Pinewood Derby Cars!!!!

[S8MS-01904]

Anyone working with a Cub scout to put together a race car??

These cars are fun and the scout gets to enjoy the building of them.

I cleaned out the garage today and held the Pack's "1st Cut Day" at my place. Some of these boys' designs are neat.

Anybody want to share their special tricks or hints??

 

[target64]

Grandson just left, last week he did his cutting. All week long he was sanding, today it was painting. It may not be pretty, nor fast ,but it is his work and for that we both can be proud. I think too many people forget it is the childs project.
Tips...add weight to the rear and use graphite on the axles and wheels.

 

[woowoo2]

Polish the axles and lube the wheels well.

 

[antdog/zook]

as mentioned, weight in the rear to push instead of in front to pull. wedge design, and graphite as mentioned too. i mde a truck once, used chisel to notch for bed. i got 1st show and 2nd for race. the next year i won.

 

[Leadeye]

Set it up so it runs on three wheels (set one slightly higher). We were going to try two wheels diagonaly opposed but the kids grew up.

 

[eldirector]

I still have my Derby cars around here somewhere. Loved spending time in the garage with my dad.

- weight to the rear. Remember, the official scale is only so accurate, so go a tad light and have some very small lead shot to fine-tune.
- 3-wheels (one rear slightly lifted)
- put the axle nails in a drill and use a very fine emery cloth to polish
- get a little grit on another nail, chuck it in a drill, and polish the inside of the wheels, too.
- I've heard of guys chucking the wheels into a small lathe or drill press, and using a fine file to insure they are perfectly round and smooth.
- very fine graphite to lube

The shape didn't seem to matter. Not much "drag" in 20 feet. Let your son design to car and paint it up. That's the best part, anyway! The rest is just the "engineering genes" my dad passed down to me.

 

[92FS]

Being in the Army at the time we moved around a lot. One place we were at they had special races for the dad's to make a car and race them. Amazingly the Cub's cars looked like they were actually made by kids that time!

 

[IndyBeerman]

Amazingly I still have 3 of my Pinewood Derby cars from when I was in Cub Scouts.

I'm 48 now, and every time my wife see's them she keeps asking me why I keep them around. I just smile back at her and say nothing.

2 of the cars was designed to look like the old Indy Offy's and I have one the looked like a 1970 Olsonite Eagle.

My dad told me what to do and I did all of the molding,sanding and painting. The only thing that I remember not doing was the tubing muffler that we put on the second Offy. If I remember correctly I won first place on appearance and racing with my Eagle.


Ahhhh.....

That was back in the simple and easy days!

 

[Bucky623]

My son and I are in the process of putting together his car. This is his first pinewood derby car. The last one I worked on was close to 40 years ago.

 

[stephen87]

I miss those days. I participated every year and never did that well, but I don't know where my cars are. I think mom still has just one of them where I did well. The others got thrown away I think.

 

[Fishersjohn48]

I still have my Derby cars around here somewhere. Loved spending time in the garage with my dad.

- weight to the rear. Remember, the official scale is only so accurate, so go a tad light and have some very small lead shot to fine-tune.
- 3-wheels (one rear slightly lifted)
- put the axle nails in a drill and use a very fine emery cloth to polish
- get a little grit on another nail, chuck it in a drill, and polish the inside of the wheels, too.
- I've heard of guys chucking the wheels into a small lathe or drill press, and using a fine file to insure they are perfectly round and smooth.
- very fine graphite to lube

The shape didn't seem to matter. Not much "drag" in 20 feet. Let your son design to car and paint it up. That's the best part, anyway! The rest is just the "engineering genes" my dad passed down to me.

QFT

I have spent a few years as Cubmaster and have built/helped build/ seen many cars. We always had an adult class so I had the chance to do a lot of tinkering.

I have used all of these suggestions and they do work. Tuning the axels and truing the wood piece that holds the axel is key.

A few other hints:

Re cut the wooden piece that holds the axel on a on a drill press if possible. They are seldom straight.

Go to a Hobby Lobby store and buy an extra set of wheels and axels so you can pick the best and in case you make some mistakes.

I chuck up the axels in a Dremel press and start with a small model makers file to de-burr the inside of the nail head and cut small grooves in the axel where the wheel will run for less friction. Emery cloth and then jewlers polish on small strips of cloth until they look like stainless steel.

Chuck up the wheels by using one of your spare axels and pressing tight to the chuck in your Dremel and true the wheels with very fine grit sandpaper. Be careful they will melt if too much pressure is applied. I usually try to make the wheel beveled so that the car runs on the outer edge of the wheel only.

White graphite seem to be the best lubricant for the axels that I have found.

Weight is critical as well as ground clearance. Make sure that you don't have anything hanging down that may rub on the raised center of the track. I have seen a lot of cars where the weight is stuck to the bottom only to rub on the track.

Stick on fishing weights are great for fine tuning at the event. A digital postal scale will get you close but not all scales are the same.

Have fun and let your cub do the majority of the work. As far as the adult cars? Go crazy!

 

[Skeetboy]

Had a great time doing this as a kid. Sand the axles smooth by chucking them in a drill and smooth them. Use graphite on them for race day. Make sure the edges of the wheels that ride on the wood are smooth also.

 

[br2710]

I was in the boy scouts for one year. My dad and I worked a longtime on my car. We added lead to get the car right up to the max. weight. The day before the dirby I got the flu and never got to see how my car would do against the others.

 

[Hoosier8]

My daughter built one (with my help).

Wedge shaped, the key is to get the axles straight. Graphite lube. Make sure you build it to maximum weight. I embedded nails in the belly with epoxy and had a few in holes drilled in the wood with nails in them that could be removed in case it weighed to much during the race.

She won.

 

[irishfan]

When I worked at the machine shop in high school it was like the guys were working on a $100K machine when it was pine wood derby time. True the wheels and polising the axles are two very popular things that I remember. The other was actually putting the axles in at an angle so the tires were canted in and only rolled on a very small area of the wheel.

Pinewood derby is a blast as well as mouse trap cars! Now those can get real complicated.

 

[steve666]

I remember gluing BB's into the bottom to get the weight right. Be careful with the pain, get it on the wheels/axels and you've got trouble. I seem to remember that making it narrow and using the BB's to make up the weight worked best. Of course, that was almost 50 years ago.

 

[CountryBoy19]

and cut small grooves in the axel where the wheel will run for less friction.

I usually try to make the wheel beveled so that the car runs on the outer edge of the wheel only.

Unless the rules have changed since I was in it, both of those suggestions are against the rules. Are you going to get caught at the local level races? Probably not, but being dishonest goes against the very basic principles of scouting.


What we did (to stay within the rules) and still gain every advantage.

-Keep your weight in the very back of the car.
-use lead weights to get you very close to the limit. We would bore a hole in the bottom of the car and pour the hot lead right in. This would typically char the surrounding wood, so you have to then go back and glue the weight it for positive holding. Then, bore a small hole and use a screw in plug for your adjustable weight. When you get to weigh in at the competition you take the plug out and add/remove weights as necessary to get right up to the max weight limit.
-When the car is finished, lube the wheels (we used graphite) and run it on a belt sander. This will be sure all the wheels are smooth and flat.
-Clear-coat and very smooth paint is your friend.
-The lower profile you can the make the car the less air-resistance it will have. Air resistance is the largest contributor


My fastest car was a double wedge shape. It was a sharp, thin point on the front and the same on the back. The wheels were taller than the car. 80% of it's weight came from lead. We had a very hard time finding enough wood to bore into and add lead. Unfortunately, it wasn't fast enough to take me on to the regional race. The person that beat me (literally by only a couple hundredths of a second) cheated and cut their wheels. Unfortunately, when we complained, the leaders didn't have the heart to DQ them. The stupid thing about it was they got DQed right from the start of the regional competition, so rather than let me advance and actually race, they let a cheater advance and nobody from our troop got to race that year.

My second fastest car was similar. It was completely flat on the bottom, we added wood to the sides to go over the wheels. It's hard to explain, but basically, if you look at the cross-section of the car it's just a big "U shape".

I also won best of show or something like that my first year. I made a retro Indy car.

One other year I made a modern-era Indy car (including paper thin front and rear spoilers).

My final year I was tired of winning the speed competitions so I made a large, oversized pickup truck. You're allowed to add wood to the exterior of the car, as long as it doesn't exceed a certain overall dimension (I forget the numbers).

I don't have pictures of my cars, but they're all sitting on a shelf at my parents house with all their respective trophies (I got a trophy ever single year I raced).

 

[Hornett]

I did the best with one wheel raised, polished the axles with jewlers' rouge and rubbing compound, used as little wood as possible and put the weight in the back.

This guy has some interesting tips.
PineWood Derby.
I leaned a lot from there.

 

[Fishersjohn48]

None of my suggestion were against any rules at any level. I take offense to that.

Edit: These were the rules at that time. I have since read more recent rules and some of these wheel modifications may now be against the current rules. All others are still relevant. I can find no ruling about the notched axel being prohibited.

 

[Mr.JAG]

I never did the normal pinewood derby cars.

I did, however, get to make and race Co2 powered derby cars. They were awesome! I've got no idea where my old cars are. I'm sure the father has them stashed in his attic somewhere. I won 2 of the 3 years I was allowed to enter though.