The original was a good start, and good for a moldable form.
This thing represents some simple modifications to the original design to make it more easily printable. There are two primary changes.
1) There is now a central hub that is a cylinder instead of a sphere. This looks interesting, and serves to give a nice anchor point to the design.
2) The part that connects the flanges to the central part is now the same diameter as the widest part of the flange. That eliminates the largest 'overhang' part when printing on its 'side'
Other than that, the attached .stl files are for tubing that has a 5/16" inner diameter. It works great with vinyl tubing of that size. Wouldn't it be funny if someone filled those tubes with a hardening epoxy after connecting it into an interesting shape?
Added a couple more pictures where the hubs are used as semi-rigid joints with vinyl tubing and wood dowels.
1) Download the .stl of your choice
3) Download the .scad
4) Change parameters (OD in particular) press 'F6', and export to .stl