Sticks to fit into each other 30 degree steps circular so 30 60 90 joints rotating a 90 degree corner!. 5% space to fit after printing with one support a the top tip to print. Sketchup file included to adjust. Print 4 at the time so 8 is the minimum to play with. But what happening if you rotate 90 degree corner? Use the 12 star version it is stronger.