Pinewood Derby Cars Have Come A Long Way

Get your graphite and hike a wheel, [Aron Hoekstra] writes in to completely embarrass us with some excellent pinewood derby cars.    In the pursuit of that extra something [Aron] consulted with his sons who came up with some cool ideas for cars, one Tron themed and the other basically a Wiimote with wheels! The official Pinewood derby rules say nothing about electronics, so as long as nothing helps the block-o-wood travel down the track faster, anything goes. This means you are free to load up whatever cool lights you want, but will have to earn your robotics merit badge some other way.

[Aron] Starts the builds by carving out the shape of the cars, each feature a hollowed out cavity underneath to accommodate the batteries and electronics. For the Tron Light Runner car, one continuous EL strip weaves in and out of the derby car’s body, and a single AAA battery runs the driver. [Aron] notes that it took around five feet of EL wire to cover the little car, which is two more than the driver is rated for. Fortunately the extra little bit of additional wire had little effect on its brightness.

The Wiimote car has detailed 3d buttons, a breadboard with a linear regulator,  and PIC 16F628 driving  blue LEDs.  For the majority of the time the PIC simply runs a chase routine for the four LEDs, but [Aron] went through the trouble to program in the Wiimote’s start-up sequence!

Shown above the [Hokestra]’s work is my older brother’s pinewood derby car (top left) and my… potato rocket… thing… (top right)  from many many years ago. I now seriously regret not considering LEDs! Although I think all that existed then was red,  green and IR.

Check out videos of the [Hoekstra] bros’ cars after the jump!



20 thoughts on “Pinewood Derby Cars Have Come A Long Way

  1. Someone at NASA etc. is going to get a “Green Jobs” multi-million Dollar grant to design the “Optimal” Pinewood Derby car. Then you will only be able to buy it if you are a member of the Pinewood Derby Union. Anyone not buying a Pinewood Derby car from the Union will be disqualified (or they’ll be knee-capped). Yeah – I’m pissed off…

  2. I am all for coolness but isn’t this the pint sized version of all show and no go?

    No extra points are awarded for coolness if you lose the race. In that case, you lost but have a cool car. Congrats?

    So this is neat but lets see some wind tunnel testing, 3d printing, CNC milling and coefficient of lubrication effectiveness testing. What’s better than graphite? Maybe use some bearing and a PTFE coated nail instead of a nail in a plastic wheel?

    Also – somebody needs to add an arduino (pro mini?) to a pine derby car, stat.

  3. These are awesome cars on their own. But…

    How much of these two cars were actually built by Aron’s kids and how much was built by him is the real question. If the kids did anything less than “almost all of it, with a little guidance, except for a few tricky bits here and there”, then it fails as a proper Pinewood Derby car.

  4. “How much of these two cars were actually built by Aron’s kids and how much was built by him is the real question.”

    Isn’t the entire point of pinewood derby to build badass cars for your kids to cream the other parents cars?

  5. My college actually just did a race to help students relieve stress :)
    They did give an award for creativity, so a friend and I made a car which had a photo transistor above a wheel and counted how many times a small white line we drew on the wheel passed. We used this to make a white LED light up on the front (the faster we went, the brighter it got), and two red on the back for brake lights when it stopped. I thought it was pretty sweet, but unfortunately we got second place to a giant pair of fingernail clippers.

  6. I remember pinewood derby…
    We had the axles Teflon coated and balanced out so only 3 wheels were in contact with the track, milled our own axle slots so we could balance the weight as far back as possible…
    good times

  7. Man, when I was in scouts I made my pinewood derby car with a jigsaw and block sander and hobby paint and tried to make it cool. A couple of the other kids used some “spare” cycles on the supercomputer at the local university to run simulations and optimize for drag (and I suspect they also had better lubricants than the stock graphite powder)…

  8. I won my pinewood derby on the second year. I tried to picture how the wind would flow across the car then used a hand saw to cut it. Dad drilled out spots in the bottom to add weight and used lots of graphite.

    Still have that trophy somewhere. :)

  9. I saved my electronics hacking for the practice track I built in the garage. Based it on the Scouts plans, but just 2 lanes since it was just for practice. Nice thing is it folds up and fits neatly on a long shelf in the garage until next year. I used the plans and help from the forums for the “Worlds Cheapest Pinewood Derby Timer”- basically there’s a switch on the start gate that starts the timer, and IR emitter/detector pairs at the end, all hooked up to the parallel port of an old laptop running free race timer software. Very cool. It helped us shave a few hundredths of a second off his average time, which on a short track like that is huge. Actually didn’t even build it until after the pack race, but the time we shaved off before the districts probably offset the fact that they put a sticker on the back that acted as an air brake because it was sticking up about 1/8″ on his and not on any of the other cars.

    In the pack race he took 1st for the Tigers and 2nd overall. He didn’t lose a single race, but it was based on times and not double-elimination. At the districts they only did double-elimination and no timer, he came in 5th. I even built my own car… something to keep me from working on his while he was at school ;-)

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