I was working out in the garage cutting some parts for the Divinity II that I was building when my 7 year old came out to show me something he built. He built a "scorpion" out of some K'Nex pieces and he added a motor and wheels.

He was very frustrated because the wheels did not produce enough ground clearance for it to roll smoothly. I told him that he needed some bigger wheels, so I decided to stop the plane build and I opened up SketchUp.

I was able to measure the current wheels and design some foam wheels to slip over them. It was a crude design, but I needed to act quickly. I used 1" Dow foam. My son was very happy, so they were a success. Attached files

 

Both of my boys are very creative. They are constantly building really cool stuff with Legos and K'Nex pieces. I've tried to show them the PP and some of the things that have been posted here on the forums, but they did not show much interest.

Now there is a small bit of interest from my 7 year. I need to make some of those 3D puzzles, I know they like those. Once they get more interested, maybe I can harness some of their creativity. It should be fun for all three of us.