Hi Non-Twisty Puzzles fans, Four Interlocking Spirals is an assembly puzzle of four identical linear spirals. It was originally designed 24 January 1998 and prototyped from waterjet-cut dense polystyrene. The object of the puzzle is to put all spirals through each other. Two spirals fit exactly into each other, but how to add the other two? Watch the YouTube video. Download the CAD file to print-it-yourself. Buy the puzzle at my Shapeways Shop. Read more at the Non-Twisty Puzzles Forum. Check out the photos below. Enjoy! Oskar