Three pairs of different burr piece styles. 22 moves to completely assemble/disassemble.

A 6-piece 5x5x3 interlocking solid that requires you to remove 5 irregular shaped pieces from a central ring. For more details: http://archive.cubicdissection.com/html/ringlock.html

6-piece level 10 burr 

Six-piece level 18.2 burr. Like new. 

This level 13 six-piece plate burr is the result of computer analysis conducted by Bill Cutler. Cutler wrote: "A computer analysis of all 6-plate burrs was run over the winter of 2001-2002; the highest level found for removing the first piece is 13. The Chocolate Dip Burr is one of these assemblies - the only way to assemble the pieces so that the dark and light colors are separated is in this level-13 assembly.

Level 8.2 six-piece burr with a non-traditional final shape. 

A nice interlocking burr

The following is copied/pasted from Eric's original description (which can be found with his much better pictures here )"I've always like the Altekruse and its pic based variants...so when I stumbled across Brian's version, I was interested. Brian kindly gave permission for me to make a batch, so here they are. I'll let brian explan the rest to you (i.e. I'm stealing the description from his site). Some years ago Brian noticed a drawing of puzzle concept in Stewart Coffin's book The Puzzlin...

The puzzle has always been fairly loose, but otherwise in perfect condition. Please see 2nd photo for a better idea. 

Fit has always been a little on the loose side. 

Beautiful chuck-style burr - it took me ages to find move #2!Eric's description is at:http://archive.cubicdissection.com/html/crystal.html

Another great burr from Eric.  See his description at: http://archive.cubicdissection.com/html/hny.html

Eric's statement that this puzzle is “extraordinarily difficult” is an understatement. He continues: “To start, The burr pieces will pack into the corner only one way. But that's just the beginning. When you remove the twelve pieces, there are 28,540 ways to construct a single burr. And only ONE way to make two burrs. Thats's right...there is a unique combination of pieces that will allow you to construct two burrs, which seems insanely improbable to me. On top of that, both burrs are high...

a wonderful puzzle

The puzzle has a loose fit. Please see the 2nd photo for a clearer idea.From Eric's write-up: “Construction of this puzzle was tricky. The humidity in my workshop was fluctuating wildly, so I opened up the tolerances more than I usually do to make sure the final product wouldn't bind up or get stuck. The good news is that I was successful there - this puzzle should work in all humidity conditions. The bad news is that the puzzle turned out looser than I would have liked, having perhaps .035 in...

From Eric's write-up: “This is the tricker iteration of the Quads and Rings series. Four wooden burr pieces interlock with three acrylic pieces with a level 17.2.6 solution. Definitely a step up in difficulty from the Q&R1 design; Yavuz has kind of laid the gauntlet down here! Achieving the checkerboard pattern is a second challenge.”For more details: http://archive.cubicdissection.com/html/qnr2.html

exchange puzzle from London

From Eric's write-up: “Every time I think I've seen it all when it comes to 4x4 cubes, someone proves me wrong. In thie case it's Mr. Hu with his excellent "Two Wheeled Cube" design. with an odd level 1.1.1.2.8 solution, this puzzle is moderate in difficulty but very high on the fun factor. The first four pieces form a shell around the heart of the puzzle; two identical "wheels" which rotate and dance around each other in a bewildering number of possble states. The meat of the puzzle is figuri...

Six piece typical diagonal burr creating a beautiful shape. Well known Stewart Coffin design but simplified because of the colour symmetry.I made a handful of these for friends and family last year and had this one left over. Great for someone who wants an inexpensive copy of a great puzzle just to actually play with. The pieces are not perfect like a Lee Krasnow or a Peterson work, so you can get some hints as some fit slightly better in certain orientations but the errors are very small so you...

Six piece typical diagonal burr creating a beautiful shape. Well known Stewart Coffin design.I made a handful of these for friends and family last year and had this one left over. Great for someone who wants an inexpensive copy of a great puzzle just to actually play with. The pieces are not perfect like a Lee Krasnow or a Peterson work, so you can get some hints as some fit slightly better in certain orientations but the errors are very small so you'd have to look for the hints in most cases. O...