Pinewood Derby Rules

General race coordinator discussions.
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Darin McGrew
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Re: Pinewood Derby Rules

Post by Darin McGrew » Sun May 19, 2013 1:51 pm

Just a few thoughts...
rcmoeur wrote:Number of Wheels:
Some cars in the Pack races had more than four wheels, and looked & ran great. But the District rules called for four and only four wheels (3 touching), so most of them didn't move up (one did by popping off the spare ones). We're thinking of changing the rules to allow a minimum of four, all within the maximum allowable wheelbase (see next comment below).
I'm trying to figure out what the problem is with designs that use extra wheels. Why would the district rules prohibit them? They don't make the car any faster. And from the design side, the look of extra wheels can be replicated with slices of dowel painted black. Unless they prohibit other store-bought bits of plastic as decoration, I don't see why extra wheels should be prohibited.
rcmoeur wrote:But this raises a question: should there be a wheelbase limit, other than the 5 13/16" practical maximum? I'm inclined to be OK with it, but Bob's a bit dubious. We'll see what we work out.
What is the purpose of the wheelbase limit? That will determine what the wheelbase limit should be.

At our workshops, we provide access to band saws and drill presses. With those tools, extending the wheelbase is well within the abilities of a kid with reasonable help from an adult. So our only limit on the wheelbase is the "practical maximum" defined in our "fit the track" rules (and is based on the nose-to-rear-axle distance, not the actual wheelbase).

But extended wheelbases aren't a silver bullet for speed. Actually, there is some evidence that a standard wheelbase with material moved from the rear to the front (i.e., moving both axles towards the rear) can be faster than an extended wheelbase.
rcmoeur wrote:Lubricants:
We don't have a reliable test for silicone, Krytox, or Nyloil. We may add a rule stating that any liquid lubricant observed leaving the car at any time is grounds for disqualification (graphite's enough of a mess).
Properly applied thin-film lubricants (e.g., Krytox 100, Nyoil) won't be "observed leaving the car".

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