Check this out! I am helping my friend and client Mark Boulding develop a series of 3-D brain puzzles. Marks vision is to help satisfy the need for tactile and mechanical aptitude while being very entertaining at the same time. This model is available for sale as well. I modeled the 2 individual pieces in 3-D Studio Max 2015 and we had Shapeways print the pieces. It was really fun to make these hollow and remove all the mass we could to make it as inexpensive as possible. It also ended up making them incredibly light. More puzzles to come so I will keep you posted!