=Introduction= Three-sided overlapping joints, tri-lapping joints, or tri joints join three frames together rigidly in all three cartesian axes by securing each with a bolt. This unique joint requires only frames, nuts, and bolts, and is the basic technique for building rigid structures from frames used throughout Replimat.
=Challenges=
=Approaches= All possible tri joint configurations are represented in each tri joint, and accessible via simple rotation or reflection.
=References=