A fully working Closing Mechanical Iris. Would look great on a door!Rendered in KeyShot (Chrome on a Cherry Back Board)You can improve the design by making the sliding outer ring a gear to be driven by a smaller gear to open and close.
STL (Stereolithography, filesize: 510 KB), OTHER (Other, filesize: 155 KB), ASM (Solid Edge, filesize: 209 KB)