X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 17 Oct 2008 21:03:50 -0400 Message-ID: X-Original-Return-Path: Received: from fmailhost03.isp.att.net ([207.115.11.53] verified) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3217215 for lml@lancaironline.net; Fri, 17 Oct 2008 11:52:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=207.115.11.53; envelope-from=dskeele@bellsouth.net Received: from fwebmail15.isp.att.net ([204.127.221.115]) by isp.att.net (frfwmhc03) with SMTP id <20081017155122H0300jnli9e>; Fri, 17 Oct 2008 15:51:23 +0000 X-Originating-IP: [204.127.221.115] Received: from [70.149.218.154] by fwebmail15.isp.att.net; Fri, 17 Oct 2008 15:51:22 +0000 From: dskeele@bellsouth.net X-Original-To: "Lancair Mailing List" Subject: Re: [LML] Re: Blue Mountain Avionics Autopilot X-Original-Date: Fri, 17 Oct 2008 15:51:22 +0000 X-Original-Message-Id: <101720081551.29873.48F8B4790008FD79000074B122230704929B0A02D2089B9A019C04040A0DBF0A040A0A059C0B@att.net> In-Reply-To: X-Mailer: AT&T Message Center Version 1 (Jul 16 2008) X-Authenticated-Sender: ZHNrZWVsZUBiZWxsc291dGgubmV0 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="NextPart_Webmail_9m3u9jl4l_29873_1224258682_0" --NextPart_Webmail_9m3u9jl4l_29873_1224258682_0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_29873_1224258682_1" --NextPart_Webmail_9m3u9jl4l_29873_1224258682_1 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable John Huft, Holy Smokes, Batman, you may have just solved my S-Tec 50 Alt hold probl= em, I hope !! See post and novel to Colyn.. I'll open the static to cockp= it input, without a filter and see what happens, after the current pain= t job on 320J is done.. Hope is eternal... Don Skeele=20=20=20=20=20 -------------- Original message from "John Huft" : ------= --------=20 One thing I do know about the S-Tec autopilot is that the pitch algorithms = are extremely sensitive to any lag or delay in the static system. On certif= ied installations the =E2=80=9Cbrain box=E2=80=9D is required to be mounte= d very close (3 feet or less) to the static ports, and the autopilot must h= ave its own static ports, and not share them with any other instrument. Als= o not allowed are the little bottles that are supposed to catch moisture in= the tubing. =20 Pitch oscillations are the main symptoms of too much static lag. =20 John Huft RV spy =20 =20 =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Wayn= e Bailey Sent: Sunday, October 12, 2008 6:49 PM To: lml@lancaironline.net Subject: [LML] Blue Mountain Avionics Autopilot =20 Small tail 360 with Stec50 autopilot.=20=20 =20 AP works OK to maintaining heading - but pitch enters oscillations eventual= ly becoming so severe requires disconnection of AP after about 30 - 40 seco= nds. Incredibly there is no 'gain' adjustment in the pitch axis of the ST= EC 50. I have read about replacing resistor on board to modify gain - but = a little uncomfortable with this option. No slop in the linkage. =20 Have not dug into the servos yet - but hoping there is a way to mechanicall= y reduce the 'gain' by extending the servo attachment point radially outwar= d on bellcrank - or ?? =20 Alternatively thinking about installing BMA EFIS Gen 4 system with new serv= o actuators. Anyone have any experience with BMA gen 4 EFIS on a close cou= pled LNC2? I do know there is gain on both axis. =20 Thanks again for the help. Wayne =20 =20 =20 --NextPart_Webmail_9m3u9jl4l_29873_1224258682_1 Content-Type: multipart/related; boundary="NextPart_Webmail_9m3u9jl4l_29873_1224258682_2" --NextPart_Webmail_9m3u9jl4l_29873_1224258682_2 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

John Huft,

Holy Smokes, Batman, you may have just solved my S-Tec 50= Alt hold problem, I hope !! See post and novel to Colyn.. I'll= open the static to cockpit input, without a filter and see what happens, a= fter the current paint job on 320J is done.. Hope = is eternal... Don Skeele

-------------- Original message from "John Huft" <aflyer@= lazy8.net>: --------------

One thing I do know about the S-Tec autopilo= t is that the pitch algorithms are extremely sensitive to any lag or delay = in the static system. On certified installations the =E2=80=9Cbrain box=E2= =80=9D is required to be mounted very close (3 feet or less) to the s= tatic ports, and the autopilot must have its own static ports, and not shar= e them with any other instrument. Also not allowed are the little bottles t= hat are supposed to catch moisture in the tubing.

Pitch oscillations are the main symptoms of = too much static lag.

John Huft

RV spy

From: Lancair Mailing List [mailto:lml@lancaironline.n= et] On Behalf Of Wayne Bailey
Sent: Sunday, October 12, 20= 08 6:49 PM
To: lml@lancaironline.net
Subject: [LML] Blu= e Mountain Avionics Autopilot

Small tail 360 with Stec50 autopilot.

AP works OK to maintaining heading - but pitch en= ters oscillations eventually becoming so severe requires disconnection= of AP after about 30 - 40 seconds. Incredibly there is no 'gai= n' adjustment in the pitch axis of the STEC 50. I have read about rep= lacing resistor on board to modify gain - but a little uncomforta= ble with this option. No slop in the linkage.

Have not dug into the servos yet - but hoping the= re is a way to mechanically reduce the 'gain' by extending the se= rvo attachment point radially outward on bellcrank - or ??

Alternatively thinking about installing BMA EFIS Gen 4= system with new servo actuators. Anyone have any experience with BMA= gen 4 EFIS on a close coupled LNC2? I do know there is gain on both a= xis.

Thanks again for the help.

Wayne

--NextPart_Webmail_9m3u9jl4l_29873_1224258682_2-- --NextPart_Webmail_9m3u9jl4l_29873_1224258682_1-- --NextPart_Webmail_9m3u9jl4l_29873_1224258682_0 Content-Type: message/rfc822 Received: from logan.com (mail.logan.com[207.58.244.114]) by isp.att.net (frfwmxc09) with ESMTP id <20081017062558M09009k25me>; Fri, 17 Oct 2008 06:25:59 +0000 X-Originating-IP: [207.58.244.114] X-Virus-Scanned: clean according to Sophos on Logan.com X-ListServer: CommuniGate Pro LIST 5.2.8 List-Unsubscribe: List-ID: List-Archive: Precedence: list Message-ID: Reply-To: "Lancair Mailing List" Sender: "Lancair Mailing List" To: lml@lancaironline.net Date: Fri, 17 Oct 2008 02:25:04 -0400 X-Original-Message-ID: From: "John Huft" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01C92E99.D26FB520" Subject: [LML] Re: Blue Mountain Avionics Autopilot This is a multipart message in MIME format. ------=_NextPart_000_0029_01C92E99.D26FB520 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit One thing I do know about the S-Tec autopilot is that the pitch algorithms are extremely sensitive to any lag or delay in the static system. On certified installations the "brain box" is required to be mounted very close (3 feet or less) to the static ports, and the autopilot must have its own static ports, and not share them with any other instrument. Also not allowed are the little bottles that are supposed to catch moisture in the tubing. Pitch oscillations are the main symptoms of too much static lag. John Huft RV spy From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Wayne Bailey Sent: Sunday, October 12, 2008 6:49 PM To: lml@lancaironline.net Subject: [LML] Blue Mountain Avionics Autopilot Small tail 360 with Stec50 autopilot. AP works OK to maintaining heading - but pitch enters oscillations eventually becoming so severe requires disconnection of AP after about 30 - 40 seconds. Incredibly there is no 'gain' adjustment in the pitch axis of the STEC 50. I have read about replacing resistor on board to modify gain - but a little uncomfortable with this option. No slop in the linkage. Have not dug into the servos yet - but hoping there is a way to mechanically reduce the 'gain' by extending the servo attachment point radially outward on bellcrank - or ?? Alternatively thinking about installing BMA EFIS Gen 4 system with new servo actuators. Anyone have any experience with BMA gen 4 EFIS on a close coupled LNC2? I do know there is gain on both axis. Thanks again for the help. Wayne ------=_NextPart_000_0029_01C92E99.D26FB520 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

One thing I do know about the S-Tec autopilot is that the = pitch algorithms are extremely sensitive to any lag or delay in the static = system. On certified installations the “brain box” is required to = be mounted very close (3 feet or less) to the static ports, and the autopilot must have its = own static ports, and not share them with any other instrument. Also not = allowed are the little bottles that are supposed to catch moisture in the = tubing.

Pitch oscillations are the main symptoms of too much = static lag.

John Huft

RV spy

From:= Lancair = Mailing List [mailto:lml@lancaironline.net] On Behalf Of Wayne Bailey
Sent: Sunday, October 12, 2008 6:49 PM
To: lml@lancaironline.net
Subject: [LML] Blue Mountain Avionics = Autopilot

Small tail 360 with Stec50 autopilot. =

AP works OK to maintaining heading - but = pitch enters oscillations eventually becoming so severe requires disconnection = of AP after about 30 - 40 seconds. Incredibly there is no 'gain' adjustment in the pitch axis of the STEC 50. I have read about replacing resistor on board to modify gain - but a little uncomfortable with this option. No slop in the = linkage.

Have not dug into the servos yet - but = hoping there is a way to mechanically reduce the 'gain' by extending the servo = attachment point radially outward on bellcrank - or ??

Alternatively thinking about installing BMA EFIS = Gen 4 system with new servo actuators. Anyone have any experience with = BMA gen 4 EFIS on a close coupled LNC2? I do know there is gain on both = axis.

Thanks again for the help.

Wayne

=

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