X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.4.51.90] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 1010548 for flyrotary@lancaironline.net; Wed, 22 Jun 2005 16:44:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.4.51.90; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 22 Jun 2005 13:43:34 -0700 Message-ID: Received: from 64.4.51.220 by BAY107-DAV18.phx.gbl with DAV; Wed, 22 Jun 2005 20:43:33 +0000 X-Originating-IP: [64.4.51.220] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: PSRU adapter plate Date: Wed, 22 Jun 2005 16:43:30 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00E4_01C57749.854A8AA0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Wed, 22 Jun 2005 16:43:30 -0400 X-OriginalArrivalTime: 22 Jun 2005 20:43:34.0085 (UTC) FILETIME=[0EA55750:01C5776B] This is a multi-part message in MIME format. ------=_NextPart_000_00E4_01C57749.854A8AA0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable The error in reasoning here (7075 is twice as strong as 6061 so it can = be half as thick) is that the bending strength of a plate is far more = influenced by its thickness than by material strength. This is in = addition to the fit problems pointed out by Dean. Just not a good idea. Tracy > My bellhousing is to heavy. Dave McC is considering buying it for his=20 > Europa, so I've been researching what it would take to replace it. I=20 > think Tracy' s adapter plate is a very elegant solution for the=20 > homebuilder (ie, those of use without a foundry).=20 >=20 > His adapter plate uses 1/2" 6061. I've been considering at 7075=20 > aluminum. It has about twice the cost but also twice the yield=20 > strength. If I could use 1/4" plate instead of the 1/2", the cost = would=20 > be comparable, but I would have the very large benefit of saving=20 > something on the order of 4lbs in a very weight sensitive area. I = don't=20 > have the expertise to run the numbers with confidence. All I can do is = > a static analysis following the directions outlined on PL's website,=20 > just like I did for the engine mount.=20 >=20 > Any advise of stuff to look for that might no be so obvious and not = show=20 > up in a static analysis? (the three axis and torsional forces are = obvious)=20 ------=_NextPart_000_00E4_01C57749.854A8AA0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
The error in reasoning here (7075 is twice as strong as 6061 so it = can be=20 half as thick) is that the bending strength of a plate is far more = influenced by=20 its thickness than by material strength.   This is in addition = to the=20 fit problems pointed out by Dean.
 
Just not a good idea.
 
Tracy



> My bellhousing is to heavy. Dave McC is=20 considering buying it for his
> Europa, so I've been researching = what it=20 would take to replace it. I
> think Tracy' s adapter plate is a = very=20 elegant solution for the
> homebuilder (ie, those of use without = a=20 foundry).
>
> His adapter plate uses 1/2" 6061. I've been=20 considering at 7075
> aluminum. It has about twice the cost but = also=20 twice the yield
> strength. If I could use 1/4" plate instead of = the=20 1/2", the cost would
> be comparable, but I would have the very = large=20 benefit of saving
> something on the order of 4lbs in a very = weight=20 sensitive area. I don't
> have the expertise to run the numbers = with=20 confidence. All I can do is
> a static analysis following the = directions=20 outlined on PL's website,
> just like I did for the engine mount. =
>
> Any advise of stuff to look for that might no be so = obvious=20 and not show
> up in a static analysis? (the three axis and = torsional=20 forces are obvious)=20
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