X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 22 Feb 2012 12:36:00 -0500 Message-ID: X-Original-Return-Path: Received: from nm24-vm0.access.bullet.mail.mud.yahoo.com ([66.94.236.143] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with SMTP id 5409192 for lml@lancaironline.net; Tue, 21 Feb 2012 20:48:52 -0500 Received-SPF: neutral receiver=logan.com; client-ip=66.94.236.143; envelope-from=browncc1@verizon.net Received: from [66.94.237.201] by nm24.access.bullet.mail.mud.yahoo.com with NNFMP; 22 Feb 2012 01:48:16 -0000 Received: from [66.94.237.107] by tm12.access.bullet.mail.mud.yahoo.com with NNFMP; 22 Feb 2012 01:48:16 -0000 Received: from [127.0.0.1] by omp1012.access.mail.mud.yahoo.com with NNFMP; 22 Feb 2012 01:48:16 -0000 X-Yahoo-Newman-Id: 407432.51071.bm@omp1012.access.mail.mud.yahoo.com Received: (qmail 42233 invoked from network); 22 Feb 2012 01:48:16 -0000 X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: kNJJmNQVM1l8qtVPM1Yopmrmsb2xNxZ_dusj2oDNZ67AZ6E PjJkLllE72_HklQwEMO8e4lklYz5eEQyOgkRzeAcv3kZOkspZLzst4cmo6of 58dK09JMjIDBYmcZl667zguGNwtcQqm2HjB9Tg1xbtpFpyp4YuGUkMa59YNX P1SkzTylySsjj8lPEADOD1mbdWQ7j83nb_mEMg6dmopbuyR.vvWtjpSHm73x EAnY8comvY1ELqNvDrQO6wmIJVnJw3fhEreZnOjdSSJLJFTzWT2H1snvzTxm bMmDBye2x3oGkneaK5kq2kMVdplXYzkMOkjy7Cex5rskLGNLgp3_lWhb4VMN gHYfJu1E6tsMs6qAbeMnuApvxtDLSj0btPZlk3DIrGXFpH7EOGp1tWNOe.ZF FPIaF8TgzohgMMweDTYQnW_LRzQUzAItv4swMDAXk9OI- X-Yahoo-SMTP: F49l9g6swBC0R9n8vJIbm7Tf3P8Xlmia8rHIwTlO__Ml Received: from new-host-2.home (browncc1@72.64.81.165 with plain) by smtp101.vzn.mail.ne1.yahoo.com with SMTP; 21 Feb 2012 17:48:15 -0800 PST From: Charles Brown Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-2--619223833 Subject: Re: [LML] 360 rudder balance X-Original-Date: Tue, 21 Feb 2012 19:48:14 -0600 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <43E6EC04-471F-4F94-BE54-C0A860FFE0A2@verizon.net> X-Mailer: Apple Mail (2.1084) --Apple-Mail-2--619223833 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 OK I have to get more specific. I only know the Legacy but I assume the = 320/360 and IV are the same. The short answer is that when you properly = balance the ailerons, they'll return to level. When you balance the = elevator and rudder, they'll have no preferred orientation. The ideal is to have a hinged surface like the elevators and rudder with = counterbalance weight *ahead* of the hinge point, which when properly = balanced will have no preferred orientation. That completely decouples = angular inertia from hinge motion. That is, when the stabilizer twists = or buffets up and down (or sidewise, on the vertical), the hinged = surface does not rotate in response. In this geometry, a "nose-heavy" = surface is just as risky as a "tail-heavy" surface. In the Legacy ailerons, the hinge point is at the upper surface of the = wing, rather than than halfway between the upper and lower surfaces.** = For this reason, the counterweight has to be *below* the hingeline. = Since the aileron is normally in a level position and the hinge motion = of interest is up and down (not fore and aft), Lancair says to balance = it in the level position. So, as long as the ailerons are level, you = get the same result as with the elevator or rudder -- the aileron won't = rotate in response to up/down wing motion. A rotated aileron is = slightly out of balance with respect to up/down hinge motion, and I = guess that means that we're slightly more susceptible to aileron flutter = or buzzing when in a turn than when flying straight and level. **Now I'm curious why -- since it forces a departure from the balancing = method of the elevator and rudder. As I recall, Mooney ailerons are = hinged just like the elevator, and they have a counterweight ahead of = the aileron just like the elevator, except that it swings *within the = wing* which severely limits aileron travel in a Mooney. I think = Cheetahs and Tigers are similar, which may be no coincidence since Roy = Lopresti cleaned up both designs. =20 On Feb 21, 2012, at 10:30 AM, Jim Nordin wrote: Hummmm =85 correct me if I=92m wrong. Balance of control surfaces is attained when the component (aileron or = elevator for example) hung at the center of rotation and given a = perturbation (trailing edge pushed down) minimally returns to the level = condition or better a small nose down condition. Any other condition = (leading edge high above level, trailing edge below level) warrants = adding weight to make the nose (leading edge) to settle below level. Nose heavy is the point here. Any other condition may result in flutter. Jim From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Charles Brown Sent: Tuesday, February 21, 2012 8:02 AM To: lml@lancaironline.net Subject: [LML] Re: 360 rudder balance =20 They should stay in any position where you let them go. They should not = return to level. If they are out of balance, they will have some = preferred orientation (as you say, will move up or down). =20 Charley Brown MS Aero/Astro Engineering =20 On Feb 20, 2012, at 6:51 AM, Bill Bradburry wrote: I have a question about balancing the flight surfaces. If they are in = balance, should they return to level from where ever you move them to, = or should they just stay where you put them. =20 I assume that if they are out of balance they will either move up or = down from level depending on whether you need to add or remove weight. =20 Bill B =20 =20 --Apple-Mail-2--619223833 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252
OK I have to get more specific.  I only = know the Legacy but I assume the 320/360 and IV are the same.  The = short answer is that when you properly balance the ailerons, they'll = return to level.  When you balance the elevator and rudder, they'll = have no preferred orientation.

The ideal is to = have a hinged surface like the elevators and rudder with counterbalance = weight *ahead* of the hinge point, which when properly balanced will = have no preferred orientation.  That completely decouples angular = inertia from hinge motion.  That is, when the stabilizer twists or = buffets up and down (or sidewise, on the vertical), the hinged surface = does not rotate in response.  In this geometry, a "nose-heavy" = surface is just as risky as a "tail-heavy" = surface.

In the Legacy ailerons, the hinge = point is at the upper surface of the wing, rather than than halfway = between the upper and lower surfaces.**  For this reason, the = counterweight has to be *below* the hingeline.  Since the aileron = is normally in a level position and the hinge motion of interest is up = and down (not fore and aft), Lancair says to balance it in the level = position.  So, as long as the ailerons are level, you get the same = result as with the elevator or rudder -- the aileron won't rotate in = response to up/down wing motion.  A rotated aileron is slightly out = of balance with respect to up/down hinge motion, and I guess that means = that we're slightly more susceptible to aileron flutter or buzzing when = in a turn than when flying straight and = level.

**Now I'm curious why -- since it forces = a departure from the balancing method of the elevator and rudder. =  As I recall, Mooney ailerons are hinged just like the elevator, = and they have a counterweight ahead of the aileron just like the = elevator, except that it swings *within the wing* which severely limits = aileron travel in a Mooney.  I think Cheetahs and Tigers are = similar, which may be no coincidence since Roy Lopresti cleaned up both = designs.    


On Feb 21, = 2012, at 10:30 AM, Jim Nordin wrote:

Hummmm =85 = correct me if I=92m wrong.
Balance of control surfaces is attained when the = component (aileron or elevator for example) hung at the center of = rotation and given a perturbation (trailing edge pushed down) minimally = returns to the level condition or better a small nose down condition. = Any other condition (leading edge high above level, trailing edge below = level) warrants adding weight to make the nose (leading edge) to settle = below level.
 Lancair Mailing List = [mailto:lml@lancaironline.net] On Behalf Of Charles = Brown
Sent: Tuesday, February 21, 2012 = 8:02 AM
To: lml@lancaironline.net
Subject: [LML] Re: 360 rudder = balance

 

They should stay in any position where you = let them go.  They should not return to level.  If they are = out of balance, they will have some preferred orientation (as you say, = will move up or down).

 

Charley = Brown
MS Aero/Astro = Engineering

 

On Feb 20, 2012, at 6:51 AM, Bill Bradburry = wrote:
I have a question about balancing the flight = surfaces.  If they are in balance, should they return to level from = where ever you move them to, or should they just stay where you put = them.
 
I assume = that if they are out of balance they will either move up or down from = level depending on whether you need to add or remove = weight.
 
Bill = B