Pinewood Derby Racing 2008
By user12607856 on Jan 27, 2008
Earlier this afternoon was this years Pinewood Derby racing event for Duncan's Boy Scout troop. After last year's abysmal performance we were determined to do better.
I read all the advice we got from comments to last year's post (thank you), and we applied some of them (the legal ones) to the design of this year's car. More on that later.
I also wanted to have a fall-back plan. Each den in the pack races against each other, and there are prizes for first and second place. Winners go on to regional events. There are also special prizes for categories such as most authentic design, most colorful, most creative etc. I wanted to make sure we had a running in one or more of those.
So we came up with the melon car. It was actually called Melon Car "Lee Baby" (geddit?), and labeled as such on the bottom of the car, just in case there was a special prize for best name, but the judges totally missed this.
You can see Duncan's car lined up with three others for its first heat and then the actual race. It came fourth. In its second heat it came second. Surprisingly, I'm not disappointed. In that first heat was also the eventual first and second placed cars overall for his den, and as you can see we were not that far behind. For a car that's totally not aerodynamic, this was quite an achievement.
After all the dens had raced, the special prizes were announced and the melon car won the category of wackiest car for the whole of the pack!
So what did we do?
First of all there is an area on the bottom of the car that was especially hollowed out, and a slice of weights was screwed in there. At the "weigh-in" a couple of weeks ago, we were quite a bit overweight, but it was easy to pull bits off until we were very close. There we just super glued a couple BB's to get it exactly at 5 ounces. There was nothing special about the position (front or back) for those weights. If anything, after they'd been trimmed, it was probably slightly heavier towards the rear of the car.
But I think the major factor was axle preparation. I used my Dremel in its drill press stand to take each axle, file down the rough part near the head, then applied a mixture of pumice and water with a cloth. Then we put the wheel on the axle, and the axle in the Dremel, and applied a generous puff of graphite dust, and let it spin at max. RPM's for about thirty seconds. We repeated this for each axle.
We also sand-papered the outside of each wheel to get the imperfections off, then applied wet-and-dry paper at max. RPM's, to make sure that was smooth too.
Finally, we set the wheels so that only three were touching the
Next year, I think we will try for an aerodynamic car and see if that improves things. I'm also not convinced 3 wheels are better than four, so I think we'll try for them all touching the track.
Anyhoo, even though Duncan didn't win, he came away with a big smile on his face and happily pinned the special certificate to the wall of his bedroom when we got home.
A vast improvement over last year.