Thursday 27 February 2014



Stewart Coffin. Check out his over 250+ designs here.

Brian Menold. Online retail shop Wood Wonders.  My copy priced at US$26 (unavailable). But available in Red Oak for US$22.

Type & Classification
Interlocking, sequential movement

6.7cm (Length) x 6.7cm (Width) x 6.7cm (Height).

Materials & Construction
The 8 pieces of the puzzle which interlock to form the cube is made of Tasmanian Rose Myrtle with the corners made from Rosewood. Construction fit and finish is very good; solid quality and value for US$26.

This is my third puzzle from Brian after Twin Pentominoes and Stacks Of Sticks both reviewed earlier in this blog. I had received this from him a while back but only got around to it this week.

This one is a real beast! Looks innocuous; just like any other 4x4x4 cube out there but a nightmare to solve, especially the re-assembly. Although only 4x4x4, it comprises 8 pieces all of irregular and non-identical shapes.

Initially I didn't think it would be that difficult; especially after I got the 1st piece out (easy) and even the 2nd and 3rd piece was removed pretty quickly with the right moves...thereafter I was stuck. I had dried the puzzle in my dry box to make sure there was no tightness due to wood expansion (and its a really good thing I did, because this puzzle probably cannot be solved if the pieces fit too snugly). 

Although I am generally lousy at interlocking burrs, I have enough experience to know that some interlocking burr pieces don't disengage in the way one would normally expect them to. So I tried a different angle...and yes, my alternate approach did work and I managed to free up pieces #4 and #5. The rest came out pretty easily thereafter. Here is where the intimidation started!

But I made one serious misstep. I forgot to document my steps with photos which I usually do, especially with burrs. After all the pieces had come apart and I had photographed them for this blog post, I started to reassemble them. Horrors! I had forgotten the orientation of the pieces and sequence. I spent a long while trying to fit the pieces together but nothing worked. General confusion pervaded.

I activated Burr Tools. While the programme did not reveal a solution (because you can't use Burr Tools on this particular type of puzzle), the final assembly of the Involute (combined with my photo of the disassembled pieces) gave me clues as to where the different pieces were positioned, relative to one other. (Those who know how to use Burr Tools would know what I mean). Aided by this, I was able to slowly piece everything back to together. Whew!

Difficulty Level
Extremely difficult; particularly the re-assembly. And Burr Tools doesn't work here either, except perhaps for the way I have described above.

For anyone who enjoys a really difficult challenge with interlocking burrs, this one is a must- have. Just remember to document your steps as you play to save you a ton of headache and frustration later. A real gem from Stewart Coffin. And for the price paid, excellent value for money too!


  1. This one isn't really classified as a burr. It's really an interlocking solid or cube. In fact Bernhard would place it in the group of Turning Interlocking Cubes. There are 3 in this series - involute, involution and convolution. Each different. I have 2 by Brian and one from Scott Peterson. They are ESSENTIAL puzzles for your collection!


  2. Kevin, yes you are right, not really a burr in the traditional sense.