This is a remix from a servo actuated leaf shutter with a couple of modifications:

I beefed up the pivot points on the leaves and increased the size of the actuator pins to make the leaves less floppy. I also modified where the gear engaged and put in a simple lever. A hole through the body is where a cable release will screw to actuate it.

It's possible to get shutter speeds of around 1/12 or 1/15 with a capable spring and a fast snap of the cable release.

I had to coat the leaves with PVA and some black ink to make the shutter light proof, otherwise the leaves would need to be printed thicker.

The picture shows the leaf shutter coupled with a mechanical iris as well as a filter holder and the spring installed. I later connected a wire to the spring and another wire to where the shutter lever ends up when the shutter is open which makes contact with the spring end to do simple X-sync flash contacts.