Pack 618

Pinewood Derby Speed Tips

1. Weight

Weight must be as close to 5.00 ounces ( 142 grams) as possible, but must not be over that. Add weight to the bottom of the car, and locate it slightly more to the rear than the front, and equally from side-to-side. Weight must be flush with the bottom of the wood body, never protruding below as it may damage the finish line sensors.

You can check your weight using a digital kitchen scale or balance made from a yardstick, two cups, and string. If using a kitchen scale, set it for grams to get a more precise reading and check for a weight close to 142 grams. If using a balance, use 57 pennies (must be dated after after 1982, earlier pennies are heavier) as an approximate 5.0 ounce weight in one cup, and the car in the other as shown. Construct the balance as shown below:

First balance the scale with both cups empty, then place the pennies in one cup and the car (or car parts) in the other. Add pennies to the car cup until balanced. Each penny you add is 2.5 grams, or about one ounce per 11 pennies. Only the pack’s scale is the official measure, so you may want to start a little light and add a few screws into pre-drilled holes in the bottom as needed at weigh-in.

2. De-burr and polish axles

Insert axle into an electric drill, and use a small file to remove burrs under the head and crimp marks along the shaft as shown below:

Next, use steel wool (while still in the drill) or very fine sandpaper to polish the surface.

3. Clean Up Wheels

Lay a sheet of fine sandpaper face up on the work table, and rub wheels until raised sidewall lettering is smoothed off. Also check for any bumps or moulding flash on the tread. Sand these until smooth.

4. Body Shape

Aerodynamics are not very important, but simply tapering from front to back may help somewhat:

It is important to keep the “nose” straight across, rather that pointed for two reasons: (1) The pointy nose may slip off of the starting gate, and (2) also may not squarely trip the finish line sensor. You may round the corners a bit, but that’s all. Do anything you want with the back and the sides, except you cannot change the width at the axles.

5. Axle alignment and lubrication

Axles should be inserted to allow a small clearance between wheel hub and body, and should be pre-lubricated with graphite. Also coat the insides of the wheels with graphite. You may want to raise one wheel slightly so that only three wheels touch the ground at a time. To test alignment, give the car a gentle nudge on a smooth floor and check if it tracks straight or pulls to the side. Cover the axles with Elmer’s or super glue to help hold them in firmly once aligned.

6. Do not play with the car when finished!

Although tempting to try racing the car on the floor, wait for after the race to do that. It will only throw out the alignment and reduce the lubricant’s effectiveness.