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How to make a fast pinewood derby car





More pinewood derby fun:

Packs around the country are preparing to hold their annual pinewood derby. There are many ways to make your pinewood derby car go faster. Here are some of them.


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GENERAL GUIDELINES FOR PINEWOOD DERBY CAR DESIGN

The possibilities are endless when it comes to picking a shape for your pinewood derby car. Before you begin, consider the following guidelines:

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, and it can create problems for electronic timing systems.

Leave enough wood in the rear of the pinewood derby car so you can place additional weight there. You will end up putting most of the weight in the rear of the pinewood derby car.

Make the maximum weight. Your car should weigh as much as it’s allowed. In most races, that’s 5 ounces. If your car weighs less than that, add coins or other weights.

Be sure that it is very clear which end of your pinewood derby car is the front and which end is the back. In many races, the race officials —- not you -— will actually place each pinewood derby car on the track. Sometimes the officials put the pinewood derby car on the track backward because they can’t tell which end is which.

Choose a design that allows the air to move over and around the pinewood derby car body in a smooth manner. Pinewood derby cars with aerodynamic profiles go faster.


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DESIGNING THE ULTIMATE PINEWOOD DERBY CAR

You don’t have to strive for the “ultimate pinewood derby car” to build a fast car and have fun competing in your pinewood derby. But if you and a helpful adult are willing to put in the extra time and effort, these tips are for you.

Bake the Block: Start with your block of wood, and before you do anything else, bake it in the oven at 250 degrees for around two hours to remove moisture and make it lighter.

pinespeed4Create the Design: Select a fast design. A rectangular car is not an aerodynamic design. The most basic aerodynamic design is a simple wedge. If you don’t have time to design a complex car, a wedge will work just fine.

Cut the Design: Draw the outline of your pinewood derby car on a sheet of paper, cut it out and attach it to your block of wood.

Make a Three-Wheeler: Raise one wheel about 1/16 inch higher so it never actually touches the track. Less friction = more speed. Rules vary from pack to pack, so make sure this is allowed in your race.

Extend the Wheelbase: The front and rear wheels should be as far apart as possible.

Determine Weight Placement: A heavier rear increases speed. Add weight to the rear of your pinewood derby car. Remember to make your car as heavy as the rules allow.

Create Glue Holes: Glue the axles firmly in their holes to ensure that they stay perfectly placed.

Sand the Pinewood Derby Car: Make it smooth to reduce friction.

Lubricate the Wheel Well: The less friction between the body and wheel, the better.


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CHOOSING AND POLISHING YOUR AXLES AND WHEELS

The quality of your axles and wheels may be the most important factor in building a fast car. Here’s how to choose and polish your axles and wheels.

derby2.jpg1. Start with a set of raw axles.

2. Can you tell the difference between the axles in the top row and the ones on the bottom? The ones on the bottom aren’t straight and will slow your car.

3. To tell which are straight and which aren’t, mark each axle with a marker about 1/2 inch from the pointed end.

4. Have an adult clamp a power drill into a vise, a device that will hold it perfectly still.

5. Have an adult help you clamp each axle into the drill at the location you marked in Step 3. Have the adult turn on the drill.

 

wobble-200x2006. Bent axles will wobble as they turn in the drill. Straight axles will hardly wobble at all. Pick the ones that wobble least.

7. Once you’ve selected the four straightest axles, use a file or fine-grit sandpaper to remove small burrs and mold marks that can cause friction and slow a car. These imperfections should be removed from both the axles and the wheels.

8. Use polishing compound from the auto supply store to polish the wheels and axles. One easy way to do this is to clamp the axles back in the drill and let the drill spin the axle while you polish it.

9. When you install the axles and wheels, 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 in a straight line.

10. Don’t forget to add graphite or another dry lubricant to your wheels and axles.


Remember: The No. 1 rule of a pinewood derby is that it’s supposed to be fun. While you should always strive to do your best, don’t get caught up in winning. Just enjoy the ride.

Adapted from the book “Pinewood Derby Speed Secrets,” DK Publishing, $12.95 softcover.

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Comments about “How to make a fast pinewood derby car”

  1. Anonymous says:

    I make it on a piece of paper first

  2. Trungle says:

    I’m going to make a tear drop shaped car with three wheels, but should I put the two wheels on the front or the back?

  3. banana says:

    I’m making a f1 race car!!!!!!!!!!!!!!!!!!!!

  4. faceplanter says:

    I once got 4th place

  5. MAC says:

    AWESOME!!!

  6. Anonymous says:

    Somebody cheated last year in my pack !!!!!!!!!!

  7. Bertie says:

    Good advice. Clamping the axles in a drill press makes it easier. I use 400 grip sand paper to polish the axles after I use a small very fine file to remove the clamp marks near the head.

  8. sam-o says:

    hey yeah right I helped with as much as I could did you think my dad let me use his electric saw

  9. Bob hinder says:

    Great advice thanks ;)

  10. ok says:

    I didn’t know that you shouldn’t point the nose, know about the three wheel trick, or that coins work as weights.

  11. Been there says:

    The best thing about derby cars is keeping them to show your kids some day. Winning only means having to go somewhere else and spend another night standing around a racetrack.

  12. Vick says:

    How do you make a pine wood derby car fast

  13. bob909 says:

    nice advice.

  14. scouterlaurie says:

    I learned last year when the boys’ cars were too light that pennies work as last minute weights.(It looked cute too since their themes on the cars were pirate ships.)

  15. chadbag says:

    The reason the “three wheel trick” works (assuming your car still goes straight etc) is that one less wheel is using up potential energy being converted to rotational energy, which leaves more potential energy for kinetic (speed) energy.

  16. cardude says:

    The three wheel thing is not allowed in our pack. All wheels have to touch. Also, there are rules about how far apart the wheel bases can be. Make sure you check your pack’s rules.

  17. Ya right says:

    The only kids that win are the ones who have a parent that spends endless hours engineering the car just right. There are no rules or governance involved with the process. It’s basically teaching kids how to cheat by having a parent do all the work. I refuse so my kid loses every year. Boy scouts is outdated and horribly organized.

  18. Buckethead says:

    How did they get the shark fin too be that tall?Isn’t there a height rule?

    • Scouterlaurie says:

      Additional wood can be used to add height. Most districts don’t have a height regulation, just width for the track and weight

  19. mark says:

    I’m a eagle scout and i used the body style of a nascar and put the weights on the bottom of the car and I’ve won first over 6 years know

  20. Maxxhotrodd says:

    I had better success putting the weight in the front, kinda did the same as the 3 wheeler, it took so much weight off the rear that the friction wasn’t as much of a factor. Also see if you can get a tire dealer to donate stick on wheel weights. They come in 1/4 ounce segments, Would love to cut the thickness of the front wheels down, but I was warned ….

  21. Supercool man says:

    I really hope these speed tricks work because last year I forgot my car and had to use a batman car and got last place and I’m not forgetting my car this year.

  22. Mase3206 says:

    That didn’t really help me. 😐

  23. boyscoutcat135 says:

    I got a perfect design for my pinewood derby car

  24. Pack 148 says:

    Thanks for the info

  25. bob says:

    I know the secrets before :)

  26. DiggerZC says:

    Put weights on car

  27. me says:

    small wheels on front or back?

  28. emac says:

    three wheel + the wedge = FAST

  29. wildcat says:

    Make sure you know your local rules. We moved the wheels back and won our first year. The 6 year reigning champ did not like it so his “committee” made sure that altering the wheel base was not allowed…without telling anyone else so the next year we were DQ’d. Won for best paint job however!

  30. concernedparent says:

    I am not sure I understand our council does not allow this:

    Extend the Wheelbase: The front and rear wheels should be as far apart as possible.

    How is it listed here?

  31. speedthree says:

    Wrong about the 3 wheels being less friction. I’m surprised that got published, it’s a myth. The friction is just transferred to the other wheels. But you do get more rotational energy and thus a faster car.

    • Hornet816 says:

      Wrong, less contact equals less friction so it does get reduced. Weight distribution gets spread out but not friction.

      • CCJack says:

        Sorry, but I think speedthree has it right. Friction is a function of the coefficient of friction, and the normal force between the surfaces. The surface area does not factor. However, the wheels have a rotational inertia that needs to be overcome, so having one less wheel to force to rotate will result in increaded acceleration.

  32. Dave says:

    The “Avoid designs with a pointed nose” guideline directly contradicts a different BSA publication. That tells you to make a narrow area in the center of the car (nearly pointed) so that the race starter has to “work” to get the car placed in the center of the track, so that the wheels are touching the sides of the track.

  33. Monty says:

    I saw one car with a notch in the front where the starting pin rested. The result was the body of the car being a bit ahead of all the others. It wasn’t against the pack’s rules, and the car didn’t win anyway…but it was sort of clever.

  34. legoman says:

    what happens if i bake it after cutting it?

    • guruage guy says:

      baking it will reduce your un-weighted mass so you can better place weight where you want it. doing so after cutting risks warping the car body. bake before cutting, especially with thin or flat shapes.

  35. Too Cool For School Meadvin says:

    Those must have been made by the pros

  36. fish 4 money says:

    which wheel should I lift, the front or the rear?

    • yyg says:

      rear wheels

      • irondad says:

        One thought- since its better to raise a rear wheel on a 3 wheeler, how does that theory work with the other “go-to” of placing weight at the rear? I would think there would be tendency for the opposite front wheel to pull up off the track.

    • Cassman says:

      Usually a front wheel, since you’re placing the weight in the back, it could wobble back and forth if you lift a rear wheel.

    • Dano says:

      Always raise one of the front wheels

    • tketch says:

      Raise a front wheel and use dry graphite. I would smoke everyone, every year. Also, take fine grit sand paper and the inside of the nail head, there are usually small burs and imperfections that add friction.

      Raising a back wheel would be disastrous. You only want one wheel fighting for direction, as it will limit the time the inside track bangs the wheels. Lifting a rear wheel wouldn’t solve it the same way.

  37. pack 352 says:

    It would be nice if there was a official rule book and measuring box.

  38. speedy-one says:

    Great info… but a good piece of pine wood, round wheels, and straight axles never hurt either… have fun

  39. SM(Ret) says:

    Your pack committee should establish an adult race. This lets the dads satisfy their personal competitive urges and lets the boys be boys. I always won with a simple wedge and the three wheel trick.

    • Ryan_L_44 says:

      yea, i usually make a wedge, always three-wheeled and axles sanded with at least 6-8 different sandpapers, each a different roughness. what really helps is cutting the sides off about 1/8 inch everywhere except where the wheel and axle are. this prevents the wheel from ever rubbing against the car, significantly reducing friction.

    • PT-37 says:

      In my pack, we’re doing that this year.

  40. RobinzAgg says:

    Cool! But how the heck do you make that shark fin car? It looks awesome!

    • dede says:

      My son’s shark fin car won first place in design and third in speed! I just purchased a $2.00 design template on-line.

  41. harry potter says:

    awsome

  42. 123football83 says:

    where do you put the gas on the wheels

  43. Awesome Dude says:

    My first car always got last,and my second car got 2 and 1. My last car got 3 and 4 and 2. Awesome!!!!!

  44. Awesome Dude says:

    Awesome! I’m a Boy Scout and you should put the weights on the bottom of the car

  45. minecarftian says:

    this is going to help so much

  46. JMAN says:

    it is ok.

  47. Paw says:

    Thx but I have the book

  48. Pee Wee Harris says:

    Back when I was a cub scout, I got 4th, then 3rd, and then 2nd (against everyone) the three years I raced. I used the three wheel trick.

  49. yoyo says:

    WOW!!!!!!!!

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