Get Tips and Tricks from the Pros
Lubricate the Wheels
No matter how much you polish your axles, there will still be friction as they make contact with the wheels. A key step in making a competitive car is to further reduce that friction by lubricating the wheels.
Rub a small amount of graphite onto the wheels using a soft piece of cloth – graphite with molybdenum typically works best.
Ways to Add Weight
To maximize potential energy, your car should weigh almost five full ounces.
Remember these two key rules:
• Put as much of your weight in the rear of the car as possible
• If you put the weight too far back, your car will pop a wheelie as it goes down the track, or it might even jump off the track
Tips for balancing the weight:
• If the track you are racing on is a very smooth track, place your weight so that the center of gravity is 3/4″ in front of the rear axle.
• If the track has bumps and rough spots, move the center of gravity forward so that it is located approximately 1″ in front of the rear axle. This placement will give your car a little more stability when it hits those bumps.
Bake the Block
Did you know that even the initial block contains weight that can be moved to the rear? All wood blocks contain water, and water is a very heavy substance. Before you do anything else to your car, put the wood block in your kitchen oven and bake it. This will cause most of the water locked up inside the wood to evaporate.
With that water gone, you will be free to put more weight near the back of the car. Children should not perform this task without adult supervision.
STEP 1: Preheat the oven to 250°F.
STEP 2: Place the block on a cookie sheet and then right into the oven for 2 hours.
Caution: Be sure to keep a close eye on what’s going on in the oven. If you neglect the block, you could start a fire or overbake the wood. If the wood begins to turn brown or black, you have the temperature too high.
Oops... Fixing a Mistake
If you accidentally make a mistake in shaping your derby car and are left with unwanted dents or dings in the wood, fill them with a lightweight spackle instead of heavy wood putty. This will make your car lighter, allowing you to add more weight to the back of your car for added speed.
Polishing the Axles
Axles straight from the kit have a set of small burrs, or imperfections, below the axle head. If you leave these burrs on your axles, they will create friction whenever the wheel and the axle head touch, which will slow down your car. Remove the burrs using your Dremel Rotary Tool.
STEP 1: Insert an axle into your Dremel Rotary Tool, leaving about 5/8″ exposed. Notice the burrs.
STEP 2: Turn your Dremel Rotary Tool on low speed. Then, use a small file to remove the burrs. Use light pressure on the file so you do not damage the axle.
STEP 3: Rotate the file to remove the burrs under the axle head.
STEP 4: Apply sandpaper to the axle. Sand the entire axle, including the inside surface of the head. This step should take about 15 seconds.