Interlocking dimple ball and shell

The model project involves two spheres, with each having a matching outer half-sphere shell (a total of 4 parts). Please read carefully as the project requires a symmetrical geometric pattern on a sphere surface. I expect to pay under $50 for these models. The sphere will have a symmetrical and equally spaced pattern of nubs (small extrusions), while he matching shell will have the exact same pattern of dimples (matching small indentations) on its inner surface, so that the sphere and its shell counterpart will fit together in an interlocking fashion. Please see these images attached. 1. Sphere - shell example with only s single nub and [login to view URL] 2. Sample dimple [login to view URL] 3. Sample spheres with [login to view URL] 4. Dimple pattern close [login to view URL] The model will be in either Autodesk Inventor or Autodesk 123D and be scalable and modifiable by me. 1. The spheres will be 20mm in diameter. 2. The spheres should be hollow allowing a 18mm diameter to fit inside, leaving a 2mm thick outer shell. 3. One sphere will have an extruded nub pattern with the matching outer half-sphere shell that will have the matching and interlocking dimple pattern. 4. The second sphere will be the opposite. It will have an indented dimple pattern with the matching outer half-sphere shell that will have the matching and interlocking nub pattern. 5. The outer shell can be 3mm thick. 6. The dimple pattern will cover the entire sphere except for a 10mm diameter area where it will mount on to a pole. 7. The sample sphere blue sphere and shell have only a single dimple for illustration purposes.