Sunday 30 November 2014

The Kray Twins

The Kray Twins, designed by Steve Nicholls was also his Exchange Puzzle during IPP34 in London this past August. For those of you non-English folks who may not know who the Kray Twins were, they were notorious gangsters that were responsible for much of the organised crime in London during the 1950s and 1960s.

The puzzle is 3D printed in ABS resin and has six pieces comprising three congruent pairs in three colours. The puzzle holds itself together pretty well with tolerance between the pieces just right. This allows the pieces to slide pretty smoothly and no force whatsoever was needed for my copy. 

This one is a "diagonal" burr with sixty degree angles; thereby making it much more confusing and harder to solve than a traditional rectilinear burr, the latter, depending on the number of moves, is already by no means easy.

6 pieces all with diagonal cuts and 3D printed in red, white
and blue, representing the colours of the Union Jack :-)

This notoriously difficult puzzle has a level solution (total 40 moves), meaning it takes 6 moves to remove the first piece, followed by 10 for the second and so on. Once you get past the first six moves, you will understand why its called the Kray Twins. This one really stumped me for a long time. I just could not get past move six for some reason.

I contacted Steve for the solution and after studying the Burr Tools file; I realized where I had gone wrong. It was unlikely I could have solved this one on my own without help. Even with Burr Tools, focus and concentration was needed to get the moves right. I found the re-assembly even harder than the taking apart. The angles just seem to make it so much harder! 

Overall IMHO, a very difficult puzzle, but I am lousy at burrs anyhow. Experienced burrists may probably find it a less of a challenge perhaps.

Steve runs a 3D printing website ( so if you would like a copy of the Kray Twins, I am sure he would be most happy to make you a one...and possibly with the colours of your choice too! 


  1. This is one of the most outstanding burr designs for many years! I loved it and even managed to solve it (both disassembly and assembly) entirely without assistance from Burrtools (in fact I don't have a BT file for it). Now if anyone would make it in wood then I would love a copy of that!!!


    1. Kevin, don't know how you managed this one but I got nowhere with it. Diagonals are even worse for me than normal linear burrs