20-Part Puzzle

George W. Hart

Other Puzzles

This puzzle is composed of twenty identical components that interlock. It is much harder than it looks. As far as I know, after me George Miller was the first to solve it. Then Toby Borland made and assembled a version of laser-cut wood. 

Here is the part design.

The above rendering might make it clearer.

Here is a stack of its components, right out of the FDM machine, before separation and assembly.
 If you have access to an FDM machine, you can make your own parts from the file available here.

There is an article about this puzzle in issue 74 of Cubism For Fun, which gives the secret of how I assembled it.