Parametric Iris Aperture

https://www.youtube.com/watch?v=wQnrqH53Npo

I've uploaded 3 sets of .stl files, including a small, a medium, and a large iris. The size is indicated in the filename "ros", meaning "radius of outer shell" in millimeters. You need one each of the shell, lid, lever, and blades in a given size. If you delve into the OpenSCAD file, you can make any size you like.

To assemble:
1. Place one blade, flat side down, inside the main shell.
2. Position the blade so that it is rotated to the "open" state, with the most-clockwise gear of the blade engaged in the most-clockwise gear of the shell.
3. Continue placing blades like this in clockwise order, at each of the gear groups inside the main shell. Each blade will overlap the blade previously placed.
4. Placing the final blade will be tricky, as it must slide *over* the previous blade and *under* the first blade.
5. Once all blades are in place, carefully lower the lever disk pegs into the blade holes. Lock it all in place by screwin