Tensile Tetras
Light-weight hanging sculptures based on tetrahedrons and using Lycra/Spandex fabric for "sails." The tetrahedron hubs print quickly and reliably. The uploaded stl file is sized for 1/4" diameter dowels with 1/8" diameter center hole. These sizes are easy to change in the SketchUp file. I use hot glue to cement the 1/4" dowels in their holes. The center poles are 3/16".
I use #4 waxed whipping twine from Marlow for the lines. Their twine grips the Lycra well. Other sizes and brands I've tried have not worked.
I cut the Lycra triangles substantially smaller than the faces of the tetrahedron. Roughly 3/4 the size.
The tetras are lovely slowly spinning in the wind!