# Pinebox derby cars



## Harold46 (Dec 24, 2009)

Has anyone got to play with these things. It's my boys first year, and we're going to give it a go. Any tips or thoughts about designs that may give us an edge?
Thanks,
Harold46


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## Homelite (Dec 24, 2009)

I have a couple of first place trophys that I attribute to using a small amount of pledge furniture polish on the axles and I spent some time sanding down the wheels and making sure the mold lines were gone and I also crowned the surfaces of the wheels to put less surface area in contact with the track and therefore less friction. Another key is to fill in the grooves at the bottom of the car that the axles slide into once the wheels are on for more aerodynamics. My cars were never pretty, but they were fast. My dad didn't help other than giving me the tools I needed and recommending what might help. He also did help with the weight. We drilled a hole on the underside of the car, centered between the axles, weighed the car and melted lead and filled the hole and sealed it over once it was cool. We put in a little less lead than was needed to get it under the weight restriction. This put equal weight on each axle and made it more aerodynamic than the lead they sell to screw to the bottom.


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## palogger (Dec 24, 2009)

One trick that we always found was to keep the cars thin as possible


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## Taxmantoo (Dec 24, 2009)

palogger said:


> One trick that we always found was to keep the cars thin as possible



Yep, the really fast cars were needles that exactly met the weight limit through drilling and filling with birdshot. They have to roll perfectly straight too.


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## loadthestove (Dec 25, 2009)

taxmantoo said:


> They have to roll perfectly straight too.



By all means ,this is the key to a fast car.Also try to get the weight evenly distributed on all four wheels.we used graphite on the axles for less friction.


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## Longshot (Dec 26, 2009)

Only one race......but won trophy!
All above suggestions sound worthwhile. Seems that you've gotta mount those wheels so they run true [straight]. Once assembled, I ran the car down an angled 1x4 and kept tweaking the axles until the car ran the entire 8' length without veering off. Gravity and drag control did the rest.


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## TomB (Dec 26, 2009)

Make sure you remove the burr from the nails that are used as axles. We use a exacto hobby file. Pine wood derby kits have real cheezy parts. It can't hurt to make sure the part as "tweeked" as possible. 

And then put them in a drill, and polish the nail with some graphite and a soft cloth. Make them shine. Check the wheel to make sure the are actually round and do not have any flat spots.

Same goes for Soap Box cars, use good bearings and good tires.

Have fun and good luck


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## oldsaw (Dec 27, 2009)

Okay, having been about everything possible for Pinewood Derby and being involved in the building about 10 cars, I can give you some tips.

Now, different packs enforce rules differently. We were usually pretty lenient, but there were cars that were made to compete in the "outlaw" class. Some packs are pretty strict and some of these tips above could disqualify your car.

According to the official rules, you are not allowed to crown your wheels, or use anything other than graphite on the axles. You must use the supplied nails and wheels

That said, aerodynamics are pretty worthless, I've seen a whole lot of brick shaped cars take a lot of prizes. It's all about getting the burrs off the nails, and aligning the wheels. Aerodynamics on a car that really attains no real speed is pretty worthless, but they can look cool. Kids like things that look cool, and it sure can't hurt.

You can get an alignment device from the Scout Shop, which can really help. They also have a wheel chuck that allows you to dress a wheel so it is flat, round, and the ridge is gone. Again, shaping is a big "no-no", so it's not worth getting disqualified over.

Remember that it's all about fun, learning, thinking, and working with your parent to create their personal "masterpiece." Don't focus on the winning, focus on the building and the thinking that went into it. You can see what others have done, then make a better car your second year. Your son will think about it all year long.

Our pack also had an "outlaw" division for Dads. You were allowed 10 ounces, solid axles, and bearings if you chose. There was a $5 entry fee as a fundraiser. I entered two cars one year and took 1st and 2nd. I took first the other two years, then retired to let others win. I just really didn't have the time to do it for a couple of years. I put some time in to a couple of those cars, but had my best time in one that took me 10 minutes, recycling the wheels and axles from the last one. If you aren't doing it, suggest it for next year. We don't have a huge pack, but we earned enough off of the entry fees to nearly pay for the track rental.


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## BlueRidgeMark (Dec 7, 2010)

TomB said:


> Pine wood derby kits have real cheezy parts. It can't hurt to make sure the part as "tweeked" as possible.



Yep.



TomB said:


> And then put them in a drill, and polish the nail with some graphite and a soft cloth.





Nope. Jeweler's rouge. THEN graphite.


All of the above. Polish EVERYTHING, get the profile as small as you can (where my kids have raced, you must use their kits, so you can't get them any narrower), make everything SMOOOTH and TRUE. And get that weight just barely legal. I like a long hole drilled down the length. Add cast .38 cal bullets for weight, as needed.


I have to say I disagree with oldsaw about aerodynamics. If you haven't done the wheels & axles right, a brick that has will beat you. BUt if you have, then the aerodynamics are the next step.


My kids have the trophies to prove this works.


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## cowboyvet (Dec 7, 2010)

Homelite said:


> My cars were never pretty, but they were fast. My dad didn't help other than giving me the tools I needed and recommending what might help.




:agree2:

I think it is great to help your son but at the same time let him do it and learn from his mistakes. 1st place lasts a day but the lessons learned will last a lifetime. To many dads take the car and tweak it every which way doing 90% of the work and just hand it to the kid to race...."well he a...he painted it"


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## bobt (Dec 7, 2010)

Have fun together, you and your son. Make it his project, not yours, and only offer advice. Do not do the work for him. Use his ideas and offer suggestions, but I repeat, your boy needs to make the car himself.

We had one kid in our troop whose Dad always made his car. I don't think the kid even painted it. His car always won the race, but by the end of the cubscout years, everyone knew that the Dad made the car. Left a funny taste in the mouths of all the rest of the boys, and they all nicknamed the kid 'Cheat" for the rest of his schooldays.


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## jryn (Dec 7, 2010)

Depending on the rules of the race, you could do several things. Many people have already posted about polishing the nails with graphite and getting rid of the casting line on the wheels. We always used a drill press on the the side of the car and melted lead fishing sinkers and poured them into the holes. The wheels will cover up the hole. I have tried various types of shapes and found the shape is not as big of a factor as the rolling resistance.
Placing a radius on the wheels is a great start if the your pack allows. If they consider this practice illegal you can bias your lead weight toward the front of the car and slightly raise one rear wheel off the ground to decrease the rolling resistance. Just make sure the wheel is low enough to catch the guide that car runs on. Good luck! And remember the dremel tool is your friend.


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