コレクション: Frans de Vreugd

Frans de Vreugd is a Dutch designer who works almost exclusively in interlocking puzzles, and specifically in the hardest corner of that family: the board burr. He is one of the leading voices in Cubism For Fun, the mechanical puzzle world's long-running journal, where he has published the research behind much of his own work.

His approach is unusual. Rather than designing by hand and testing by feel, de Vreugd uses computer search to find the hardest configuration a given puzzle form can take, then builds that. The result is a body of work where the difficulty is not an accident of craftsmanship but the actual design target.

The board burr papers

Three of his Cubism For Fun articles are still referenced by designers today: Some Notes on Dic's Dozen (2000), Extreme Boxed Burrs (2001) and Cracking the Six-Board Burr (2003). The last of those is the groundwork for the puzzle we carry.

His designs

Torture Burr, Bent Board Burr #6, Boxed Six Board Burr, Japanese Wood Joint Burr and Japanese Joint Burr are the designs he is best known for. They share a signature: very few pieces, a shape that looks manageable, and a move count that is not.

What we carry

Extreme Torture is a six-piece board burr from 2002 that takes 69 moves to take apart, at burr level 28.21.9.8.3. It was built, deliberately, to be the hardest six-piece board burr that could be constructed. Expert difficulty, four hours and up, and it ships disassembled.

More of his designs are in production and will be added here.

Best for

Solvers who have run out of hard burrs and want one that will genuinely beat them for a while. Collectors who track designers rather than shapes. Anyone who has read a level notation and wanted to know what 69 moves actually feels like in the hand.

If you are new to this family, start with the burr puzzles collection and work up. The 6-piece burr guide explains the structure these designs are built on.