Mechanical iris (Iris diaphragm) is a type of intricately designed mechanism. The center can gradually open and close. There are several ways to design and construct an iris mechanism. And you can see lots of variations on the market.
In this article, we will share some design files. If you have a laser cutter, 3d printers, and some other tools, you can download the files and build them by yourself.
There is another type of similar structure, but different.
Mechanical Iris/Iris diaphragm-Gear Structure

1.Fixed Plate, 2. Gear Sector, 3. Shaft, 4. Blade, 5. Bolts, 6. Shoulder Bolts, 7. Driving Plate
Bolts (part 5) are used to assemble the Fixed Plate onto other equipment. There is internal gear structure on the Fixed Plate, but you cannot manufacture the gear on a gear cutting machine. It is designed for laser cutting or 3d printing.
The Gear Sector (part 2) and Blade (part 4) are connected by Shaft (part 3) tightly. It is best to expand the hole a little inside the Shaft after assembling them together.
The Shoulder Bolt (part 6) is used to connect Driving Plate (part 7) to the Fixed Plate (part 1). If possible, you should add some glue on the screw.
You can download the files here.
Mechanical Iris/Iris diaphragm-Bar Structure

1. Fixed Plate, 2. Shaft, 3. Blade, 4. Link Rod, 5. Shoulder Bolt, 6. Bolt, 7. Driving Plate
The Shaft should be assembled on Link Rod and Blade tightly. You can achieve the goal by expanding the inside hole of the shaft.
The mechanism can be assembled onto other devices by bolts 6. Shoulder bolt 5 is used to connect Fixed Plate and Driving Plate. And we recommend to use some glue between the Fixed Plate and the Bolts. Before doing that, you should put bolt 6 in the correct location.
Shutter Mechanism-Hexagon Cutout

1. Fixed Plate, 2. Bolt, 3. Shoulder Bolt, 4. Short Shaft, 5. Long Shaft, 6. Blade, 7. Driving Plate
The cutout is a hexagon. When you rotate the Driving Plate, the blades open or close gradually. You should enlarge the inside hole of the shafts to ensure the shafts are connected on Blade securely.
These parts are not designed for FDM 3D printers. So, if you plan to print these parts with an FDM printer, there may be some problems. Of course, you can still have a try, and then sand the part to make them work.
About planetary gear set, please read this article.
Two-blades rotating iris mechanism or taiji mechanism is a similar structure, read more here.
Four-blades sliding mechanical iris structure is here.
If you need a similar mechanism that can be used on industrial products, read this article.
You can get more 3d models on cgtrader , Etsy or cults3d. If you need a motorized mechanical iris, please contact us. And there are more videos about mechanical models on my Youtube channel or on Dailymotion. Free 3DPDF files are downloadable here: twothreed.com.