X-Virus-Scanned: clean according to Sophos on Logan.com X-PolluStop-Diagnostic: (direct reply)\eX-PolluStop-Score: 0.00\eX-PolluStop: Scanned with Niversoft PolluStop 2.1 RC1, http://www.niversoft.com/pollustop Return-Path: Received: from [65.54.169.53] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c4) with ESMTP id 861910 for flyrotary@lancaironline.net; Fri, 08 Apr 2005 13:41:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.169.53; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Fri, 8 Apr 2005 10:41:08 -0700 Message-ID: Received: from 4.174.3.22 by BAY3-DAV23.phx.gbl with DAV; Fri, 08 Apr 2005 17:41:07 +0000 X-Originating-IP: [4.174.3.22] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] idle speed with RD1 redrives? Date: Fri, 8 Apr 2005 13:41:05 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01C53C40.9C840B40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Fri, 8 Apr 2005 13:41:05 -0400 X-OriginalArrivalTime: 08 Apr 2005 17:41:08.0183 (UTC) FILETIME=[2565FE70:01C53C62] This is a multi-part message in MIME format. ------=_NextPart_000_004A_01C53C40.9C840B40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageThe torsional resonant point is highly dependant on how smoothly = the engine idles. If you have no misfires, the RD-1C hits resonance at = around 800 rpm. If you have any misses at idle, this immediately = introduces a much higher amplitude and lower frequency excitation to the = system and it will show up at a higher rpm. In summary, the "rattle point" is more dependant on idle quality than = absolute rpm. Do not be too concerned about this however. It will = cause no harm to the drive or engine. The drive has been torture tested = for over an hour running on one rotor over the full range of throttle = settings. If you've ever run a twin rotary on one rotor, you know how = violent this is. George Graham ran his Mazda transmission redrive on = one rotor for about 2 seconds before every gear tooth on one gear was = stripped off. =20 Tracy (now canoeing to the post office one last time before departing = for S'nF) Greetings, I asked this a couple times, but it was always buried at the end of = long messages, which gives me a clue how few people make it to the end = of those :-) IIRC, the RD1 drives have a low rpm point where they're known to = rattle. I guess this is torque reversals, or something like that from = the engine. Anyway, can someone confirm that this is true, and tell me = what rpm this is supposed to happen at? I've never been able to idle = below 1500 or so, but now, I could probably idle down to 1000 easily. = The problem is that I seem to hit this rattle mode at 1100-1200 rpm, so = I've got my idle set at 1400 for now. =20 Thanks, Rusty (wondering if I should have inspected the redrive following the = oil out) PS- TIG and Plasma machines both got 1.5 inches of water before I = picked them up, but I dried them out yesterday, and they both work now = (thank goodness). Fortunately nothing expensive was damaged in the = flood, assuming we don't have to replace the carpet in the great room. ------=_NextPart_000_004A_01C53C40.9C840B40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
The torsional resonant point is highly dependant on how smoothly = the engine=20 idles.  If you have no misfires, the RD-1C hits resonance at around = 800=20 rpm.  If you have any misses at idle, this immediately introduces a = much=20 higher amplitude and lower frequency excitation to the system and it = will show=20 up at a higher rpm.
 
In summary, the "rattle point" is more dependant on idle quality = than=20 absolute rpm.   Do not be too concerned about this = however.  It=20 will cause no harm to the drive or engine.  The drive has been = torture=20 tested for over an hour running on one rotor over the full range of = throttle=20 settings.  If you've ever run a twin rotary on one rotor, you know = how=20 violent this is.  George Graham ran his Mazda transmission redrive = on one=20 rotor for about 2 seconds before every gear tooth on one gear was = stripped=20 off. 
 
Tracy  (now canoeing to the post office one last time before=20 departing for S'nF)

Greetings,
 
I asked this = a couple=20 times, but it was always buried at the end of long messages, which = gives me a=20 clue how few people make it to the end of those = :-)
 
IIRC, the RD1 = drives have=20 a low rpm point where they're known to rattle.  I guess this = is=20 torque reversals, or something like that from the engine.  = Anyway, can=20 someone confirm that this is true, and tell me what rpm this is = supposed to=20 happen at?  I've never been able to idle below 1500 or so, but = now, I=20 could probably idle down to 1000 easily.  The problem is that I = seem to=20 hit this rattle mode at 1100-1200 rpm, so I've got my idle set at 1400 = for=20 now. 
 
Thanks,
Rusty = (wondering if I=20 should have inspected the redrive following the oil = out)
 
 
PS- TIG and = Plasma=20 machines both got 1.5 inches of water before I picked them up, but I = dried=20 them out yesterday, and they both work now (thank = goodness). =20 Fortunately nothing expensive was damaged in the flood, assuming we = don't have=20 to replace the carpet in the great=20 room.
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