'Just' a couple o’ 6-piece burrs

I’ve recently come across a couple of rather interesting, if not innocuous-looking six-piece burrs. 

The first is a copy of Bill Cutler’s L5 Notchable Burr. One of my puzzling buddies recently decided to slim down his collection a bit and spend the proceeds on some camera equipment – and it would have been rude not to support his new venture, so I bought a few puzzles from him, including this one. 

Giving credit where credit is due, Bill’s website lists this design as being “Discovered by computer program in 1987” – coyly avoiding to mention the fact that he happened to have written the program to explore the possibilities and is the guy who’d been studying these burrs in more depth than anyone else around – so I reckon we can all agree that this is Bill’s design, so what if he used some of the newer tools available to designers. 

As the name suggests, it’s a level 5 burr (i.e. minimum of five moves to remove the first piece) consisting of only notchable pieces (i.e. pieces that can be cut simply by taking notches out of a stick) and it has a unique solution – in fact, it isn’t possible to construct a burr from notchable pieces to give a higher level solution – but there are other notchable designs with the same level... 

This one was made by Jerry McFarland and one of the mahogany pieces has his customary JM stamp on it ... along with the digits ‘71’ – which confuses me as I don’t think it refers to the design, and it can’t be when it was made... any thoughts?

It’s a fun little burr to play with - in spite of it ‘only’ having a level 5 solution, assembling it is a pretty decent challenge, and taking it apart involves a good degree of progressively opening it up more and more before the first piece will emerge – really interesting little burr – and a good spot among the thousands that Bill’s analysis must have thrown up.

The second burr came to me by a slightly more circuitous route – all-round Burr-wizard Guillaume Largounez (yip, the same guy who facilitated those monster burrs!) got in touch a little while back and asked if I was interested in a copy of Abad’s Level 9 burr. 

As it wasn’t a name that I recognised, I did a little surfing and had a look at the pieces laid out on Ishino’s web-site – and one look at the pieces will show you why it’s now a well-known design ... a point that Guillaume made in his email – those pieces are a serious challenge to manufacture! Comparing these pieces to the notchable ones above is like comparing chalk and cheese – a couple of these pieces require all sorts of wood-working shenanigans to get a square corner in there. 

Guillaume had convinced Maurice Vigouroux (yip, him again) to make up a few of these in Satin Bloodwood and after a small dent hit my bank account, one of them duly headed in my direction.

This is a mean little burr... assembled on the shelf it looks like any other standard six-piece burr – but start playing with it and it gets your attention rather quickly – there’s a lot you can do with these pieces, and a few blind alleys to get lost down. The solution appears to consist of a couple of stages where you start by opening things up a bit, then move a piece or two ‘out of the way’ before opening it up some more and eventually, nine moves in, the first piece comes free – at that point you won’t be surprised that it pretty much crumbles in your hands when you see quite how far apart all the bits are at that stage. 

A really interesting burr designed by Rafael Guarinos Abad and expertly made by Maurice Vigouroux – very chuffed to have one of those in my collection – a really unusual little guy.