Piston Puzzle

Easy to print puzzle which I created from an aluminum copy that I purchased a few years ago. I printed this copy at .75 scale but the file is for the original size of the aluminum puzzle (60 mm, 60 mm, 40 mm). The puzzle, even at 3/4 scale, slides easily and works well.

After printing the hardest part is putting it together correctly. There are a few ways to get all of the keys ("pistons") into the house but when put together correctly only one piston should be able to move.