X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 15 Oct 2008 01:41:32 -0400 Message-ID: X-Original-Return-Path: Received: from QMTA07.westchester.pa.mail.comcast.net ([76.96.62.64] verified) by logan.com (CommuniGate Pro SMTP 5.2.8) with ESMTP id 3212601 for lml@lancaironline.net; Tue, 14 Oct 2008 13:21:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.62.64; envelope-from=nrgarvin@comcast.net Received: from OMTA01.westchester.pa.mail.comcast.net ([76.96.62.11]) by QMTA07.westchester.pa.mail.comcast.net with comcast id Sdh41a00G0EZKEL57hMBJP; Tue, 14 Oct 2008 17:21:11 +0000 Received: from nrggateway508 ([71.234.119.74]) by OMTA01.westchester.pa.mail.comcast.net with comcast id ShM81a0021cQ7z33MhM8UC; Tue, 14 Oct 2008 17:21:08 +0000 X-Authority-Analysis: v=1.0 c=1 a=YFk6_ZFzSbYA:10 a=xhtew6kqXK0A:10 a=nZWdTn2QpGOvlVO-alQA:9 a=SxXHkmGNILELt8_3VVoA:7 a=iMx6cEY8tWcf6c4ufJuhX6mZVUYA:4 a=EzXvWhQp4_cA:10 a=gi0PWCVxevcA:10 a=SSmOFEACAAAA:8 a=de2Gs5FU-wCmMtpFMbQA:9 a=XzAmFe_uvtXgWFS1iA8A:7 a=uxbcl04ObtxKk1xqcIamCicXCoAA:4 a=37WNUvjkh6kA:10 From: "neal garvin" X-Original-To: "'Lancair Mailing List'" References: Subject: Stec AP Pitch Gain - Was Blue Mountain Avionics Autopilot X-Original-Date: Tue, 14 Oct 2008 13:21:09 -0400 X-Original-Message-ID: <000601c92e21$3fc23360$6601a8c0@nrggateway508> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C92DFF.B8B09360" X-Mailer: Microsoft Office Outlook 11 thread-index: AckszYlJjk6KUBFPSPWgO7AdcePpzQBUhZ3Q X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C92DFF.B8B09360 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I know several people who have done the pitch gain resistor change with their Stec. It is common and routinely done to correct the oscillations many airplane models experience, especially experimentals. Some people solder in short leads to put a variable resistor on the outside which allows testing various resistances to get the best result before making the resistor change permanent. Stec should have documentation available to guide you or bring the unit to an avionics shop to do it. You should be able to find several shops that have done this before. There should also be builders here who have gone through this and can share their experiences. -Neal Glasair IISRG N15F (will put the autopilot in "soon") _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Wayne Bailey Sent: Sunday, October 12, 2008 8:49 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_0007_01C92DFF.B8B09360 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I know several people who have done = the pitch gain resistor change with their Stec. It is common and routinely done to correct the oscillations many airplane models experience, especially = experimentals. Some people solder in short leads to put a variable resistor on the = outside which allows testing various resistances to get the best result before making = the resistor change permanent. Stec should have documentation available to = guide you or bring the unit to an avionics shop to do it. You should be able = to find several shops that have done this before.

 

There should also be builders here = who have gone through this and can share their = experiences.

 

-Neal

Glasair IISRG N15F (will put the = autopilot in “soon”)

 

 

 

From: = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Wayne Bailey
Sent: Sunday, October 12, = 2008 8:49 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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