Beercan Iris Experiment

There's nothing like a quick experiment to see what the constraints on the problem are. Beyold, the quick and dirty (actually quite smelly) beercan iris.

I just cut the pieces by eye from an old beer can, so they're fairly thin aluminium sheet. I didn't optimize the shape in any way and, for this purpose, I didn't need to deal with a fancy closing mechanism - fingers work fine.

Conclusions:

Anyway, hope that helps you. Certainly helped me understand the problem a bit better.