X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 03 Mar 2010 07:51:48 -0500 Message-ID: X-Original-Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.3.3) with ESMTP id 4150550 for lml@lancaironline.net; Wed, 03 Mar 2010 07:43:37 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=super_chipmunk@roadrunner.com X-Original-Return-Path: X-Authority-Analysis: v=1.0 c=1 a=3oc9M9_CAAAA:8 a=Ia-xEzejAAAA:8 a=fLuM78UsAAAA:8 a=Vb7KFvBdAAAA:8 a=wS3mEkvijFq1Ma9vPv0A:9 a=94kx_I3jHlXkgYoJzIwA:7 a=l4Jkqz07PKez0i8ceHkMFn9WiQ0A:4 a=KY_pjOnbxUQA:10 a=nW9Zi9phB58A:10 a=6e4CQMaF2vYA:10 a=U8Ie8EnqySEA:10 a=EzXvWhQp4_cA:10 a=3jk_M6PjnjYA:10 a=UoDJzkQbp9wA:10 a=qhhs9DduLznxwKjM:21 a=AOm9z7p1t5udHece:21 a=XK3iCRrj4rC-LWWw6dcA:9 a=mtug8_5s7SnJSk2rO9UA:7 a=VoN4UTbd2PitaRc-g18wS-zjppAA:4 X-Cloudmark-Score: 0 X-Originating-IP: 74.65.190.246 Received: from [74.65.190.246] ([74.65.190.246:61102] helo=Laptop) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id A8/65-08021-4595E8B4; Wed, 03 Mar 2010 12:43:01 +0000 X-Original-Message-ID: From: "Bill Wade" X-Original-To: "Lancair Mailing List" References: In-Reply-To: Subject: Re: [LML] Re: Reichel Trim Wheel X-Original-Date: Wed, 3 Mar 2010 07:43:22 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_04F7_01CABAA5.33328700" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18005 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18005 This is a multi-part message in MIME format. ------=_NextPart_000_04F7_01CABAA5.33328700 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable There's an article in the EAA Experimenter about Paul Lipp's 235. = Among other mods he describes spring-loading the aileron trim but using = a trim tab for pitch. The way I picture it is that a trim tab maintains its relative effect = with change in airspeed whereas spring loading will change. (The spring = would compress due to the additional load on the surface, allowing the = surface to deflect). I don't know enough about the subject to say one way or the other. My = question is- do those with the spring-loaded pitch trim have to adjust = trim very often as their speed changes? My reason for asking is that my IV-P elevators are going to need more = lead than I can pack into them. I've been thinking about a spring-loaded = system for trim so I can lose the weight of the trim tab and MAC servo. = What I have in mind would be a fiberglass leaf spring that would act in = both directions. Although I'd like to use a mechanical control I may end = up using a linear actuator (Velocity builders might recognize that = setup). Looking for comments- Bill Wade ----- Original Message -----=20 From: Sky2high@aol.com=20 To: lml@lancaironline.net=20 Sent: Tuesday, March 02, 2010 1:07 PM Subject: [LML] Re: Reichel Trim Wheel=20 With reference to Marv's explanation: There is more to it than benefits from reduced weight and drag. Many, = if not most, LNC2 builder/pilots reduced the arm of the elevator bell = crank from 4 inches to 3. This modification resulted in reducing the = stick throw by 25% and also increasing stick forces by 25% - a really = good result because of the pitch "sensitivity" of these aircraft. Of = course when one changes a part of a system, the whole system is = affected. Finer pilot control of stick movement was required (famous = two-finger grip) and a stronger trim spring was needed to manage the = higher trim forces. A consequence of using the stiffer spring was the = need for more friction to hold the crucifix trim lever position and more = difficulty in fine tuning pitch trim. The Reichel trim wheel resolves = the spring/friction issues while still allowing the pilot to overcome = any trim setting with stick movement (that is, causing the trim wheel to = unwind). Benefits abound from this system including no possible = electric trim runaway in the all important pitch axis. Another benefit of the Reichel Wheel is the window with its precise = trim position indicator. Mine is marked with the neutral elevator = position and the elevator is set to that position before each takeoff - = a known control surface position with pitch control totally in my hands. Since my experience is with my own small tail 320 (and others with = small tails), we will have to await the comments of others on its = efficacy with either a Mk II tail 300 series Lancair or a Legacy. =20 Scott Krueger In a message dated 3/2/2010 10:12:48 A.M. Central Standard Time, = marv@lancair.net writes: Posted for "Bay Elliott" : Hi Marv, I am a relatively new Legacy builder (last 6 months) and I am not = familiar=20 with the Reichel Trim Wheel. What are the advantages of this system = over=20 others and is it applicable to the Legacy? Warm Regards, Bay Elliott Executive Vice President, The Farwell Group, Inc. =20 Executive Recruiting Consultants (305) 529 4811 bay@farwellgroup.com =20 [I thought I would move this out onto the LML to invite further = discussion and get some assistance from folks who know more about the = intricacies of trim systems than I do. =20 The earlier LNC2 was designed with a trim system that used a spring = bias applied to the elevator pushrod to control the overall elevator = position. It was controlled by a small cruciform trim lever that moved = the biasing springs forward and aft. Dick Reichel invented his trim = wheel to replace the lever, allow finer and more precise trim = adjustments, and to provide folks with the same sort of trim wheel that = they had flown with in any number of certified aircraft. =20 Trimming the location of the entire control surface is probably = aerodynamically preferable (less drag) to moving a trim tab to use the = airflow to move the control surface, and the removal of the trim tab = eliminates its weight and complexity, as well as those of the servo = motor and linkages... ie, less counterweight required for balance. = There are probably other aero issues, but I leave those things to folks = more knowledgable than I in these matters. =20 Whether or not a a spring biased trim system would be applicable to = the Legacy, I can't see why not, at least for those folks who are still = building and can opt to incorporate it into their control system... I = don't know how the trim tab is built on the Legacy elevator, but if it's = cut from the elevator similarly to the method used on the LNC2, that = part of the process could be bypassed and the work, weight and = complexity of the trim tab mechanism could all be left out. To my = knowledge no one has incorporated this into a Legacy, but that doesn't = mean that it couldn't be done. =20 The only disadvantage with the spring bias system at this point is = that it is totally manual. Once I finish with the basic trim wheel = system I'm going to look into motorizing it while still allowing manual = adjustments. ] -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_04F7_01CABAA5.33328700 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
  There's an article in the EAA Experimenter about Paul Lipp's = 235. Among other mods he describes spring-loading the aileron = trim but=20 using a trim tab for pitch.
 
  The way I picture it is that a trim tab maintains = its=20 relative effect with change in airspeed whereas spring loading will = change. (The=20 spring would compress due to the additional load on the = surface, allowing=20 the surface to deflect).
 
  I don't know enough about the subject to say one way or the = other.=20 My question is- do those with the spring-loaded pitch trim have to = adjust trim=20 very often as their speed changes?
 
  My reason for asking is that my IV-P elevators are = going=20 to need more lead than I can pack into them. I've been thinking about a=20 spring-loaded system for trim so I can lose the weight of the trim tab = and MAC=20 servo. What I have in mind would be a fiberglass leaf spring that = would act=20 in both directions. Although I'd like to use a mechanical control I may = end up=20 using a linear actuator (Velocity builders might recognize that = setup).
 
  Looking for comments-  Bill Wade
 
 
 ----- Original Message -----
From:=20 Sky2high@aol.com=20
Sent: Tuesday, March 02, 2010 = 1:07=20 PM
Subject: [LML] Re: Reichel Trim = Wheel=20

With reference to Marv's explanation:
 
There is more to it than benefits from reduced weight and = drag. =20 Many, if not most, LNC2 builder/pilots reduced the arm of the elevator = bell=20 crank from 4 inches to 3.  This modification resulted in reducing = the=20 stick throw by 25% and also increasing stick forces by 25% - a really = good=20 result because of the pitch "sensitivity" of these = aircraft.  Of=20 course when one changes a part of a system, the whole system is=20 affected.  Finer pilot control of stick movement was required = (famous=20 two-finger grip) and a stronger trim spring was needed to manage = the=20 higher trim forces.  A consequence of using the stiffer spring = was the=20 need for more friction to hold the crucifix trim = lever position=20 and more difficulty in fine tuning pitch trim.  The Reichel trim = wheel=20 resolves the spring/friction issues while still allowing the pilot to = overcome=20 any trim setting with stick movement (that is, causing the trim wheel = to=20 unwind).  Benefits abound from this system including no possible=20 electric trim runaway in the all important pitch axis.
 
Another benefit of the Reichel Wheel is the window = with its=20 precise trim position indicator.  Mine is marked with the = neutral=20 elevator position and the elevator is set to that position before each = takeoff=20 - a known control surface position with pitch control totally in = my=20 hands.
 
Since my experience is with my own small tail 320 (and others = with small=20 tails), we will have to await the comments of others on its efficacy = with=20 either a Mk II tail 300 series Lancair or a Legacy.   
 
Scott Krueger
 
In a message dated 3/2/2010 10:12:48 A.M. Central Standard Time,=20 marv@lancair.net writes:
Posted for "Bay Elliott"=20 <bay@farwellgroup.com>:

 Hi Marv,
 I am a=20 relatively new Legacy builder (last 6 months) and I am not familiar =
with=20 the Reichel Trim Wheel.  What are the advantages of this = system=20 over
others and is it applicable to the = Legacy?

 Warm=20 Regards,

 Bay Elliott
 Executive Vice President, = The=20 Farwell Group, Inc.  
 Executive Recruiting=20 Consultants
 (305) 529=20 = 4811      bay@farwellgroup.com
 

[I=20 thought I would move this out onto the LML to invite further = discussion and=20 get some assistance from folks who know more about the intricacies = of trim=20 systems than I do. 

The earlier LNC2 was designed with = a trim=20 system that used a spring bias applied to the elevator pushrod to = control=20 the overall elevator position.  It was controlled by a small = cruciform=20 trim lever that moved the biasing springs forward and aft.  = Dick=20 Reichel invented his trim wheel to replace the lever, allow finer = and more=20 precise trim adjustments, and to provide folks with the same sort of = trim=20 wheel that they had flown with in any number of certified = aircraft. =20

Trimming the location of the entire control surface is = probably=20 aerodynamically preferable (less drag) to moving a trim tab to use = the=20 airflow to move the control surface, and the removal of the trim tab = eliminates its weight and complexity, as well as those of the servo = motor=20 and linkages... ie, less counterweight required for balance.  = There are=20 probably other aero issues, but I leave those things to folks more=20 knowledgable than I in these matters. 

Whether or not a = a=20 spring biased trim system would be applicable to the Legacy, I can't = see why=20 not, at least for those folks who are still building and can opt to=20 incorporate it into their control system... I don't know how the = trim tab is=20 built on the Legacy elevator, but if it's cut from the elevator = similarly to=20 the method used on the LNC2, that part of the process could be = bypassed and=20 the work, weight and complexity of the trim tab mechanism could all = be left=20 out.  To my knowledge no one has incorporated this into a = Legacy, but=20 that doesn't mean that it couldn't be done. 

The only=20 disadvantage with the spring bias system at this point is that it is = totally=20 manual.  Once I finish with the basic trim wheel system I'm = going to=20 look into motorizing it while still allowing manual=20 = adjustments.

 <Marv>      = ;  =20 ]



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