The Block of Wood Part 3

Connell said last night that “we are in control of our cars this year.” I wasn’t exactly sure what he meant by that, but when pressed he meant that this year, we seem to know what we are doing. This is the sixth year of building cars, so I’m glad we are finally getting the hang of things. 🙂 Our goal this year, like every year is to have fun. We’ll be happy to have a respectable showing and maybe even win a heat or two.

Two years ago our cars were the slowest in the field. I don’t know what I did, but our cars were horrible. I spent the better part of that “off season” learning more about the secrets to a fast pinewood derby car. We showed improvement last year, but still had room for improvement. Last year we took Connell’s car to PWD Racing in Rosemount and learned the speed secrets used by the cars that win the district and council competitions. Connell took first in his den last year and went on to the district competition. Liam and my cars were respectable, but did not place. The challenge is to try to replicate the processes at home in a less than controlled environment.

Friction is the enemy of a fast car. The first step to reducing friction is polishing the axles. The nail-type axles come out of the box with a bur from the manufacturing process that inherently provides friction. To remove the bur, I rigged up fixture to hold a moto-tool and placed the axle in the chuck. We set the moto-tool at the lowest speed and lightly filed the bur off the nail.

Step 1 File off the bur.

The next steps are to use extra fine grit sand paper to sand off any marks on the axle and to polish the axles to an incredible smoothness. We start with 400-grit sandpaper for up to 2 minutes on the axle. Again the speed of the moto-tool should be at a low setting.

Step 2 Using ultra fine sandpaper.

Next, with the tool still running, is to rub the axle with a piece of cloth to clean and to buff up the shine.

Step 3 – Buffing up the shine.

Ok, sounds easy enough right? Well repeat steps 2 and 3, with a progression of 600, 800, 1000, 1500, & 2000-grit sand paper…for each axle!!!!

Sanding the axle for 2 minutes per step is flexible, depending upon the attention span of the operator. I found that 45 seconds to a minute per step is about right to keep my boys engaged. With that said, it’s about a half-hour operation to polish all four axles.

Step 4 is to treat the newly polished axles. We typically press the nail point end of the axles about 1/3 of the way into a piece of styrofoam, I (the adult) spray the axles with the a dry silicone spray. There is a product called “Jig-a-loo” that is ideal, however it is no longer available for sale in the U. S. I settle for using a WD-40 product that dries without a residue.

Next Step – Polishing the Wheels.

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