This model shows the volume of intersection between the sphere x^2+y^2+z^2=2 and z=x^2+y^2. One .stl file has the equations imprinted on the surface, the other does not.

This file was designed and printed by my WLU summer research student Ryan McDonell ('17).

Printed on a MakerBot 2X printer with the following settings: 2 shells,
0.20mm layer height, 10% infill (hexagonal pattern), color matched supports, raft on.

The object was printed sideways with the equations upper-most. We ended up tilting the object by 18 degrees down from the edge between the paraboloid and the sphere, so that the object would have some supports. (We were worried it would fall over.) We've included the .thing file for this print.