Saturday, March 26, 2011

Matthew's first pinewood derby

Originally uploaded by jbellis
Matthew was extremely enthusiastic about his cub scout pinewood derby car. I took the approach my own dad did: I'd help him cut out the basic shape (that he drew on the side with a pencil) and weight it; the rest was up to him.

I asked Google and a bunch of other dads about weighting approaches but nobody had a better approach than what my dad had come up with: drill out some holes (narrower at the entrance, so the lead can't fall out if you drop the car) and melt solder into it.

The wussification of America threw me a curve, though: you can't actually get lead solder anymore as a matter of course. You can get acid core solder, or you can get silver solder, both of which are much more expensive -- and less dense -- than lead solder. Fortunately, you can still find lead on the internet, so I ordered enough for a couple years of cars. The photo is of Matthew and me melting some into the back of his car.

(Matthew was tickled to death with the novelty of such a soft metal, and unrolled the solder and twisted it into ... interesting shapes. It's easy to melt solder into a hole if you have a straight line that you just feed into the heat source. It's a little more challenging when your straight line, isn't.)

Friday Rachel took Matthew and Melissa to the planetarium. I drove back early from Austin to take Isaac while they did that. It also fell to me to deliver Matthew's pinewood derby to the official weigh-in.

I was not impressed with the official race scale. It claimed to be accurate to three significant figures, but Matthew's car started at 5.19 (Rachel's scale had put it at 5.0) and drilling out 5 holes to lighten it got it down to 5.15. Five more holes got it to ... 5.15 still. Something doesn't add up there!

There was exactly one electrical socket in the room, on the opposite side from the scale. And every time I wanted to check my progress I had to unplug the drill so Isaac wouldn't hurt himself. Isaac wanted to help, so we got into a routine: when I stopped drilling, Isaac would pull out the plug.

It took almost half an hour before we were done. Isaac had been extremely patient, so I took him across the street to the Dollar General to get him a treat. He picked out a bag of cheetos, and we took it to the playground for a snack. He started munching and immediately started coughing. Initially I didn't think anything of it but he kept coughing after each cheeto. I took a closer look; it turned out to be Flaming Hot cheetos. I didn't know they even made such a thing. I need to look a both sides of the packaging, apparently.

I showed Isaac that drinking water was more effective than coughing, then I tried a couple... and coughed. They're not all that spicy but something in it kind of tickles your throat. The bag is still sitting on the kitchen counter but it will probably get thrown away uneaten.

Isaac ran around the playground for a while but I hadn't been thinking ahead when I dressed him, and I'd put sandals on him rather than hunting down a pair of socks and his sneakers -- like most playgrounds here, this was covered with wood chips that sneak into sandals. So he was done pretty quickly. Sorry, kid. I let him watch cartoons when we got home to make up for it. Then Rachel fed him some leftover pizza when she got home.


Our little family said...

Our girls got to do derby cars since Rusty is in scouts. He uses bullets as the weights! He takes the tips off and inserts them into holes. Works pretty well, is really cheap and easily accessible.

Rachel Ellis said...

Great idea!