X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 29 Jun 2008 21:18:15 -0400 Message-ID: X-Original-Return-Path: Received: from yw-out-2324.google.com ([74.125.46.28] verified) by logan.com (CommuniGate Pro SMTP 5.2.4) with ESMTP id 2996641 for lml@lancaironline.net; Sun, 29 Jun 2008 11:31:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.46.28; envelope-from=msteitle@gmail.com Received: by yw-out-2324.google.com with SMTP id 3so702168ywj.7 for ; Sun, 29 Jun 2008 08:31:16 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:references; b=gFYznXUn4PMBtiU/aCvIOi/q8QSF6ilXlN4gywmHNh+MCcLQCgMA0ebjAzu9IsUido HcJ2sJfjltTk2QvQFFjJFDaS/OQEJd15mORMagik7UcILdw6K4RyudqBS2C7OHRo49kO b38Y5UevACFM1JbFCwjZunRivpe6XfKo2i00o= Received: by 10.150.82.42 with SMTP id f42mr6476557ybb.197.1214753476592; Sun, 29 Jun 2008 08:31:16 -0700 (PDT) Received: by 10.151.9.4 with HTTP; Sun, 29 Jun 2008 08:31:16 -0700 (PDT) X-Original-Message-ID: <5cf132c0806290831l5981f8afo785589cb49dbc7d3@mail.gmail.com> X-Original-Date: Sun, 29 Jun 2008 10:31:16 -0500 From: "Mark Steitle" X-Original-To: "Lancair Mailing List" Subject: Re: [LML] Runaway Trim In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_14875_8345321.1214753476560" References: ------=_Part_14875_8345321.1214753476560 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline I've been following this thread and find it quite interesting, but we seem to be going in circles. A fellow builder and I were discussing this a whil= e back and his solution sounded ultra simple and foolproof (if that is truly possible). He suggests adding an ON-OFF-(ON) switch between the relay and the trim servo. Normal operation would be in the ON position. If the rela= y sticks, or the coolie switch sticks closed, you would momentarily move the switch to the (ON) position, thereby reversing the polarity to the servo an= d reversing its direction. Once yo get the trim back to a controllable trim setting, you would release the ON-OFF-(ON) switch and it would automaticall= y spring back to the OFF position, interrupting power to the servo. Has anyone used this approach, and if so, how does it work? Mark Steitle Lancair ES On Sat, Jun 28, 2008 at 11:06 PM, Steve Colwell wrote: > My Legacy experienced Runaway Pitch Trim on the first flight. > Fortunately Test Pilot Josh Brungardt was at the controls, had previously > located the trim circuit breaker, pulled it, cycled the coolie hat, then = was > ok. I called RAC about the problem and learned they have a new larger re= lay > to replace the older smaller one. I ran the pitch servo, wiggled the wir= es > and connectors many times with no faulting. RAC doubted the relay was th= e > problem but I replaced the pitch and roll relays anyway. I also installe= d > the Adjustable Trim Speed Control that allowed pitch trim to operate at = =BD > the normal speed=85=85.much better. > > > > Steve Colwell Legacy 15SC > > > ------=_Part_14875_8345321.1214753476560 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline I've been following this thread and find it quite interesting, but we s= eem to be going in circles.  A fellow builder and I were discussing th= is a while back and his solution sounded ultra simple and foolproof (if tha= t is truly possible).  He suggests adding an ON-OFF-(ON) switch betwee= n the relay and the trim servo.  Normal operation would be in the ON p= osition.  If the relay sticks, or the coolie switch sticks closed, you= would momentarily move the switch to the (ON) position, thereby reversing = the polarity to the servo and reversing its direction.  Once yo get th= e trim back to a controllable trim setting, you would release the ON-OFF-(O= N) switch and it would automatically spring back to the OFF position, inter= rupting power to the servo.  Has anyone used this approach, and if so,= how does it work? 

Mark Steitle
Lancair ES

On Sat, Ju= n 28, 2008 at 11:06 PM, Steve Colwell <mcmess1919@yahoo.com> wrote:

My Legacy expe= rienced Runaway Pitch Trim on the first flight.  Fortunately Test Pilot Josh Brungardt was at the controls, had previously located the trim circuit breaker, pulled it, cycled the coolie hat, then wa= s ok.  I called RAC about the problem and learned they have a new larger= relay to replace the older smaller one.  I ran the pitch servo, wiggled the wir= es and connectors many times with no faulting.  RAC doubted the relay was the= problem but I replaced the pitch and roll relays anyway.  I also installed the= Adjustable Trim Speed Control that allowed pitch trim to operate at =BD the normal spe= ed=85=85.much better.

 <= /p>

Steve Colwell&= nbsp; Legacy 15SC 

 


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