ONE OF OUR WINNING TROPHIES! AND IT'S A BIG ONE!

Imagine the look on your son or daughter's face when they get presented with one of these!

Getting Started!

Secrets To Success
A Step By Step Guide To Winning The Pinewood Derby

By Joe Raccio

 

Introduction:

I’m not going to waste your time getting into great detail of why I have chosen to write this pamphlet. Let’s just say out of love for my son, and my desire to please him, as well as my desire to win, led me to learn through trial and error, some facts and tricks to getting the most out of my pinewood derby experience, and hopefully yours. I know there are other documents out there, but the fact is I have consistently won using my methods and I’d like to pass them on to you. I think we all have the same needs. Achieving the ultimate goal of winning the pinewood derby without the disappointment of a sad little boy or girl. Good Luck, and keep racing!

Rules:

Before we begin Check out your local rules and regulation. Most organizations provide you with a kit that contains instructions. Some may provide you with only the raw materials. AGAIN, CHECK YOUR LOCAL RULES! The basic rules usually involve:

Car length
Car width (including wheels)
Weight of car (usually 5 oz and use every once)
Shape of wheels (check rules for what’s permissible)
Shape of axels (check rules for what’s permissible)

First Things First, Some Things You’ll Need From Derby Monkey Online Your Local Hobby Shop:

Pinewood Derby Kit
Weights (tubular)
Wheel Mandrel
Metal File (Rat-tail, or Triangular)
Graphite Lubricant (Hob-E-Lube)
Spray Paint and Primer
Sandpaper (medium, fine, very fine, extra fine, super fine)
Polishing Paper or Pumice




1. Where To Begin?

If this is your first time constructing and/or designing, your own pinewood derby car the task can seem very intimidating. Don’t let it get the best of you. Soon your block of wood will begin to take shape and actually resemble something that looks like a car. The first thing you need to do, even before you take the block out of the box, is to start thinking of what shape you want your vehicle to be. You can find all kinds of stencils and shapes simply by going to any Internet search engine (I prefer Google.com) and typing in the words, “pinewood derby templates.” Right there before your eyes you’ll have access to literally thousands of stencils or templates that you can print out free of charge and trace onto your wood car body! It’s as easy as that! We usually print out a variety of templates and let my son pick out the design he likes! This will be his or her introduction of how to design their car. Try not to get too hung up on the shape of the car. Keep it simple, especially if you’re a first timer. Try to keep the shape aerodynamic which will lessen wind resistance (we’ll talk more about that later).

2. Time To Cut

NOTE: PLEASE WEAR SAFETY GLASSES WHEN CUTTING OR DRILLING

Now that you’ve chosen your design, and traced your design on your block of wood, it’s time to cut your block of wood into the shape of your car. You’ll need some tools. If you have woodworking tools such as a scroll saw, or band saw . . . great! This will make things easier, but if you don’t a coping saw will do the job. You’ll also need a drill with an adjustable drill head. Several different sized drill bits, several different grains of sandpaper (for rough finishing, and fine finishing), polishing paper, measuring devices (such as a ruler, spaces, etc.), and weights. Now you’re ready to go.

 If you’re working with a younger child you may want to handle this part yourself, otherwise work with your child, and carefully begin to cut out your car from the template you transferred earlier. A vise may help at this point but is not necessary. Once you’ve completed the cutting process, and you have a “rough cut” of your car, it’s time to “shape” your design.

3. Shaping

Shaping begins with using the different grains of sandpaper we spoke of earlier. The idea is to make your car exterior as smooth as possible thus lessening the wind resistance and preparing the car for painting. “Lessening wind resistance,” you may ask. This is a 5 oz block of wood. Remember we are dealing with the complete package here. Moreover, in a pinewood derby race 1/100th of a second could make the difference between winning and losing! Every nano second is one in your favor! Begin with medium grain sandpaper between 80-120 grit, and finish off with fine grain sandpaper between 150-180 grit. You’ll also want to round out all the edges and corners on your car. Not only will this make your car more aerodynamic, and less wind resistant, but will give your car a sleek, 21st century appearance. Any child should be able to fully participate in this step, and will get great satisfaction, as their car becomes a smooth, aerodynamic car body. Typically, when you can close your eyes and run your fingers over the smooth surface as if you’re touching nothing, you’re done!


4. Drilling And Spacing the Wheel Base

We consider the spacing of the wheelbase a very crucial factor in producing a winning pinewood derby car. Lengthening the wheelbase or elongating the wheelbase as far as allowable, in our experience makes for a faster pinewood derby car. IT’S ALWAYS WORKED FOR US! You car will come with a precut slot to put you axels. If allowable by rules, fill those slots with wood putty and sand smooth. Take the front edge of the wheel and place it against the front edge of the chassis, the inner hub of the wheel should be flush with the bottom edge of the chassis. Now with the axel or pencil mark the base through the center of the wheel hub. This is where you will drill the new axel hole. The drill bit you use should be smaller than the diameter of the axel. You want the axel to fit very tightly into the new axel hole. You do not want to have to glue the axel in the hole. Repeat this step exactly, on the remaining three wheels. Sand smooth with your fine grain 150-180 grit sandpaper. You car should really be starting to take shape and we are now ready to “prime” the chassis.



5. Priming or Sealing

Some believe this procedure isn’t necessary. We believe that if you want a nice smooth professional looking paint job then sealing or priming the wood for painting is the only way to go. Use a good quality hobby paint such as Testors, which comes in 3oz spray cans. The small 3oz spray cans are easy to use and inexpensive for quality paint. We usually use an enamel-based primer, white, which usually takes a little longer to dry, but we’ve found it to have the best quality. Use primer generously so it fills the pores of the wood, and seals the body, but don’t over due it, you want a nice smooth finish. We usually put several even coats on instead of one thick coat. Let dry overnight if possible, than proceed to the painting process.

6. Painting

This is when you car really begins to take shape, and begins to take on a personality all its own. Painting your pinewood derby car is no different from painting a real automobile. Hopefully, you’ve already selected your color or colors. We’ve always tried to keep it to one solid color, with a different color-racing stripe, lightning bolt, something of that nature. It’s just really a personal thing and how creative you want to be. We’ve always used a high-gloss enamel-based Testors type of paint in the 3oz spray can. Spray paint gives you a much more profession appearance then hand paint. We get a piece of 2X4 or plywood and place two nails in the rear and one in the front in a triangular patter to support the rear-end and nose of the car. Two nails in the back and one in the front, this will give you easy access to all angles of the car. Spray a nice even coat over the entire car. Remember several nice even coats are the way to professional type finish. After spraying a few coats on, let paint dry completely. The next day inspect car for any blemishes on the paint surface. If need be, sand blemishes with very fine girt sandpaper, if not continue to paint car with several more smooth even layers. Allow paint to dry again overnight. Once totally dry, we like to spray the car again with a high-gloss clear coat finish. This will make your car standout, with a beautiful professional like shine. Allow drying 24-48 hours before attaching axels and wheels. In the mean time, it’s time to get the axels and wheels ready for racing.

7. Axel Polishing

This is probably the most tedious, yet most important task of producing a winning pinewood derby car! You will need to have some polishing equipment, such as a metal rat-tail file, extra fine, and super fine sandpaper, pumice polishing paste, and perhaps a piece of steel wool. Each axel needs to be inspected and polished to a mirror shine. Why? Because it will reduce friction and friction is the ultimate enemy in a pinewood derby race. This separates the men from the boys. Put your hard work into polishing the axels, wheels, and you’ll be that much closer than the next guy will to coming home with the big trophy. The rest is just cosmetics; this is what wins the race!

De-Burring The Nail Head

If using the nails that come with your kit like most of us do these nails when machined and have burrs on them from the process. These burrs need to be removed (see figure #2). These burrs if not removed will rub up against the wheels and cause friction, which will slow your car down. Remember friction is the enemy here and we want to eliminate as much as possible.

figure # 2








To begin insert nail into the chuck of your cordless drill or electric drill if you don’t have a cordless, and tighten so it’s good and snug (see figure #3). If possible, place drill in a vice to keep drill level. Start the drill with the axle spinning and use light pressure on a rat-tail or triangular file to remove burr and slightly taper nail head (see Figure 4). Tapering the nail head will help to reduce friction of the nail head rubbing against the wheel.

figure # 3







figure # 4











Polishing The Nail Axel, First Stage:

Now that we’ve de-burred the head of the nail, it’s time for the polishing stage. The portion of the nail where the wheel will ride on the axel is again scared by the milling process of making the nail. We need to get this part of the axel as smooth as possible to reduce the friction against the wheel. This an important step and we need to finish with a mirror type shine. Cut extra fine sandpaper into ¼ inch strips to begin the first stage of polishing. Secure the nail into drill chuck and start drill. Sand as shown in figure 5 below. You may dampen the paper in water to enhance the process. You’ll want to polish the inside of the nail head as well as the shaft, as the nail head may be scared from the de-burring process earlier. Two or three strips of paper should be plenty to complete this process.

figure # 5

Polishing The Nail Axel, Second Stage:

Once the first stage is complete, we are ready to move onto the second and final stage. Cut your super fine sandpaper into ¼ inch strips and proceed. Secure the nail into the drill chuck and start drill. Sand as shown in figure 5 below. Polish with good pressure until you achieve a mirror like finish. Axel polishing with our “ultimate polishing paper” is now complete. At this point, we recommend taking the axels and placing them in a zip lock baggie and covering the axels with your Hob-E-Lube OR MONKEY DUST powered graphite (which can be purchased at you local hobby or DERBY MONKEY ONLINE.) You will also need this when we “lube” the axels and wheels later on).

figure # 5

 

Now with the second stage complete we’re ready for the third and final stage with the pumice we spoke of earlier. Usually pumice comes in a powered form. Simply mix with a little water to form a dense paste. You don’t want it too thin so mix a little water at a time. Start drill. Apply pumice to a soft cloth, touch the cloth to the axel (figure 6), and polish the axel until it has a mirror shine. At this point, we recommend taking the axels and placing them in a zip lock baggie and covering the axels with Hob-E-Lube OR MONKEY DUST powered graphite (which can be purchased at you local hobby or DERBY MONKEY ONLINE. You will also need this when we “lube” the axels and wheels later on).

figure # 6 cloth with pumice

8. Wheel Smoothing

Smoothing of the wheels is just as essential as polishing the axels. Like the axels, the wheels that come with your kit are not completely smooth. The wheels are made through a plastic injection process, and the wheels are left with molding marks and burrs where they break them off the mold. This will slow your car down, because it will add friction to the wheel against the track. Look closely at your wheel and you will see these marks yourself, and know what we mean when we say, “smooth the wheel.” Remember we need to eliminate as much friction as possible, so we need to “smooth” the wheel, inside the hub as well as outside the round. “Smoothing” inside the hub is important, because this is the part of the wheel that will be rubbing or causing friction against the axel. “Smoothing” the outside or round of the wheel is important because this is the part of the wheel that will be rubbing or causing friction against the track itself.

Let’s Get Started, First Stage:

You’ll need a wheel mandrel (available at your local hobby shop OR DERBY MONEY ONLINE), which is a device to hold the wheel into the drill chuck. Attach wheel to mandrel and attach mandrel into drill chuck (see figure 7). Cut a strip of extra fine sandpaper 280-320 grit, start drill and lightly touch sandpaper to wheel. Hold in place and let the drill do the work. Sand the outside of the wheel until smooth. If wheel has raised lettering sand that smooth as wheel. This will lessen wind resistance (remember we are talking between 1/100th to 1/1000th of a second between winning and losing, this can make a difference). Continue First stage until wheel is smooth.

figure # 7

Second Stage:

Now with super fine 360-600 grit sandpaper, repeat the process from the first stage.

Note: For the second stage dip cut strip of super fine sandpaper in water to further smooth all surfaces of the wheel. Surface of wheel should now be very smooth and shiny and move to Third Stage, sanding the hub.

Third Stage:

You’ll need to bore out the inside hub of the wheel. Using a penknife or a kitchen paring knife hold the wheel in one hand a carefully bore or remove the burrs of the inner hub (see figure 8). You don’t need to bore a lot in this process, just enough to remove the burrs. Be careful, we don’t want to damage the wheels. Now with a piece of steel wool (because it’s easy to move through the entire hub), or your extra fine sandpaper sand the inside of the hub until smooth. Your wheels are now complete. Place them in zip lock bag, with axels with Hob-E-Lube graphite powder until ready to attach to car body. We are now ready to “weight” the car.

figure # 8

9. Weight

The weight plus gravity is what’s going to help propel your car down the track. The more weight you have, the faster your car will go. Check, your local rules but most derbies’ we’ve participated in allow a maximum weight of five ounces. You will want to use every once you can.

The question that comes up most often is where the best place to distribute the weight is. Some people insist it’s best to weight the car in the front. What we’ve experienced is front weighted cars get a good jump out of the start gate, but lose a considerable amount of momentum as they propel down the track. Cars that are weighted in the rear, are slow getting out of the start gate and heavy in the rear-end as they propel down the track. So where’s the best place? Through our trial and errors, we’ve discovered that the best place to weight the car is right at the balancing point of the car. We’ve found our car to start quickly and then actually get a burst of speed as it comes down the track and through the straightaway.

Finding the balancing point is actually quite easy. On a flat surface take a round pencil and lay your car bottom down on the pencil. Slowly move your car left or right until the chassis balances on the pencil. When the chassis balances you’ve found the balancing point. Mark it with a pencil. You’re going to drill a hole right through the balancing point. You can purchase tubular weights at your local hobby store or Derby Money Online. You’ll need to drill a hole about 3/8 of an inch in diameter (see weight package for exact diameter size of weights) through the balancing point. You’ll want to start with a smaller drill bit and work you way up to the proper size to avoid splitting the wood. The tubular weights are slotted so you can cut them with a hacksaw. Push one of the weights through the whole you drilled, measure, remove and then cut the weight to size. Now drill two more holes, one a 1/8th of an inch to the left, and one a 1/8th of an inch to the right, of the balancing point. Push the weights in the new hole, measure, remove, and cut to size.

Before permanently installing your weights it’s time to bring you car chassis, the weights you measured and cut, your axels and wheels to be weighed. Bring extra weights. Usually your local hobby shop, grocery store or post office will be more than happy to let you use their scale. Remember we want as close to 5 ounces as possible. If you need more weight add some of the extra weight that you brought with you to the scale to see how much more you need to add. If you have, too much weight cut off the excess weight from the weight you had previously measured.

Once back home, before setting the measured and cut weights back into holes, add a little white glue to hold weights firmly in place and prevent weight from shifting. Fill holes with wood putty, smooth and allow to dry. Touch up wood putty with a small paintbrush to match the color of your car. You car is now weighted to precision and it finally time to put it all together.


10. Putting It All Together

You’ve done the hard part; now let’s put it all together.

Let’s start with the axel holes. Take some of your graphite lubricant and with your fingertips and work it into the paint around the holes. Just enough so, when we attach the axels and wheels, the hub of the wheel will rub against the graphite and not against the bare paint.

Installing The Axels and Wheels

Now put the axels through the wheels and insert the axels into the holes we drilled earlier. You don’t want to push the wheels all the way in against the chassis of the car. We went to leave a little space of about 1/16th of an inch between the wheel hub, and the car chassis (see figure 9). To achieve this a simple butter knife from your kitchen cupboard will do the trick. Place the tip of the knife flat between the hub and the chassis and press the axel and wheel firmly against the knife blade. Repeat this process on the other three wheels. Wheel and axel installation is now complete.

butter knife
figure # 9

Balancing And Alignment

Almost there. Now put car on level surface and with a ruler (preferable metric for more accurate measurement) measure the space between the surface and bottom edge of each corner of the car chassis. Adjust each axel up or down until all four corners are level, and all four wheels are touching.

Finally, slightly adjust the front left axel so the wheel is not touching the surface. That’s right; we are only going to have three wheels touching the race surface. Why? That friction thing again. One less wheel touching the race surface means less friction on the race surface resulting in a faster car. Now add some of your graphite-powdered lubricant to the axels between the hub and the chassis, between the axel head and the wheels, and spin each wheel for about five minutes each to work it in. Put car on flat surface and give it a little push. Car should move easily ten to twenty feet in a nice straight line. If need be adjust axels accordingly.

Right before you weigh your car at the official weigh-in, add a little more graphite to the areas mentioned above, and give each wheel a few spins.

That’s it you’re finished. Good Luck and Happy Racing!!