remain the same. With the right approach, you can create a competitive entry.
How To Make A Pinewood Derby Car
This section breaks down the entire process into manageable stages. You will start with understanding the rules and gathering materials, then move through design, cutting, sanding, weighting, axle preparation, and finally, painting and detailing. Following a logical sequence is key to a successful build.
Gather Your Official Kit And Tools
Your journey begins with the official BSA Pinewood Derby kit. This contains the essential components: a block of pine, four nails for axles, and four plastic wheels. Do not substitute these parts unless your specific rules allow it, as this could lead to disqualification.
You will also need a basic set of tools. Having these ready before you start will make the process smoother and safer.
- The official BSA Pinewood Derby kit (block, wheels, axles)
- Pencil and paper for design sketches
- A coping saw, band saw, or sharp utility knife for cutting
- Sandpaper (multiple grits from coarse to very fine)
- A drill and bits for weight holes (optional but recommended)
- Graphite powder or liquid lubricant (check rules for legality)
- Primer, paint, and clear coat
- Fine-grit sanding block
- Car body weights (tungsten putty, cylinders, or lead weights)
- Super glue or wood glue
- A ruler or tape measure
- A small hammer or vise for axle insertion
Study The Rules And Design Your Car
Before you draw a single line on your block, obtain and read your pack’s official rules. Key restrictions often govern maximum weight, minimum width, wheelbase length, and ground clearance. Ignoring these can result in a car that cannot race.
With the rules in mind, sketch your car design on paper. Consider both aesthetics and aerodynamics. A sleek, low-profile design often has less air resistance. Trace your final design onto the wooden block using a pencil. Remember to mark where the axles will go and where you plan to add weight.
Common Pinewood Derby Design Templates
- The Wedge: Simple and aerodynamic, with weight pushed to the rear.
- The Rail Rider: Designed to run along the center guide rail of the track for stability.
- The Bullet: Rounded and narrow, mimicing a projectile.
- The Classic: A traditional, recognizable car shape with a defined hood and trunk.
Cut And Shape The Wooden Block
Secure your block in a vise or clamp it firmly to a work surface. Using your saw, carefully cut away the excess wood outside your penciled lines. Take your time with this step; you can always sand off more material, but you cannot add it back.
After the rough shape is cut, begin the sanding process. Start with a coarse-grit sandpaper to smooth out the major cuts and shape the curves. Progress through medium, fine, and finally very fine grits. The goal is a perfectly smooth surface with no visible tool marks. This prep work is crucial for a professional-looking paint job later.
Drill Holes For Weight Placement
This is a critical step for speed. The maximum weight limit is almost always 5.0 ounces. Your goal is to build a car that weighs exactly 5.0 ounces on race day. The wood block and wheels alone will be far too light, so you must add weight strategically.
Drilling holes allows you to place weight low and towards the rear of the car, which improves stability and potential energy. Use a drill bit slightly smaller than your weight cylinders. You can drill from the bottom or the rear. Test fit your weights as you go, checking the car’s weight on a scale frequently.
Prepare The Axles And Wheels
The factory nails (axles) and plastic wheels have imperfections that create friction. Reducing this friction is one of the most effective ways to gain speed. First, polish the axles. Remove the burr from the nail head and then polish the shaft with fine sandpaper or a metal polishing compound until they are mirror-smooth.
Next, address the wheels. The inner hub and the tread often have mold seams. Gently sand these seams away. You can also slightly bevel the inner hub to minimize contact with the car body. Never sand the outside tread that contacts the track, as this is usually against the rules.
Proper Wheel Alignment Techniques
Misaligned wheels cause drag. To ensure they run straight, you can use an axle alignment tool or a simple jig. The goal is to have all four wheels touching a flat surface evenly and with the axles perfectly perpendicular to the car’s body. A small dab of glue in the axle holes after final alignment will lock them in place.
Add Weight To The Maximum Limit
With your holes drilled, it’s time to add the weight. Tungsten putty or cylinders are popular because they are dense, allowing you to add a lot of weight in a small space. Fill the drilled holes with your chosen weights, securing them with a dab of glue if necessary.
Continuously weigh your car on a precise digital scale. You want to get as close to 5.0 ounces as possible without going over. A pro tip is to leave it 0.1 ounces under during assembly. This gives you a buffer for the final layer of paint and clear coat, which will add the final fraction of weight.
Apply Primer, Paint, And Details
Once the car is shaped and weighted, wipe it down with a tack cloth to remove all dust. Apply a thin, even coat of sandable primer. Let it dry completely, then lightly sand it with very fine sandpaper. This creates a perfect surface for your paint.
Apply your chosen paint in several thin coats, allowing each to dry fully. Thin coats prevent drips and runs. After the color is solid, you can add decals, racing stripes, or numbers. Finish with 2-3 thin coats of clear acrylic spray to protect the paint and add a shiny finish. Let the car cure for at least 24 hours before handling.
Lubricate And Perform Final Checks
On race day morning, apply your lubricant. Graphite powder is the traditional and widely accepted choice. Put a small amount into the wheel hub and on the axle, then spin the wheel to work it in. Avoid over-lubricating, as excess powder can attract dust.
Perform a final inspection. Weigh the car one last time on the official scale. Ensure all wheels spin freely and the axles are secure. Give the car a gentle test roll on a flat surface to check its alignment. Your pinewood derby car is now ready for competition.
Advanced Tips For Competitive Racers
For those seeking an extra edge, these advanced techniques can shave precious fractions of a second off your time. They require more precision and should be done carefully.
First, consider raising one front wheel. By bending the axle slightly or using a raised axle hole, you can lift one front wheel off the track. This reduces rolling friction from four points to three, though it must be done in a way that doesn’t violate rules about all wheels touching the ground at the start.
Second, focus on precise weight distribution. The ideal is to have the heaviest weight as far back as possible, but keep the car balanced so it doesn’t wheelie or become unstable. Some builders aim for a balance point about 1 inch in front of the rear axle.
Common Mistakes To Avoid
- Ignoring the official rules for your specific race.
- Rushing the sanding process, leading to a rough finish.
- Adding too much weight early and having to drill it out.
- Forgetting to polish axles and remove wheel seams.
- Using paint that is too thick, which adds uneven weight.
- Gluing the wheels to the axles, preventing them from spinning freely.
- Not letting paint and clear coat dry completely before handling.
Pinewood Derby Car Frequently Asked Questions
What Is The Best Shape For A Pinewood Derby Car?
The best shape is typically a sleek, wedge-style design that is narrow at the front and wider at the rear. This shape minimizes air resistance and allows for optimal rear weight placement. The exact dimensions should always conform to your local rules.
Where Should You Put The Weight On A Pinewood Derby Car?
Weight should be placed low and to the rear of the car, approximately 3/4 to 1 inch in front of the back axle. This maximizes the car’s potential energy as it sits on the starting ramp and helps maintain traction and stability down the track.
How Do You Make The Wheels Faster On A Pinewood Derby Car?
You make the wheels faster by reducing friction. Polish the metal axles to a mirror shine, remove the mold seams from the plastic wheels, and use a dry lubricant like graphite powder. Proper wheel alignment is also crucial for reducing drag.
Can You Use Any Kind Of Paint On A Pinewood Derby Car?
You can use most acrylic or enamel model paints. Spray paints often give the smoothest finish. Avoid overly thick paints, as they can add uneven weight. Always use primer first for better adhesion and a more professional result.
What Is The Trick To A Fast Pinewood Derby Car?
The trick is a combination of factors: reaching the maximum weight limit (5.0 oz), placing that weight low and to the rear, minimizing wheel and axle friction through polishing and lubrication, and ensuring perfect wheel alignment. Attention to detail in each step is what leads to speed.