I had one of these when I was a kid, and my son is currently obsessed with tornados....so, 3D printer to the rescue!
Add two bottles, some water, spin once and enjoy!
I would recommend printing with 100% infill to avoid leaks.
If you like this project or want to know more about 3D printing, check out my new book "The Makerspace Workbench" from Maker Media!