Brain Breaker Blocks

If you’re bored of Lego, this 3D printed self-interlocking construction block will break your brain. It takes minutes to print, months to figure out!

See here for video for demonstrates of the concepts outlined below: https://youtu.be/j10wzy0qGOg

See here for stable download: https://social.thangs.com/m/728419

Officially known as an “SL Block,” this octocube shape is part of a family of “topologically interlocking assemblies,” that is, shapes that hold together without the use of connectors or adhesives to form self-interlocking structures. Self-interlocking structures have interesting architectural and engineering applications.

A ends of a single “SL” block resemble an “S” and an “L.”. In assembly, SL blocks always occur in pairs, called a “Conjugate Pair.” In the pictures and video, conjugate pairs are shown with one white and one black piece.

Conjugate pairs lock together in six different ways, called “engagements,” to form “SL Strands.” Each type of engagement adds