Monday 18 November 2013

Convolution Ball

Convolution Ball

Stewart Coffin. The Convolution Ball is based on Coffin's Convolution. For a list of his puzzle designs, click here.

Pelikan. For their website (which you will probably require Google Translate), click here. Mr Puzzle of Australia also retails the Convolution Ball on behalf of Pelikan for A$135/-.

Type & Classification

8.5cm (diameter) x 10.5cm (Height with stand)

Materials & Construction
The puzzle comes in different wood combinations which include exotic woods from the following; maple, walnut, birch, ash, apple, pear, cherry, oak, beech, plum, acacia, mahogany, ebony, wenge, walnut, paduak, rosewood, amaranth, bubinga, owango, jarah, meranti, and iroko. Pelikan is well known for their solid craftsmanship and the Ball is no exception; really excellent quality. Fit and finish is snug without being too tight and pieces move smoothly against each other. 

The Convolution Ball consist of seven interlocking pieces forming a perfect sphere. Each of the seven pieces comprise of different smaller pieces glued together. The object is firstly to disengage the pieces and thereafter, reassemble them. As the puzzle is very well made, all the joint lines are virtually invisible. I spent a fair amount of time figuring out how to get the first piece loose. It was all trial and error pushing at various points of the sphere to see what could or could not move.

Once the first piece slid out, the rest came out pretty naturally. Just to be sure, I rested my Convolution Ball in my camera dry box for a couple of days to ensure there was no lock-up.

Reassembly was just as challenging. The pieces are all of varying shapes and sizes. Everything now had to go back in reverse order. I had taken the liberty of arranging all the pieces nicely on my desk in the same order which they were disengaged, so that I would have a easier time assembling. This plus photo documentation, just to play it safe. 

The first three pieces came back together quite nicely and easily. However, I took much longer with the subsequent four. But since every piece had curved edges, this helped since I was trying to form back a sphere which can only take place if the pieces were in their general right orientation. Still I had to refer to my photos for assistance for one or two of the pieces.

One point to note about the Ball; be very carefully while you are handling it. All the pieces have been cut to very exacting tolerances and have sharp corners. One accidental drop would almost certainly twist off or blunt a corner and damage the puzzle for good. Worse still if you dropped the whole ball or it rolled off your table...

The Convolution Ball right with the Pelikan Egg
Difficulty Rating
Difficult overall. Finding that one first piece that moves is the key to "unlocking" the Ball. For those living in high humidity countries, find a way to "dehumidify" the Ball first before playing. Otherwise if the pieces are too tightly pressed together, you may end up not finding the first piece that is intended to move.

Aside from being a challenging interlocking puzzle, the Convolution Ball, with its multi-coloured exterior, is also really a handsome work of wood art that would stand out well amongst your multitude of similar/same looking burrs. A must-have indeed!


  1. Good tip on the care. I have a Convolution and one piece has the tip broken off. This is a bummer because when you assemble it the ball has an indent on it, and you can tell where one of the pieces is.

  2. I nearly dropped the ball onto the ground while handling it...luckily it was not from very high and there was thick carpeting underneath so no dents as far as I could detect.

  3. I absolutely love this puzzle! Jakub has made such a good job of it. I particularly like how the pieces can fit together incorrectly and it still starts to be ball shaped but you only discover it later when the full assembly proves impossible.