For most burr shapes, such as the 6-piece burr, if you have no internal holes, then the first piece that moves will come out all the way. This is because the burr shape is 'rectilinearly convex'. This is not true for the standard 24-piece burr shape. I decided to design a 24-piece burr in which:

1) there are no internal holes
2) the pieces are all notchable
3) many moves are required to remove the first piece

Here is the result of several weeks of design effort, using computer programs to assist in the process. It takes 7 moves to remove the first piece.

The construction of this puzzle is very good, with an excellent fit, not too loose, not too tight. Of course the pieces are precision milled from solid sticks.

36 copies made for sale, each signed and dated. This puzzle is shipped disassembled; solution available upon request.