How to add weight to a Pickup Pinewood Derby Car
The heavier your pinewood derby car, the faster it will go. Most race rules limit the weight to 5 oz so you want your car as close to the limit as possible. The Pickup block will need about 2.0 oz of additional weight to bring it up to the 5 oz limit.
You should install the weights in your car before you paint it.
Before adding the weights to your car, put the car block, wheels, axles and any other accessories that you will be adding to your car on a scale. Then add the weights until the total is 5 oz. (paint will add very little to the weight of your car). If you are using the lead weights, trim the length of the three weights equally until the total weight is 5 oz. You can cut the weights with a hack saw, coping saw or wire cutters.
When your car is complete, weigh it again. If it is over 5 oz, drill a few holes in the bottom of the block about an inch behind the front axle to remove some wood.
Below are two suggestions for adding weights to your pinewood derby car.
Lead Wire Weights
Lead is inexpensive, dense and is easy to work with but lead is toxic. Always use gloves when working with lead and make sure that none of the lead is exposed after you install it in the block.
You will need:
- One set of Lead Wire Weights
- Drill and 5/16" drill bit
- Wood putty
- Hack saw, coping saw or wire cutters
- Using a 5/16" drill bit, drill three equally spaced holes in the back of the car. Drill high enough to go over the rear axle slot. The depth of these holes should be slightly deeper than the length of the weights.
- Insert the weights in the holes. The end of each weight should be at least 1/8" into the end of the block. This will leave room for the wood putty. Drill the holes deeper if needed.
- Weigh the block, wheels, axles and weights again. Adjust the amount of weight if needed for 5 oz.
- Seal the weight holes with wood putty. Allow to dry in a warm place for 12 hours.
- Sand the wood putty until smooth and flush with the car block.
You can now paint your car and add the wheels and axles.
If the completed car is less than 5 oz. drill one or more shallow holes in the bottom of the car in front of the other weights and insert some of the leftover lead weight in the holes. Seal with wood putty.
Tungsten is very dense but it is more expensive than lead. The density gives you a speed advantage because more of the weight can be placed farther back on the car.
You can use a combination of cylinders and a flat weight for optimum results.
You will need:
- Six Tungsten Cylinders
- One Fine Tune Cylinder
- One Tungsten Plate
- Drill and 3/8" drill bit
- Wood putty
- Screw driver
- Using a 3/8" drill bit, drill three equally spaced holes into the bottom of the block behind the rear axle but forward enough that the screw used by the Tungsten Plate will not contact the center cylinder. Drill deep enough to hold two cylinders each. If your block only needs five cylinders then drill the middle hole just deep enough to hold one cylinder and any needed Fine Tune Cylinder. The holes will be close together so we recommend starting the holes with a smaller bit or use our Weight Guide (see below).
- Insert the weights in the holes. The end of the weights should be flush with the bottom of the block (the Tungsten Plate will hold the cylinders in place). Drill the holes deeper if needed.
- Weigh the block, wheels, axles and weights again. Adjust the amount of weight if needed with the Fine Tune Cylinder. Drill holes in front of the rear axle to hold the Fine Tune Cylinder if needed. The Fine Tune Cylinder can be cut with a scissors or knife.
- Insert the weights in the holes. Attach the Tungsten plate to the bottom as far to the rear of the block as possible but still overlapping the cylinders. Place the weight so that the screw will not come into contact with any of the cylinders.
- If you installed weights in front of the rear axle, fill these holes with the wood putty. Allow to dry in a warm place for 12 hours then sand the wood putty until smooth and flush with the car block.
- Paint your car and add the wheels and axles.