Pine Wood Derby Secrets????

[Jack Diemer]

I am about to experience my 1st Pinewood Derby in the next week or so.

What are some of your best tips to make the cars go fast?

I use some kind of Teflon spray for my table saw top. Should I be using this on the nails, or would this create extra friction between the nails and the graphite. Any comments appreciated.

[Gary Max]

Jack the two key factors are weight and fricton.
If you do a internet search you can find several sites about pinewwod dreby's.
Getting the nails polished and 5oz in the right place--that's the trick.

[Mark Patoka]

Jack,

I was in the same situation as you a few years back with my boys. As was mentioned, you'll find a ton of info on the net. Someone even did a scientific study on exact placement of the weight distribution for optimal performance.

From my experience, the most critical is that the two axles are parallel so the wheels run true. Some people will trim the wheels to make them skinny thus reducing friction. I also let my boys polish the heck out of their axles and they would spend a lot of time sanding the finish.

Just make sure to follow your organizations rules such as no bearings or washers or liquid lubricant if they apply. We had to eliminate a few cars in the pre-inspection for using those things.

[Steve Ash]

When my son was in it, I got a tip from someone who told me that if the car needs weight to bore out a hole near the front of the car, fill with fishing sinker lead (getting it to the weight limit of course) and then seal it shut with hot glue.
His idea was to put weight forward to aid in the drop of the auto to the bottom of the track. My son took second place, so I guess the young man in first had a better secret....Good Luck!

[Dave Brandt]

Definitely getting the axels parallel is key. I'm not so sure about the weight distribution theory. My son's car (a few years back) had the weight towards the front. Funny thing was, his car actually ran faster we he placed in on the track backwards! Polish the axels using your drill prill and also spin the wheels against some sandpaper or emery cloth to eliminate any form leftovers. I'm not sure if it's allowed, but maybe even try shaping the wheels so they come to more of a V shape (less surface friction). Good luck.

[Michael Stafford]

Rub powdered graphite into the wood surface where the wheels meet the body and use powdered graphite on the axles. Make sure the head of the nail where it meets the wheel is polished smooth as glass. Axle parallelism is key as is the initial lineup at the release as the farther the car drops down the track before hitting the guide strip the faster the speed is at the bottom...Have fun and let your son build the car...

[Chris Padilla]

http://www.pinewoodpro.com/

Go nuts...even getting top of the line stuff is no where near the cost of our ww'ing addiction.... :) ...though it approaches it! ;)

[Chuck Fischer]

You know I'm no scientist, but wouldn't putting the weight toward the rear of the car make it faster... because if the cars are pointed downward as on the track I raced on, then the car with the weight highest from the ground has greater kenetic energy, doesn't it?

Well the guy that beat my butt had a wedge design with all the weight in the rear and he cut most of the center of the car away so basically he had two rails running down the sides of the car with a cross brace in the front and a cross brace in the back so that if the car bottomed out there would be very little surface area to rub on the rail... thus eliminating friction. My car had better wheel alignment, but he took the gold.

Chuck

[Jack Diemer]

So far here is what I have done. (with the help of my son of course)

1. Filed, sanded and polished the nails.
2. My son had the idea to build a bone shaped car with a dog driving. In all my internet searching, I had not seen that, but I am sure it has been done before.
3. I moved one axle back (within a quarter inch) which is legal, I did this because of a mistake, not to make it go faster. (I did use Oak instead of pine on the new piece, I am wishing I had used ebony or purpleheart)
4. Painted the car with white enamal, then I sprayed it with a clear gloss paint, and it ruined the paint job. Did this twice before I realized that it wasn't going to work.
5. Drilled two holes for weight, one in the middle, and the other in back. I filled the back with about two ounces of sinkers, and I filled the middle with 4 dimes. Total weigh equals 5.1 ounces. If it weighs heavy, and can remove up to .25 oz by taking out the 4 dimes.
6. On the last coat of paint, I drizzled the graphite all over the sticky paint where the wheels will rub.
7. The only think I have done to the wheels themselves is sand off the burr from the injection molding machine.

Here is what I haven't done.

1. I have not attached the wheels to the cars. I will do this tomorrow paying very good attention to allignment.
2. I have not cut any slots in the nails to allow less friction. (don't think I am going to)
3. I have not used any dry teflon spray on the nails heads. (I am still trying to figure out if this would help)
4. I have not tested the car
5. Have not posted pictures here yet either.

Now the totally original idea I came up with.
1. Everyone goes on and on about how the graphite makes everything work so much better, but my guess is that after the 1st race or two that all that graphite flies off. My idea is to build litte reservoirs by each wheel that hold graphite and slowly feeds it to the nail head. It would have to be done with a very small drill bit, but I figure if I can keep constant graphite on the axles that our car will do better in the later rounds. (you can never touch the car after the race starts. My thought is that the little shake from stopping the cars at the end of the track would drop a little bit of graphite.
2. I will post some pics once we get done tomorrow.

[Dan Mages]

Best of luck with the car!! I wish I had this info available to me when I was building mine 20 years ago!!

Dan

[Martin Shupe]

Jack,

You might consider canting the wheels 3 degrees, so that only the inside edge touches the track. Usually tapering the wheels themselves is illegal, but canting was legal in my area last year, and it works!

You will have to drill the axle holes at an angle to accomplish this. I got an angle vise at Woodcraft that was able to hold the car still at the right angle.

[Bob Smalser]

Pine Wood Derby Secrets????

Yes.

Let the boy make his own car with the bare minimum of help and enjoy the experience...forgetting about being competitive.

The kids have just about the same amount of fun whether they come in first of thirty first and get a whole lot more out of it if the car is "theirs" rather than "Dad's".

There are so many hypercompetitive, heavyhanded Dads out there living vicariously through their kids that what it takes to win is usually counterproductive to what the child should take away from it.

We've still a couple-three cars still after 20+ years around mounted on little display stands I suspect wouldn't be there if I was the one who did most of the work on the cars.

[Jack Hogoboom]

Jack,

Make sure you check the rules. For my boys, using graphite was illegal.

Here are the tips that have served me well with two sons:

1. Flip the block around so the front is the long end.

2. Try to get as much weight out of the body as you can.

3. Put as much weight as you can at the back of the car. The weight is then higher up and has more potential kinetic energy.

4. Wax the wheels and the axels. Don't forget to wax where the nail head contacts the wheel.

5. Make sure that you don't press the nails all the way in. There should be some gap between the inside of the wheels and the body of the car.

6. Definitely cant the wheels so that less than the whole wheel touches the surface. If you're really good, try to make it so only three wheels touch.

7. Make darn sure the car runs as straight as you can. If the car hits the side of the track, it wastes energy.

8. Wax the body.

9. Make sure your son gets to design the car. After all it is his car. The shape is irrelevant as long as it's light and the weight is in the back.

My youngest took second place yesterday and was tickled to death. :D

Have fun!!!!!!

Jack

[David LaRue]

When I was a kid I raced a pine wood derby car I made myself completely. I made it to the finals with the car, but in the final round my axles came flying off (along with the car from the track) The problem was I used a tube of cement but it was porcelain cement, not a wood glue. Ooops! I certainly leaned the difference between adhesives after that, and to get Dad invovled early! :(

A while back I helped a friend make a pine car with their kid. I had lots of fun! The car did not come close to winning due to the wheel alignment issues notes in posts above. But hey it looks cool! ;)

Top View
http://home.comcast.net/~mywoodshop/assets/images/PineCarCanopyup.gif

Side View

http://home.comcast.net/~mywoodshop/assets/images/Side-View-of-racecar-crop.jpg

[Marshall Harrison]

Bob was right. This is your kid's race and he'll have fun regardless of where he finishes.

I finally stopped doing the races as I let my kids do their own cars but the races were so "rigged" by other fathers building the cars and the kids having nothing to do with it. My kids had fun building their cars but competing with adults took something out of it.

Too much copmetiveness any everything kids do these days for there to really be much fun.

[Rick Whitehead]

Amen to Bob's post. It's the kid's race,and they should be the ones competing, not the dads.
In our church, there were two dads whose kid's cars won the speed category every year. I knew we couldn't compete with them on speed, so I always encouraged my kids to compete in the design category. And they did win a couple of times in that category.
Good luck with it, and HAVE FUN!!
Rick

[Jonathan Shaw]

I remember my pinewood derby car. It looked kinda chunky and had a messy paint job, somewhere between gold, copper, and bronze. I had a lot of fun making it. I, too, am very much appreciate that dad helped me as I needed help, but did not in any way make or design the car for me. Of course, I've never been the competitive type...

So I guess this is an odd first post for me! I'm just getting started with woodworking, and have learned a ton from reading everyone's posts for a while. Thanks! I'll post some pictures once there is something to post a picture of. :)

Jonathan

[David LaRue]

Let me be the 1st to welcome you to the creek. Pull up a stool and set a while. It's a nice place to be, and share your ideas, and expeiriences.

So, jump right in, the creek is warm. :)

Dave

[Jack Diemer]

Some more insights, Having a woodworking shop, I had all the 1st graders form the den come over and get their cars started. The kids drew the cars ahead of time and then the dads helped shape the cars. Most of the kids painted their own cars. I think the kids really enjoyed their 1st woodworking experience and some of the dads too.

My son totally designed the car (all his idea), did all the decal work, and made a lot of key decisions when things started to go wrong (with the paint job). Since the paint job turned out so bad, my son decided to rub the graphite all over the bone, so it is actually a silvery gray now. I did work on the speed things, but since many of those were done on a drill press, my son had little interest watching since I do not let him touch the power tools yet. Anyway, our car isn't the prettiest, but I think it will be fast.

My graphite feed thing was a big failure and actually caused me to have to do some major rework to car. I ended up not using any of the slots that came precut in the car. I had to drill holes next to where the axles were suppose to go. I paid very carefull attention to make sure all the holes were drill at a 90 degree angle. As it turns out, the car goes very straight, but I noticed that only three wheels actually touch the ground. I hear this makes the car go faster, but I never planned for it to happen. Anyway, the race is next Saturday, hopefully my son has a good time.

Being an engineer, I can't myself when it comes to the Physics of what makes these go fast. I think this Pinewood Derby thing is a great experience for both me and my son since neither one of us had done anything like this before.

[Bob Smalser]

There are so many hypercompetitive, heavyhanded Dads out there living vicariously through their kids that what it takes to win is usually counterproductive to what the child should take away from it.


Don't get me started on Little League, either. ;)

[Dave Brandt]

Our races always included an "unlimited" class, where the parents could race their own cars for bragging rights. Two years in a row, my car was beaten in the finals by one of the scouts' little sisters! :( Sheesh.

[Chad Pater]

Our races always included an "unlimited" class, where the parents could race their own cars for bragging rights. Two years in a row, my car was beaten in the finals by one of the scouts' little sisters! :( Sheesh.

:p Ok, a lot use "lol" or "roflmao" but that wouldn't do this justice Dave! Thanx for the good laugh!
Chad

[Jack Diemer]

We just got back from our 1st Pinewood Derby.

The car did not go as fast as planned, and we took 4th in our Den. We stayed around and watched all the awards. They gave away 8 trophies. (about 70 kids) The top three fastest cars got trophies, and then they gave away awards for the fastest looking car, best paint job, most original design (went to a pencil), and judges choice. Well my son's "dog driving the bone" aka "USA Bow Wow" took the Judges choice award. It was pretty exciting because the Judges choice award was the last award given during the night. See the proud scout showing off his hardware.

fyi, the design was all my son's, and all that crap I tried to do to make the car go fast didn't help win us win anything. :p

[David LaRue]

His smile is simply proceless! Way to go dad! :D Way to go scout! :D

[Jim O'Dell]

His smile is simply proceless! Way to go dad! :D Way to go scout! :D

And made all the effort SOOOO worth it!!! CONGRATS!! Jim.