Have your scout draw a design on paper then cut it out and attach it to your block of wood.
Use your imagination. Be creative. Shape has the least to do with winning. A beaver driving a log or even a pickup truck is more interesting than a wedge and will be just as fast. The aerodynamics of a small block of wood doesn't mean much in thirty feet.
Keep the car a full seven inches. It has to do with the physics of velocity and length of travel of the weights, but shall not exceed 7 inches.
The maximum overall width (including wheels and axles) shall not exceed 2-3/4 inches. that the rules give you. This will allow the wheels to travel farther before hitting the center strip.
The minimum width between the wheels shall be 1-3/4 inches so the car will clear the center guide strip on the track.
The minimum clearance between the bottom of the car and the track surface shall be 3/8 inch so the car will clear the center guide strip on the track.
The wheel-base (distance between the front and rear axles) may not be changed from the kit body distance of 4-1/4 inches.
Leave a lot of wood in the back of your PWD car to put in the weights.
Use the groove closest to the end of the block of wood as the rear axle.
Avoid designs with a pointed nose. A pointed nose will make it difficult for your Pinewood Derby car to rest on the pin at the starting gate. It may also cause your Pinewood Derby car to get bumped around when the pin drops.
2. Cut and Shape Your Design:
Use a coping saw to cut out the rough shape of your Pinewood Derby car. You can also ask a responsible adult to make these cuts using a power tool.
Use sand paper to smooth your car’s edges and shape it to your design. An adult can also use a rotary tool or other tool to help you.
Wheight your car, remember the goal is 5oz, use all the parts of your car including wheels, that way you will know how much extra weight you will need.
Get the weight as close to the 5 ounce limit as possible. Add the last little bit of weight with lead tape from the golf shop. This can be trimmed with scissors at the last minute. Remember, the official scale may not weigh the same as yours.
What kind of weight? Tubular weights can be sunk in the sides; flat weights, like those sold at Hobby Lobby, Michael's & Council stores can be attached to the car bottom if it is carved in a bit. Incremental weights ( with pre-marked grooves) are easier to snap off into the size you need. Some folks just use BB's, nuts & bolts, etc., but these must be glued so that they can not move. No movable weights or mercury are allowed.
Use the round weights found at the hobby shops and craft stores. This allows us to stick the weights out the back of the car. We paint them and tell everyone that they are jet engines or tail pipes. What they really do is allow us to get the weights as far back as possible.
Keep the weight low on the car and in the center (Left/Right of the car). Put the weight just in front or behind the rear wheels for less wheel chatter.
Sanding makes the paint stick better, and also makes the car go faster. You can use 120 grit sandpaper to start.
Paint the car with the a paintbrush or with spray paint, making a thin coat.
Many thin coats are better than 1 thick coat, as it has less chance to run or drip and spoil the looks of the car.
Let the car dry between coats, and sand after the paint has dried.
The final sanding should use 2000 grit sandpaper.
After sanding, you can attach whatever decals or lettering you might want.
Put the wheel on the nail axle and put it on your car, maybe tapping lightly with a hammer. Make sure they are aligned perfectly straight. You can test the alignment of your axles by pushing your car across a smooth floor or table. It should roll smoothly in a straight line.
Going Straight
1. Put the axle in at a downward (5-10 degrees) angle. This provides two benefits. The first is the only the inside edge of the wheel is in contact with the track. This seems to make the car go straighter with less wobble. The second benefit is that the wheel rides to the outside of the axle and doesn't come in contact with the body. This tip is for experts only. First timers have trouble getting this right. If you have to email me to ask about it, you shouldn't do it.
2. Axles must be in straight front to back. That is square to the body. True the axles, don't trust the slots! If you have one, use a drill press to ensure all axles are straight. One of the front and two of the back should be measured to be the same height.
3. After pressing in the axles, test the car for crooked wheels...roll it on the floor. If the wheels are on straight, the car should roll 8-10 feet in a fairly straight line. Should the car turn left or right, you need to tinker with the axle placement without removing them from the car body, until it rolls straight.
4. Do not put the axles in at the top of the groove. Put them in at the middle. This lifts the car off the track a bit more and reduces the chance of rubbing on the center strip.
5. Glue the axles in place. Nothing is worse than having the wheel fall off as you cross the finish line.
6. Once you match a wheel and axle together with graphite, keep them together. They wear into each other as a matched set.
6. Lubricate the Wheels:
1. Use graphite only. Oil damages the paint and collects dust. I'm told that the graphite works better than the new white Teflon.
2. Break in the wheels by spinning them with lots of graphite.
3. Right before check-in, fill the wheels wells with graphite and cover with stickers like a hub cap. You can paint the 1 inch stickers in a contrasting color. It looks great!
4. Put a small drop of white glue where the axle goes into the car body and put powdered graphite on it there. That causes less friction if the wheel should rub against the car body.
5. Other than the good polishing of the axles, dump the axles and wheels in a ziplock bag with some graphite and shake them for a few days prior to the race. That way the wheel and the axles are as slick as can be.
