X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail27.syd.optusnet.com.au ([211.29.133.168] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTPS id 1010673 for flyrotary@lancaironline.net; Wed, 22 Jun 2005 19:23:09 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.133.168; envelope-from=lendich@optusnet.com.au Received: from george (d211-31-107-82.dsl.nsw.optusnet.com.au [211.31.107.82]) by mail27.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j5MNMHCU006027 for ; Thu, 23 Jun 2005 09:22:18 +1000 Message-ID: <009001c57781$414785a0$526b1fd3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: PSRU adapter plate Date: Thu, 23 Jun 2005 09:22:26 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008D_01C577D5.122E70E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_008D_01C577D5.122E70E0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable I agree Tracy the flexing would be my concern - this alone could lead to = failure of the plate. One would need significant development and costly = testing to identify the lightest possible stiffening required. This = could bring it up to the weight of the 1/2" plate with recesses. George ( down under) 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 = > 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=20 > a static analysis following the directions outlined on PL's website, = > 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_008D_01C577D5.122E70E0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
I agree Tracy the flexing would be my concern - = this alone=20 could lead to failure of the plate. One would need significant = development and=20 costly testing to identify the lightest possible stiffening required. = This could=20 bring it up to the weight of the 1/2" plate with recesses.
George ( down under)
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=20 by its thickness than by material strength.   This is in = addition to=20 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
> Europa, so I've been = researching what=20 it 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=20 directions outlined on PL's website,
> just like I did for the = engine=20 mount.
>
> Any advise of stuff to look for that might no = be so=20 obvious and not show
> up in a static analysis? (the three axis = and=20 torsional forces are obvious)=20
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