X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 13 Jul 2009 08:32:09 -0400 Message-ID: X-Original-Return-Path: Received: from web36904.mail.mud.yahoo.com ([209.191.85.72] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with SMTP id 3754801 for lml@lancaironline.net; Sun, 12 Jul 2009 19:52:42 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.85.72; envelope-from=chris_zavatson@yahoo.com Received: (qmail 31784 invoked by uid 60001); 12 Jul 2009 23:52:04 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=Zjpn0qOWJ1TlBmZKq5GkNiRhGt2r0nDcMT2XG/UhLRUf5wnVeLNrpCqzf/sMqLSC4c/NgaJk5SGn0VIWFACuYyrrGiR3FOJKz0MD9HHlOewgBiVnmqbezNe4ObNBMgkNSU5MooCIdBb5rvUE89Wws+5L1sg0zY3L4C9+2siEyyI=; X-Original-Message-ID: <81548.30836.qm@web36904.mail.mud.yahoo.com> X-YMail-OSG: uvDPIyEVM1kPFvxHwU1vMB_MnPAommX5awTe9yz0DvOR18JMH0XBznwaOr6JTsv4.PgoBA289HZoHqKlhtExXL_P4w5AfjAI5kckCVgDpcW81qKyvnTQEURQDV4raWqofnmzvs2rsY8ChV80ay6A_3.KuRJy9NGhA.uh7v8Pard1COYgv5wbxXQYhq4xt6fYPRVIyN0EBH5dsVaNj9b38PwENUFyBRG6_AA7FoDjCxon6o8HLlCcBiE7UPl37Af1jW3GdkZfXygoXw1UczDhpz_R_KZxJJDm9yzlq.IU6hGzrg4AXdbMls.gPJ1.K_x94kJxeBbossEAF9R8vyddU8wiXpd9iS3Yh3CNDBMacp_TIn3BAWBSfA-- Received: from [99.154.149.93] by web36904.mail.mud.yahoo.com via HTTP; Sun, 12 Jul 2009 16:52:03 PDT X-Mailer: YahooMailRC/1358.21 YahooMailWebService/0.7.289.15 References: X-Original-Date: Sun, 12 Jul 2009 16:52:03 -0700 (PDT) From: Chris Zavatson Subject: Re: [LML] Shimmy, Bearing Block Bearing Slippage X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-700137395-1247442723=:30836" --0-700137395-1247442723=:30836 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Mike,=0ANot being too familiar with the ES mounting of the nose gear, I fou= nd it interesting to=A0learn that the bearings=A0are inserted such that sid= e load could move them.=A0 For the 320/360 design, the bearing seat is outb= oard thus preventing side loads from being able to move a bearing.=A0 Side = to side movement is however just as=A0much a concern=A0if the spacer that s= eparates the two bearing blocks is not perfectly sized.=A0 This is another = one of those inputs to shimmy that can't really be quantified easily.=A0 Id= eally one would have no play whatsoever in this joint, but also have no fri= ction in the bearings that could impede gear free-fall.=A0 I don't know how= this is handled in the ES and IV, but in the 320/360 a fixed length tube i= s placed in between the bearing blocks.=A0 Getting just the right length wa= s always difficult.=A0 After a number of nose gear removals and installs, I= finally decided a better design was needed.=A0 The solution was an adjusta= ble length spacer that allows fine tuning of the preload on the nose gear pivot beari= ngs.=A0=A0A similar solution in the ES might=A0help remove that joint as a = contributor to the shimmy equation.=A0=0Ahttp://www.n91cz.com/StrutSpacer/s= trut%20spacer.htm=0A=0AChris Zavatson=0AN91CZ=0A360std=0Awww.N91CZ.com=0A= =0A=0A --0-700137395-1247442723=:30836 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable

Mike,

=0A

Not being too familiar with the ES mounting of= the nose gear, I found it interesting to learn that the bearings = ;are inserted such that side load could move them. For the 320/360 de= sign, the bearing seat is outboard thus preventing side loads from being ab= le to move a bearing. Side to side movement is however just as m= uch a concern if the spacer that separates the two bearing blocks is n= ot perfectly sized. This is another one of those inputs to shimmy tha= t can't really be quantified easily. Ideally one would have no play w= hatsoever in this joint, but also have no friction in the bearings that cou= ld impede gear free-fall. I don't know how this is handled in the ES = and IV, but in the 320/360 a fixed length tube is placed in between the bea= ring blocks. Getting just the right length was always difficult. = ; After a number of nose gear removals and installs, I finally decided a be= tter design was needed. The solution was an adjustable length spacer that allows fin= e tuning of the preload on the nose gear pivot bearings. A simil= ar solution in the ES might help remove that joint as a contributor to= the shimmy equation.
http://www.n91cz.com/StrutSpacer/strut%20spacer.htm=

=0A

=0A

Chris Zavatson

=0A

N91CZ

= =0A

360std

=0A

=0A=0A --0-700137395-1247442723=:30836--