These pieces snap together to form a spherical truncated icosahedron, a shape recognizable as a football or soccer ball.
See here for video: https://youtu.be/C-KsbcPzaH4
In the model shown, the “Penta” pieces are printed in black, the “Hex” pieces are printed in white. A complete ball requires 20 of the “Hex” pieces and 12 of the “Penta” pieces. The files provided will create a ball that is 100mm in diameter.
This design minimizes that amount of material needed to print large spheres, and also allows for multicolour balls by printing pieces in different colours. You do not need supports to print, but you will need to ensure good bed adhesion.
The pieces hold together on their own and will not need glue.
When assembling, be aware that the connection tabs on the hexagonal pieces are different depending on whether that side is connecting to another hexagonal piece or a pentagonal piece.
Pentagonal pieces only ever connect to hexagonal pieces, so the pentagonal tabs are all the same.
The tolerance between pieces is intentionally tight and will require some force to assemble. You can loosen the fit by filing of the thicker bottom layer “elephant foot” on each piece, or by scaling up the pieces slightly to increase the space between. Be sure to do a few small test prints first before printing a whole batch.