Received: from ARDEC-LCSS.ARPA.ARPA (TCP 30003004013) by AI.AI.MIT.EDU 19 Feb 87 08:36:06 EST Date: 19 Feb 87 08:18:00 EST From: "CLSTR1::BECK" Subject: magic construction To: "cube-lovers" Reply-To: "CLSTR1::BECK" RE: CONSTRUCTION Since I have suggested that people might want to take their MAGICs apart I have prepared the following directions. I would appreciate comments as to their clarity and completeness. ................................... For those of you who would like to take MAGIC apart and then put it back together here are some hints. First get out your tools, a heavy duty paper clip or a nut pick will do (black electrical tape is helpful for keeping the strings in place when putting it back together) and then pull the string over the corner of a square (strings do break, the weak point is the crimp so minimize the pulling and stretching you do by the crimp also when you reassemble put the crimp in the middle of a long channel). Keep doing this until the puzzle is completely disassembled. If you failed to take notes you may have missed the following. The loops of string (they are actually nylon fishline and they are redundant, ie, each path is taken by two strings, with 16 strings in all) are threaded through the channels, one set of strings takes the long path on the front face and the other set of strings takes the short path on the front face (the opposite is true on the back face OR adjacent square) with both sets of strings going in the same direction on the same face. Thus the strings on the front faces are perpendicular to those on the back face of the same square. NOTE: The strings are not really redundant. They are placed to maximize lateral stability (twist of the squares). This is done by having the strings (there are two) of a given channel routing form the same sandwiching order where they cross over to the next square. The string that uses the long channel and the string that uses the short channel cross at separarte points. Each string criss crosses itself at this point (making 4 string segments at the cross over point) with one part of itself in the NE channel and its other part in the NW channel. The stability is gained by having the NE going string sandwiched between the NW going string (or vice versa) for both crossover points, ie , sets of strings. Both patterns shown below are used on the same set of three squares (THIS UNIT IS CALLED A TRIPLET.). string #1 in string #2 in SHORT channel ON TOP LONG channel ON TOP for squares 1&3 for squares 1&3 ---- ---- ---- ---- ---- ---- |/ \ | / \|/ \ | | / \|/ \ | / \| TRIPLET HAS BOTH |\ \ | / /|\ \ | AND | / /|\ \ | / /| STRING PATTERNS | \ \|/ / | \ \| |/ / | \ \|/ / | | \ /|\ / | \ /| |\ / | \ /|\ / | ---- ---- ---- ---- ---- ---- After having made two triplets there will be two squares free. They are used to join the triplets. Place one of this extra squares between the two triplets, ie, where the "AND" is in the diagram above and thread the strings through the channels as if this square was the middle square of a triplet (REMEMBER THAT the STRINGS GO ONLY ONE WAY ON each face OF A SQUARE). THEREFORE, THE ENDS OF THE PREVIOUSLY MADE TRIPLETS WILL BE THE ENDS OF THIS NEW TRIPLET ALSO. THIS WILL CAUSE THESE ENDS TO HAVE TWICE AS MANY STRINGS AS THE MIDDLE SQUARES OF THE TRIPLETS AND IN FACT IF YOU LOOK AT MAGIC YOU WILL SEE THAT THE NUMBER OF STRINGS IN THE CHANNELS ALTERNATES FROM SINGLE DENSITY TO DOUBLE DENSITY, ie, either 2 or 4. CUSTOMIZATION OF MAGIC In the disassembly process an easy thing to do is to break the circularity of the puzzle by removing one square, leaving a chain of seven squares. This can be done by lifting the strings off a single density square. The square will come out but its strings will stil be entangled with the puzzle. You will now have to temporarily lift strings off the adjacent squares to disentangle them. This can be done easily. You now have a chain of seven squares. Each hinge can be manipulated without the constraint of being connected as a loop. A basic hinge between two squares has the following motions: NOTE: The flipping of the pieces changes the direction of the squares as shown by the arrows. POSITION 1 folded A folded B ________ _______ _________ _________ sq 1 TOP sq 2 top sq 1 on bot sq 2 on bot >>>>>> >>>>>> sq 2 on top sq 1 on top ________ _______ _________ _________ POSITION 2 >>>>> A unfolded B unfolded ________ _________ SQ 1 TOP SQ 2 TOP <<<<<<<< <<<<<<< ________ _________ ________ _________ SQ 2 TOP SQ 1 TOP >>>>>>> >>>>>>> ________ _________ The robustness of this hinge permits the making of all possible planar patterns that has each square butting up to the edge of another square. ------