Restrictive and subjective rules set

[Stan Pope]

[jzarvey]

The River North Pinewood Derby Rules constrain all of those. [...] it doesn't seem reasonable to say, "(T)hey are effectively the BSA Rules-in-the Box."

Agreed! The "lenient" rules were jzarvey's Ojibway District rules that his Pack uses, not the River North Pinewood Derby Rules.

The District race also uses the lenient rules set. This will be the second year in a row with those rules at both the Pack and District level. We have done well under those rules. Den & Pack champ last year. 2nd in age group & 10th overall at district last year. If we want to participate under the two sets of rules, and be competitive, we will have to make a second car for the Council race.

I asked for and received clarification to rule 17 (Axles) and was told that if the outer diameter of the nail head is changed, it is an illegal axle.

I also asked for and received clarification on rule 19 (wheels) and was told to take the wheels out of the package and put them on the car. No work on any part of the wheel is allowed.

It was also brought to my attention that there is another document that is considered part of the rules that I had not noticed. It is called a "visual example of the rules" Check it out here.

Looks like Rule 19 in this "visual example of the rules" makes a traditional type Rail Rider illegal, no bent axles.

I talked with my scout about these rules and whether he wanted to race. He said that he doesn't want to because "I can't do anything to the car to make it go fast." He is used to truing his wheels, polishing bores, bending his axles, and tapering the heads of the axles. He said building this car would be boring. I am trying to help him change his mind, because the more I think about it, this could be an exiting challenge.

Time to search DT for some tricks of the on this type of ruleset.

I look forward to seeing everyone's opinions and any pointers in the right direction for a possible build of a car.

[Speedster]

Actually, a rail rider (sort of) can be built. I just did it. You can't have a 2 1/2 degree cant on the back wheels but you can have a degree that will make the wheels migrate to the heads of the nails. I used the screw technique and kept turning the screws until the wheel started to lean. I then backed it off so the wheel would sit flat. The nails were angled enough so the wheels would stay against the heads of the nails. The DFW was a challenge but I dislike our rules so much I knew what I had to do. Nail, after nail, after nail, after nail went into the drill press until I found the one that was the most bent. Again, I put as much Positive cant and toe-in that I could but made sure the wheel sat flat. I couldn't master the angle I wanted on the NDFW and get the wheel to touch the ground so I installed a straight nail and called it a day. The wheel migrated to the head of the nail. Physics? Josh won 1st place in his Pack yesterday. I thought about our District Executive and smiled.

[jzarvey]

Congratulations. I was thinking about using no camber since it seems to me that camber is not allowed by the rules. Toe on the other hand appears to me to be legal and would also give the desired effect. We will also try your method.

Thanks for the tip,

[Speedster]

I'd like you to do a little test. Take a wheel and axle and hold the wheel straight up and down on a table. You'll notice the nail is running downhill. This is the way it is going to end up in the car. You are going to insert the nail straight into the slot using the tool. You will then push the nail down with the screw until you get to the angle you had while the wheel was sitting flat on the table. The wheel will be sitting flat on the inspectors table but the angle of the nail will cause the wheel to migrate to the nail head. You might even be able to go a tiny bit farther with pushing the nail and still satisfy the inspector. Isn't this Fun?

[jzarvey]

Speedster, thanks for the tip. I had thought of set-screws to locate the axles. We had seen it in a PWD DVD. I think it was called Pinewood Derby Physics. Great video that helped my scout and I understand more about what makes PWD cars tick. Also, the rules allow for drilled axle holes and extended wheelbase. We are still in the design phase for this car. There are races on two different dates, so if we don't make the February 23rd race, there is another in April that will include the Council Championships. It would mean a lot of races with no re-prep in between, but is an alternative if we can't "git 'er done" before the February race.

Thanks again,

[Stan Pope]

You may augment the variation supplied by the out-of-the-box almost straight axles by drilling the desired angles into the block. For assistance with the computations and with holding the block properly on the drill press table, see http://www.stanpope.net/camdrill.htm" target="_blank. To help you and son decide what angle to use if you know your target drift, see http://www.stanpope.net/driftcomp.htm" target="_blank.

[jzarvey]

Thank you Stan. The calculator should help a lot. We are all set as far as the drill press being square.