Pinewood Derby Times Volume 14, Issue 5

– Feature Article – Shop Talk: “Frame and Skin” Car Construction

– Humor

– Pinewood Derby Car Showcase

– Q&A

Feature Article

Shop Talk: “Frame and Skin” Car Construction
By James White

I would like to share the “Frame and Skin” car construction method used by my grandson (Aaron Shain) and myself for pinewood derby car building.

We start with a normal pinewood derby block with drilled axle holes. After cutting out the profile we want, we remove all material except the frame of our car, and then we apply a rock hard varnish to the areas where the wheel hubs will rub the frame.

Figure 1 – Frame of Car
(An additional support piece was added over the front axle holes)

Next we build side extenders to be glued to the frame sides.

Figure 2 – Side Extenders
We then add a carbon fiber rod for stiffness down the car center and glue a 1/64 inch thick model plywood bottom skin onto the frame.

Figure 3 – Carbon Fiber Rod, and Bottom Skin
Tungsten weight is then added into the two rear pockets (not shown in photos). We target 4.85 ounces with all parts included. Tungsten putty is used as trim weight after the car is complete. The putty is placed into 1/8 inch holes drilled into the bottom of the car between the two rear axles.

Next, a 1/64 inch thick top body skin is cut out and glued to the frame.

Figure 4 – Top Skin

Figure 5 – Top Skin Installed

Fender tops are placed over the wheel wells (if desired). At this point, we install the prepped wheels and axles to do some tuning and testing.

Figure 6 – Fender Tops
After a paint job is applied, we are ready to race!

Figure 7 – Finished Car
(Photo is of a sister car, so the wheels are different)

More of James’ frame and skin cars are shown in the car showcase.


Are you the Weakest Link?

Below are four (4) questions. You have to answer them instantly. You can’t take your time, answer all of them immediately.

OK, let’s find out just how clever you really are.


GO!!! (scroll down)

First Question: You are participating in a race. You overtake the second person. What position are you in?

Answer: If you answered that you are first, then you are absolutely wrong! If you overtake the second person, you take his place, you are second!

Try not to mess up in the next question.

To answer the second question, don’t take as much time as you took for the first question.

Second Question: If you overtake the last person, then you are…?

Answer: If you answered that you are second to last, then you are wrong again. Tell me, how is it possible to overtake the LAST person?

You’re not very good at this are you?

Third Question: Very tricky math! Note: This must be done in your head only. Do NOT use paper and pencil or a calculator. Try it.

Take 1000 and add 40 to it. Now add another 1000. Now add 30. Add another 1000. Now add 20. Now add another 1000. Now add 10. What’s the total?

Scroll down for answer.

Did you get 5000? The correct answer is actually 4100. Don’t believe it? Check with your calculator.

Today is definitely not your day. Maybe you will get the last question right?

Fourth Question: Mary’s father has five daughters: 1. Nana, 2. Nene, 3. Nini, 4. Nono. What is the name of the fifth daughter?

Answer: Nunu? NO! Of course not. Her name is Mary. Read the question again.

If you got them all wrong, you ARE the WEAKEST LINK!

Pinewood Derby Car Showcase

Here are a few more of James White’s frame and skin cars.


Is it best to bend the rear axles or drill angled holes in the block?

The pros and cons of this question were covered in the previous article on Rail-Riding.

There are proponents of both methods. Personally, I favor using bent axles. This allows the builder to tune the rear wheels for best alignment.