Every year in the winter the boys scouts have the traditional Pine Wood Derby. Each participant gets a block of pine wood witch two grooves at the bottom indicating where the axles are supposed to go. Further there are 4 plastic wheels with one nail each.
Our scale. Old School!
The task of the scout is to cut out some race car shape out of the rectangular shape, polish and paint it and finally put on the wheels. Not really a very difficult task but for a good part the hand of the adult is still required. The boys of the den compete directly and the car has a weight limit of 5 ounces, which usually requires quite some weight addition as the wood is not very heavy. Weight, together with the frictionless running of the wheesl, is the most important factor for making the car go fast. So, putting on the maximum allowed weight is critical. Everyone is therefore using a more or less sophisticated scale. We went for the old school Revell scale, 5 ounces corresponds to 25 quarters and 7 ounces to 35. Looking at the scale though the 8.01 (Classical Mechanics) trained expert immediately realizes that the car has to be symmetrically constructed such that the center of gravity is at the center of the slot foreseen for the car. Most people today of course go for a nice small digital scale, but in the car check-in our cars came out perfectly. Last year I had bought little weights but they did not stick too well to the car with the adhesive tape and they were actually not so inexpensive either. This year we used wood glue and coins from our large coin collection. Most of them pennies but also some nickels for the 7 ounce class cars. This worked much better though it looks kind of funny.
Last year we had build one car for Ivan. It was our first exercise and we focussed on a nice design style of the old formula one cars, a so called I shape. The car was at the time at the proper weight but the wheels were not quite straight on the body. I had carefully hammered them in but they tilted a bit in the groove. The car ran fine…. but probably a little to much friction loss. Nevertheless Ivan won a trophy for the nicest I shape design. Unfortunately, I could not go to the race that year (2012) as I was in Geneva on race day. This year I did not have to travel and as the other kids were also interested to build a car we got two pine wood derby kits and the old kit from 2011 when Ivan and I did not build the car. So we were going to make three cars, well I did not really believe we could do it but at least we had the material.
This year I was going to be more careful in putting in the nails. I used a drill to make straight holes just big enough to fit the nails and adding some glue to make sure they would not come out, but that is actually one of the last steps. Gisele and Ivan started there car design first. We came up with a simple wavy design for Gisele and Ivan decided for a design looking much like a pickup truck, Gisele quickly noticed the car looked like a slipper and we had some good laughs in the basement while we were working there together. Gisele’s body came ready first, after cutting and lots of sanding, and she decided for a simple orange and green coloring with a pink bottom. I had bought some decent colors because the Revell colors are not as shiny. We used small paint brushes and I had to help a little to fill out all the difficult corners. Ivan’s car came next. Ivan has recently been infatuated with with Greek and any other type of mythology and there was no surprise when he had a green tripod, an orange wing, red clouds and yellow lightnings all over his car. The base color we choose to be black to underline the nice motives. Also here I had to help to get the colors properly spread. We had started early on the cars and the project went into hibernation for a while.
A few weeks later we were back at it and completed the coloring and started to prepare the wheels. Graphite powder and some buffing of the nails followed. Unfortunately, we lost one of Gisele’s car’s nails and had to replace it with a somewhat smaller one. Not a huge difference but large enough as it turned out later on race day. Blake had been attentively following the car building in the basement and was growing unhappy as nobody was going for his ‘favorite color’ — blue, so that finally we decided to start his car. We had some discussion about the design and we went after same proposed drawings with a quite flat design with just a spoiler at the end. This car was done very quickly as I had the steps down. The main color was of course blue and red on the sides. The bottom was supposed to be pink as well. Here I had to do a lot of painting :-).
To be continued ….
