Dini Surface

thingiverse

A 3D rendering of a Dini surface starts with design in Sage. The resulting file is exported to X3D, included here, then imported into Blender. In Blender, edit the X3D file to remove artifacts left behind by Sage, such as a cube of lines around the figure. Then, "thicken" the surface so that Cura recognizes it as a solid object: select Properties -> Modifiers (wrench icon) -> Add Modifier -> Solidify; set Thickness to 0.2 and click Apply. Now export to STL, then import STL into Cura. In Cura, scale because graph units in Sage become millimeters in Cura, and situate the figure on a print platform. Then export STL again to form the STL thing file here. Here is the Sage code to generate the figure: x=var('x'); f(x)=cos(x)+ln(tan(x/2)); u,v=var('u,v'); parametric_plot3d([cos(u)*sin(v),sin(u)*sin(v),f(v)+0.1*u],(u,pi/2,6*pi),(v,0.2,2),aspect_ratio=1). Since Sage is Python-based, be sure to check line breaks.