X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from bay0-omc2-s22.bay0.hotmail.com ([65.54.246.158] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2087706 for flyrotary@lancaironline.net; Wed, 06 Jun 2007 13:32:23 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.246.158; envelope-from=thomphy@msn.com Received: from hotmail.com ([207.46.8.151]) by bay0-omc2-s22.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Wed, 6 Jun 2007 10:31:42 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 6 Jun 2007 10:31:42 -0700 Message-ID: Received: from 71.214.125.237 by BAY118-DAV13.phx.gbl with DAV; Wed, 06 Jun 2007 17:31:37 +0000 X-Originating-IP: [71.214.125.237] X-Originating-Email: [thomphy@msn.com] X-Sender: thomphy@msn.com From: "Thomas Phy" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Single rotor video Date: Wed, 6 Jun 2007 10:41:10 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C7A827.322624E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-OriginalArrivalTime: 06 Jun 2007 17:31:42.0906 (UTC) FILETIME=[8C6451A0:01C7A860] Return-Path: thomphy@msn.com This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C7A827.322624E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable This also reminds me of when I was watching my trucks radio antenna = while driving in freezing fog. As the ice built up on the antenna, = instead of just passing through the air, it started osculating all over = the place. I could actually feel a vibration in the truck! It was scary = to watch but very interesting. I can just imagine a flight surface, = trying to flutter, acting the same way. Now we can watch Rusty do the = same thing! High speed camera would be very useful. TP ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Tuesday, June 05, 2007 2:49 PM Subject: [FlyRotary] Re: Single rotor video In a message dated 6/5/2007 1:34:30 P.M. Eastern Daylight Time, = bartrim@gmail.com writes: Holy Crap, Rusty, I'm really impressed! I don't think it is just one force involved. When the blade is = accelerated violently, the blade hub moves forward and the outer 2/3 or = so lags behind a bit. The blade then is hinged in effect at a point = about 1/3 of diameter, and since that hinge line is not parallel with = the propeller shaft centerline, the tip of the prop moves off its = preferred track. It is then amplifying the expected bending of the = blade in opposition to the thrust being generated.=20 Try reducing the propeller pitch to nil, so that there is no thrust at = all and each blade will be at its stiffest against the acceleration, and = deceleration forces. (sell the gyro) Try a different prop.=20 Even thick fixed pitch wood props move fore and aft at the tips in = response to thrust. A wood prop would not be acting up like the very light weight and = flexible piece you have there.=20 You might try over balancing, or adding weight to the counter weights, = and then add just a bit to the very edge of the starter ring. (sell the = gyro).=20 I suspect that the problem gets less impressive at higher revs. Lynn E. Hanover -------------------------------------------------------------------------= ----- See what's free at AOL.com. ------=_NextPart_000_0010_01C7A827.322624E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
This also reminds me of when I was watching my = trucks radio=20 antenna while driving in freezing fog. As the ice built up on the = antenna,=20 instead of just passing through the air, it started osculating all over = the=20 place. I could actually feel a vibration in the truck! It was scary to = watch but=20 very interesting. I can just imagine a flight surface, trying to = flutter, acting=20 the same way. Now we can watch Rusty do the same thing! High speed = camera would=20 be very useful.
TP
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Tuesday, June 05, 2007 = 2:49=20 PM
Subject: [FlyRotary] Re: Single = rotor=20 video

In a message dated 6/5/2007 1:34:30 P.M. Eastern Daylight Time, = bartrim@gmail.com writes:
Holy=20 Crap, Rusty, I'm really impressed!
 
 
I don't think it is just one force involved. When the blade is=20 accelerated violently, the blade hub moves forward and the outer 2/3 = or so=20 lags behind a bit. The blade then is hinged in effect at a point about = 1/3 of=20 diameter, and since that hinge line is not parallel with the = propeller=20 shaft centerline,  the tip of the prop moves off its=20 preferred track. It is then amplifying the expected =  bending of=20 the blade in opposition to the thrust being generated.
 
Try reducing the propeller pitch to nil, so that there is no = thrust at=20 all and each blade will be at its stiffest against the = acceleration, and=20 deceleration forces. (sell the gyro)
 
Try a different prop.
 
Even thick fixed pitch wood props move fore and aft at the tips = in=20 response to thrust.
 
A wood prop would not be acting up like the very light weight and = flexible piece you have there.
 
You might try over balancing, or adding weight to the counter = weights,=20 and then add just a bit to the very edge of the starter ring. (sell = the=20 gyro). 
 
I suspect that the problem gets less impressive at higher = revs.
 
Lynn E. Hanover



See what's free at AOL.com.=20
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