A friend who is into puzzles pointed me at this 3D puzzle http://www.cs.tau.ac.il/~efif/applications/puzzles/knot/ so I whipped it up in a few minutes in OpenSCAD.
If you get stuck, there is an animation showing the solution at http://www.youtube.com/watch?v=xNtNQRTdxps
| blue.stl | 18.8KB | |
| gordian-knot-all.dxf | 8.6KB | |
| gordian-knot-all.stl | 95.6KB | |
| gordian-knot.scad | 4.5KB | |
| green.stl | 10.6KB | |
| orange.stl | 15.5KB | |
| purple.stl | 15.5KB | |
| red.stl | 19.6KB | |
| yellow.stl | 15.5KB |
