Pinewood Derby Car weight compartment

Step 5 Gentlemen, start your engines.

You are ready to race.

During the day of the race cars, and owners, will go through registration where the cars will be weighed. This is where this project pays for itself. Invariably, your scale, and the judges scale, will show different weights due to manufacturer, curvature of the earth, distance from your home to the Earth's core vs distance of the race location to the Earth's core, relative humidity, low battery, high tide, low tide, Sun spots, Van Allen Belts, etc., etc. Simply pop the lid off, and add or subtract weights until 5oz is achieved once more.

"WYLIE COYOTE - SUUUUPAAAAA GENIUS!!!"

Comments

[wanna beco]

Kholle, do you have any links to verify this info.

And to the OP, is the rear of the car the best spot for the weights? I thought that having them nearest the nose was most beneficial?

[PinewoodDerbyDen]

pinewoodderbyden.com

[CementTruck]

You might want to reply to kholle1 using the reply button beneath his comment.

I read this somewhere, but can't remember where. I am just paraphrasing from memory:
In the past people have cheated by using some sort of mechanism that rolled a ball bearing from the back of the car to the front. The mechanisms were hidden inside the car. The act of the bearing striking the front of the car after the launch gave the car an added boost of speed. The car's owners were disqualified after someone got suspicious and checked the car.

In regards to the weight placement, right in front of the rear axle is considered the best placement. If it is behind the rear axle it makes the front too light and makes the nose want to hop every time the front wheels roll over the track joints. You want the center mass (weights) positioned as high up as possible on a slope because once the car is level the center mass's momentum can no longer be affected by gravity. Since the rear of the car is the last portion that makes it to the flat track gravity is pulling the center mass down until that point in time.

http://www.pinewoodprofessor.com/weight.html

[wanna beco]

Great, thanks for that info... I can't wait to race!!

[CementTruck]

I embedded the BBs in play dough/clay the first time I tried this. The clay also added some weight while keeping the BBs (and itself) immobile. The consecutive races later I used hot melt glue and dropped BBs in the hot melt before it cooled. Both ways worked fine.

Thanks for the comment.

[kholle1]

Great idea.  However, I must point out under many group's rules all parts including the weights must be fixed to the car.  That is they are not allowed to move relative to the car.  BB's and fishing weights are allowed but must be glued or fixed in place.