Now here is a rather nice 2-piece interlocking caged burr puzzle that I had some fun playing with. Two In Frame (TIF) is the design of Andrey Ustjuzhanin of Russia. Ustjuzhanin has to-date 115 puzzle designs to his name published on www.puzzlewillbeplayed.com.
The TIF was the exchange puzzle of Bernhard Schweitzer of Germany at IPP37 in Paris this past August. Bernhard makes his own puzzles and runs a puzzle site called www.puzzlewood.de. While his site is in German, you can easily do a Google translate to read it in English. Anyway the nice pictures of the many puzzles in the site gallery speak for themselves.
TIF basically comprises a cube-shaped cage that locks two odd-shaped pieces inside. Each of the two pieces consists of 8 units. Apart from this Type B here, there are also Types A and C. For A and C, there are also just two pieces each 8 units, and identical cages but the pieces for each puzzle are differently shaped. Not sure what made Bernhard choose Type B over the other two since all three solutions of A, B and C are the same level of difficulty. Although the TIF has only two removable pieces, nonetheless it still has a level 8.2 solution, meaning that it takes minimum 8 moves to remove the first piece and 2 moves to remove the second. Nothing to be scoffed at here!
The exchange copy came in Smoked Cherry for the cage and Maple for the pieces. Construction fit and finish is decent and the pieces slide smoothly but snugly. My copy became stuck after I got back to Singapore from IPP due to the high humidity but within a day or two in the dryer, everything worked as intended. Maple expands rather quickly when there is high humidity and the day after I solved the puzzle, the pieces felt unusually tight again. Dimensionally the TIF measures about 70mm all round.
TIF is one of those burr puzzles that I generally enjoy and can manage without any aid; mainly because they are lower level burrs that are more suited for a non-burrist like myself. This is one of those puzzles that I could take the pieces apart AND scramble them and not forget how to put them back together. No Burr Tools needed-ha! Of course the fact that the TIF has only two pieces helps a lot in the remembering of the orientation of the pieces during assembly. For an experienced puzzler and even a non-burr enthusiast, not at all that difficult, although the re-assembly may be a tad more challenging, which is usually the case in burr puzzles.