Conic Sections
This is an entry in the manipulative mathematics design challenge. It is a cone assembled from sections which illustrate the definitions of a circle, parabola, hyperbola and ellipse. The pieces fit together with two dowels. All can be printed without supports.
This is accompanied by the following study modules:
http://www.thingiverse.com/thing:183683
http://www.thingiverse.com/thing:183882
http://www.thingiverse.com/thing:185141