This paper identifies an abstraction that is found in the equations that describe the 3D interaction between cuboidal permanent magnets and applies this to the magnetic design of a gravity compensator. It shows how the force between magnets and its position-sensitivity, important design parameters for magnetically levitated 6-DoF gravity compensators, may be translated into the magnetic domain and verifies this with 3D analytical models. With this information, a number of basic gravity compensator topologies is derived. These topologies are subsequently investigated in more detail, with specific focus on combining a high force with low position sensitivity.