Mine and my son's first car.

[RhuntIII]

This was my first pinewood derby car build. I've watched every interweb video till I'm blue in the face. I pick a drawing off the net and changed it up a little to my likings. Altho what I thought was a fast looking car proved to be less than par on the track. I thought I would go with a rail rider type car and after seeing the wooden track probably built in the 80's and a couple of test runs the night before the race I knew this was a bad idea.

I'm gonna need help on building a faster car. Go figure.

I would like to post up some pics of my cars, then take the questions a little further.

First if I could get some help on posting pics then move into question on the car. I'm not sure what a URL is.

Thanks and go easy on the new guy.

 

[Chief]

First of all welcome to the forum! Now about posting your pics. You need to have a photobucket account or something like that. Load your photos into photobucket and then once they are loaded you can copy and paste them here on the forum using the little flower looking icon in the tool bar. Also, something that will help more than anything is to use the search tab...click on that and type what you are looking for there.

 

[Kinser Racing]

Here's a great place to start.

http://www.pinewoodderbyonline.com/post/keys-to-win-from-the-pinewood-derby-king-5782181?pid=1272943640#post1272943640

Ask questions all you'd like but these are the main guidelines you'll want to follow. /images/boards/smilies/thumb.gif

 

[BulldogRacing]

Welcome to the forum. Photobucket is the best place to start so you can post pics. After you load your pic click on the pic you want to post here on the forum. You'll see that photo bucket has 4 types of code you can choose from. You want to choose IMG, just click it and it'll say copied. Come to the forum and past it. Good luck.

 

[Vitamin K]

imgur.com is also a great image host that offers bbcode quicklinks that you can paste in.

 

[RhuntIII]

http://s1061.photobucket.com/user/RhuntIII/media/IMG_2291_zps3044deb9-1.jpg.html?sort=3&o=6&postlogin=true

I think that link should give y'all an idea of the car.

 

[RhuntIII]

We did win the best built built and best looking car. "The car that looks the fastest."

These are our rules.

Rules
1. You must use an official BSA pinewood derby car kit (available from the scout shop.)

2. You may NOT file down the wheels. Cars with altered width of the wheels will be disqualified. The tread must remain flat.

3. The weight of the car may not exceed 5 oz.

4. It is recommended that you check the clearance of the car if you place any weights below the car.

5. Cars must be made during the current year.

6. The width of the car may not exceed 2 3/4".

7. The length of the car can not exceed 7 inches.

So I did a few things different from you posted Kinser.

#1 I did not drill axle holes. I used the axle slots.
#2 I bent the rear axles.
#3 The weight was on top of the rear axle, about 1" in front of the axle and 1/8oz behind the axle
#4 I used graphite for lube but others were using oil
#5 I did not narrow the dominate side of the car by 1/16
#6 I followed the rail rider
#7 I'm not sure of the wheel gap but it was the Wheel gap tool from derby monkey
#8 I did 1" over 4' but the track was in such poor condition I though it would be better to try to make the car go as straight as possible after the Friday night testing.

I hope this will get us started to building a faster car.

 

[BulldogRacing]

You have really loose rules, it will allow for a very fast car. Pros will chime in here and help you out, I was in your shoes and the first thing I can tell you is don't bend the rear axles. Use the silver bullet that Derby Dad for hire sells, this will help you get great alignment. I started out spending a lot of cash on tools that hurt more than helped. If you follow that post by kinser you should find a heck of a lot more speed than running your car straight with bent rears. This is a great place to learn to become fast, good luck and again welcome.

 

[Vitamin K]

I just wanna say, that is a very nice looking car for a first effort! I'm sure you'll come up with several things that you want to change to tune for speed, but I admire your wood-working skills already!

 

[RhuntIII]

Thanks again for the help guys. Were y'all able to see all the photos or just the one?

 

[down4derby]

Usually with a street stock type car 1" of steer in 4' is not enough. Start with 4" in 4'.

 

[Fumbles]

Holy Cow- that's some advance planning on the drawings! My son and I just kind of wing it when it comes to a design, now I'm feeling like I need to draw it out more or something.

 

[ngyoung]

Even with a rough track you are better off rail riding. That will give you the best chance of keeping your rear wheels from hitting the rail the least. I am not sure if you're asking what can be done to salvage the car you currently have or if you want help building a whole new one.

If you're trying to salvage then I would mainly focus on axles and wheel bore polishing. Depending on your car's under body I would try to move around 2oz of weight behind the rear axle if possible. The rest can go in front of the rear axle, the goal being to try and get your CoM somewhere between 5/8"-1" range in front of the rear axle. It seems that yours may be quite a bit farther forward based on your description.

Do you have a drill press or know someone else with one you can use? If you spend any more money on PWD parts in the future, make it the silver bullet. That will give you the best chance to drill aligned and canted rear holes. None of the fastest cars racing in leagues use bent rear axles. Can a decent builder make a fast car with bent axles? yes, but that same racer can build it faster using angled holes and straight axles. With the bent axles you are going to be challenged to get the 2 rear wheels aligned parallel to one another.

If you are using the slots you would likely be better off using straight axles then take a flathead screwdriver and pry the tip of the axle up slightly to create the cant. Another option is shimming the slot with wax paper. A lot of guys much faster then me would suggest just running straight axles in the rear if you can't use angled holes. Usually there is some slight bend in stock axles and you can turn the axles to find the position that still allows the wheels to migrate to the axle head.

 

[ngyoung]

Looking at more of your pictures...For the fenders, make sure you have a relief cut on the bottom inside edge so that the wheel will hit the rail before the fender will. It is better that a spinning wheel rubs vs the non spinning fender.

 

[RhuntIII]

I don't think I'll be salvaging these two cars, they now serve a greater purpose in the hands of a 4yr old and will be building three new cars. I'm planning to stay with the same style car and just improve on the design.

Young, that notch out of the fenders, excellent point. I do have a drill press, band saw, jig saw, belt sander and Dremel. My plans are to turn out new drawings then move onto cutting. Being that the next race is a year away I'll be in no hurry. I have sailboats and race cars to build and I'm planning on doing this when it's not hunting season. /images/boards/smilies/smile.gif

My CoM was about 1 1/8 on that car and 1 1/4 on my son's.

So this "silver bullet" block looks like a solution to the rear axle issue.

What else can it do?
Interweb links so I may research this tool?

I'll added a few more photos to the bucket.

http://s1061.photobucket.com/user/RhuntIII/media/IMG_2291_zps3044deb9-1.jpg.html?sort=3&o=14&postlogin=true

 

[ngyoung]

Check out http://5kidsracing.webs.com/drillingaxleholes.htm

The silver bullet will be the best bang for your buck in gaining speed. The top 3 priorities IMHO for speed in PWD is weight placement, alignment, and polished axles. Of those 3, alignment usually is what gets neglected the most in scout derbies. Most people know to put the weight in the back so that is usually pretty even playing field. I put axles up pretty high only when we're comparing raw BSA axles with all the burs and crimp marks. The majority of scouts just put everything together and never touch the axles. The ones that actually do try to be competitive do some form of axle polishing.

while you're there read through the cub scout workshop and cub scout build tips section. That is the one site that will have instructions for the majority of the process.

Also if you haven't done so already read this:

http://www.pinewoodderbyonline.com/post/keys-to-win-from-the-pinewood-derby-king-5782181?pid=1272943640#post1272943640

 

[RhuntIII]

Young,
That's a lot of homework you just posted up. Thanks for the link, I've got some studying to do.

 

[BulldogRacing]

I've read from guys here that fenders are less effective if they extend taller than the top of the wheel. You might want to shrink the height of yours.

 

[RhuntIII]

So, insetting the FDW 1/16" is a good idea, what about insetting the raised wheel as well? Narrowing the front wheels a total 1/8".

 

[HMH Racing]

FDW is all that is needed