A Mechanical Freelancing Hub

We require a specialized mechanical design in 3D CAD format for manufacturing a custom plastic disc/lid that fits mason jars. The design is relatively simple, featuring a plastic disc with three holes, but it must fit the jar perfectly to ensure it is 100% airtight and leakproof. Accurate sizing in terms of thickness and edge shape is crucial to achieve this.

The final design should be optimized for 3D printing and suitable for physical production. Ideal skills for this project include proficiency in 3D CAD software, a solid understanding of mechanical design principles, and prior experience designing for 3D printing manufacturing processes.