X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [65.54.250.78] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 916619 for flyrotary@lancaironline.net; Sat, 07 Jan 2006 11:56:20 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.250.78; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sat, 7 Jan 2006 08:51:51 -0800 Message-ID: Received: from 4.171.174.74 by BAY115-DAV6.phx.gbl with DAV; Sat, 07 Jan 2006 16:51:51 +0000 X-Originating-IP: [4.171.174.74] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: RD-1B Service alert & Rusty's damper question Date: Sat, 7 Jan 2006 11:51:46 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0097_01C61380.BCB79F90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Sat, 7 Jan 2006 11:51:46 -0500 X-OriginalArrivalTime: 07 Jan 2006 16:51:51.0384 (UTC) FILETIME=[A831C580:01C613AA] This is a multi-part message in MIME format. ------=_NextPart_000_0097_01C61380.BCB79F90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageService Alert on B drives=20 I will publish a service alert later today on the website = (www.rotaryaviation.com) on B drives = used on turbo charged 13Bs and 20B engines. =20 Decided to do this after reviewing Steve Brooks input shaft problem. = His input shaft was previously used for well over 100 hours on Ed = Anderson's drive (fairly early drive) with no problems. It used the = welded style sun gear attachment to the input shaft. Steve's turbo = engine apparently had enough torque to break the weld in the same way = that Dave Leonard's (another turbo) did. =20 Shortly before starting C drive production (4-23-03) we changed over to = a drilled and pinned input shaft. This service alert requests = (strongly) that any B drive used on a turbo charged 13B or 20B engine = delivered before this date be inspected for presence of a pinned input = shaft. If the sun gear is welded instead of pinned, the input shaft = should be returned to RWS to have it drilled and pinned prior to any = flight. This service will be performed for only the cost of materials = and shipping. No problems have been encountered on RD-1, RD-1A or RD-1B = drives used on normally aspirated engines but if you wish, this update = can be done for a nominal service charge ( parts & shipping + shop time = TBD). Damper question=20 Rusty was asking the dimensions and durometer of the rubber dampers in = the drive. I think the question was aiming to change durometer in order = to change the resonant frequency on his one rotor installation. The = diameter of dampers is 1.374" and durometer is currently 50. I don't = think changing this will significantly change the fundamental (lowest = order) resonance that occurs at low speed (idle area). This is = primarily affected by the system lash. The dampers significantly affect = only higher order harmonics which can't often be felt but can be very = destructive to the drive train. =20 Bottom line is I think it would be a wasted effort to change the rubber = dampers. Tracy ------=_NextPart_000_0097_01C61380.BCB79F90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Service Alert on B drives
 
I will publish a service alert later today on the website (www.rotaryaviation.com) on B = drives=20 used on turbo charged 13Bs and 20B engines. 
 
Decided to do this after reviewing Steve Brooks input shaft = problem. =20 His input shaft was previously used for well over 100 hours on Ed = Anderson's=20 drive (fairly early drive) with no problems.  It used the welded = style sun=20 gear attachment to the input shaft.  Steve's turbo engine = apparently had=20 enough torque to break the weld in the same way that Dave Leonard's = (another=20 turbo) did. 
 
Shortly before starting C drive production (4-23-03)  we = changed over=20 to a drilled and pinned input shaft.  This service alert requests=20 (strongly) that any B drive used on a turbo charged 13B or 20B engine = delivered=20 before this date be inspected for presence of a pinned input = shaft.  If the=20 sun gear is welded instead of pinned, the input shaft should be returned = to RWS=20 to have it drilled and pinned prior to any flight.  This = service will=20 be performed for only the cost of materials and shipping.  No = problems have=20 been encountered on RD-1, RD-1A or RD-1B drives used on normally = aspirated=20 engines but if you wish, this update can be done for a nominal service = charge (=20 parts & shipping + shop time TBD).
 
Damper question
 
Rusty was asking the dimensions and durometer of the = rubber dampers in=20 the drive.  I think the question was aiming to change = durometer in=20 order to change the resonant frequency on his one rotor = installation.  The=20 diameter of dampers is 1.374" and durometer is currently 50.  I = don't think=20 changing this will significantly change the fundamental (lowest order) = resonance=20 that occurs at low speed (idle area).  This is primarily affected = by the=20 system lash.  The dampers significantly affect only higher order = harmonics=20 which can't often be felt but can be very destructive to the drive = train. =20
 
Bottom line is I think it would be a wasted effort to change the = rubber=20 dampers.
 
Tracy
 
------=_NextPart_000_0097_01C61380.BCB79F90--