[B]Who's Gettin Ready 4 Pinewood Derby's?[/B]

I grind out a hollow spot just in front of the rear wheels and fill it with lead body solder.

 

I don't have any kids but, did participate in Pinewood as a kid. My church is having an Awana Pinewood derby work shop tommorrow. I offered to bring out my AA/Fuel front motor dragster to display for the kids to sit in, get pics and ask questions. Have any of you thought of displaying real race cars, or hot rods, at these events to show the kids? Many do not normally get a chance to see race cars.

Steve
www.pontiacheaven.org

<DIR>Hosting 11th annual Pontiac Heaven, show, swap, drags, party and all around good time. Saturday April 4, 2009 at Speedworld near Phoenix, Az
Also hosting- 7th annual Nostalgic Show and Go! and swap coming Sunday April 5, 2009 to Speedworld. Phoenix, Az
</DIR>

 

This will be my 8 year old's 1st pinewood build. I never did it as a kid and know nothing for tricks so everything posted so far has been great. Any additional tips you guys can give would be greatly appreciated. I just hope I can resist the urge of totally taking over the build and let my boy do most of it.

 

My favorite year with my boys was when we seriously streamlined a car hoping for better speed. After getting smoked a couple of times I put it on the track backwards (square end) it was faster that way. So much for streamlining.

 

I should clarify that where you want your weight is entirely dependant on the track you run. Our pack has been around for 63yrs now and has one of the fancy four lane alum. tracks. It's half down and half out, so you need a car that's fast both ways. Sometimes a frontrunner on the hill will be overtaken by a rear weighted flatrunner. That's just how it is in rodding, finding the best compromise for your environment. And again, find some good wheels,***(I meant to say that the internet Wheels for no allowed mods are garbage)*** I haven't even counted how many we've accumulated that are only good for holding up a mock-up during the build! Another thing new guys might find useful is our use of wire coathanger-made U-shaped stands that I grind down to axle size and slip into both front and rear on ea side. They're great for holding it when it comes time to paint but be careful not to break open your axleholes knocking the car around. The kids always seem to have msihaps during the build and out comes to ole epoxy agin! Oh, and when it comes to paint use a sanding sealer before primer to get a good finish and when topcoating we always squirt graphite into the clear around the axle holes while it's still wet!

So let's see if I can share some pics here...
Starting with progress last year then on to my daughter's Family Div cars. She ran Sally. I build while she chatters endlessly! Such a prayer answered of a little girl! Then she sprays em. and again supervises my detailing! the watercolors wore offa her 355Ferrari.
My boy's cub cars. He's better than I was at his age. I like to think I've been a good mentor. I wish you could see the paint on the one lookin like a sand-dragster!!!! Like green pearl crackle glass! We messed it up and spent a week spraying, baking, sanding, repeat to fix the clear and it was AWESOME!!!!!
And mine, The King and GT.
Sorry, no HAMB specific stuff, Closest is the Indycar inspired one that grampa made for him his first year. Wasn't competetive, so I used that as inspiration for him to work on making each one his own statement. He's always won since! 1st, 2nd(cuz a car axle-boned him on the rebound from the semi win) and 1st. Style of builds is all pretty random as to what the kids want to do!

 

Just looked back thru this post and am Amazed at how COOL you guys's stuff is. Wood, steel, sometimes you can just SEE the heart that goes into a car of any scale...

So here's my progress on this year's car. The only one started so far.

 

Man this thread got me teary-eyed! My lil dude will be 2 next month and just learned how to ride a bike (see my sig) and I was thinking of Pinewood Derby and Scouts today as I unpacked all my cars! ONE OF THE BEST MEMORIES I HAD AS A KID, OF COURSE I WON 2 outta 3 years!


www.stridertk.com bikes for 2-4 year olds!

 

Nice to hear a few of you guys are actually letting your kids do most of the work. Derby cars that look like they came out of a design studio are cool looking, but hardly a true father/son effort.

 

Those look a little intricate for a cubster to build.... I remember when I was a cubster that I had to do most of the building. I even remember bitching about how they other boys cheated because their dads built their car and thats why I lost, he he! Isn't thier rules about how much dad helps, weight limitations, wheelbase and such?

 

I'm pretty proud of my boys designs! We went to the craft store and got a set of french curves and got a scale ruler among other tools at the hobby shop and I printed out some car block outlines I made on graph paper and let him start designing cars like the ones he sees in alla my carmag's! Then I set to training him with the Dremel and turned him loose to tear up some pieces of 2x4! (And the occasionally scuffed finger!lol) Man it's all about imagination and training! Anybody can make something that looks like design studio work! Just look at all the great cars posted here already!
Tho I admit to helping him Alot to get the Corvette he wanted, I didn't do more than asked to help with.

 

i'll just say
having the axles just not quite straght across from each other
then if 3 wheels are set at a slight angle so tire tread surface is not flat (castor out)

and the fourth wheel is set up a little bit high and the balance is set so the car will rock front to rear when put on the incline
it will have a natural tendancy to ride on the edges of two wheels 1 front 1 opposite side rear
reducing surface drag , self centering on the track

now having the lowest profile slab shape that equilizes lift and downforce
no wing shape! mirror image profile
slightly wider in the nose tapering narrower at the rear

you'll have a winner

we did this all by accident and beat out all local cars

after the fact we examined the car for the reason it won so well ...

mostly just a quick eyeball (no measuring) during set up and work done by a eager scout

 

Here is out last Cub Scout pinewood dirby cars. My son made the blue one and I made the pink one for my daughter to race.

 

In December 2000 / January 2001, I "helped" build my nephew's racer ... a '32 5wd "Bonneville Competition Coupe":


click to enlarge

It was chopped, channeled and painted '56 Cadillac 'Mandan Red' ... just like his Grandfather's Hot Rod (except gravity powered vice HEMI powered ) ... IIRC, he took first place in his class (he was a Tiger Cub) ... and third for the entire Cub Scout Pack (I still say those fathers cheated! ) ... He also got an award for "Best Looking Car" (or something to that effect).

Here's some more HAMB friendly Pinewood Derby cars:

 

There are some good tips here so far, and I won't go into some of the "cheats" that I have used, But here is something that I have found that will give you a starting line advantage.

In the picture below. The car has a silver nose wing. It isn't a wing. It is a "start bar" The track we used had pins to hold the car on the start line. To start the race, the pins rotated forward. The "start bar" is mounted high and is made from brass wire so that I can adjust it so that it rest againt the pin as high as posible. when the pin rotates forward, my car gets a head start. This also works on starting gates that drop straight down. If your stating gate moves up, bend the bar down to just obove the track.

As mentioned before, wheel size is important. All of them must be the same. I see that some of you have tried to narrow the tread like a knife edge. this helps rolling resistance at the tread, but it created bind at the axel. It is better to have a slight dish on the tread surface so that the wheel tracks true. This creates knife edges on the out side edges of the tires reducing the flutter or ossilation of the wheel on the axle.

I also put teflon washers on the body and head of the axel where the hub of the wheel rub. glue them in place or there is no benifit.

Weight transfer is a speed secret too. If your track is a long incline, it is better to have the weight in the front. If your track is a steep hill with a long flat straight (50/50), the weight should be as far back as you can get. The track this car raced on was a 50 / 50 track. Streep hill, long flat straight. Many of the kids cars stalled on the flat not making it to the finish. This car seemed to accelerate to the finish.

 

Force = Coefficient of friction x weight (Normal force).

Unless you know your axles are super smooth with a buttload of graphite, extra weight can slow you down. The cars are more or less equal to the bottom of the hill (They accellerate at ~32.2 ft/sec per second, the inertia / momentum takes them to the finish line. In a nutshell, three times the weight means you HAVE to build up extra momentum. friction also works against building up momentum...like riding the brakes on the hill AND on the flat. More or less, this race is more about reducing friction.
I'm thinking this year I will set the car up so we can adjust the weight after the competition is over and see where the point of diminishing return is on added weight.

 

Here is a pic of the two cars I could find, my wife put the other two and my trophys some where that I can't find them. There alittle beat up and dusty from 25+ years of storage. The wheel covers where legal then and kept the graphite in contact with the axles through all the races.

 

Etboy

Where did you get the old style wheels for your cars?

 

I always extend my wheels as far as possible on the body to stabilize the car. Also buy at least 4 car kits to pick four good wheels. I put them on a high speed lathe and true them up and put a slight round taper to the wheel edges. Check the inside of the nails for small burs, we also polish the nails on a dental lathe. We also put a small notch in the front of the car that rests against the starting pin to give the car a slight head start. Good luck, Ron.

 

[ The graphite comes outa the tube too course, so we grind it with mortar and pestule(sp?) then apply some to the installed wheel and wick it in with rubbing alcohol on a #1 brush, push in with a toothpick, repeat. It's mostly wheels and axles.

what does wick it in whith rubbing alchohol mean?
i went to hobblobby a baught a mortar and pestule $2 it makes sense to make it finer thank you.

 

Since the rules specifically say that we can't use anything but graphite, I figured that letting the graphite ride into the oversize hole between wheel and axle on a disolving fluid like alcohol would be fine. Wicking would be like how a wick picks up fuel and carries it to burn in a lamp. Just make sure you've got good spinning wheels before wasting time mounting them up. Crazydaddyo explained why our wheels track so well! Did it by accident too! By chucking the wheels in my cordless drill(my drill press sucks) and turning them on the sandpaper to smooth down the casting dimple it turns out that we have dished out the center for even less track friction. Good wheels, SUPER polished axles(no rules about what we can do to those!) are about all that seems to matter as long as there aren't appendages grabbing wind. I tried to handicap myself with the"King" superbird. 3/8" high @ front so it 'd be slow outa the gate, steeply inclined windshield and a wing of questionable aero. Whooped alla the wedge's again. So have fun designing yer car, don't let speed guru's dictate it to you!

 

Well, We just got back from our pack race. My boy took 1st in his den and 4th overall. Pretty proud of him, especially considering it was his first and he is only 7. I did spend 2 hours polishing and prepping the axles and wheels....
My car (open class) took 1st. the wheels would stay spinning for a good 45 seconds after the race!

 

lets see a pic of the creations you guys raced
and congrats to your boy

 

good tips here for sure, let me add that putting the weight in the rear goes faster, so does a longer wheel base and here is the best tip of all, a 3 wheeler goes the fastest, bend up one of the front wheels.

 

We just raced for the first time last weekend. My son took 6th place out of 58? cars. He could of cared less about winning though. He had a blast! I know what we will do different for next years build.

 

We just got back from my youngest son's Pack Championship and we kicked ASS!!!! It was our last Pinewood Derby.....four sons spread over 16 years and we did not lose a heat race. Yeah, we are not proud of kicking the butts of those kids who built their own cars, but this was it....our last chance to kick the ASSES of those shits who have been cheating their way to the top over the years!!!! Cheat? Kind off. We got FASTER each run!!!!!! I gave my son the choice (given that this was his last attempt) of building it on his own or "goin' fast" and he chose the latter...."Dad, I am tired of those Dads kickin' our butts."

OK, call me a shit and I accept the kicks to my knees. My son is elated and the little shits who "owned" the Pack Championship with their cocky Dads can kiss our butts!

"If you ain't first, you're last!"

Shitty Dad

 

Here are our winners. The black "Champion" car with the trophy is my 7-year-olds. I did the big cut, he sanded and painted it. I prepped the axles (with his help) and he tapped them in place, then I adjusted them for 3-wheel action. I polished them then sprayed them with slip plate, which is a dry-film lubricant (spray on graphite is what it is) and buffed them. The wheels would spin for a good 45 seconds after the race was over! I did the same to my car, the orange top-fuel car. My 7-year old picked out this design, helped sand it, but I felt like I did too much so I had him build one by himself and I raced the orange car. My younger two got to help so that they could have a team racer, which we rode all the way to 1st place! I was really impressed with my boy, he was a very good sport, claiming "why do I keep winning? this is crazy" and not getting sore when he got beat in the pack championship races. My nephew (also in my den) won 3rd in the den, so I am feeling pretty good. I prepped his axles too. I took 4th in the pack championship in my first race too, it was pretty neat.
I used lead body solder for weight on my car, which came in at a svelt 4.7 ounces. My sons car used the trophy topper and the hotwheels car for a total of dead on 5 oz. we had a lot of fun. Can't wait till next year.

 

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I understand what you are saying, but I just hope none of the kids in my pack think of me as one of those dads. My boys car was simple, he built it himslef with a little guidance and instruction from me. and I prepped the axles which where the majority of the speed comes from, that and weight distribution. I know that my orange car looked like a dad built it, at leaste compared to the other kids cars, so if I had let my boy race that one, it would have looked really bad and considering I am the den leader, I didn't want that to happen. my car would have smoked all the other kids' cars, it had one car that was competitive in the open class and I beat it 4 times. the one loss was the time that for some reason my car jumped the track. only car to jump track the whole day. it was odd. Congrats to all the boys and dads out there. Its all about having fun and maybe a little about trophys....

 

ok on the dad built topic i think a dad needs to be right be side the boy and guide them help draw a line or 2 show them where to file and sand. i am also a cubmaster and in our pack we have a build night dads bring down band saws belt sanders wood fiels lots of sand paper ect.and we all work together to get started. we also have a hand full of single moms this is real good for their scouts. now dad doing all the speed tricks to the axels i think is ok to just have jr beside show him what and why you do it.i think it is a great chance to bond with my boys.

here are last years cars i ran the saw they sanded and field thier ass of probably why we are going simpler this year

 

When my boy and I did the axles, I had him running the drill while I worked the files and sand paper. I explained to him all about why we were doing it. We had fun.