X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 09 May 2013 21:01:25 -0400 Message-ID: X-Original-Return-Path: Received: from nm12.access.bullet.mail.mud.yahoo.com ([66.94.237.213] verified) by logan.com (CommuniGate Pro SMTP 6.0.4) with ESMTPS id 6250043 for lml@lancaironline.net; Tue, 07 May 2013 21:25:02 -0400 Received-SPF: neutral receiver=logan.com; client-ip=66.94.237.213; envelope-from=browncc1@verizon.net Received: from [66.94.237.193] by nm12.access.bullet.mail.mud.yahoo.com with NNFMP; 08 May 2013 01:24:26 -0000 Received: from [98.138.85.46] by tm4.access.bullet.mail.mud.yahoo.com with NNFMP; 08 May 2013 01:24:25 -0000 Received: from [127.0.0.1] by smtp103.vzn.mail.ne1.yahoo.com with NNFMP; 08 May 2013 01:24:25 -0000 X-Yahoo-Newman-Id: 832839.89108.bm@smtp103.vzn.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: 8qL3iPEVM1nftlVJ9sdhyvjfY81PlAqXLwXrOdWSwLS7.GY DLSTbt8uWjcxI0i10AgakiXhTqRzrgih7K8cDDgEg1.LzibBovqzGXhCQLrv HwAK.M32avPJM2FUW2Q4LjcYAM9IYQzQWPltx_tWFfOt_DVYvTK_9Ac2qJSn mu79Da274BXvcjx7ASBe1I0U7iNbru6PgJwe27NUCDGmJ.0JkAvhGJpLyIiJ CFPEMO5okP8mkLdZqjBCP3DrhFcjtGW1ojpziPaG0HXTU52pDVBpwj6qK1cj Uqwt1ZQNqJ92ewYz7iENPX7V7jd3qiWBFr83yU6FETIXZ2rV5H45MFhe4STJ bDbITdGQESOEHzPlMUYLcdT.MXqNDiyMrTTEf1eJgbKgqvMFuHvj5ikAxUN4 ciMPcNGl_jkH2CFsBThLdZiDnAcKKf20J8QIAFw6AuN2OQnQ37KbjL04Jjbs e_ODUE7MUZk64cHMJPtpPafdSm7L6eaei0OT_K5eCRHiSeM2wZqcl7UFKhiT alFWotoufUu4- X-Yahoo-SMTP: F49l9g6swBC0R9n8vJIbm7Tf3P8Xlmia8rHIwTlO__Ml X-Rocket-Received: from chass-imac-2.home (browncc1@72.64.105.53 with plain) by smtp103.vzn.mail.ne1.yahoo.com with SMTP; 08 May 2013 01:24:25 +0000 UTC From: Charles Brown Content-Type: multipart/alternative; boundary=Apple-Mail-3-974524212 Subject: [LML] Re: Subtle bug in backup gyro installation X-Original-Date: Tue, 7 May 2013 20:24:24 -0500 References: <13D1ABB4F2F831418BAA12AC3281839ED18F2E0453@ICT-EXCH.MCICO.COM> X-Original-To: Lancair Mailing List X-Original-Message-Id: <68730710-FFDF-4C8E-9B04-21CCF809F571@verizon.net> Mime-Version: 1.0 (Apple Message framework v1085) X-Mailer: Apple Mail (2.1085) --Apple-Mail-3-974524212 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Colyn, here's some more explanation as you requested. Doug Edwards runs = Mid-Continent's gyro shop. As you can read below, he indicates that=20 1. My original gyro probably did *not* go bad from caging knob position = (but caging knob position caused bad indications in the replacement = gyros) 2. It's bad for a gyro to sit still for long periods (months), and 3. when the knob's pulled out, the first thing contacted is the caging = ring which levels the roll and that constraining the roll bearings will = actually feed into a pitch indication, which is what we saw that totally = mystified us. So the advice is: install the gyro soon after it's delivered, and make = sure the caging knob can relax fully. CB Begin forwarded message: From: Doug Edwards Date: May 7, 2013 10:40:04 AM CDT To: "'browncc1@verizon.net'" Subject: RE: [LML] Re: Subtle bug in backup gyro installation Good morning Charley, It is difficult to pinpoint why the outer Gimbal bearings had a short = life. I do not believe it was related to the knob placement on the caging = shaft, A contributing factor may have been the shelf life from our original = sale date to Lancair being 5/3/2010 and the 9/2011 install date. All gyro=92s have = a 6 month shelf life due to the oil in the Gimbal bearing will settle to the = bottom of the bearing and the oil may even escape from it intended area causing premature = bearing wear. =20 As you have already discovered, the caging shaft set screw groove has = approximately .110 (+/-) adjustment (Groove is actually .207 but the knob bottoming out limits to = approx. .110 of knob location/adjustment) The Caging Pin assy. comes in initial contact with the Caging Ring at = .170 (+/-) of shaft pull, therefore holding the =93Roll=94 In the level position. With a total of .280 (+/-) shaft pull, the Caging = Pin contacts the Pitch cam, which is where it comes into play if the Pitch bar climbs or descends due to the amount of pressure on the = Pitch cam and the specific amount of pressure is a result of knob location when panel/lighting ring interfere with the knob. =20 As I had mentioned during your visit, the Outer Gimbal bearings (Roll = Gimbal) affect the Pitch alignment and Inner Gimbal bearings (Pitch Gimbal) affect the Roll alignment due to = torque and inertia created by the Rotor spinning @ 20,000 RPM. =20 Please let me know if you have any questions. =20 =20 Best Regards, Doug Edwards Mid-Continent Instruments and Avionics (800) 821-1212 ph www.mcico.com =20 From: Charles Brown [mailto:browncc1@verizon.net]=20 Sent: Monday, May 06, 2013 9:09 PM To: Doug Edwards Subject: Fwd: [LML] Re: Subtle bug in backup gyro installation =20 Doug, did y'all figure out=20 1. Whether the partially extended cage knob may have hastened my gyro's = demise? and 2. Why it causes gyros to "climb" if extended a little further? =20 (I already figured out one thing -- the original installation of the = gyro probably had the knob clamped on the post as far out as possible; = whereas the loaner, and my refurbished gyro, both had knobs put on by = you guys that were clamped closer to the instrument, preventing = retraction as far as was possible in the original) =20 --Apple-Mail-3-974524212 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252
Colyn, here's some more explanation as you = requested.  Doug Edwards runs Mid-Continent's gyro shop.  As = you can read below, he indicates that 

1. =  My original gyro probably did *not* go bad from caging knob = position (but caging knob position caused bad indications in the = replacement gyros)
2.  It's bad for a gyro to sit still = for long periods (months), and
3.  when the knob's pulled = out, the first thing contacted is the caging ring which levels the roll = and that constraining the roll bearings will actually feed into a pitch = indication, which is what we saw that totally mystified = us.

So the advice is:  install the gyro = soon after it's delivered, and make sure the caging knob can relax = fully.

CB


Begin = forwarded message:

From: Doug Edwards <douge@MCICO.com>
Date: May 7, 2013 = 10:40:04 AM CDT
Subject: RE: [LML] Re: = Subtle bug in backup gyro installation

Good = morning Charley,
It is = difficult to pinpoint why the outer Gimbal bearings had a short = life.
I = do not believe it was related to = the knob placement on the caging shaft,
A contributing factor may have = been the shelf life from our original sale = date
to Lancair = being 5/3/2010 and the 9/2011 install date. All gyro=92s have a 6 = month
shelf = life due to the oil in the Gimbal bearing will settle to the bottom of = the bearing
and = the oil may even escape from it intended area causing premature bearing = wear.
As = you have already discovered, the caging shaft set screw groove has = approximately .110 (+/-)
adjustment (Groove is actually .207 but the knob = bottoming out limits to approx. .110 of knob = location/adjustment)
The Caging Pin assy. comes in initial contact with = the Caging Ring at .170 (+/-) of shaft pull, therefore holding the = =93Roll=94
In = the level position. With a total of .280 (+/-) shaft pull, the Caging = Pin contacts the Pitch cam, which is where it comes into = play
if the = Pitch bar climbs or descends due to the amount of pressure on the Pitch = cam and the specific amount of pressure is a result = of
knob = location when panel/lighting ring interfere with the = knob.
As I = had mentioned during your visit, the Outer Gimbal bearings (Roll Gimbal) = affect the Pitch alignment and
Inner Gimbal bearings (Pitch = Gimbal) affect the Roll alignment due to torque and inertia created by = the
Rotor = spinning @ 20,000 RPM.
 
Please let me know if you have = any questions.
Best = Regards,