Base plate for ventilation manifold

This base plate is intended for reuse in other projects. As it is my first self-created model, I ask for your indulgence.

The diameter of the opening is 18cm, and the distance between the screw centers is 20.05 cm. The screw holes are slightly larger to compensate for tolerances. The screw holes are offset by 60° each. Have fun remixing. To better check if it fits, a test print with only two layers is included as a separate print plate. Additionally, there is also a plate with the basic shape without holes, for adapting to your own hole patterns.

The first photos are of the test pattern.