# Math Monday: Giant Burr Puzzles

## Giant burr puzzles

By George Hart for the Museum of Mathematics

For the Math Midway exhibition, The Math Museum created a set of large geometric puzzles. The one seen here is a traditional six-piece burr puzzle in which the six notched pieces of wood interlock in a clever way. When assembled, there are two pieces each in the X, Y, and Z directions. Even if you’re familiar with this type of puzzle, it is an entirely different experience to solve it on a giant scale.

Plans for the six pieces of this particular puzzle are shown below. Any woodworker can make these from 4-by-4 stock, which you can buy at any lumber yard. All cuts are 90 degrees and all dimensions are an integer multiple of half the width.

If you prefer, instead of cutting, you can simply glue together unit cubes. Here are the six parts assembled from 104 one-inch hardwood cubes. In this version, the ends are shorter, but the central interlocking portion is the same. (Add four more cubes to each end if you want the proportions of the colorful version shown in the opening image.)

They assemble into this rather sculptural puzzle. Many other burr designs are possible—some easier and some harder than this. If you build this puzzle and then find you can’t solve it, try the applet by JÃ¼rg von KÃ¤nel here, which will solve any burr puzzle in this family.

## 2 thoughts on “Math Monday: Giant Burr Puzzles”

1. Anonymous says:

Also known as ‘devils fist’

Comments are closed.

### Gareth Branwyn

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.

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