This puzzle is an extension of a fairly well known wooden puzzle consisting of six interlocking sticks.
The basic puzzle exists in a variety of forms, sometimes a cube, sometimes an octagonal block but in fact the underlying structure is always the same.
The six pieces meet in the centre as three pairs, horizontal, vertical and crosswise.
Each piece is slotted in a different way to allow the join and there is one final piece with no slots that goes in last to hold the whole puzzle together.
If eight of these simple puzzles could be assembled as the eight corners of a cube it should be possible to make a puzzle with twenty-four pieces.
It's a lot easier to say that than to do it. The eight simple puzzles have to be 'synchronised' so that the whole puzzle doesn't result in an immovable lump. I found it impossible to visualise the problem well enough to design the puzzle in cold blood.
In the end, I resorted to trial and error. After several attempts, I eventually found a solution. More by luck than judgement, I was able to assemble the puzzle by cutting each piece to fit as I went along.
This left me with a bigger problem. I now had a puzzle so fiendishly difficult that I almost didn't dare take it apart again. I thought about marketing it as a toy, but decided that selling a virtually impossible puzzle might not be the best way to make friends. The years passed, other things intruded, eventually I forgot how to assemble it, lost the drawings I had made, and with them I lost the solution. So, for many years it has been gathering dust in a cabinet.
The invention of the digital camera eventually solved the problem. I've taken a sequence of photographs as the cube is dismantled and it is now possible for me to take it apart and reassemble it by studying the photos.
You can see how long this has been sitting in the cabinet by the patina on the wood, faded where it has been exposed to light.
But then I started thinking...
In the same way that the original simple puzzle has three pairs of sticks meeting horizontally, vertically and crosswise This puzzle has three sets of eight sticks meeting horizontally, vertically and crosswise.
If eight of these puzzles could be assembled as the corners of a cube in the same way,
it might be possible to make a puzzle with ninety six pieces... (whimper)