Monday, March 3, 2008

Derby Day

As I mentioned in an earlier post, this past Saturday was Pinewood Derby day for Joshua's Cub Scout Pack. Despite our exceptionally late start on his car and some last minute cramming, we had a great time and did very well.

First, the finished product. This is how Josh's car turned out.




This is almost the look we were going for. A little more time and we could have done a bit more with it. I really prefer the very simple design. Not a lot of paint, low slung and rudimentary weights such as nuts and bolts showing. It is a look that makes the other dads... er, kids think, dang an ugly car like that must be fast.

Given more time, we would have done a lot more sanding and would have had that covered with even more coats of lacquer to give it the finish of a new gym floor. It takes a little convincing to make your cub approve of the very simple design again, time constraints this time meant there was less time to deliberate other ideas this year.

We are already however back to the drawing board contemplating ideas for next year. We are thinking of going with a car that would look like a wii controller on wheels. We could call this car "Wii would like to race". We'll keep our eyes out for spare parts needed for this design throughout the year.



As everyone knows, one of the keys to the successful pinewood derby car is getting the maximum weight allowed on the car since this is a gravity controlled race. (Force = Mass x Acceleration) 5 oz. maximum is the limit according the the rules.

We made 4 or 5 trips to the post office's self-serve kiosk the night before the race placing various components on the scale trying to get this car as close to the 5 oz. weight limit as possible. I'm sure our many late night-visits to the post office put our faces on some Homeland Security list somewhere.

Our first trip showed us weighing in at a whopping 7.4 oz. Ouch. Time for another visit to Home Depot. Eventually, I think we found a good combination and our first weigh in on the official race scale the next day had us at 4.9 oz. Not bad. A couple of more tiny screws were added to the car's belly and we were at a perfect 5.00 oz.

Once we got the car to the perfect weight and got the graphite all loaded up, we took the car to the track for a couple of test runs. It was then that we learned we were in for a fun afternoon. This car was FAST.

The video below is of one of Josh's first heats of the day's races. It was a three car race and that is Josh's car on the far right.

It is amazing how tiny the difference is in time between first and last place cars. It really does come down to detail. Here is another still photo of Josh's car winning yet another race. Note how short the distances are between the first and last place cars.

Our stake has an amazing track setup with timer that record each car's runtime down to the 100th of a second. For the event, Josh ended up with the fastest overall average race speed of just 2.66 seconds.

Josh participated in 12 races total and won 10 of them outright. This was good enough to get him to the finals where he came ever-so-close. Ultimately he was beaten in the final by .01 seconds. Dang! That gives us something to shoot for next year I guess. Josh was of course thrilled and had a great time which was the most important thing of all.


One of our favorite thing to do at the races is check out all the cars that are entered. There were some really neat and creative ideas including my personal favorite, the skateboard car. It was slow but design made up for it.


On the table below, Josh's car is the one car that is upside-down. I wouldn't let him keep it there wheels-down with kids running in and out grabbing their cars for races, cars could be (and were) knocked off the table.

1 comment:

Keri_B said...

Can't wait to see next years car...don't forget where you hid the wheels!!! :)