X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 23 Apr 2009 20:40:51 -0400 Message-ID: X-Original-Return-Path: Received: from [64.12.137.7] (HELO imo-m26.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3592735 for lml@lancaironline.net; Wed, 22 Apr 2009 09:33:22 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.7; envelope-from=Sky2high@aol.com Received: from imo-da03.mx.aol.com (imo-da03.mx.aol.com [205.188.169.201]) by imo-m26.mail.aol.com (v107.10) with ESMTP id RELAYIN2-349ef1c14196; Wed, 22 Apr 2009 09:31:00 -0400 Received: from Sky2high@aol.com by imo-da03.mx.aol.com (mail_out_v40_r1.5.) id q.c0b.57258197 (33856) for ; Wed, 22 Apr 2009 09:32:15 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Wed, 22 Apr 2009 09:32:15 EDT Subject: Re: [LML] Re: Balancing MkII Elevators X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1240407135" X-Mailer: AOL 9.1 sub 5006 X-Spam-Flag:NO X-AOL-IP: 205.188.169.201 -------------------------------1240407135 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Rob, et al, Yep and a certain aileron that contains a trim tab and actuator require even more balance weight. Grayhawk In a message dated 4/22/2009 8:27:23 A.M. Central Daylight Time, rwolf99@aol.com writes: I, too, was surprised at how much lead I needed to balance my 360 ailerons. In fact, I have those lead half-rounds going nearly full-span (two of them, flat surface to flat surface). But let's stop to think about it. We need as much "moment" (mass x distance) in front of the hinge line as behind it. In practice, we have more weight (balance weight) forward of the hinge line than we do behind it (the control surface itself) since the CG of the control surface is generally much further behind the hinge line than the balance weights are forward of it. This is certainly the case with the ailerons, but less so for the rudder and elevators, since they have those forward overhangs for aerodynamic balance. For preliminary design purposes, my airplane design group assumes that the balance weights weigh 1.5 times the weight of the control surface alone. Bottom line -- your balance weights need to be at least as heavy as the control surface, and up to 50% more. Yup, it's a lot. - Rob Wolf ____________________________________ The Average US Credit Score is 692. _See Yours in Just 2 Easy Steps!_ (http://pr.atwola.com/promoclk/100126575x1221621490x1201450102/aol?redir=http://w ww.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=62&bcd=AprilAvgfoot er421NO62) **************Big savings on Dell XPS Laptops and Desktops! (http://pr.atwola.com/promoclk/100126575x1220433404x1201394533/aol?redir=http:%2F%2Fad.doubl eclick.net%2Fclk%3B214133109%3B36002181%3Bk) -------------------------------1240407135 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Rob, et al,
 
Yep and a certain aileron that contains a trim tab and actuator= require even more balance weight.
 
Grayhawk
 
In a message dated 4/22/2009 8:27:23 A.M. Central Daylight Time, rwolf99@aol.com writes:
I, too, was surprised at how much lead I needed to balance my 360 ailerons. = ; In fact, I have those lead half-rounds going nearly full-span (two of them,= flat surface to flat surface).  But let's stop to think about it. = We need as much "moment" (mass x distance) in front of the hinge line= as behind it.  In practice, we have more weight (balance weight) forwa= rd of the hinge line than we do behind it (the control surface itself) since= the CG of the control surface is generally much further behind the hinge line= than the balance weights are forward of it.  This is certainly the case= with the ailerons, but less so for the rudder and elevators, since they have= those forward overhangs for aerodynamic balance.

For preliminary design= purposes, my airplane design group assumes that the balance weights weig= h 1.5 times the weight of the control surface alone.

Bottom line -- you= r balance weights need to be at least as heavy as the control surface, and= up to 50% more.

Yup, it's a lot.

- Rob Wolf

Big savings= on Dell XPS Laptops and Desktops! -------------------------------1240407135--