X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 11 Jan 2008 09:50:42 -0500 Message-ID: X-Original-Return-Path: Received: from vms048pub.verizon.net ([206.46.252.48] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2638737 for lml@lancaironline.net; Thu, 10 Jan 2008 02:03:00 -0500 Received-SPF: pass receiver=logan.com; client-ip=206.46.252.48; envelope-from=tom.gourley@verizon.net Received: from jacky0da39824a ([71.111.158.160]) by vms048.mailsrvcs.net (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPA id <0JUF00DST2727280@vms048.mailsrvcs.net> for lml@lancaironline.net; Thu, 10 Jan 2008 01:01:53 -0600 (CST) X-Original-Date: Wed, 09 Jan 2008 23:01:44 -0800 From: "Tom Gourley" Subject: Re: [LML] Re: Instrument panel hardware X-Original-To: "Lancair Mailing List" Reply-to: "Tom Gourley" X-Original-Message-id: <003801c85356$a95e94e0$650610ac@jacky0da39824a> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Mailer: Microsoft Outlook Express 6.00.2900.3138 Content-type: multipart/alternative; boundary="----=_NextPart_000_0035_01C85313.9A83C4B0" X-Priority: 3 X-MSMail-priority: Normal References: This is a multi-part message in MIME format. ------=_NextPart_000_0035_01C85313.9A83C4B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable "He said it would interfere with the compass. He said I should use brass = or stainless hardware, which is fine but i can not find nutplates made = of this." I stopped by the hangar today, got a K1000 nutplate from the parts = drawer and placed it right next to my mag compass, actually touching the = housing. I then moved the nutplate all around the compass within a half = inch of the compass housing. At no point could I detect any change in = the compass indication. I then got the pocket compass I carry when I go = hiking. (Never really used it while hiking; I just always carried it.) = It's a good compass; fluid damped with a very low friction pivot and = quite sensitive. At 1" from the endpoint of the compass needle I saw a = very small deflection, less than 2 degrees, when moving the nutplate = around. At 1-1/2" there was no visible movement of the needle. No = matter how I moved the nutplate around if it was than an inch from the = needle nothing moved. =20 Unless you're going to rivet a nutplate to the face of your compass I = don't think you need to worry. Besides, adjusting the compensation = screws when you swing your compass should correct for any small amounts = of ferrous material near the compass. By the way, small magnets are an entirely different story, which should = be no surprise. I found a small round refridgerator magnet that caused = a noticeable defleciton, up to 5 degrees, in my pocket compass from as = much as 2 feet away. A magnetized screwdriver produced similar results. = I suppose if your nutplates have been stuck to a magnet for a while = they might cause some compass error within 3 or 4 inches of your mag = compass, so don't use a magnetic pickup to get nutplates out of the = parts drawer. Tom Gourley ------=_NextPart_000_0035_01C85313.9A83C4B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

"He = said it would=20 interfere with the compass. He said I should use brass or stainless = hardware,=20 which is fine but i can not find nutplates made of=20 this."

I stopped by the hangar today, got a = K1000 nutplate=20 from the parts drawer and placed it right next to my mag compass, = actually=20 touching the housing. I then moved the nutplate all around the = compass=20 within a half inch of the compass housing. At no point could I = detect any=20 change in the compass indication. I then got the pocket = compass I=20 carry when I go hiking. (Never really used it while hiking; I just = always=20 carried it.) It's a good compass; fluid damped with a very low = friction=20 pivot and quite sensitive. At 1" from the endpoint of the = compass=20 needle I saw a very small deflection, less than 2=20 degrees, when moving the nutplate around. At 1-1/2" there was = no=20 visible movement of the needle. No matter how I moved the = nutplate=20 around if it was than an inch from the needle nothing=20 moved.

Unless you're going to rivet a nutplate = to the face=20 of your compass I don't think you need to worry. Besides, = adjusting the=20 compensation screws when you swing your compass should correct for any = small=20 amounts of ferrous material near the compass.

By the way, small magnets are an = entirely different=20 story, which should be no surprise. I found a small=20 round refridgerator magnet that caused a noticeable = defleciton, up=20 to 5 degrees, in my pocket compass from as much as 2 feet = away. =20 A magnetized screwdriver produced similar results. I suppose if = your=20 nutplates have been stuck to a magnet for a while they might cause some = compass=20 error within 3 or 4 inches of your mag compass, so don't use a magnetic = pickup=20 to get nutplates out of the parts drawer.

Tom Gourley

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