Trip-let blocks (like in GEB)
by zec, published
The attached OpenSCAD script allows you to create trip-let blocks: shapes whose projections along the x-, y-, and z-axes can be completely different. Probably the most famous trip-lets appear on the cover of Douglas Hofstadter's book <i>GÃ¶del, Escher, Bach: An Eternal Golden Braid</i>.
Instructions on how to customize the trip-let produced can be found in the comments of trip-let.scad. The script is <i>very</i> basic. Most notably, it does not detect whether the created trip-let actually has the desired projections or even whether the block is in one piece. You will probably have to experiment with various rotation settings before you find a workable trip-let.
A couple of example trip-lets from the script (including an approximation of one from the cover of <i>GEB</i>) have been attached in STL format. You'll need to scale and translate the model appropriately before printing.