LISA AND LOTTIE

Designer: Dr. Volker Latussek

This puzzle measures: 70 mm x 85 mm x 70 mm

Material: Elm/Bubinga

Dr. Volker Latussek wrote about it: 

“Some of my puzzles start with a complete set of pieces, for each of which I have looked for a matching box to formulate a packing problem. Published examples of this are YIN YANG (6), TETRA-FLOP (8) and today LISA AND LOTTIE (10). For LISA AND LOTTIE, Toshiaki Betsumiya had already proposed a complete set of ten pieces with GEMINI in 1987, each consisting of two half cubes (0.5x1x1) with a common contact area of at least one quarter (0.5×0.5). A few years ago, I initially asked myself which eight pieces could be packed into the cube-shaped box (2x2x2) of CASINO. At that time, I had to find the answer with the help of a self-written Fortran program in order to be able to present the BOX (2.5x2x2) for the ten pieces today. There are 25 ways to build a corresponding cuboid (2.5x2x2), but only one way to put the pieces through the opening – which is the reason why I asked Pelikan to make a small batch of LISA AND LOTTIE. The uniqueness of the solution is very surprising to me, as I assumed there was no solution, even though the opening (1.5×2) is impressively large. If you are willing to look at the ten pieces and how they interact, you will find the solution. Along the way, you can store the ten pieces in the box.”

Kevin Sadler wrote about it:

“This incredible piece of puzzle analysis by Dr Latussek is definitely one for the collection of the hard-core puzzler. It is not for the faint-hearted – it is difficult… really REALLY difficult! The Pelikan team have made this exquisite puzzle from Bubinga with an Elm box.
 
Unusually for one of Volker’s creations it is sent out completely assembled in the box. The entry hole seems much much larger than the usual we have seen for the Flop series which gave me hope…until I tried to take them out of the box. I managed to take 4 of them out and then got stuck – are there rotations? No matter what I tried, I could not rotate any of the remaining pieces at all. This was very odd. Jakub never makes mistakes like this so I had a closer look and I then noticed that one of the sides of the boxes was removable. Once I had actually seen all the pieces, I had a bit of a panic! There were a lot of pieces and they were quite complex.
  
This meant that if I could find one of the 25 possible cuboid assemblies then at least I could get it back inside. Off I went on my search. So far I have been totally unable to assemble even a cuboid to put back through side of the box, let alone find a way to put them all in through the hole in the top. I made a BT file for this one and found that the assembly in the box is not possible without some rotations so even if you do cheat a little bit then there is still going to be a huge challenge for you – there are 25 assemblies and 4 possible orientations of each to try. 100 possibilities even with the actual assembly shown is definitely a massive task. I am saving this for when I have a LOT of time on my hands. This is an incredible piece of puzzle analysis and something for the true puzzler.”