Return-Path: Sender: (Marvin Kaye) To: lml@lancaironline.net Date: Mon, 29 Sep 2003 20:29:35 -0400 Message-ID: X-Original-Return-Path: Received: from [32.97.166.32] (HELO prserv.net) by logan.com (CommuniGate Pro SMTP 4.1.4) with ESMTP id 2608469 for lml@lancaironline.net; Mon, 29 Sep 2003 19:40:14 -0400 Received: from b8p5r1 (slip-12-65-198-226.mis.prserv.net[12.65.198.226]) by prserv.net (out2) with SMTP id <2003092923395420200lj887e>; Mon, 29 Sep 2003 23:39:55 +0000 From: "Larry Henney" X-Original-To: "Lancair List" Subject: CG Neutra Point X-Original-Date: Mon, 29 Sep 2003 18:46:13 -0500 X-Original-Message-ID: <000a01c386e3$e21793c0$e2c6410c@b8p5r1> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01C386B9.F9418BC0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.2627 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C386B9.F9418BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Eric, Jerry, Ron, My neighbor Don Saint spent some time banging me in the head with a 2x4 last night. He explained my errant thinking regarding the interrelationship of the CG and my horizontal stab incidence. His comments clarified that as we push the CG aft toward the neutral point (CG collocated with center of pressure) control forces with decrease. Additionally, speed with increase. The unique fact that my elevator is sitting a touch tail low at high speed is roughly unchanging as the CG is moved aft. This bit of drag could be reduced also in a separate discussion. That is, the H.S. could be chopped out and reinstalled with a slightly higher leading edge. He described some very interesting neutral point analysis. It seems the neutral point can be easily extrapoloated with minor CG shift studies (spring scale and a couple 25 lb shot bags). I am looking forward to at least doing this analyis with Don and perhaps considering a CG adjusting system. Of course this system while appoaching the neutral point will NOT exceed the aft design CG of the airframe. My CG is now very far forward. Don routinely races 1" forward of his neutral point. I hope my confused thinking originally about this whole topic hasn't mislead anyone. Larry Henney ------=_NextPart_000_000B_01C386B9.F9418BC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Eric,  Jerry,=20 Ron,
 
My = neighbor Don=20 Saint spent some time banging me in the head with a 2x4 last = night.  He=20 explained my errant thinking regarding the interrelationship of the CG = and my=20 horizontal stab incidence.
 
His = comments=20 clarified that as we push the CG aft toward the neutral point (CG=20 collocated with center of pressure) control forces with decrease. =20 Additionally, speed with increase.
 
The = unique fact that=20 my elevator is sitting a touch tail low at high speed is roughly = unchanging as=20 the CG is moved aft.  This bit of drag could be reduced also in a = separate=20 discussion.  That is, the H.S. could be chopped out and reinstalled = with a=20 slightly higher leading edge.
 
He = described some=20 very interesting neutral point analysis.  It seems the neutral = point can be=20 easily extrapoloated  with minor CG shift studies (spring = scale and a=20 couple 25 lb shot bags).
 
I am = looking forward=20 to at least doing this analyis with Don and perhaps considering a = CG=20 adjusting system.  Of course this system while appoaching the = neutral point=20 will NOT exceed the aft design CG of the airframe.  My CG is now = very far=20 forward.  Don routinely races 1" forward of his neutral=20 point.
 
I hope = my confused=20 thinking originally about this whole topic hasn't mislead=20 anyone.
 
Larry=20 Henney
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