HANDS-ON FUN

PUZZLE DESIGNERS SEARCH FOR THAT SATISFYING CLICK

- STORY: SIOBHAN ROBERTS / NYT

Friction is a force that opposes the motion of one object relative to another - and it's always an important consideration for Junichi Yananose, a Japanese Australian puzzlemaker.

The plan for a new puzzle might work perfectly within the design software, Yananose explained in an email interview, but once the pieces are machined and put together, "friction interferes and spoils the enjoyment".

"When bringing an idea into form, I pay close attention to the tactile experience during play," Yananose said. For example, he typically prefers to soften sharp corners along the edges of puzzle pieces with a flat, angled cut a chamfer, typically at 45 degrees - even if that compromises aesthetics.

"If leaving the edges sharp would make the puzzle uncomfortable to handle, I will not hesitate to choose chamfering," he said.

Yananose, who goes by Juno, and his wife, Yukari, run a puzzle business called Pluredo from their home in Queensland, Australia. His finely crafted wooden creations sell out quickly.

In November, he debuted Magnus 60, an assembly puzzle. Specifically, it's a burr puzzle, comprising 60 rectangular, notched and interlocking sticks made from six types of wood.

"One puzzle requires chamfering at roughly 2,000 places, which can feel overwhelming at times," he said.

Once assembled, Magnus 60 is roughly spherical. Its design is based on the symmetrical properties of two classic geometric solids: the regular dodecahedron (which has 12 regular pentagons as its faces) and the regular icosahedron (with 20 equilateral triangular faces). The puzzle is named after Magnus J. Wenninger, a mathematician, Benedictine monk and prolific builder of colourful paper polyhedra models, who died in 2017.

"No matter who uses mathematics or how they use it, the result is always the same," Yananose said. "And the fact that there are only five regular polyhedra never changes."