X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wproxy.gmail.com ([64.233.184.202] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 928681 for flyrotary@lancaironline.net; Mon, 16 Jan 2006 14:06:18 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.233.184.202; envelope-from=russell.duffy@gmail.com Received: by wproxy.gmail.com with SMTP id 37so1217700wra for ; Mon, 16 Jan 2006 11:05:33 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:from:to:subject:date:message-id:mime-version:content-type:x-priority:x-msmail-priority:x-mailer:in-reply-to:x-mimeole:importance; b=idrlpEHLvgaC5Wz0DHGubk8YyglneN40m/1CIy8rDkJx3O9nkAAmgpu1ge1c13skNFNKMxUNvZbPKNmEHmySpK/cVbTsRvOT/quNoG4C1wlbHdQzNafaTJN7kkfzD5QF/X+UX69CRYBqcWeg/MdNv624TKdGbTan8Y6BAV/ANjM= Received: by 10.54.108.2 with SMTP id g2mr8932730wrc; Mon, 16 Jan 2006 11:05:33 -0800 (PST) Return-Path: Received: from rd ( [65.6.194.9]) by mx.gmail.com with ESMTP id g3sm2813960wra.2006.01.16.11.05.32; Mon, 16 Jan 2006 11:05:32 -0800 (PST) From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: shake, rattle and hum Date: Mon, 16 Jan 2006 13:05:31 -0600 Message-ID: <014c01c61acf$d2e82720$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_014D_01C61A9D.884DB720" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_014D_01C61A9D.884DB720 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable but the talk of adding weight to the flywheel triggered memory of earlier talk of 'rocking couple' on the 2 rotor engines, which if I read correctly, is the reason for the counterweights. All correct as I understand it. When I mention adding weight to the = flex plate, I'm very careful to keep the balance the same. I went so far as = to weight the groups of washers and bolts that I was adding, then mixed and matched them until I got 4 equally weighted sets. The point of the test = was to add mass, not change the balance. Is all of your counterweight on one end of the eshaft? If so, could the engine be rocking, causing the prop blades to not run true? =20 On a single rotor, the counterweights (one on each end of the shaft) = have to be heavier than normal, and they have to both be opposite of the rotor = to counterbalance the weight of the rotor. =20 =20 I'm pretty confident that there's nothing wrong with the balance of the rotating assembly. I've run one test without the prop, which completely eliminated the prop oscillation. That thing was steady as a rock = sitting on the trailer :-) I also got none of the 2500-3100 vibration, nor the = drive rattle at 2000. I'm going to test this one more time without a prop, = then try the IVO prop (two blade, less weight) to see if it changes anything. = =20 =20 I'm starting to believe that the dampener system on the RD-1C drive just isn't going to work for the single rotor. Don't take this as a knock against the drive, because it works fine for what it was designed to do = (2 and 3 rotors). Tracy was very up front about the fact that he had not considered anyone using it on a single, therefore no reason to believe = that it would be suitable. I knew full well that it might have these = problems, but I figured that some lucky list member may just end up with a = discount on an RD-1C and flex plate combo :-) =20 Does anyone know if Atkins ever got his single rotor belt drive built, = and if it works? Anyone got a suggestion for a ducted fan that might work = for the Kolb (Bernie, Perry?) =20 Off to Panama City... =20 Rusty =20 ------=_NextPart_000_014D_01C61A9D.884DB720 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

but the talk
of adding weight to the flywheel = triggered=20 memory of earlier talk of
'rocking couple' on the 2 rotor engines, = which if I=20 read correctly, is
the reason for the counterweights.

All correct as I understand = it.  When I=20 mention adding weight to the flex plate, I'm very careful to keep the = balance=20 the same.  I went so far as to weight the groups of washers and = bolts that=20 I was adding, then mixed and matched them until I got 4 equally weighted = sets.  The point of the test was to add mass, not change the=20 balance.

Is all of your counterweight on one end of the = eshaft? If so,=20 could the
engine be rocking, causing the prop blades to not run=20 true?
 
On a = single rotor, the=20 counterweights (one on each end of the shaft) have to be heavier than = normal,=20 and they have to both be opposite of the rotor to counterbalance the = weight of=20 the rotor.  
 
I'm = pretty confident=20 that there's nothing wrong with the balance of the rotating = assembly. =20 I've run one test without the prop, which completely eliminated the prop = oscillation.  That thing was steady as a rock sitting on the = trailer=20 :-)  I also got none of the 2500-3100 vibration, nor the = drive=20 rattle at 2000.  I'm going to test this one more time without a = prop, then=20 try the IVO prop (two blade, less weight) to see if it changes=20 anything.  
 
I'm = starting to believe=20 that the dampener system on the RD-1C drive just isn't going = to work=20 for the single rotor.  Don't take this as a knock against the = drive,=20 because it works fine for what it was designed to do (2 and 3 = rotors). =20 Tracy was very up front about the fact that he had not considered anyone = using=20 it on a single, therefore no reason to believe that it would be=20 suitable.   I knew full well that it might have these = problems,=20 but I figured that some lucky list member may just end up with a = discount on an=20 RD-1C and flex plate combo :-)
 
Does anyone know if Atkins ever = got his=20 single rotor belt drive built, and if it works?  Anyone got a = suggestion=20 for a ducted fan that might work for the Kolb (Bernie, = Perry?)
 
Off to = Panama=20 City...
 
Rusty
 
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