Melting Block

Melting Block

I saw the Melting block puzzle in someone's stash at the 4th Midlands Puzzle Party and didn't get to have a try at it - there was so much there to see and play with that I did not dare spend too much time on a packing puzzle when I am frankly rubbish at them. It is a particularly attractive wooden puzzle and I love stuff made out of wood (and aluminium and brass and steel and...) I did ask where it had been bought and a few days later I emailed Wil Strijbos to see whether he had any more available. Within minutes he emailed back to say he could add one to my previous order and it was a pretty reasonable €25! I am really quite determined to improve my skills at packing puzzles!

It has been reviewed by Allard here - I am sure that the version I saw at the puzzle party was not this one.

About a week later my new stash arrived and I was more than pleased to see the extra puzzle. The look and quality of this puzzle is definitely up to Wil's usual standard. It consists of a nice wooden box with a lid that can slide on. Within the box there are 8 blocks of a lighter wood of varying dimensions in 2 layers. Looking fairly closely shows a very small gap on one side but very little "wiggle room"! On the lid is an extra block made from a darker wood held in a small frame - this block acts as a handle to help slide the lid on or off. The aim is to repack all the blocks within the box but include the 9th darker block with it. Looking at the picture at the top it looks impossible - there just doesn't appear to be enough space at all. I tipped the blocks out in the hope that there would be more "wiggle room" to possibly make this puzzle a little easier. As you can see below the 2nd layer of blocks have exactly the same x & y dimensions as the top layer - they are just a different thickness. My heart sank a little when I saw this!

2 layers of blocks - not much space!

I really don't have much of a clue how to go about this sort of puzzle! I am sure there must be a mathematical approach using exact measurements but I have not seen one documented. I started by just plonking blocks in at random and really got nowhere, so next I looked closer at the really big pieces. Doing this helped because it showed me that there can be only 1 orientation for 2 or 3 of the blocks. Having established this, I thought that the rest would be fairly straight-forward - but as usual I was wrong. It took me another 30 minutes to find the rest of the placements and at this point the puzzle's name comes clear - the extra block just seems to "Melt" into the group and now the box is fully packed. The lid still closes over the top too - lovely.

"Melted" into the box

I have tried this several times (without having memorised the solution) and each time it is quite a challenge. If you would like one then it is available from Wil (Contact me for his email address) but if you were thinking of making one yourself then this would be an easy one to start with - it is a design in this book available from Amazon. A google Sketchup file can be found here.