X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 09 Apr 2010 16:53:14 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-mealy.atl.sa.earthlink.net ([209.86.89.69] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4215020 for lml@lancaironline.net; Thu, 08 Apr 2010 21:23:25 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.69; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=WI+CVjcGSw2OiDI5WUxDsBkrk/j0Tyl9mNh9acg7hP5NBMAjhLAyJzHlI4eQsNLZ; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.178] (helo=ccaselt3) by elasmtp-mealy.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1O02vp-0002v4-TL for lml@lancaironline.net; Thu, 08 Apr 2010 21:22:50 -0400 X-Original-Message-ID: <522176AF492C4A55AC0F8603DF68072E@nvidia.com> From: "Colyn Case at earthlink" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: fixes for S-TEC 50 alt hold X-Original-Date: Thu, 8 Apr 2010 21:22:48 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_1A1E_01CAD761.A3287E60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940ebb519bc7cc077c79aaef8ab3da13d00350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.178 This is a multi-part message in MIME format. ------=_NextPart_000_1A1E_01CAD761.A3287E60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable That's amusing Gary. I have a 172rg installation with a 55X in it. It took me almost a year = to get it debugged. Shortly after my installation (2000) there was a big deal with larger = cessna's having this problem, only this time Tom at avionics west = provided sufficient evidence that I think stec finally paid attention. However, there was another problem, and that was that the dsub housing = on the back of the control module cracked, making it impossible to = obtain sufficient insertion force to get a good connection. It was = from this experience that I gained a serious respect for run-away = auto-pilots. especially ones that have auto-trim. since then it's been very good... Colyn IVP with TruTrak ----- Original Message -----=20 From: Gary Casey=20 To: lml@lancaironline.net=20 Sent: Thursday, April 08, 2010 9:13 PM Subject: [LML] Re: fixes for S-TEC 50 alt hold I don't know whether or not it's related, but in my Cardinal I had a = problem with my S-TEC altitude hold when it (the autopilot) was new. = The altitude hold function was divergently unstable - would start to = oscillate and then get worse and worse. Tried all sorts of static = systems and finally disconnected the static source entirely and used = cabin pressure - seemed to work slightly better. I was going back and = forth with the factory -they initially insisted there was "no problem" = and said I should take it back to the installer to have them fix their = installation. Then I broadcast the problem on the net and received = replies from all over the world about the same problem. I sent copies = to S-TEC and they immediately said "send it in," so I did. It came back = with no documentation so I called: "We just checked it out and found no = problem." Oh, yeah? I installed it and it worked perfectly. All the = earlier S-TEC autopilots, including the 55, used analog circuitry, so = the change gain components had to be changed. They never did admit they = had a problem, but I'll bet after that a lot of owners sent theirs back = for the same "inspection." Gary ES with TruTrack -------------------------------------------------------------------------= ----- To:"" one other comment on the static source: the a/p doesn't care how = accurate the static source is, only that it changes with altitude. = Therefore some people have found that (on spam cans) putting a dedicated = static port in just for the pressure transducer works well. ...or you can just use the vents to fine tune your altitude.... ------=_NextPart_000_1A1E_01CAD761.A3287E60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
That's amusing Gary.
 
I have a 172rg installation with a 55X = in=20 it.   It took me almost a year to get it = debugged.
Shortly after my installation (2000) = there was a=20 big deal with larger cessna's having this problem, only this time Tom at = avionics west provided sufficient evidence that I think stec finally = paid=20 attention.
 
However, there was another problem, and = that was=20 that the dsub housing on the back of the control module cracked, = making it=20 impossible to obtain sufficient insertion force to get a good=20 connection.   It was from this experience that I gained a = serious=20 respect for run-away auto-pilots.   especially ones that have=20 auto-trim.
 
since then it's been very = good...
 
Colyn
IVP with TruTrak
----- Original Message -----
From:=20 Gary=20 Casey
Sent: Thursday, April 08, 2010 = 9:13=20 PM
Subject: [LML] Re: fixes for = S-TEC 50 alt=20 hold

I don't know whether or not it's related, but in my Cardinal I = had a=20 problem with my S-TEC altitude hold when it (the autopilot) was new. =  The=20 altitude hold function was divergently unstable - would start to = oscillate and=20 then get worse and worse.  Tried all sorts of static systems and = finally=20 disconnected the static source entirely and used cabin pressure - = seemed to=20 work slightly better.   I was going back and forth with the = factory -they=20 initially insisted there was "no problem" and said I should take it = back to=20 the installer to have them fix their installation.  Then I = broadcast the=20 problem on the net and received replies from all over the world about = the same=20 problem.  I sent copies to S-TEC and they immediately said "send = it in,"=20 so I did.  It came back with no documentation so I called: =  "We just=20 checked it out and found no problem."  Oh, yeah?  I = installed it and=20 it worked perfectly.  All the earlier S-TEC autopilots, including = the 55,=20 used analog circuitry, so the change gain components had to be = changed.=20  They never did admit they had a problem, but I'll bet after that = a lot=20 of owners sent theirs back for the same "inspection."
Gary
ES with TruTrack

To:
""=20 <lml@lancaironline.net>
=
one other comment on the static = source:  =20 the a/p doesn't care how accurate the static source is, only that it = changes=20 with altitude.   Therefore some people have found that (on = spam=20 cans) putting a dedicated static port in just for the pressure = transducer=20 works well.
 
...or you can just use the vents to fine = tune your=20 altitude....

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