Yes, Aerophilia is a sickness

[hemigeno]

With people talking about dreams involving Aero cars, I thought I'd share how my penchant for Aero cars has affected even my kids' activities at Church.

My youngest two children are involved in a weekly Church program called AWANA, and they have an annual "Gran Prix" race.  For the race, the kids are supposed to build their cars, which are run on a downhill (gravity-only powered) track.  You are given a block of wood, wheels and axles which must be used.  Unfortunately, I can't add wheel bearings, bushings or washers to make it go faster.  Weight can't exceed 5oz.  Enough of the particulars...

Anyway, I'm working with my kids to carve this block of wood into something that resembles a car.  I gave them the choice of some generic looking old sprint-style race car, or I had sketched the outline of a Daytona on the side of the block.  Of course, they both chose the Daytona profile...  I'm such a proud Dad!

Last night, my 11 year old daughter and I set out to cut her block of wood into a Daytona shape.  She did a lot of the cutting herself, but I did have to help with some of the harder cuts to make.  Overall, I thought it turned out pretty well.  She wants to paint it turquoise, although I don't know if I can find Q5 at the hardware store 

[hemigeno]

One down, one to go

[Howie]

I too have that picture framed that is under the carving. My son is in boyscouts and is having the pinewood derby car. I was given the rules which state no bearings etc etc. A scout leader whom I work with told me to put the wheels arc in at 5 degrees and have only 3 wheels touching. Less resistance. Also sand the axles with 600 grit to get the burrs off that you can not see. That is what I was told.  I do like the daytona car. Good cutting and carving. Good luck.

[PocketThunder]

are you gonna hollow out the area under the wing? 
a pillar trim?
fender scoops? 

[hemigeno]

put the wheels arc in at 5 degrees and have only 3 wheels touching. Less resistance. Also sand the axles with 600 grit to get the burrs off that you can not see.

Great tips!

Now, is the 5 degree reference for Toe-In, or Camber?  I haven't set the drill press up for the kids to drill the holes for the axles, so I can still make that adjustment. 

To polish the axles, I've thought about putting the axle pins in the drill press and polishing them up at the point where the wheels will bear.  I suppose that not too much can be done with the plastic wheels themselves.

Any ideas on what type of lubricant to use?  Seems like it would have to be a light oil of some sort to keep friction down.

Thanks,

Geno

[Howie]

In my rules it says no liquid lube. It didnt say anything about dry lube. The 5 deg is not toe in but camber I believe. I get to build one too as the parents get to race against parents when the kids are done. I was going to go with a gas tank as in salt flats racer. Wing car is good though.

Do hollow out the wing area. remember wind resistance at that speed you need all the help you can muster.

[hemi68charger]

you go boy !!!!

Those look cool.........

[hemigeno]

I don't know if I'll be able to hollow out the wing area.  I had thought of that, but my fear is that the material left would be too brittle and likely wouldn't survive the day.  Besides, I wouldn't know what angle to sand the wing/airfoil down to 

Oh, and PT, I'll let the DieCast guys worry about fender scoops.  A little tough to carve those out with a hand-held coping saw, and these definitely won't be going into mass-production any time soon.  I did think about using some silver paint for the A-pillar deflector look though.  It would look better if I whittled down the "greenhouse" of the car (from the roof to the body belt) like the originals, but I know the kids wouldn't be able to do that work.  This is SUPPOSED to be their project, but like so many others it ends up being the parent's primary responsibility. 

[mikepmcs]

Looks like another fine use for the ........DREMEL!!!!
Lookin pretty good.

[Howie]

Ya, Dremel  Go for it!

[Blown70]

Use graphite to lube, always worked when I won...

[THE CHARGER PUNK]

dammit geno now i think im gonna build one just for the hell of it-MATT

[69_500]

Ah Gene, I'll have you know that it is a sickness.

When I was 8 I did my first pine wood derby for Cub Scouts. My car, was a Daytona. I just cut the front to match the shape of the nose cone, and actually glues a plastic wing from a model kit on the back. And then hollowed out a spot in the front, to add lead weights. Won first prize that year.

[triple_green]

AWANAs 

[hemigeno]

AWANAs 

Here are the cars after sanding them up.  The kids are coming up to the office tonight to polish up the axles and drill the holes.

I suppose I should have asked a follow-up question of Howie about whether the camber for the axle holes was positive or negative camber.  Just thinking about it logically, I have assumed that it would be negative camber where the car would sorta squat down just a little lower than the centerline of the wheels.  That way, the wheel will tend to ride up on the axle against the metal end (the axles are shaped pretty much like a nail).  If it were positive camber, it seems like the wheel would have a tendency to travel on the axle shaft until it made contact with the wood body of the car.  I'm guessing the friction would be less with the wheel riding against the metal end of the axle rather than against the wood body of the car.

If I've got it backwards, oh well... there's always next year, right?

[THE CHARGER PUNK]

Sweet , u should get a dremmel and cut out those wings

[Brock Samson]

very very cool   

[hemigeno]

Sweet , u should get a dremmel and cut out those wings

See my earlier post:

I don't know if I'll be able to hollow out the wing area. I had thought of that, but my fear is that the material left would be too brittle and likely wouldn't survive the day.

My son is 8, and Hot Wheels cars tremble in fear when he plays...  Heck, marbles tremble in fear when he plays...  There is NO WAY the wing would last more than 10 minutes, and it just wouldn't look right with a nosecone but without the wing.

[69_500]

This weekend when I'm in the attic putting up stuff, I'll see if I can dig up my pinewood car from when I was little. It was painted R6 red, and it had a plastic wing on it from the  model kit from the early 80's.

[hemigeno]

That'd be cool to see your old Pinewood car if you can find it, Danny.

The kids came up and worked on the cars tonight as planned.  Here are a few "action" shots and the "finished" products (for tonight, anyway):

[mikepmcs]

that's what i'm talking about.  Teach em young!!!

Way to go Dad!!!!!

v/r
Mike

[whitehatspecial]

This thread makes me miss the pinewood derby days. I can share a tip that worked well for us. Besides polishing the axles (I had the kids put them in a cordless drill and use 1000 grit sandpaper, then polishing compound), we tapered the inside surface of the axle (nail head) so it was slightly cone shaped. That way the wheel only comes in contact with a very small area of the end. Graphite was the only lubricant allowed. 

[70charger_boy]

Looks like a wingcar that I can afford

[taxspeaker]

So now Gene, 13 years later-are the kids of these 2 working on wing cars for soapbox? Sure hope so! The old threads are as much fun to read as the new ones sometimes.

Bob

[70charger_boy]

Wow, thanks for getting me out of retirement

[XH29N0G]

This is way before my time at DC.com. 

What a gem.  kids, cars, and aero.





Makes me feel good to see.  I have a son about the same age who always loved automotive aero and hopes to make that his profession.

[moparchris]

Reminds me of when I used to teach an Engineering course in high school.  One of our first projects was designing a co2 powered drag car.  The kids had to design the car in 3-d modeling CAD and then build it to spec.  I then set up a racetrack in the room and we had a couple of days of "eliminations" for fun.  One time the kids asked me to build my own car so they could race the teacher.  I build a goofy version of the Sox & Martin 70 Cuda,
Painted it Red,White and Blue.  I think the teacher ended up winning the eliminations LOL!!
This also gave me a wonderful excuse to take the kids on a field trip to the Winternationals at Firebird Raceway. Then they could see the physics involved in real race cars.
This was when you could have fun being a teacher.