X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.136.55.15] (HELO outbound-mail.dca.untd.com) by logan.com (CommuniGate Pro SMTP 5.2c1) with SMTP id 2552307 for flyrotary@lancaironline.net; Sun, 02 Dec 2007 15:06:02 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.136.55.15; envelope-from=alwick@juno.com Received: from Penny (71-32-251-184.ptld.qwest.net [71.32.251.184]) by smtpout06.vgs.untd.com with SMTP id AABDXGD9AAH4YE9S for (sender ); Sun, 2 Dec 2007 12:04:48 -0800 (PDT) Message-ID: <00D60E4B2BBF4ABAB680CF03ECCC35DF@Penny> From: "Al Wick" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Giving up on single rotor Date: Sun, 2 Dec 2007 12:03:37 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0161_01C834DB.5EFCB100" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545 X-ContentStamp: 8:4:1782424314 X-MAIL-INFO:0f51a9d104851530259d79a98539b9d560008079d510ddf47401f564a53d958095e5408405cd09d510e02020ade9e164d4a09149 X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkMoKx9xWApebOJff4+EqQNrVJZa0zXXDrA== X-UNTD-Peer-Info: 10.181.42.36|smtpout06.vgs.untd.com|smtpout06.vgs.untd.com|alwick@juno.com This is a multi-part message in MIME format. ------=_NextPart_000_0161_01C834DB.5EFCB100 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageWould be interesting to see some numbers. I look at it from point = of view of trying to clip a wave. That portion of frequency response = which is out of phase would clip it. Same principal as noise canceling = headphones. -al wick ----- Original Messae -----=20 From: Richard Sohn=20 To: Rotary motors in aircraft=20 Sent: Sunday, December 02, 2007 10:13 AM Subject: [FlyRotary] Re: Giving up on single rotor What you really want to do is stay with the natural frequency of the = coupler below or above the exiter frquency, in our case the RPM, and = give it as much damping factor possible. For a rubber coupler, this = means having it soft for low frequency, and on an as short as possible = distance from the center of rotation for good damping effect. It worked for me. Richard Sohn N2071U ------=_NextPart_000_0161_01C834DB.5EFCB100 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Would be interesting to see some = numbers. I look at=20 it from point of view of trying to clip a wave. That portion of = frequency=20 response which is out of phase would clip it. Same principal as noise = canceling=20 headphones.
 
-al wick
 
----- Original Messae -----
From:=20 Richard = Sohn=20
Sent: Sunday, December 02, 2007 = 10:13=20 AM
Subject: [FlyRotary] Re: Giving = up on=20 single rotor

What you really want to do is stay = with the=20 natural frequency of the coupler below or above the exiter frquency, = in our=20 case the RPM, and give it as much damping factor possible. For a = rubber=20 coupler, this means having it soft for low frequency, and on = an as=20 short as possible distance from the center of rotation for good = damping=20 effect.
 
It worked for me.
 
Richard Sohn
N2071U
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