OT--Pine Wood Derby--got any tricks?

Just wondering if any of you fellers have any tips on how to make the fastest machine...I wanna stay legal but at the same time would love to see my boy win the trophy...he would get a big kick out of that!!!

Thanks in advance!

PS I would call it a knife edge on the wheel.

just my 2 bits dont me to rile anyone

Mark

Sounds to me like another activity that becomes parents competing against one another. What the heck does that teach a kid?

Maybe they all ought to get the same kit of build materials and have a fixed amount of time to put it together.

Some of these kids will grow up to be guys who spend $20,000 to run pre-1960 tractor in out-of-the-field tractor pulls.

Talking about this on the phone with my son. He said they're sellin these cars on ebay already made for $250.

Joe

Brady

But the important thing is for your kid to have FUN. You don't have to win to have fun. The time that your child spends with you building the car makes the kid a winner. And please be sure that you let him make the car.

Win or lose children must learn to be a good sport. I have seen parents come unglued because their car did not win. Then you hear dad say how much time HE not the kid spent on the car. Most kids that age have fun watching the cars go down the track. Just my 2 cents from 25+ years of scouting.

Run with maximum amount of weight allowed.

Center of gravity about 5/8" in front of the rear axle. You want it back as far as possible which places the weight as high as possible for the start - this is the potential energy that makes the car go (the change in the height as the car travels down the ramp), but too far back will make the car unstable and "hunt" as it travels. If you have time, play with the CG.

Long wheelbase - as long as the rules allow.

Low profile.

Polish axles. Polish them again.

Sand wheels true, crown them so you run on a line around the wheel, not the full wheel width. If you can, take material off the wheel to make it as light as possible. The weight needs to be "up the ramp" and not tied up in the wheel. An arbor for your drill to mount and turn the wheel is needed, look for one at the hobby shop.

Run a pipe cleaner covered with powdered graphite through the hub a zillion times.

Run on three wheels. Lift a 4th front wheel about 1/16" off the track. By having the CG way towards the back the car will run fine. Or run two on one side and offset a wheel towards the rear on the opposite side. This design will win, but it needs to run stable and true, so some risk in trying it.

Study the starting gate and mount a front edge (spoiler or bent wire) to contact the pin as high as possible as this will give the car a split second advantage at the start. You often win the drag race with the hole shot, and there is no risk here of leaving too soon.

Graphite for lubricating the wheel bearings. Use too much, work it into the hub, rub it on the wheel tread too.

Don"t run the wheels too tight, ~3/32" lateral movement on the wheel.

I cut a slot square with the wood body blank and epoxy (JB Weld) the wheel axles in place. It"s a real disappointment to be repairing the car at the race. Don"t get glue on the wheels!

Go for the design award with a novel theme. My daughter won recently with a canoe and teddy bears floating on "water" (painted wheels blue amoung other details). The fishing pole made from a paper clip, bead, and thread, complete with hook and worm put it over the top. We did all we could for speed, but the aerodynamics of a fishing pole and teddy bear are rather limiting...

Have fun.

Then stand back and watch, the boys are there for fun, the adults are there to win. I've seen some real shady tricks the adults try to give their kid an edge. Kinda sad example of what the kids are being taught.