Discussion Forum - Northstar Chevelle Club

Bowtieman427 · Active Member

Pinewood Derby Cars

Dave Seitz · Mega Poster

Well once again the kids have the Pinewood Derby and built their cars mostly on their own. In the past I had shown them how to do a trace layout on the wood block. With the other things they have learned in the past this year being laid up they had to do even more. Other then spray painting the main body "because they kept running it and resanding it" they did everything and only needed help with wheels and axels. Now my oldest son decided to make a Jurassic Park Jeep with hand painted logo and such. The youngest Aaron decided to make a two tone brown wagon with a 113 on the doors and the NCC logo and name on top of the car. I'll post pics of the cars after the race Sat Afternoon.

The winning cars are the same every year and the parents do not allow the child to touch the car before or after the race.

I told my kids I'm happy even if they don't win because I know they built their own cars.

SShink · 3K+ Club

Now I know why my son's cars always got blown by on the track. It was because of guys like you!

The cars he built weren't far from the look of the block of wood that came in the kit, other than some polishing of the axles, and that was it. He had a 3 wheeler not by design, but because he put one of the front wheels higher than the other by accident!

He did win a 3rd place his 2nd year, so it made all the worrying worth it for him. It was actually kind of stressful for him and he worried about losing all the time. We supported him as much as we could knowing the cars weren't going to do very well. But other than the axle polishing, he did it all by himself.

-- Edited by SShink on Saturday 28th of January 2012 08:01:31 AM

John D · 2K+ Club

Looking Good!
As the "Co-builder" of 3 Grand Champions, and the 1973 Champion myself, the Pinewood is my favorite Scouting event!

The dragster & weinermobile were my entrants into the "Dads Race", and the red wedge is my 1973 car.

A few Tips & Tricks that have worked for us that you may or may not already use or know about:
Weight
- Our best has been having the weight around 2" forward of the rear axle, in as small/dense of a weight-pack as possible.
- We take the finished car (minus paint & final assembly) and weigh it & all the parts.
- Using chunks of real lead used automobile wheel weights (from the local tire shop) bring the weight up to exactly 5.1 ounces (yes 5.1 - more later).
- Carve a cavity in the bottom of the car to approximate & accept the amount of lead needed.
- Melt & pour your weight pack. Finish the car.

Wheels & Axles
From looking at the trophies, you seem to have wheel & axle prep down. But here's a few you may not know about...
- before final polishing, cut a slight groove in the "bearing" surface of the axle. (Graphite reservoir).
- Buy, or scrounge through several kits. Look at the inside of the wheels. Assemble a set of wheels with all the same casting number. Now you have
4 wheels from exactly the same injection mold.
- Using toothpaste, gently spin-polish the tread surface until it looks like a mirror.

Not Breaking the Rules, but using them to an advantage...
- Build a 3-wheeler. Raise one of the front wheels ever-so-slightly so it doesn't touch the track. It will still act as a guide on the center strip, but not roll. Instant 25%
cut in rolling resistance!
- (this one is on the edge)... - While "prepping & truing" the wheels on the arbor, accidentally... ahem... cough... "crown" the tread surface of the wheel just a tiny bit, creating a high-spot/ridge exactly in the center of the tread surface. You'll be running on "skinny's" instead of big meats.

- "Play the Game" with the digital scale. This is probably the most important trick of all. Remember above when I said to build the car to 5.1 ounces (overweight)?
- Bring a cordless drill and 1/4" bit to race day. Weigh the car on the "official" scale. You'll fail, by being heavy.
- Zap a few minor touch holes in the weight pack (it's on the bottom so it won't show) and re-weigh. Get the car where it "tickles" the digital readout 5.0, 5.1, 5.0, 5.1
- Touch it one more time with the drill.. just a shaving.
- You are now at legal 5.0 ounces of weight... but actually the car is 5.09999999 ounces. "Playing the Game" with the scale.

Dave Seitz · Mega Poster

I can only direct certain portions of the car because "Leave me alone I can do it" was stated long ago. There cars do not look the best when they do all the brush work by free hand but it is "THEIR" car. The Den leader was not really shocked I make the kids do so much work she was supprised that the kids cut them out on the band saw. She also noticed each of the boys knew angles to do multiple cuts and they taught the others. This troop allows any Scout Family to enter in another set of divisions, no I did not notice that the Dad, daughter and son of the same families seem to win every year. Didn't notice the hissie fit one father had when he lost, or the group of parents that wanted that SOB Tech inspector removed because he is mean and his scale must be wrong. Oh Wait yes I happen to be that SOB Tech Inspector, and I don't give a crap what your scales at where ever have said your car weighs, IT IS OVER 5 OUNCES ON THIS SCALE!

John D · 2K+ Club

Had the same problems... "we weighed it at the Post Office"... "My scale at work in the lab is checked daily and good to 10 to the -3 of a gram"... blah blah blah. The rules say the Pack scale is the official scale, and race day is the official weigh-in.

We had a specific statement in our "rules & regs" making it VERY clear that the cars would be weighed at "tech" on race day, AND THAT IS THE OFFICIAL WEIGHT. You will be allowed to add or subtract at the race in the pits, and once the car is 5.0 oz it's put in the paddock under lockdown.