pinewood derby-o-rama

[robriley]

well, i thought it post a couple of pics. of some pinewood derby cars.
My son jackson is in the cub scouts and the pinewood derby race is march 26th.
here is his car that we built together.
the wheels that are on it are the ones that we have to use...and they are ugly...but we are stuck using them.
this car was a block of wood when we started. i just cut the simple wedge shape, and jackson sanded it all smooth. i used my dremel to make a hole for the skull head to be recessed into so it looks more like he is "in" the car, rather than just setting the skull on top of it. He also put the wood sealer on it after it was sanded, and he sprayed the first coat of green paint (not bad for a 7 year old).
the green is testors laquer, and there are 2 coats of testors clear laquer over it.
There is a full metal chassis under the car for weight (the cars have to weigh no more than 5 oz.) the boower and roll bar are also metal for added weight, plus there is a little weight in the skull. there is a parachute out back, and it's covering a 3/8" hole in the back of the body that has weight in it. This car weighs 4.987 oz.
Jackson picked out the decals and he put the flame decals on (i put the name decals on the sides). I polished the cheap nails that they give you for axles, and i also smoothed and polished the tires. We are aloowed to add dry graphite to the wheels and axles for lube.....we can not use any sort of "wet" lubricant....we are allowed to use dry lubricants such as graphite powder. whe the polished axles and the graphite, these wheels spin like they have bearings.

and here's my car....the adults are going to race when the kids are done with their race. I have been issued a challenge by one of the pack leaders, and he put up $20.00 to race against me.
so, i got a block of wood and started cutting and carving...and here's what i came up with.
I cut pockets under the car with my dremel, and stuffed them with weight. (we are following the same rules that the kids have to follow). the zoomie pipes are metal (more weight) and there is weight stuffed inside the skull. i used my dremel to cut out an ares for the skull to be recessed into. the paint is testors gold and purple laquer that i faded by using a ziplock baggie. i put alot of clear on this one to really make it shine. I did the same routine to the axles and wheels for my car (and yes, this will have the same exact wheels that are on jacksons car).
i think after the race, i wil put a set of fat mpc slicks on the back, and some skinny dragtser spokes on the front to make it look cool.
my car weighs 4.995 oz.
oh yeah, i sprayed my skull with glow in the dark clear, so he has the nice erie green glow when it's dark.

[flatheadgary]

man! it never ceases to amaze me how talented some of you guys are. what a great imagination to come up with these. nice job!! let us know how you both do.

[mykturk]

Pair of great looking very cool cars!
Here's a tip, if you have time or for future use, try and center the weight as best as possible, that way, no one axle has more weight than other (more weight on an axel will create drag, however minute, and you want as little as possible.)... Do some test rolls and see if they pull to one side or another, you want it to roll as straight as it can, if they rub the track sides as they go, that's drag too. One last thing, I always have a few extra small screws in the bottom and take it right to the weight limit, if it's over at check in, remove screws till compliant. Good luck to you both! Hope you come home twenty dollars heavier!

[robriley]

yep that's exactly what i did with the weight. the green car has a full metal chassis under it that is balanced.
the purple car has "log" weights under it, and they are centered between the axles. there is also a small weight behind the rear axle right in the center, and the same size weight in front of the front axle in the center.
we have already done test rolls, and both of these cars are fast and they roll straight.
i have spent alot of time making sure that everything is straight, smooth and balanced.
actually i think i've spent a little too much time on both of them.
after seeing some of the other cars that will be competing, the 2 that i have are way over the top.
no one has seen our cars yet, they will be revealed on race day.
the rules are pretty strict as far as weight, car length, height, clearance underneath, axles and wheels. but we are free to use whatever we want for weight.
both of my cars have weight that can be removed if needed.
i used a digital mail scale to weight them while building them.
but, that's not saying that the scale i used will show the same weight as the official scale will at weigh in. that's why i made some of the weight removeable on both cars.
i think i am one of 2 dads that has REALLY gotten into this.
there are about 25-30 kids in Jacksons pack, and the majority of the dads are not good with tools.

[badroadahead]

Very nice cars. Love those skulls and blown engines.

I used to build these with my son and had lots of fun doing so. One year the adults built cars, I built "Jaws" the car looked like a shark....didn't win though.

One of the guys I work with has won for the secong year ina row told me that he only has 3 wheels touching the track. This he explains removes some friction.

GOOD LUCK!!!!! With the work you two have done it's a sure win!!!

Dave

[robriley]

yeah there are a few tricks like that.
the car has to have 4 wheels, but it does not say that all 4 have to touch the track.
one less wheel creating friction could be the difference between winning and loosing.
you can also install the wheels at a slight angle, so that they are riding on the extreme inner or outer edges, and not on the flats on the wheels.
the first thing i asked was if we could slice the wheels to make them thinner, but i was told no. the only thing we can do to the wheels is to sand them smooth to remove mold marks, and polish them.
we can not round the "tread" or re-shape the profile of the wheels at all.
i did chuck mine up in the dremel, and sort of trued them up with out removing alot of material.
the wheels are crappy, and they are not prefectly round, but i made ours better.
i will also use dry graphite on the axles because we can not use any type of wet lubricant. we can use dry lubes such as graphite.
looks will not have anything to do with winning a race...but i wanted our cars to at least look good and to stand out when everyone looks at them. they do pick a best looking car before the races start.
if we don't win...and least we'll look good trying....lol

[moparmarc]

Ah the fun of pinewood derby cars! Here is my son's from last year. The paint is dupli-color and most of the decals are from the Crusader chopper kit and the head and taillights are from the scrap box.
Hosted on Fotki
Hosted on Fotki
Hosted on Fotki

[gfgcollects]

Good ones Rob, and these are great father/son projects. Up here we call them KubKars and it's been about 18 years since my son and I did a couple of them. I'll have to dig them out and post a couple of shots, if you don't mind.

Gerry G