Archive of the Yahoo! Groups mailing list for the Bug hand-launch glider 2002-2018

From: "dimple_kwok" <henry.kwok@...>
Date: Tuesday, August 10, 2004 9:02 PM
Subject: I have a major realisation about the Bug
I have been building a few bugs and they never flew really well in my hands. Today I looked at the plan again and suddenly I realised something that I have missed before! The airfoil is not flat bottomed! If one draws a line perpendicular to the TE of the rib it will intersect at the bottom of the LE notch rather than along the bottom of the airfoil! It may have been obvious to you all but I have always assumed that the airfoil is flat bottomed and thus make and mount the wing as such. By doing this I am sure I have given the wing a huge positive incidence and I have the feeling that this is one of the contributing factors why my previous bugs never few well. The other problem I have is the wing never sit securely on the fuselage but rather rocking with the wingtips seesawing. Now looking at building my 4th attempt - Apart from building the wing as a semisymmetrical one as what the airfoil would suggest I have also decided to change the fuselage to one that is used in apogee hlg designed by mark drela. Certainly I will use 2 locating dowels at the LE of the wing to eliminate the rocking problem. This fuselage will also have a thinner profile and straigher pushrod runs which I am sure will help. Does anyone has good way to produce the wing the way it is intended to be? Thanks Henry