It is a mechanism similar to shutter mechanism. There are two leaves. The shape is similar to Chinese Taiji or Tai Chi.When you rotate the Drive Partor the middle plate, the center hole can open or close gradually. The center hole's diameter is 100mm, outer size is diameter 230mm and thickness is 12 mm. Most parts are designed for laser cut. The parts' thickness are 3 mm. Most parts can be 3D printed too, it you plan to do that, resin material should be the best option.

To assemble the parts togther,some metal parts and glue are needed: Diameter 2mm length 5mm-pin; Diameter 2mm,length 12 mm pin; M2X12 screw; M2 hexagon nut. Refer to the BOM in the attachment. Due to the part's quality, maybe you need to do some handwork.STEP and DXF (vector format) format files are included. Before you buy the digital files, you can download the free 3DPDF first : https://www.twothreed.com/Video on Youtube: https://youtube.com/c/DTomsenAssembly tutorial: https://www.tanerxun.com/assemble-2-blades-rotating-iris-diaphragm-for-laser-cut/.html