This is a smaller, 4-leaf redesign of emmett's totally amazing Preassembled Iris Box (http://www.thingiverse.com/thing:1811143). After studying emmett's design carefully and with some advice from emmett himself, I managed to design a 60mm diameter version that prints faster. I also increased the internal clearances somewhat to make it less challenging to print. Like emmett's, it prints pre-assembled and without supports. Thanks, emmett!
Update: In my original version, the outer sphere was a little wobbly when closed and could cause jams. I've updated it to help prevent this problem. I've also included the Solidworks (2011) model for anyone to hack on.