This is a FreeCAD script for generating versatile joints to assemble tubes in a icosahedron shape. Enter the inside and outside tube diameter and run the script.
I made an example with aluminium tubes. As the result is quite rigid I will use it as a support for a small table but an icosahedron can be used in many different ways. Show me what you did in the comments!
Step 1: Get the Parts
You need 30 tubes and 12 joints. I printed the joints and cut the tubes with a hacksaw at the same length (the length you want! It just has to be the same length). The tube I used were 9 cm length and had a 8 mm outside diameter (6 mm inside diameter).
Use freeCAD and the script to generate the suited joint for your tubes. I already wrote an instructables to explain how to use the scripts in FreeCAD here: https://www.instructables.com/id/Snow-Flake-Gener...
I had good results with a custom printing support. If you don't like it and want to make your own, just comment the corresponding lines (add # at the begging of the lines in the support section).
Step 2: Assemble the Parts
In the first three pictures I show how I clean the joins with only two cuts on each wall (still 120 cuts but it is not that long)
Then carefully assemble the tubes with the joints.