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Six Piece Burrs

The 6-Piece Burr is one of the oldest and best-known burr shapes. I have been interested in 6-piece burrs since I saw my first one in a drugstore window when I was about 12 years old. At first I attempted to determine all the ways one could construct a 6-piece burr using standard 'notchable' pieces, but the job was too large. Many years later, I solved this task using a computer. I was particularly interested in burr puzzles which required many moves to take out the first piece. In the early 1980's I wrote my first program to take apart interlocking puzzles made from cubes, and this led to the 3 year analysis of all 35.5 billion 6-piece burrs. Many of the 6-piece burrs that we sell are the results of this analysis. Others were designed by humans, with or without the help of computer programs. And still others use unusual pieces or were overlooked by the computer program. We particularly like: Bill's Baffling Burr - this computer-assisted design appeared in Scientific American. Love's Dozen - discovered by Bruce Love, this has the highest level possible (12). Computer's Choice Unique-10 - The best of the computer-discovered 6-piece burrs. Programmer's Nightmare - the computer couldn't see that this was a good design!

Rectilinear Burrs

Most of these designs require several moves before the first piece can be removed. Like the 6-Piece Burr, these puzzles have interlocking square rods meeting at right angles, but they have many more pieces. The 6-piece burr has too few pieces, I thought, to hide any ingenious movements required to make a burr difficult to take apart, so my early designs had lots of pieces. We particularly like: Wausau'82 & Wausau'83 - not too many pieces, but challenging to take apart. Lovely - an invention of Bruce Love, it takes 18 moves to remove the first piece. S/M 24 - a computer-assisted design, this features notchable pieces in a standard shape with no internal holes, but still takes a number of moves to get it started.

Non-Rectilinear Burrs

These puzzles have unusual geometrical shapes. They are composed of interlocking rods, but the rods are not square or do not meet at right angles. Most of these designs are easy to take apart. We particularly like the Hybrid, but very few of these have been made for sale.

Box Filling Puzzles

The challenge is to fit a number of 3-dimensional pieces into a box. Many of the box-filling puzzles sold by Bill Cutler Puzzles, Inc. feature pieces which are all rectangular solids. You might think this would make them easier then packing with, say Pentominoes, but you might be surprised. Our favorite: The Boxed Box - 23 pieces in which every dimension is different, and they fit into the box without leaving any holes.

Miscellaneous Puzzles

A few puzzles are listed here that don't fall under the other categories, or are not sold directly by Bill Cutler Puzzles, Inc.


Two self-published booklets on 6-Piece Burrs are available.

Computer Programs

These programs were written to be used as tools for designing, solving, or analyzing puzzles. One of the programs can be used to solve a variety of 2-d and 3-d packing puzzles. The other program can be used to solve interlocking puzzles which are based on a cubic grid.

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