From cube-lovers-errors@mc.lcs.mit.edu Mon Dec 21 14:52:35 1998 Return-Path: Received: from sun28.aic.nrl.navy.mil (sun28.aic.nrl.navy.mil [132.250.84.38]) by mc.lcs.mit.edu (8.9.1a/8.9.1-mod) with SMTP id OAA01635 for ; Mon, 21 Dec 1998 14:52:34 -0500 (EST) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Date: Sun, 20 Dec 1998 16:41:43 -0500 (EST) From: Nicholas Bodley To: Roger Broadie Cc: Cube Mailing List , Charlie Dickman , Mark Glusker Subject: Re: Newer mechanism? (Was: Re: re-assembling a 2x2x2?) In-Reply-To: <002c01be2a01$f6ba7020$7ac4b0c2@home> Message-Id: On Thu, 17 Dec 1998, Roger Broadie wrote: (Interesting to read about the lawsuit...) }Nicholas Bodley wrote (17 December 1998) }inside of a 4x4x4. The Taiwanese version is less clearly described - }the internal faces are said to form a tongue and groove mechanism - }but probably also had an internal spider like the conventional 3x3x3 - }is this Nicholas Bodley's version? In the mechanism I know for a 2X2X2 Cube, at its center is a piece like a jack, that is, one of the pieces in the traditional game, but without the knobs at the ends. You could also think of it as three rods intersecting at a common point, and mutually orthogonal; it's as if you had plus and minus x, y, and z axes defined by the directions of the rods. These create the axes of revolution for one half relative to the other. The cubies are hollow, and their mating faces have curved cutaways. To keep the cubies from moving too far from each other, 12 "clips" extend from the center outward. If you think of a deeply-grooved pulley, cut pie-style into quarters, you have a general idea. The curved-cutout edges of the cubies fit between two curved, parallel sides of the "clips". Finally, the "clips" are kept engaged with the cubies either directly by square cross-section extensions of the center "jack", or by hollow square rods that pivot on (smaller) cylindrical extensions. Just as the ball in a 4^3 is locked to one half, the "jack" is, also. The big problem with this mechanism is that unless the parts can deform sufficiently without breaking (the actual case; they can do so), it's impossible to assemble or to disassemble as molded. If it were made of metal, it couldn't be assembled without design changes. Illustrations are really needed here; this mechanism is a challenge to describe understandably! I'd think that the internal ball uses a variant of the tongue and groove scheme, if it's like the 4^3. |* Nicholas Bodley *|* Electronic Technician {*} Autodidact & Polymath |* Waltham, Mass. *|* ----------------------------------------------- |* nbodley@tiac.net *|* The personal computer indusztry will have become |* Amateur musician *|* mature when crashes become unacceptable. --------------------------------------------------------------------------