monk3947
Free 3dpdf file and assembly: https://www.tanerxun.com/3d-printable-gift-box-design-plan-02/.html
It is a gear structure box design plan. There are several gears and racks. When you rotate the side gear with a “key” and handle, the four blades opens or close gradually. The center hole is diameter 90mm. The whole unit can be mounted on other parts with the 4-M3 bolts.
Parts are designed for 3d printing. It is best to use resin material, and there need to be some hand work too. You need to prepare some metal screws by yourself to assemble parts together, and some glue may be need too. When you print the part, take care of the quality, it is important to make the mechanism run well.
STEP and STL files are included. Ignore the OBJ,FBX format files, they are just for cgtrader’s requirement.