X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail11.syd.optusnet.com.au ([211.29.132.192] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTPS id 2130199 for flyrotary@lancaironline.net; Wed, 20 Jun 2007 18:09:01 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.192; envelope-from=lendich@optusnet.com.au Received: from george (d220-237-251-221.dsl.nsw.optusnet.com.au [220.237.251.221]) by mail11.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id l5KM8B9b012676 for ; Thu, 21 Jun 2007 08:08:12 +1000 Message-ID: <001a01c7b387$7fd08f80$ddfbeddc@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] PP construction methods Date: Thu, 21 Jun 2007 08:08:13 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0017_01C7B3DB.50A3A4A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0017_01C7B3DB.50A3A4A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageRusty, I Heard similar stories, but am sure Lynn is correct in that, if their = done correctly their OK. The one's I seen weren't so good. The new method of welding to the steel liner, eliminates any possible = leak. I originally suggested welding to the inner and outer aluminium, = but someone suggested that wasn't feasible, as it was too difficult to = get access to. So Tig welding to the steel liner is good but you have to use a steel = tube - which you can't weld externally. So I came up with a method of = Tig welding a aluminium tube and flange to the exterior, which has an O = ring seal to the steel tube, and passed it by Bill J. who felt it was a = good idea. Probably could use a couple of O rings if you felt like it. = The advantage of this is that the O ring will allow for differing = expansion and contraction rates which might put stress on the inner tig = welding. Am elegant solution IMHO. On the side ports, your suggestion would be OK. Of course the factory PP were integral to the injection casting. George ( down under)=20 Greetings, One of the things that's always bothered me about making a PP housing = is leakage. I've heard very experienced folks say that eventually, any = PP housing you make will leak, and it's easy for me to imagine that = happening. I don't think I've heard the same thing about factory = housings though. How are the ports installed in the factory PP housing? = =20 The other problem with a conversion is the side ports. I know people = fill these with their favorite epoxy, but I'd worry about that coming = loose, and getting into the rotor. How much would it hurt the PP = operation if you just sealed the ports on the outside of the side = housings with a plate where the intake would have been? =20 Cheers, Rusty ------=_NextPart_000_0017_01C7B3DB.50A3A4A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Rusty,
I Heard similar stories, = but am sure=20 Lynn is correct in that, if their done correctly their OK. The one's = I seen=20 weren't so good.
The new method of welding to the steel = liner,=20 eliminates any possible leak. I originally suggested welding to the = inner and=20 outer aluminium, but someone suggested that wasn't feasible, as it was = too=20 difficult to get access to.
So Tig welding to the steel liner = is good but=20 you have to use a steel tube - which you can't weld externally. So I = came up=20 with a method of Tig welding a aluminium tube and flange to the = exterior, which=20 has an O ring seal to the steel tube, and passed it by Bill J. who felt = it was a=20 good idea. Probably could use a couple of O rings if you felt like = it. The=20 advantage of this is that the O ring will allow for differing expansion = and=20 contraction rates which might put stress on the inner tig welding. Am = elegant=20 solution IMHO.
On the side ports, your suggestion = would be=20 OK.
Of course the factory PP were integral = to the=20 injection casting.
George ( down under) 
 
 
Greetings,
 
One of the = things that's=20 always bothered me about making a PP housing is leakage.  I've = heard very=20 experienced folks say that eventually, any PP housing you make will = leak, and=20 it's easy for me to imagine that happening.  I don't think = I've=20 heard the same thing about factory housings though.  = How are the ports = installed in the=20 factory PP housing? 
 
The other = problem with a=20 conversion is the side ports.  I know people fill these with = their=20 favorite epoxy, but I'd worry about that coming loose, and getting = into the=20 rotor.  How much would it hurt the PP operation if you just = sealed=20 the ports on the outside of the side housings with a plate where the = intake=20 would have been?  
 
Cheers,
Rusty
 
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