(This is the process that was created by us through experimenting with Inventor) *( Autodesk Inventor was used to create the CAD files for this project) (P= Water Polo Ball V= Volleyball)

Step 1: Step 1: Create the Hemisphere

Start a 2D sketch in the XZ Plane, and create a circle in sketch mode, with the desired diameter(P= 8.522 V=8.15)
Finish the sketch and extrude the circle by its radius (P= 4.261 V=4.075)
Fillet the top edge by the radius (P= 4.261 V=4.075)
Create a “Tangent to Surface and Parallel to Plane” plane that is tangent to the top of the hemisphere and parallel to the flat bottom of the hemisphere.

Step 2: Step 2:Create Your Design

Start a 2D sketch on the new plane
Create the bottom of your design by using arcs, and the offset tool to create the gaps you need to extrude.
Make a construction line in the middle of your ball, and then mirror the bottom design to the top so it is uniform
Finish the sketch and then extrude the gaps you created(Your gaps will not extrude if there are overlaps with the lines or gap in between them so you will need to go and extend or trim the problematic lines to make it extrude)
Extrude the horizontal gaps the least amount you can with the line still extruding and fully appearing on the ball( *Order is by farthest to closest to the center P= 4.2 (Vertical), 3.6 (Horizontal), 2.2 (Horizontal), 1.2 (Horizontal) V= 3.9 for all lines)
You can personalize your ball by extruding more designs on top of it. For example: Jacob extruded a ten on the top of his ball because ten is his number in water polo.

Step 3: Step 3: Printing and Assembley

Save the file as an STL file and use that file to 3D print two versions, try to keep the density low ~15-20
P=Lulzbot 3D Printer, Buildtak plate(temperature had to be adjusted), Lulzbot HS tool head with a diameter of 0.8 mm. V(and polo ball first draft)= Lulzbot 3D Printer, normal Lulzbot plate, Lulzbot Mini AeroStruder Too Head with a 0.5 mm diameter.
Take the two hemispheres and put a lot of superglue on one side and make sure to line up the gaps and to keep pressure on the ball while the glue dries. Wipe away any excess glue that seeps out.