X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 08 Jan 2008 20:00:57 -0500 Message-ID: X-Original-Return-Path: Received: from smtp1.av-mx.com ([137.118.16.57] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2636817 for lml@lancaironline.net; Tue, 08 Jan 2008 19:47:26 -0500 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.57; envelope-from=pinetownd@volcano.net Received: from DennisDell (65-166-101-114.dsl.volcano.net [65.166.101.114]) (Authenticated sender: pinetownd@volcano.net) by smtp1.av-mx.com (Postfix) with ESMTP id A9608290414 for ; Tue, 8 Jan 2008 19:46:46 -0500 (EST) X-Original-Message-ID: <005b01c85259$1a58bfd0$6601a8c0@DennisDell> From: "Dennis Johnson" X-Original-To: "Lancair Mailing List" Subject: Legacy Wing Bolts X-Original-Date: Tue, 8 Jan 2008 16:46:41 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0058_01C85216.0B6D4DD0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0058_01C85216.0B6D4DD0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Thanks to Bob Mackey and Kyrilian Dyer for correcting my error about the = correct torque for the Legacy's wing spar bolts. I always enjoy = improving my understanding of this stuff! The Legacy assembly manual version I have doesn't give a torque spec, so = thanks Kryrilian, for the 40 pound/feet spec in the newer version. I'm = not 100% sure I remember right, but I think the bolts are 3/4" diameter = and when I look that up in the standard torque tables, the torque ranges = from 155 pound/feet for a low grade bolt to 380 pound/feet for a grade 8 = bolt. http://www.thelenchannel.com/1torque.php No way could I achieve = that much torque in such a cramped space, but I probably got more than = the 40 pound/feet I needed. =20 I guess I was partially correct in that the loading on the spar bolts = aren't in dynamic tension other than to achieve enough static force = between the spar bushings to resist the shear load. (But I was clearly = wrong to say that the bolts were loaded in shear, which they aren't.) = At least that would explain why the new version of the manual calls for = only a fraction of the standard torque for that size bolt. =20 Dennis Johnson Legacy, 110 hours=20 ------=_NextPart_000_0058_01C85216.0B6D4DD0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

Thanks to Bob Mackey and Kyrilian Dyer for correcting my error = about the=20 correct torque for the Legacy's wing spar bolts. I always enjoy = improving=20 my understanding of this stuff!

The Legacy assembly manual version I have doesn't give a torque = spec, so=20 thanks Kryrilian, for the 40 pound/feet spec in the newer=20 version. I'm not 100% sure I remember right, but I = think the=20 bolts are 3/4" diameter and when I look that up in the standard torque = tables,=20 the torque ranges from 155 pound/feet for a low grade bolt to 380 = pound/feet for=20 a grade 8 bolt. http://www.thelenchanne= l.com/1torque.php =20 No way could I achieve that much torque in such a cramped space, but I = probably=20 got more than the 40 pound/feet I needed.

I guess I was partially correct in that the loading on the spar = bolts=20 aren't in dynamic tension other than to achieve enough static force = between the=20 spar bushings to resist the shear load. (But I was clearly wrong = to say=20 that the bolts were loaded in shear, which they aren't.) At least = that=20 would explain why the new version of the manual calls for only a = fraction of the=20 standard torque for that size bolt.

Dennis Johnson

Legacy, 110 hours

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