Logical Progression
Designed and copyrighted by Rick Eason
Sixteen pieces in an Ltetrominoe shape, each with holes in three cubes and a long pin that will stick through three holes in other pieces.



The pieces 
Not the solution. But you get the idea. 
Objective: Build a cube with the sixteen pieces. There is a single solution.
This puzzle was carefully designed to have a logical way of solving it. The pieces are such that the puzzle is rich in discovery during the solution process. With a little insight, the entire puzzle can be assembled piece by piece without any guesswork.
I really hate to give out solutions, but if you really just want to put the puzzle together, here is a solution assembly sheet that will get you there. Note that it has little relation to the way you are likely to solve it by hand. Before giving up and looking looking at the solution, however, you might first try looking through the solution logic for the puzzle.
An ancester of this puzzle is my Double Hole Pin Cube presented as my exchange puzzle at IPP20 in Los Angeles in 2000.
© R. Eason, 2019