Sun is a very interesting interlocking puzzle designed by Jos Bergmans. Two separate pieces which form almost closed loops require to be connected in such a way that the two semi-circles end up fitting together to form a completed circle, the sun.

The copy I have is made by Eric fuller and was offered in his most recent set of puzzles at Cubic Dissection. Made from Sapele with a Maple veneer for the sun the puzzle measures 2.6″ x 3″ x 3″ so it’s a good size and the construction is superb. Eric hand glued each joint, including a couple of triple mitre joints using a granite plate and a machinists square to ensure that every joint was at exactly at right angles, and it really shows in the finished puzzle. Attention to detail is superb. Three different wood combinations were available when Eric produced the Sun, including the inverse of my copy, Maple with a Sapele sun, and Walnut with a Maple sun. As always Eric has signed and dated the puzzle. 36 copies were made available.

The goal of the puzzle is to interleave the two pieces of the puzzle, to create one solid object where the two halves of the sun line up. Looking at the pieces, they initially seem like closed loops so joining them together at all seems impossible. With a little study though, there is one place where the two pieces will allow for an initial move to link them together, and that’s where the fun starts.

Normally with this sort of rectilinear puzzle, some of the pieces have rounded edges, or parts of the edges have been taken away to allow the pieces to move past each other, such as the Cast Coil from Hanayama. This puzzle however has no corners or edges rounded, and all the moves, slides and rotations happen because there’s just enough room for the pieces to move past each other, making this as close to a perfect example of this style of puzzle as is possible.

Once you have the two pieces intertwined, there’s a couple of easy rotations, then you find yourself at a dead end. (At least I seem to every time I solve this puzzle!) I’ve solved it a good few times now, and each time I spend several minutes trying to figure out where to go next. There are a good few dead ends in the puzzle, so the challenge is fairly good. I seem to go though the same set of wrong moves at the start each time before finding that magic move and from there the solution seems to just flow, and I have it solved very quickly thereafter. I took around 20 minutes to solve this for the first time, but each time after that it still takes me 10 minutes, so I’d say is has some good replay value.

Taking the two pieces apart seems much easier than putting them together, so I’m glad that Eric shipped the puzzle in its unsolved state. It’s a really fun puzzle, and very well made. I’m happy to have been able to get a copy of this for my collection.

As I mentioned earlier, the detail and quality of the work in this copy of the puzzle is superb. Just look at the triple mitre joint above, and you’ll see what I’m talking about. Despite Eric commenting that the construction was painstaking, I think he’s right to be very pleased with how these turned out!