Here is my version of a 3d printed mechanical iris. Although I don't remember where I saw it first, I do remember wanting to make one. My first thought was to simply print one out from Thingiverse, but I didn't like any of the designs there, so I made my own. Here is the link to the 3d printed parts. The video below shows me assembling the parts with a hot glue gun. Feel free to replace hot glue with super glue. For those who are interested, I go into more detail on my website with the problems I faced when designing this.