Hextix Interlocking Toy

This is the fit-together puzzle Hextix, described in Stewart Coffin's book _Geometric Puzzle Design_ (A. K. Peters 2007). 12 sticks are required, nine with two notches, three with three notches. Base is optional, but makes assembly slightly easier.

Different assembly patterns exist - shown is the easiest, with the three pieces with extra notches (red in my build) going on last. Assembly with same-color triplets parallel is possible but harder.