Klein Bagel 3

This is the 'bagel' form of a Klein bottle, a 4 dimensional object with a single surface (lacking 'inside' or 'outside'), projected into 3-space as a self-intersecting solid. The 'bagel' form is a figure 8 spun into a torus, and twisted 180 degrees as it turns so that it forms a single surface object. Only some of the strips of the surface have been printed, to reveal the inner structure.The surface is 'non-orientable': it's a one-sided surface which, if traveled around the torus, could be followed back to the point of origin while flipping the traveler upside down. The model was created in Mathematica and repaired with Microsoft's 'Netfabb in the Cloud'. The parametric formula can be found in Wikipedia under 'Klein Bottle'. This differs from my other Klein Bagels in that the strips are cut through the cross section of the twisted torus, rather than around it.