Pinewood Derby - Car Building Progress

[accadacca]

Is anybody else getting ready to race? Have you taken home trophy's in the past?

I googled "winning pinewood derby car designs" and looked for a winner.

Here is the progress so far on our car. My boy wanted a Utah Utes car.

Inspiration


My boys sketch






First color


Second color




Final color




Now I need to put on the wheels, lube them up and weigh the car. More pictures when its complete.

[Iceaxe]

I'm undefeated in Pinewood Derby.

I've built dozens as a scout, father and friend... in my family pinewood derby racing is serious business.

A few of the things I do....

Polish the axles and lube them with graphite. Use lots of graphite before every heat.

I always bring a car that is slightly over-weight, about half the time they just let it run. And if they say its too heavy I drill out some lead until I'm at the max weight allowed. Don't forget to bring a drill so you can lighten the car if required.

Your car is pretty, but I'm not sure you left enough wood to insert enough lead to get it up to max weight. Max weight is a huge advantage, anyone not at max weight has already lost.

[accadacca]

Can you just weigh them with a food scale? I am hoping to add weight at the bottom if needed. I need to have it weighed this Thursday, but would rather have it close and certainly not lighter than allowed. My boy won the potato derby a couple months ago and now we have a reputation.

[Iceaxe]

It normally takes a fair amount of lead to bring the cars up to max weight.

I drill the bottoms of my cars and put cast lead .44 slugs in the holes to bring the car up to weight. The last slug will bring the car over weight, that slug I drill until I'm at max weight. I finish the bottom of the car over all slugs except the one with the drill hole. I want my car as aerodynamic as possible. Also make certain you have no low spots under the car that can drag on a poor racetrack.

One reason I leave the car overweight is not all pinewood derby scales are equal and I want to be at max weight.

You have to know the rules to race.... you have to know how to stretch the rules to go undefeated over a lifetime.

[REDFOX]

The more weight at the rear of the car the faster it will roll. I helped my boy set his 4 wheeled car to roll on 3 wheels. Less drag and friction. The forth front wheel was functional, however it was installed on purpose to just skim the track. Getting your car to roll as straight as possible is important. A little trick in adding weight to the rear of the car is to buy lead tailpipes from a hobby store. I think that 5 ozs is the max weight. Good luck !

[accadacca]

Thanks for all the tips...I'll be using them.

I need to install the wheels, add weight and find a way to weigh it.

[Iceaxe]

I need to install the wheels, add weight and find a way to weigh it.

I use a letter scale.

[Mtnman1830]

Here is the link to the races from last year...

http://www.bogley.com/forum/showthre...pinewood+derby

We won first place. They didn't let us add more graphite between races, just between heats. It wasn't well ran, and watching the races, I told my boy to put it in the middle track (the cars in that land were winning most often) and he came out on top.

A few years ago, we came in third with the same car. I wish we would have had time to make a car, but we didn't know about it until the night of the race. I am just glad he didn't play with his car, just kept it up on his shelf.

Video to his race:

[Scott Card]

I think there are some lead weight kits that you can screw to the bottom of the cars that are flat and longish. I used that to weight my kid's car last year and he did well. Some kid came with some ultra professional done/painted car that you knew the kid never touched. Sure enough, uncle, A DANG ENGINEER, made the whole thing for the kid. Yes he won, that is the uncle won. All of Ice's suggestions really work, max weight, sanding the axles really well, tons of graphite.

The only thing I would add is to also inspect the wheels. Make sure there are no burrs on them and that they too are very smooth.

One question is weight in front or weight in back? My non-engineering brain says put the weight in front..... Help me out here.

[Glockguy]

We would always go buy "headlamps" and wire at Radio Shack for ours. It was a big hit and the battery in the back is good for the weight.

[Sombeech]

[Mtnman1830]

You can also adjust the axles, so the wheels run on the outside edge... Ebay has wheels from the same mold. It gets pretty involving when you are searching for tips... I had a lot of fun just looking at the extent that people go with this.

[Iceaxe]

Lots of good ideas and suggestions above.

Most of these events are poorly run so just paying attention and using good observations skills to your advantage will pay big rewards.

Watching and inspecting the lanes is a big deal. One lane is usually much faster and one lane is normally a real dog, so pay attention to which lanes are visually fast and producing winners. And tell your kid to shut up and not start telling all his friends your observations or you will end up with 20 kids lined up for the fast lane and no one for the dog.

Normally the kids just line up and start racing. Watch which heat you are in and who you are racing against. It's to your advantage to race against the crappy cars as much as possible. You don't want to come up against the well build (dad engineered) cars and be eliminated quickly.

Because of other engineering concerns my weight usually ends up in the middle of the car.

I stick my axles in an electric drill and use some very fine emery cloth to spin all contact surfaces to a mirror finish.

I also put my wheels on a lathe and spin them so they are true and have a minimal contact patch, but that is probably beyond most peoples capabilities.

Make sure the car rolls true (straight).

One big problem I see a lot is low spots under the car that drag on the poorly built tracks (usually at transitions), that will kill you, I put nothing under the car and make sure the bottom of my car is clean as possible.

[JONBOYLEMON]

A nickel to the first guy to prove weight in the back or the front makes a difference.

[Jaxx]

Yay! I just won a nickle!

http://boyslife.org/hobbies-projects...speed-secrets/

[JONBOYLEMON]

Cuz its on the internet does not win you a nickel..... I want actual proof, not some statement w/o a reason and proof.

[Iceaxe]

He said "prove it" not just cut-n-paste what some clown wrote up.

I would NOT do a lot of things that article mentioned. And I'm not a fan of 3-wheelers. Too hard to get the car to run true and almost impossible to stop the car from becoming unsettled through the track transitions.

But I'll ask the question anther way.... Do you really think the car actually knows where the weight is located?

[tallsteve]

Some things that worked well for me over the years with my 3 boys. 1- Sand the wheels with very fine grit sandpaper. The wheels that come in the kit usually have molding burrs on them. Spin them mounted to a drill, holding the sandpapaer lightly against the wheel. 2- Spread out the wheelbase. Cut your own axle slots as far forward and rearward as you can. 3- Do the other things mentioned above: polish the axles, try to have it roll on 3 wheels, etc. We always had fast cars.

[Jaxx]

Cuz its on the internet does not win you a nickel..... I want actual proof, not some statement w/o a reason and proof.

He said "prove it" not just cut-n-paste what some clown wrote up.

Tough crowd. I was hoping an article from boys life magazine with a snippet of a book that was written would be good enough for an e-nickle. I guess not.

[Iceaxe]

Yo Acca... hows the car coming along?