Based on some inspiration from the internet I have designed an iris mechanisme with 5 blades. The previous iris mechanism had 3 blades and had a different mechanism. https://www.printables.com/model/270201-iris-mechanism-based-on-3-blades
I really like this design and it needs no glue. With the right printer settings it just snaps together. I created 3 different designs for the the teeth. They can be selected as per your style.
Printing instructions:
I have printed the model on layer height 0.2 mm
Assembly instructions:
The author marked this model as their own original creation.