The clearance under a pinewood derby car is an important factor to consider when building and racing these miniature vehicles. The ideal clearance is typically around 3/8 to 1/2 inch. This allows the car to smoothly glide over the track without scraping or getting stuck. Having too much clearance can result in instability and loss of control, while too little clearance can cause excessive friction and slow down the car’s speed. Achieving the perfect balance of clearance is crucial for maximizing performance and increasing the chances of success in pinewood derby races.
how much clearance under pinewood derby car
Car Length: Maximum 7 inches.
Car Width: Maximum 2 ¾ inches.
Wheel Clearance: Minimum 1 ¾” between the wheels.
Body Clearance: Minimum 3/8” underneath to avoid rubbing on the track.
Do aerodynamics matter in pinewood derby?
Creating an aerodynamic Pinewood Derby car design can significantly reduce air drag. You don’t have to go overboard with complexity; a simple wedge-shaped car instead of the standard block can give you a 14-car advantage at the finish line.
Is it better to have a heavy Pinewood Derby car?
To optimize the speed of a Pinewood Derby car, it is crucial to focus on weight and minimize friction and air drag. Increasing the weight of the car within the limits set by your pack’s rules will enhance its speed. Therefore, it is advisable to maximize the weight of your car.
Reducing friction and air drag is equally important. Ensure that the wheels of your car spin smoothly without any contact with the car’s sides. Additionally, consider polishing the axles to eliminate any imperfections or burrs. To provide lubrication, apply a generous amount of dry graphite.
For additional guidance on constructing a swift Pinewood Derby car and discovering scientifically proven techniques to enhance its speed, explore more tips and resources.
Is a lighter pinewood derby car faster?
Grooved axles tend to perform better than nongrooved axles due to minimizing contact between the wheel bore and axle shaft, reducing friction and slowing down the car.
If smooth axles are required for competition, you can choose between our 4094 and 4097 axles. The 4097 axles are official BSA nails that have been modified to remove crimp marks, beveled the head, and lightly polished. The 4094 axles are flawless clones of the BSA nail with a slightly beveled head. The 4094 axles generally outperform the 4097 axles as the flaws in the latter need to be reduced by reducing the diameter.
For the fastest axles, we recommend the Pro Grooved Stainless Steel Axles (part 4052). These axles have an excellent fit with various wheel brands, including BSA PineCar, Awana, and Maximum Velocity. The two-step shaft design also simplifies installation.
In terms of wheels, lighter wheels are typically faster. This is because less energy is required to start rolling when the pinewood derby car is released. Lighter wheels also allow for better weight distribution in desired locations, rather than compensating for heavier wheels.
Coning the wheel hub can also contribute to a faster pinewood derby car. Coned hubs reduce contact with the car body and focus more on the axle, minimizing braking when the wheel touches the body. Most BSA wheels already have coned hubs, but we offer a ProHub Tool for those that don’t.
To increase tread, we recommend using a 600 or 800 grit wet sandpaper instead of the coarser PineCar supplies sandpaper.
Can a Pinewood Derby car have 3 wheels?
At Maximum Velocity, our extended wheelbase car kits and blocks are drilled in a way that one of the front axles will be slightly raised above the other three axles. Some customers complain that their kit was misdrilled, but the raised wheel is actually part of the design and will make the car go faster.
Building a four-wheeled car with one front wheel lifted may seem silly, but the real question is whether it makes the car faster. This article will explore this topic and provide data to answer this question.
The initial thought is that a raised wheel would reduce friction on the track and between the axle and wheel bore. However, this is not true. The amount of friction present is based on the weight applied and the type of surface coefficient of friction. The amount of surface area is not relevant. Since the weight of the car would be shifted to the three wheels on the ground, the frictional surfaces would be unchanged.
So where does the advantage come from? There are three advantages:
1. Quicker start: By lifting one wheel, the amount of energy needed to start the wheels spinning is reduced by 1/4. Reducing the weight of the wheels will also provide a quicker start.
2. Alignment simplification: Only three wheels need to be adjusted instead of four. Often, only the front steering wheel needs to be adjusted.
3. Elimination of weak wheel: Sometimes, one of the wheels does not spin as nicely as the others. By placing the weak wheel in the raised position, its performance won’t affect the car.
Tests were conducted to prove these advantages. Five runs were made with four wheels on the ground, and five more runs were made with the wheel raised. Both BSA and Awana wheels/axles were tested, and the data showed that using a raised wheel consistently gave an advantage over four wheels on the ground.
To raise a wheel, make sure the center of gravity of the car is behind the midpoint. This ensures that the raised front wheel stays off the ground. Either front wheel can be raised, but it is recommended to raise the left wheel. Drill the raised hole 1/16 inch higher than the other holes to avoid the risk of the raised wheel climbing over the center lane guide. Use the ProBody Tool II to deepen the axle slot on one side or angle one front axle to get a wheel off the ground. Ensure that the raised wheel spins freely and does not act as a brake by touching the center lane guide.
In conclusion, it is often difficult to get all four wheels to touch the ground evenly. Unless prohibited by local rules, raising one front wheel can provide a little extra performance boost.
Source: Pinewood Derby Times Volume 4 Issue 14
Do heavier pinewood derby cars go faster?
Image via Wikipedia
It’s that time of year again. Cub Scouts from schools, churches, and community centers worldwide are gathering for the annual Pinewood Derby race. Our Cub Scout pack has a category specifically for dads, allowing me to build my own car.
Pinewood Derby track at St. Image via Wikipedia
My son, with my assistance on the more difficult and dangerous tasks, is largely responsible for building his own car. I believe it’s important for him to have ownership over his creation. However, I have done extensive research to find the best performance tips to make my car as fast as possible.
Here are some of the tips I’ve discovered:
1. Place all the weight in the back of the car. In pinewood derby racing, weight plays a significant role in speed. Unlike other races, aerodynamics have little effect in such a short race. Tungsten weights are recommended due to their high density.
2. Lubricate the car at the body-wheel friction point. Instead of painting the car at the small semicircle point where the wheels meet the body, sand it to a smooth finish using fine sandpaper. Then, apply dry graphite to reduce friction and increase wheel speed.
3. Pay attention to axle preparation. Use a file and fine sandpaper to remove any burrs or defects near the head of the nail. Some people even spin multiple axles in a power drill to identify the straightest ones and eliminate any with noticeable wobble.
4. Ensure the wheels are ready. Depending on your pack’s rules, polishing or sanding the business side of the wheel can improve rolling resistance. You can also apply powdered graphite to the wheel edge to further reduce friction. If improved wheels are not allowed, you can polish the wheels’ bore with graphite. A good test is to flick the wheels with your finger and see if they can freely spin for 20 seconds.
5. Check the alignment of the wheels once they are mounted. Place a long board and mark off a racing lane about 6 inches across. Put the board on a slight incline and allow your car to roll a few feet. If the car significantly moves to one side or the wheels have shifted, adjust the axle up or down to align them properly.
These are my quick tips for improving the speed of your pinewood derby car. Do you have any speed secrets to share? Let us know in the comments.
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Is a shorter pinewood derby car better?
Modifying the Wheelbase
It is not clear how different organizations determine the location of axle slots on their pinewood derby kits. In the past, the BSA wheelbase was longer than the current standard of 4 3/8 inches. Awana kits use a wheelbase of about four inches, while other organizations and kit makers have slightly different measurements.
However, none of these standard wheelbases are ideal for speed and alignment. The longest possible wheelbase is the best for going straight, as seen in top fuel dragsters. These dragsters have a very long wheelbase and overall length.
Extending the wheelbase of a pinewood derby car can provide several advantages. On ramp-flat tracks, the best speed is achieved by locating the center of gravity (COG) of the car as far back as possible while maintaining stability. This is typically about one inch in front of the rear axle. By moving the rear axle as far back as possible, the COG can also be moved backward, increasing performance.
A longer wheelbase also allows for a greater turning distance. A shorter car turns more quickly, but a pinewood derby car should go as straight as possible, so a longer wheelbase is advantageous.
If you are allowed to modify the wheelbase according to your local rules, there are two methods you can consider.
Method 1: Retaining the existing wheelbase but moving it as far back as possible. This can be done by drilling new axle holes, cutting new axle slots, or using the existing slots. If you choose to drill or cut new slots, locate the rear axle 11/16 inch from one end of the car, and then locate the front axle at a distance from the rear slot equal to the wheelbase on the original block or the maximum allowed in the rules. If you choose to use the existing slots, make a line 11/16 inch from the axle slot and cut through the car on that line. Glue the removed piece onto the opposite end of the car to achieve the desired wheelbase.
Method 2: Creating the optimum wheelbase by creating new holes or slots at a distance of 11/16 inch from the ends of the car. New axle slots can be cut using a ruler, a square, and two hacksaw blades. Alternatively, axle holes can be drilled using a drill press or the ProBody Tool and a hand drill or Pin Vise.
Before making any modifications, make sure to check your local rules regarding wheelbase restrictions. Some rules may require using the kit’s wheelbase, while others may allow for adjustments.
Extending the wheelbase can provide a distinct advantage for your pinewood derby car, so take advantage of this performance enhancement if allowed by your local rules.
Can you put weights under a pinewood derby car?
Product Catalog: Wedge Weight
The Wedge Block is an essential component for maximizing the speed of your pinewood derby car. Most race rules limit the weight to 5 oz, so it’s crucial to get your car as close to this limit as possible. To achieve this, the Wedge block requires approximately 25 oz of additional weight.
To ensure optimal weight distribution, it is recommended to install the weights before painting your car. This will allow for better control and balance during the race.
Before adding the weights, place your car block, wheels, axles, and any other accessories on a scale. Gradually add the weights until the total weight reaches 5 oz. It’s important to note that the weight of the paint will have minimal impact on the overall weight of your car.
Once your car is fully assembled, weigh it again. If it exceeds the 5 oz limit, you can make adjustments by drilling a few holes in the bottom of the block, approximately an inch behind the front axle. This will help remove excess wood and reduce the weight accordingly.
Here are some suggestions for adding weights to your pinewood derby car:
1. Tungsten Putty: This versatile and easy-to-use putty allows you to add weight precisely where you need it. It can be molded and shaped to fit any space within your car.
2. Lead Weights: These small, dense weights are perfect for fine-tuning the weight distribution of your car. They can be easily attached using adhesive or screws.
3. Steel Plates: These flat, thin plates are ideal for adding weight to the bottom of your car. They can be secured using screws or adhesive.
4. Zinc Washers: These small, circular washers can be stacked and glued together to create a custom weight configuration. They are lightweight yet effective in adding the desired weight.
Remember, the key to a successful pinewood derby car is finding the perfect balance between weight and aerodynamics. With the Wedge block and the right combination of weights, you can enhance your car’s performance and increase its chances of crossing the finish line first.
In conclusion, the length of a Pinewood Derby car does not necessarily determine its speed. While a shorter car may have less friction and weight, it does not guarantee a faster performance. The design, weight distribution, and wheel alignment are crucial factors that can greatly impact the car’s speed.
Similarly, having three wheels on a Pinewood Derby car is not recommended. The standard design includes four wheels, and removing one wheel can lead to instability and poor performance. It is best to stick with the traditional four-wheel setup for optimal speed and stability.
When it comes to weight, a heavier Pinewood Derby car does not necessarily translate to faster speeds. While weight can provide more momentum, it can also increase friction and drag. Finding the right balance is key, as an excessively heavy car may struggle to reach top speeds.
Contrary to popular belief, the weight of a Pinewood Derby car does not directly determine its speed. Other factors such as wheel alignment, lubrication, and track conditions play a significant role in determining the car’s performance. It is important to focus on optimizing these factors rather than solely relying on weight.
Adding weights under a Pinewood Derby car is a common practice to fine-tune its performance. By strategically placing weights, racers can adjust the car’s center of gravity and improve stability. However, it is crucial to follow the rules and regulations set by the race organizers to ensure fair competition.
In terms of aerodynamics, while they may have a minimal impact on the overall speed of a Pinewood Derby car, they can still make a difference. Streamlined designs and reducing drag can help the car maintain its momentum and reach higher speeds. While aerodynamics may not be the sole determining factor, they should not be overlooked when aiming for optimal performance.
In conclusion, building a winning Pinewood Derby car requires a combination of factors such as weight distribution, wheel alignment, aerodynamics, and track conditions. It is important to experiment, fine-tune, and optimize these elements to achieve the best possible performance.
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