Two versions (3 as of 7/29/15) of a Klein-Bottle type Hot Air Balloon, inspired by a conference logo I designed. After seeing the challenge I decided to try and make the balloon portion of my logo into a 3d model and try to create wind blades so it would spin in the wind. Whirlygig1 has thinner edges on the blades, and Whirlygig8 has thicker edges. I used some parametric equations I came up with in Mathematica to create the model and export it as a .stl file. Cleaned up some small cracks where edges meet with NetFabb (free version). Edit: 7/29/15: Made whirlygig1 with the thin edges, and it did not turn out that well around the loop. Whirlygig8 with the thicker edges turned out much better. I also posted an updated file: Whirlygig9 has slight modifications to the top and doesn't have the small torus/donut at the bottom of the balloon. It didn't seem that necessary with the thicker blades. I have someone printing it for me this week, so I'll try and update with a pic of whirlygig9 on Monday 8/3. See the video of whirlygig8 here: https://youtu.be/pePyM8GfSrg (I attached it to a fishing spinner and then to a bush branch. The branch on the bush was blowing a bit too, accounting for the up and down movement.) Thanks to those who have "liked it" already - this is my first time posting on thingiverse - kinda fun!I designed my model with parametric equations using Mathematica, then exported to a .stl file. I'm trying to print them upside-down to minimize the cleanup and supports that are needed.