Return-Path: Received: from mail.his.com ([205.177.25.9]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-52269U2500L250S0V35) with ESMTP id com for ; Tue, 27 Jul 1999 07:11:46 -0400 Received: from hk53 (pm9-176.his.com [205.252.121.176]) by mail.his.com (8.8.5/8.8.5) with SMTP id HAA20618 for ; Tue, 27 Jul 1999 07:15:06 -0400 (EDT) Message-ID: <000301bed821$818bdd60$b079fccd@hk53> Reply-To: "Avionics Systems" From: "Avionics Systems" To: Subject: S-Tec 50 problems Date: Tue, 27 Jul 1999 07:16:41 -0400 X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> The S-Tec autopilots use very slow-moving servos, so all settings must be correct in order for them to control the aircraft properly: 1. Bridle cable tension - the 320 and 360 use a bridle cable to connect the pitch servo to the elevator tube. Make sure the tension is 15 +/- 2 lbs. 2. Clutch torque setting - if the clutch torque is set too low, the servos will slip when loads increase, resulting in deviations. Reading and setting the torque requires a special adapter - time to see your local S-Tec dealer (and the servo has to come out). 3. Servo speed and computer gain - The servos and computer gain settings must be set at S-Tec for the 320 / 360 (or any particular aircraft). If the autopilot was purchased used from another aircraft without going to S-Tec for conversion to your aircraft, it will not work properly. With all these conditions met, the S-Tec should work well under all conditions, but you should not use it to fly through severe turbulence - that can overload and burn out the servo drive outputs in the computer. Also, don't hand fly the aircraft with the autopilot engaged, that can also damage the computer. David Buckwalter Avionics Systems >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML homepage: http://www.olsusa.com/Users/Mkaye/maillist.html