X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf16aec.mail.bellsouth.net ([205.152.59.64] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2090490 for flyrotary@lancaironline.net; Thu, 07 Jun 2007 22:46:47 -0400 Received-SPF: none receiver=logan.com; client-ip=205.152.59.64; envelope-from=rusty@radrotary.com Received: from ibm58aec.bellsouth.net ([65.6.194.9]) by imf16aec.mail.bellsouth.net with ESMTP id <20070608024611.BVPC9726.imf16aec.mail.bellsouth.net@ibm58aec.bellsouth.net> for ; Thu, 7 Jun 2007 22:46:11 -0400 Received: from rd ([65.6.194.9]) by ibm58aec.bellsouth.net with ESMTP id <20070608024611.KXJG6559.ibm58aec.bellsouth.net@rd> for ; Thu, 7 Jun 2007 22:46:11 -0400 From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Single rotor video Date: Thu, 7 Jun 2007 21:43:57 -0500 Message-ID: <000401c7a977$2c3a2940$6e01a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C7A94D.43642140" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 Thread-Index: AceogicvsxCDjDs6SJiJPRVXGIdB+gA8zi2A In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0005_01C7A94D.43642140 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Greetings, =20 I shot some more video today, of the original shore 60 damper, and then = of the new shore 50 damper. The 50 was noticeably better, particularly in = that it completely eliminates a severe resonance that was happening at 2700 = rpm. With the 60 shore, at 2700, there was a very audible "rattle", and the = air filter shook so hard it was a blur. My guess is that the shore 50 = moved it from 2700 to somewhere below the 2500 I'm using as a minimum. =20 =20 I'm sort of dazed from looking at video, but the prop flex is certainly = not gone. It's a bit cleaner with the 50 shore, but not by a huge amount. = The worst flex is between 2500 and 3000 rpm, and that's also the point where = the trailer rocks from the force of the prop. It's quite likely that's at = least contributing to the problem, but there's no denying that the torque direction, and prop flex direction are coupled together. =20 =20 I can already think of lots more tests, but the 50 shore damper stays, = and I wish they made a softer one. I also think anything over 3000 rpm is not = a problem, and this might be a limitation that could be lived with. I've = got about 16 hours of driving in the next few days, so I'll have plenty of = time to think of what to do next. =20 =20 Rusty (a bit more optimistic today) =20 =20 ------=_NextPart_000_0005_01C7A94D.43642140 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Greetings,
 
I shot some=20 more video today, of the original shore 60 damper, and then of the new = shore 50=20 damper.  The 50 was noticeably better, particularly in that it = completely=20 eliminates a severe resonance that was happening at 2700 rpm.  With = the 60=20 shore, at 2700, there was a very audible "rattle", and the air filter = shook so=20 hard it was a blur.   My guess is that the shore 50 moved it = from 2700=20 to somewhere below the 2500 I'm using as a minimum.  =
 
I'm sort of=20 dazed from looking at video, but the prop flex is certainly not = gone.  It's=20 a bit cleaner with the 50 shore, but not by a huge amount.  The = worst flex=20 is between 2500 and 3000 rpm, and that's also the point where=20 the trailer rocks from the force of the prop.  It's quite = likely=20 that's at least contributing to the problem, but there's no denying = that=20 the torque direction, and prop flex direction are coupled=20 together.  
 
I can already=20 think of lots more tests, but the 50 shore damper stays, and I wish they = made a=20 softer one.  I also think anything over 3000 rpm is not a = problem, and=20 this might be a limitation that could be lived with.  I've got = about 16=20 hours of driving in the next few days, so I'll have plenty of time = to think=20 of what to do next.  
 
Rusty (a bit=20 more optimistic today)
 
 
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