X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2176524 for flyrotary@lancaironline.net; Fri, 13 Jul 2007 22:00:03 -0400 Received-SPF: none receiver=logan.com; client-ip=205.152.59.70; envelope-from=rusty@radrotary.com Received: from ibm67aec.bellsouth.net ([65.6.194.9]) by imf22aec.mail.bellsouth.net with ESMTP id <20070714015928.UJBD22257.imf22aec.mail.bellsouth.net@ibm67aec.bellsouth.net> for ; Fri, 13 Jul 2007 21:59:28 -0400 Received: from rad ([65.6.194.9]) by ibm67aec.bellsouth.net with ESMTP id <20070714015927.QMTE9531.ibm67aec.bellsouth.net@rad> for ; Fri, 13 Jul 2007 21:59:27 -0400 From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Single Rotor Run Date: Fri, 13 Jul 2007 20:59:27 -0500 Message-ID: <009201c7c5ba$9c150280$a301a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0093_01C7C590.B33EFA80" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 Importance: Normal Thread-Index: AcfFsvsK0Umuy3eMRmWEB2uFJeJVmAABdS1A In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0093_01C7C590.B33EFA80 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit What torque pulses? Today was the first run with the complete engine in flight configuration, meaning engine - psru - prop. No vibration out of the ordinary. It, off curse, is shaking at 1300 RPM idle, just as my Soob does. Once it goes over 1700 running like an electric motor, almost. Sounds great Richard. What prop are you running? A couple thoughts come to mind about why you might not have the same torque reversal problems I have. One is the damper in the Hirth gear box. It might just be that it's exactly right for the job. The other possibility I've mentioned before is that maybe you're benefiting from one of the PP shortcomings. As I understand it, PP engines tend to have less power down really low in RPM's. Perhaps this lack of torque is what's keeping you from having the torque reversal problems. I don't see a down side to this, and it would be THE reason to go with PP for me (if indeed it has anything to do with it). Cheers, Rusty ------=_NextPart_000_0093_01C7C590.B33EFA80 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
What torque pulses? Today was the = first run=20 with the complete engine in flight configuration, meaning engine - psru = - prop.=20 No vibration out of the ordinary. It, off curse, is shaking at 1300 RPM = idle,=20 just as my Soob does. Once it goes over 1700 running like an electric = motor,=20 almost.  
 
Sounds great Richard.  What prop are = you=20 running?  
 
A couple thoughts come to mind about why you = might not have=20 the same torque reversal problems I have.  One is the damper in the = Hirth=20 gear box.  It might just be that it's exactly right for the=20 job.  
 
The other possibility I've mentioned before is = that maybe=20 you're benefiting from one of the PP shortcomings.  As I understand = it, PP=20 engines tend to have less power down really low = in RPM's. =20 Perhaps this lack of torque is what's keeping you from having the torque = reversal problems.  I don't see a down side to this, and it would=20 be THE reason to go with PP for me (if indeed it has anything = to do=20 with it).   
 
Cheers,
Rusty
 
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