X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf24aec.mail.bellsouth.net ([205.152.59.72] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2093932 for flyrotary@lancaironline.net; Sat, 09 Jun 2007 20:46:58 -0400 Received-SPF: none receiver=logan.com; client-ip=205.152.59.72; envelope-from=rusty@radrotary.com Received: from ibm68aec.bellsouth.net ([65.6.194.9]) by imf24aec.mail.bellsouth.net with ESMTP id <20070610004623.VANP2319.imf24aec.mail.bellsouth.net@ibm68aec.bellsouth.net> for ; Sat, 9 Jun 2007 20:46:23 -0400 Received: from rd ([65.6.194.9]) by ibm68aec.bellsouth.net with ESMTP id <20070610004622.CXOU5117.ibm68aec.bellsouth.net@rd> for ; Sat, 9 Jun 2007 20:46:22 -0400 From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Single rotor video Date: Sat, 9 Jun 2007 19:46:22 -0500 Message-ID: <000001c7aaf8$c44a1830$6e01a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C7AACE.DB741030" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 Importance: Normal Thread-Index: AceqqFrs8L/j74GrTvqiY1Jm2NUqfwATfy1A In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C7AACE.DB741030 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable This could just be silly, but how about reducing the torque the engine = can produce at lower revs, by backing off the timing and over-leaning the injection system. Once through the problem RPM, then back to ideal power settings.=20 =20 Hi Lynn, =20 If it's a silly idea, then I'm as guilty as you are for thinking about = it. One thought in particular was that it might be a vote for using a PP = engine. It will be interesting to see how well Richard's engine does with a real prop. =20 =20 Another idea was reinforced this morning. The Hirth F30 engine on the = two place Dominator has a centrifugal clutch on it, that doesn't engage = until about 2500 rpm. Now THAT would be perfect for the single rotor. The = only downside is drag from the freewheeling prop if the engine quit. =20 =20 The idea of running with no pitch was to eliminate blade stiffness as a part of the problem. =20 =20 Understood, but don't we know that blade stiffness IS the problem? =20 =20 A friend had one of those props on his ultra-light and it touched the chassis on run up, where the wood prop of the same diameter did not.=20 =20 The Warp, and even worse, the IVO props are flexible, and nothing's = going to change that. I saw a prop strike mark on a gyro today that required = about 5" of flex from the Warp prop, so I'm thinking this is just normal for = them. The Warp Drive is solid carbon fiber, and bulletproof when it comes to hitting things that go into it during flight. I consider it a must have = for a pusher, since I know that it's not a matter of if, but when something = will go through it. I'll just have to give it enough wiggle room :-)=20 =20 Rusty (depitching and playing more tomorrow)=20 ------=_NextPart_000_0001_01C7AACE.DB741030 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
This could just be silly, but how about reducing the torque the = engine can=20 produce at lower revs, by backing off the timing and over-leaning the = injection=20 system. Once through the problem RPM, then back to ideal power = settings. 
 
Hi=20 Lynn,
 
If it's a = silly idea,=20 then I'm as guilty as you are for thinking about it.  One = thought in=20 particular was that it might be a vote for using a PP=20 engine.  It will be interesting to see how well Richard's engine = does with=20 a real prop.  
 
Another idea was=20 reinforced this morning.  The Hirth F30 engine on the two=20 place Dominator has a centrifugal clutch on it, that doesn't = engage=20 until about 2500 rpm.  Now THAT would be perfect for the = single=20 rotor.  The only downside is drag from the freewheeling prop=20 if the engine quit.      
 
 The idea of running = with no=20 pitch was to eliminate blade stiffness as a part of the = problem.  
 
Understood, = but don't we=20 know that blade stiffness IS the problem?   =
 
A friend had one of those props on his ultra-light and it touched = the=20 chassis on run up, where the wood prop of the same diameter did = not. 
 
The Warp, and even=20 worse, the IVO props are flexible, and nothing's going to=20 change that.  I saw a prop strike mark on a gyro today = that=20 required about 5" of flex from the Warp prop, so I'm thinking = this is=20 just normal for them.  The Warp Drive is solid carbon fiber, and=20 bulletproof when it comes to hitting things that go into it during = flight. =20 I consider it a must have for a pusher, since I know that it's not a = matter of=20 if, but when something will go through it.   I'll just have to = give it=20 enough wiggle room :-) 
 
Rusty = (depitching and=20 playing more = tomorrow) 
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