SOLIDWORKS and the Pinewood Derby

So this month’s challenge was to help my son with his first Pinewood Derby car for Cub Scouts. Conner being only 7 and notIMG_4523 as interested as I was at reliving my old Scout days had only one requirement and that was to make the car look “cool”. So what to design for a 7 year old that is cool and that easily narrowed it down to two categories, Lego or Minecraft. As neat as it would have been to build a scaled up mini fig I did not think he had the attention span to spend hours cutting and sanding. We went with the much simpler block figures of Minecraft and looking at all the characters he decided on Enderman.

So being the nerd that I am decided that we needed to deign it in SOLIDWORKS. We set out on our design of turning our 7”x 1-1/4”x1-3/4” block of wood into something race worthy.

Pinewood Derby-Block

With a couple of cuts we had our design but the next challenge from removing so much material was that we now only had a car that the body weighed about 1.5oz. when the max weight was 5oz.

Pinewood Derby-Block-Cut

Adding the wheels and nails only brought us up to 2.1oz with a high Center of Mass so how to add some weight and lower the Center of Mass was the next challenge.

Pinewood Derby-Assembly1

Because the car was so thin there was no good way to hollow out the car and add weight so we had to add to the bottom without adding more than 1/8”. Adding a simple steel plate gave us an additional 2oz and lowered our Center of Mass.

Pinewood Derby-Assembly2 Pinewood Derby-Assembly3

Our end result was a pretty fast car but it only brought us home in 4th place for his den. Now that Conner has seen what the Pinewood Derby is all about he has already started plans for next year’s car as he wants to win the overall Pack trophy. So I think this means you will see another article next year with a new design and a full SOLIDWORKS Simulation analysis testing different designs and weight positions.

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Josh Altergott

Support Manager

Computer Aided Technology, Inc.

Josh Altergott
Josh Altergott is Support Manager at Computer Aided Technology, a SolidWorks Value Added Reseller with locations in Kentucky, Missouri, Kansas, Indiana, Wisconsin and Illinois. He is a regular contributor to the CATI Tech Notes blog. http://blog.cati.com/