ibkevin

+1

Also, take some tools with you just in case the judges scale says your car is over weight.

JPTL

Nice effort w/the 928 - particularly the inset wheels.
My sons & I have done the Pinewood for a couple of years now. Because they were so young, the first year I helped them considerably and both won 1st in the den's age class, then made it to the pack finals.
I was feeling a bit guilty about "Dad's" entries going to the pack finals until our car got spanked by a car that was so much of a product of "Dad's" efforts that I'm not sure the scout even touched it during its creation. He was allowed to touch it for the pictures of him holding his (Dad's) car on the podium. Seeing this made me realize the importance of the scout at least being involved in its creation, sharing some time with his dad and learning about physics. The winning car was pretty much a wedge with hot-poured lead as a ballast.
Last year my youngest son drew what he wanted his car to look like. It looked a bit like the Green Hornet's car. I helped him get it shaped, painted, etc. and had a pretty heavy hand in its finish (pics)...but he completely understood what it took to make it fast. It was really fast & made it to the pack finals, but still as a result of my tweaking it.
This year my oldest did his completely on his own. It was respectable, but didn't make it to the finals. What I did notice was how proud he was of getting so far with his own creation - and even beating some 'Dad' cars.
In addition to some of the things that were said:

• Make sure that the insides of the wheels make as little contact with the body as possible & get graphite on those contact points.
• After buffing the burs off the wheels (avoid flat spotting) get a thin coat of graphite on the 'tread' area of the wheels. Graphite will keep the wheels from picking up tiny crumbs and sawdust, etc. from the track. The tiniest bit of crud sticking to a wheel will be the difference between winning & losing.
• It's possible to put too much graphite on the wheels/axles. Too much will slow the car down.
• Max out on the weight. Get to the max. allowable weight. Harbor Freight sells little digital scales that are great to have on the day-of in the event that something falls off, or it comes in too heavy at weigh-in.
• Alignment is critical. Test drive the car several times to get it to track correctly. Going from side to side on the track is what slows these down.
• A tiny bit of toe-in is better than toe-out. A negative camber also helps to keep the wheels out at the nail ends & away from touching the body. Too much negative camber however, and the inside top of the wheels will rub the body.

leperboy

Our Pack has a Dad division and a Kid division. The dad division has no trophies or awards. It's more about bragging rights and fun. Here are my seven-year-old son and my car so far. You can guess which is which. He wants to win the trophy for "Most humorous". I'm just having fun pretending I'm a car designer. For both of us the only power tool used has been a Dremel. Otherwise, all hand cut and sanded.

Tony

Love the 928!!!

Sitting in the garage...bare block in hand...reading the notes!

Fun stuff. My son wants an F1.

We have the design penciled in and i have a scroll saw ready to go.
Granted he wont "build" the entire thing but my take on the spirit of the competition is to show my son how to use some of the tools we plan on using as well as some of the physics involved. Design limitations...designing within a ceratin set of rules...etc etc.

I never did this as a kid, so this is all new to me.

Question.

We put our wheels in a power drill(poor mans lathe) yesterday clamping the chuck down on the axle area. My son pulled the trigger and held the drill steady in the vice and i used a sharp carpet knife to "razor" the wheels. they are now nice and skinny, but still the "stock" wheels' I had heard people doing this, but now i see some of the rules on line and you cant drill "alter" the wheels"........yet there are websites that sell wheels that go completley against all the rules have read?

can you turn the wheels and make them skinnier? They are currently still the same rolling diameter but skinnier.

Rob Edwards

The only rules that matter are the ones the scrutineer in your local Scout pack follows. We were allowed to smooth the wheels but could not affect the width of their contact patch with the track, so no knife edging.

Tony

ok...all i have are the rules in the box? I guess i better check with some one.
Thanx


What do you guys use when you have to add a bit of weight? Lead sinkers?n Tire balance weights?

leperboy

There are a lot of choices. You can drill a hole and melt led into it. You can use sinkers, or coins, or tire balance weights, or gold tooth fillings or silver ingots. Basically anything with high density. I used fishing sinkers last year. Put them in a body cavity and put some gorilla glue over it, and ended up having to tape a quarter to the rear of the car on race day.

I suggest if you use something permanent like lead melted into the body, come in slightly below on your scale just in case there is variation with the scale at the derby. You can add a little at the race if you need to.

Matt

Rob Edwards

Rout out a cavity behind the rear axles + big steel washers + Elmer's wood glue. The glue allows precise adjustments in weight. Leave plenty of time for the glue to dry, like a week or so. 1/2" of glue turned out to be slow to solidify....

My father drilled the nose of my Bugatti type 35 in 1977, and filled it with lead shot and kleenex. Can't get lead shot in California now. In fact, my Pinewood derby car is known by the State of California to cause dain bramage and cancer.

Tony

Il post pics later but its actually looking pretty cool. Issue now is, it is pretty darn light! I went to the tire shop to get some old weights that they rip off rims. We dremmeled a cavity underneath as far back as possible and now will hot epoxy them in.

Its the wheels and the axles now that we have to do some more research on.

Did you guys 'pre" positions your axles so when the car sits the camber is zero?
if you drive the nails in straight the wheels tend to tip inward..negative camber.???