Every last inch

 The Thrifty Rocketeer blog continues...

I saw it tonight when I stopped by to see if there was anything new for me at HL.  Not only did I take a look at the model rocketry display, but also took a glance at the clearance shelves as well.

There, hanging on a single peg, was a small blue cardboard box, all alone, and without any fanfare or picture to show the contents.  I had expected that it was going to be a printer cartridge or something for a craft paint project, but I was wrong.

The plain white lettering on the blue box said it was a micro-burnishing tool kit for the Pinewood Derby kit.  Huh?

Now, I recall the Pinewood Derby from my days as a cub scout in the mid-1960s. The basic concept is to take a fairly standard block of pine with two wire axels and

four black plastic wheels and turn it into a racecar.  

The block of wood can be carved to any shape, and the wheels attached so that it will roll down an inclined plane or track and drag race five or six other cars at the same time.  After each heat, the winner then competes with the winners from other heats, until finally, one fastest car is declared.

Now, there are some limits here, as the car must be under a particular weight limit, and you can't soup it up with any sort of engine.

My father and I set to work on one in January when it was particularly cold out in the woodshop garage. My father, an electrical engineer and woodworker, had a pretty good grasp on the principles behind the contest. But he was more excited about it than I was. He encouraged me to shape the block into what basically looked like a 1930s race car, complete with large curved hood, back rest and minimal wood removed.  His theory was that the more wood that remained intact, the heavier the car would be, and therefore, the faster it would roll down the track via gravity.

He had overlooked the amount of wind resistance a block of wood had, though he did try to encourage me to round off the sharp edges and lines, figuring the more air-stream dynamic the block, the better.

That was a step in the right direction.

The winning cars all had been whittled down to a minimum shaft with barely any wind resistance, and barely any axel between the two front wheels. That reduced the friction of the axel to as little as possible. 

After consulting with some other scout leaders or parents, my father learned a lot of "tricks" or expectations based upon experienced racers. He learned that we could add or subtract weight, as long as it wasn't apparent to the spectators. Therefore, he learned the maximum weight allowed, and convinced me to drill 3/4" holes up the bottom of the car. We then poured led shot into the holes, and sealed them up with wood putty. As they dried, we resealed the cracks again, and then painted the entire car a sick shade of lime green with paint that was left over from our living room remodeling of the prior summer.

Well, the wood putty dried, but almost cracked when we turned the car over once again.  I frankly don't know how the shot stayed in place for the competition.

Once again, we were off on the wrong foot, as now I had a heavy clunky, air-resistant entry.  As you might expect, the competition wasn't much fun, as my car didn't make it out of the first heat.  We were both shocked to see how far off the mark we were compared to the other cars.

My father had one more ace up his sleeve.  He had been coached that we could lubricate the wheels via the axel... a stiff wire than ran through a very narrow tube that was trapped under a wooden insert that filled the two slots under the block.  He confidently shot graphite down the tube and made sure that the wheels spun well.

We lined up the car for a second heat (I think it was double elimination or something) and my car performed better, but not out-performing the other striped down models.

The closest I can describe the winning car, is that it was a funny car dragster... all frame and virtually no body or block of wood.  In essence, my car was completely the opposite of the way all other experienced scouts had gone. And, it was the only one that looked that way.

So, when I came upon this "burnishing tool kit" this week, I got the idea that the competition had advanced once more, and now scouts were expected to use the drill/brush to clean off any burrs or friction making bumps on the wire axel that might have slowed their entry.

I don't know if this is right, but I immediately thought it was over-kill.

But then I recalled how I pondered why someone would feather the leading edge of a fin... reduce the air resistance in a rocket... or add a little extra black powder... just to go higher.

I was told my by "Elmer" that these were all steps one would take when you were clawing for just a few more feet... or every last inch... if you were in a competition.

Maybe Pinewood Derby has changed since I was a scout. But it still seems excessive that someone is selling a burnishing tool to polish an axel for what should be a friendly but spirited competition.

This has been the Thrifty Rocketeer saying, "Feather those fins".