Kagen’s Twisted Burr

A little while ago my eye happened to fall upon a six-piece burr that looked a little different – there appeared to be some little sticky-outy bits one the sides of the burr pieces – it looked interesting and I duly enquired about it and found it might be for sale… and then during the course of establishing a price, I discovered that, quite by accident, I’d enquired about a very interesting little piece indeed. 

Back in 2002, Kagen Schafer had entered two puzzles in the IPP22 Puzzle Design Competition – his Block Box duly won the Puzzlers’ Award and First Prize, but his Twisted Burr didn’t win any silverware. Which is a pity, because it’s a really fun little puzzle…

It starts out looking just like an ordinary six-piece burr, albeit one with a few extra lugs on each piece that locks into the pieces on each side of it… now thinking about it a little will probably drive you a little batty… if every piece is captured by the pieces on either side of it, and they’re doing that across all three planes simultaneously, then surely nothing could move… and indeed I wouldn’t be possible to have built the jolly thing in the first place, now would it?!

OK, OK – we all know about impossible dovetails and the like, and we know that if a woodworker is good enough, he can make some of those cuts at strange angles and things might just be able to slide in strange axes… and we all know that Kagen is an extremely talented woodworker… 

Playing with this little lump of teak for literally a couple of seconds will show you that things slide around… quite a bit! In fact, if you slide one piece relative to any of its neighbours, it will immediately send all of the other pieces sliding in a beautifully choreographed manner…

Slide them far enough and you reduce it to a little pile of pieces…

…which shows you there are just two sorts of pieces, each with a pair of slots on the sides and ridges on the base. 

With a relatively low piece-count and the fact that there are only two types of pieces, reassembly isn’t massively challenging, but it’s a really fun little puzzle – especially given the wonderfully funky movements that literally involve all of the pieces at once… all of the time!