From cube-lovers-errors@mc.lcs.mit.edu Tue May 11 15:16:14 1999 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 PAA21349 for ; Tue, 11 May 1999 15:16:14 -0400 (EDT) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Sender: davidb@u.washington.edu Message-Id: <373875FF.5EBFA011@iname.com> Date: Tue, 11 May 1999 11:25:03 -0700 From: David Barr To: WaVeReBeL@webtv.net, cube-lovers@ai.mit.edu Subject: Re: "Negative" Turning References: <11000-3733527C-9578@postoffice-123.bryant.webtv.net> The reason that "negative turning" is necessary is because the prior turn did not get the faces lined up exactly. Let's look at the sequence "R U". You turn the right face a quarter turn, then you turn the upper face a quarter turn. If you make the R turn a fraction of inch too far, then the cube will correct itself when you try to make the U turn. But if you make the R turn a fraction of an inch too short, the upper face will lock if you first try to turn it clockwise. The "negative turn" doesn't lock up because it is counterclockwise. When you then start to turn the U face counterclockwise it straightens up the R face so that the U face is free to turn in either direction. "Negative turning" is sometimes necessary, but a better solution is to always either overturn or underturn by a fraction of an inch depending on which way you plan on making the next turn. So if you are planning on turning "R U", make sure your "R" is a fraction of an inch past a quarter turn, but if you are planning to turn "R U'", make sure your "R" is a fraction of an inch short of a quarter turn. David