Final Design

Iris Shutter Concept

The final design is shown below. The iris that will be manufactured for NPOI is an adaptation of a proven design. Several businesses produce motorized irises that match our dimension ratios, however at a smaller scale. Currently produced designs have a maximum aperature of around 3.94 inches and an outer diameter of 5.12 inches. Therefore, the ratio of inner to outer diameters is 77 percent, which requires a total of 20 leaves. This must be adapted to the required dimensions. The required maximum aperature is 23 inches with a maximum outer diameter of 28.75 inches. This yields a ratio of 80 percent. In order to address the larger ratio, the design is modified to have a total of 23 leaves.

To the left is a depiction of the iris fully open.

Here, the iris is shown partially closed.

The iris is now fully closed, protecting the mirror underneath.