Multi-Twist Möbius Bands

Möbius strips with 1, 3, 5, and 7 twists. These .stl files were exported straight from Mathematica, and then run though Netfabb to repair a few defects in the mesh . Sometimes shapes like the Möbius can have problems with their normal orientation, but I think these are ok for printing. They check out as "orientable" in Netfabb's analysis anyway. I've printed them all without problems.

Here is the Mathematica code I used, for those who are interested in such things...

twists = 5; (* number of twists*)
width = 1.2; (* width of "ribbon" *)
thickness = 1; (* thickness of "ribbon" *)

Export["5twistmobius.stl", ParametricPlot3D[{(1 + v/2*Cos[twists/2*u])*Cos[u], (1 + v/2*Cos[twists/2*u])*Sin[u], v/2*Sin[twists*u/2]}, {u, 0, 2*Pi}, {v, -width, width},
PlotStyle -> Thickness[thickness], PlotPoints -> 10,
MaxRecursion -> 5]];

ParametricPlot3D[{(1 + v/2*Cos[twists/2*u])*
Cos[u], (1 + v/2*Cos[twists/2*u])*Sin[u], v/2*Sin[twists*u/2]}, {u,
0, 2*Pi