X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from [64.12.136.170] (HELO imo-m11.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 2030256 for flyrotary@lancaironline.net; Mon, 07 May 2007 12:03:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.136.170; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m11.mx.aol.com (mail_out_v38_r9.2.) id q.cf0.f045741 (60435) for ; Mon, 7 May 2007 12:02:20 -0400 (EDT) Received: from webmail-db15 (webmail-db15.webmail.aol.com [205.188.105.80]) by ciaaol-d01.mail.aol.com (v115.11) with ESMTP id MAILCIAAOLD014-ec13463f4d8bd; Mon, 07 May 2007 12:02:19 -0400 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Engine mount mockup Date: Mon, 07 May 2007 12:02:19 -0400 In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: wrjjrs@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8C95ED8396211DC_AA0_422E_webmail-db15.sysops.aol.com" X-Mailer: AOL WebMail 25698 Received: from 65.161.241.3 by webmail-db15.sysops.aol.com (205.188.105.80) with HTTP (WebMailUI); Mon, 07 May 2007 12:02:19 -0400 Message-Id: <8C95ED8396211DC-AA0-229F@webmail-db15.sysops.aol.com> X-AOL-IP: 205.188.105.80 X-Spam-Flag: NO ----------MB_8C95ED8396211DC_AA0_422E_webmail-db15.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" Lynn's comments are great as usual. In addition we should consider shot peening the motor mount. Shot peening is a great idea to help normalize stress in any medium to high stress assembly. Bill Jepson The design is not what is commonly seen for that kind of junction. It leaves the angles in bending along the fold lines. However, if the loads are not enough to cycle the joint in bending, then it's good enough. The mild steel to 4130 connection is OK for light loads. The angle inserts in 4130 would help a bit. Double the part of the angle against the firewall with a piece of 1/8 4130 as a big washer but don't load the bend (or weld area). Paint the bend and the tube to angle joints with just a bit of white lacquer. Grit blast the joints with rice hulls and paint without any primer. Just enough to prevent rusting. Should a problem develop, the paint will crack along the failure and be obvious. Enamels and powder coats will stretch and conceal the crack. Lynn E. Hanover See what's free at AOL.com. ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com. ----------MB_8C95ED8396211DC_AA0_422E_webmail-db15.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii"

Lynn's comments are great as usual. In addition we should consider shot peening the motor mount. Shot peening is a great idea to help normalize stress in any medium to high stress assembly.

Bill Jepson

The design is not what is commonly seen for that kind of junction. It leaves the angles in bending along the fold lines. However, if the loads are not enough to cycle the joint in bending, then it's good enough. The mild steel to 4130 connection is OK for light loads.

The angle inserts in 4130 would help a bit. Double the part of the angle against the firewall with a piece of 1/8 4130 as a big washer but don't load the bend (or weld area).

Paint the bend and the tube to angle joints with just a bit of white lacquer. Grit blast the joints with rice hulls and paint without any primer. Just enough to prevent rusting.

Should a problem develop, the paint will crack along the failure and be obvious. Enamels and powder coats will stretch and conceal the crack.

Lynn E. Hanover

See what's free at AOL.com.

AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.

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