X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from imo-m27.mx.aol.com ([64.12.137.8] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1874607 for flyrotary@lancaironline.net; Wed, 28 Feb 2007 15:24:53 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.8; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m27.mx.aol.com (mail_out_v38_r7.6.) id q.c3e.10222cfe (45776) for ; Wed, 28 Feb 2007 15:23:54 -0500 (EST) Received: from webmail-de03 (webmail-de03.webmail.aol.com [205.188.104.24]) by ciaaol-r01.mx.aol.com (v114_r3.2) with ESMTP id MAILCIAAOLR015-b2d045e5e4da267; Wed, 28 Feb 2007 15:23:54 -0500 References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: engine mount 4130 vs 304 SS Date: Wed, 28 Feb 2007 15:23:54 -0500 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_8C9298D808DB7C4_E34_3871_webmail-de03.sysops.aol.com" X-Mailer: AOL WebMail 24019 Received: from 65.161.241.3 by webmail-de03.sysops.aol.com (205.188.104.24) with HTTP (WebMailUI); Wed, 28 Feb 2007 15:23:54 -0500 Message-Id: <8C9298D80901A22-E34-1D06@webmail-de03.sysops.aol.com> X-AOL-IP: 205.188.104.24 X-Spam-Flag: NO ----------MB_8C9298D808DB7C4_E34_3871_webmail-de03.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" Charlie, Almost always some kind of a monocoque built up structure. Also some forms of aluminum have a yield strength near that of steel. More likely the structure accomodates the materials shortcomings. Bill Jepson -----Original Message----- From: ceengland@bellsouth.net To: flyrotary@lancaironline.net Sent: Wed, 28 Feb 2007 11:36 AM Subject: [FlyRotary] Re: engine mount 4130 vs 304 SS Russell Duffy wrote: > Greetings, > > As I ponder my choices for mounting the single rotor engine, I noticed > something that surprised me. 304 stainless is cheaper than 4130 steel. > One thing that's always bothered me about steel tube type construction > is the concern for rusting inside the tubes, so stainless is appealing. > There must be a catch here. > > Is there a good reason I should use 4130 instead of 304? Either will > likely be sized much larger than needed, since I don't have the means to > do any proper analysis of the strength. > > Thanks, > Rusty (Autoflight drive supposed to be shipping next week) > Well, after wading through all the replies, everyone seems to be ignoring the obvious answer: aluminum. :-) Sounds heretical, but there are AL mounts that have been flying for decades on certified a/c. IIRC, some of the bed mounts for Franklins are AL. Charlie -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com. ----------MB_8C9298D808DB7C4_E34_3871_webmail-de03.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii"
Charlie,
 Almost always some kind of a monocoque built up structure. Also some forms of aluminum have a yield strength near that of steel. More likely the structure accomodates the materials shortcomings.
Bill Jepson
 
 
-----Original Message-----
From: ceengland@bellsouth.net
To: flyrotary@lancaironline.net
Sent: Wed, 28 Feb 2007 11:36 AM
Subject: [FlyRotary] Re: engine mount 4130 vs 304 SS

Russell Duffy wrote: 
> Greetings, 
> > As I ponder my choices for mounting the single rotor engine, I noticed > something that surprised me. 304 stainless is cheaper than 4130 steel. > One thing that's always bothered me about steel tube type construction > is the concern for rusting inside the tubes, so stainless is appealing. > There must be a catch here. > > Is there a good reason I should use 4130 instead of 304? Either will > likely be sized much larger than needed, since I don't have the means to > do any proper analysis of the strength. > > Thanks, 
> Rusty (Autoflight drive supposed to be shipping next week) 
> Well, after wading through all the replies, everyone seems to be ignoring the obvious answer: aluminum. :-) 
 
Sounds heretical, but there are AL mounts that have been flying for decades on certified a/c. IIRC, some of the bed mounts for Franklins are AL. 
 
Charlie 
 
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