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When it comes to making a super fast Pinewood Derby car for Cub Scouts, there’s a ton of noise and bad advice. You don’t have to leave it to luck, though a little certainly helps. Here’s some great advice–using real science–to make a winning Pinewood Derby car.
First things First
Always–ALWAYS–check with your Pack rules and make sure you follow them. Rules vary from council to council and even pack to pack. Even though the local scout shop sells snazzy wheels, my kid’s pack only allows us to use the wheels that come in the BSA kit.
Weight is Key
Pinewood Derby cars need to weigh in at 5oz and not a smidge more! But it’s also critical to get your weights in the right spot. You want the car’s center of gravity towards the rear axle to maximize kinetic energy.
Yep, we’re using science! You’ll want that weight about an inch in front of the rear axle–any further back and you risk popping a wheelie.
And hey, don’t take my word for it! Check out NASA scientist Mark Rober’s post in Boys Life!
What Kind of Weight Should You Put in a Pinewood Derby Car?
In the old days we just melted down lead fishing weights, but we don’t really want the kids handling toxic materials, do we? Instead, you can pick up tungsten or zinc weights like these at Amazon, the scout shop or your local hobby shop. Ideally, you’ll get weights that are adjustable–good weights can be cut or snapped off in fractions of an ounce.
You can also use coins to safely add weight to your car. Pennies weight about 2.5 grams (that’s 11 pennies to an ounce) and quarters weight about 5.6 grams, or 5 quarters to an ounce.
Weights can be hidden inside a hollowed section of the car or glued to the top and made part of the decorations.
How to Weigh a Pinewood Derby Car
Not everyone has a super accurate scale for measuring their Pinewood Derby racers. A kitchen scale might be good enough, but did you know the post office has a free scale you can use?
Yep, just take your car to the self service kiosk and “pretend” to mail it. Since my post office is open all night, I’ve gone in after hours and used the scale.
*Isn’t that scale the cutest?
You want to make sure the Pinewood Derby car “rides the rails.” So instead of trying to get the car to roll exactly straight, have it drift into the track’s center rail a bit.
The axle nails can be bent upward a bit to reduce friction–here’s a video to show you how.
You can also reduce friction by raising one wheel off the track just a bit. Double check your pack’s Pinewood Derby rules to make sure this is allowed! The car will move faster if you have to get only three wheels moving. Just lift that 4th wheel a little so it still looks good on display.
Click Here to watch a (former) NASA engineer build a super fast Pinewood Derby car.