X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [201.225.225.169] (HELO cwpanama.net) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 928857 for flyrotary@lancaironline.net; Mon, 16 Jan 2006 16:28:21 -0500 Received-SPF: none receiver=logan.com; client-ip=201.225.225.169; envelope-from=rijakits@cwpanama.net Received: from [201.224.93.110] (HELO usuarioq3efog0) by frontend3.cwpanama.net (CommuniGate Pro SMTP 4.2.10) with SMTP id 56296723 for flyrotary@lancaironline.net; Mon, 16 Jan 2006 16:29:31 -0500 Message-ID: <004f01c61ae3$a38a8360$6e5de0c9@usuarioq3efog0> From: "rijakits" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: shake, rattle and hum Date: Mon, 16 Jan 2006 16:27:22 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004B_01C61AB9.BA5E9330" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 This is a multi-part message in MIME format. ------=_NextPart_000_004B_01C61AB9.BA5E9330 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit MessageHi Rusty, ----- Original Message ----- From: Russell Duffy To: Rotary motors in aircraft Sent: Monday, January 16, 2006 12:58 AM Subject: [FlyRotary] Re: shake, rattle and hum You had made mention of the prop being set at a high pitch angle, and that you were going to reduce the pitch thinking that was part of the prop oscillation problem. Did you reset the pitch angle? If you did then apparently that was not the problem. Hi Bob, Yep, I changed the pitch from 15 degrees at the tip, to 10 degrees, and it made no difference. Why not reduce more, go all the way to nearly flat pitch, from what I remember that prop is a little on the big side for the Kolb, isn't it. Even if it doesn't produce any thrust (flat pitch), it works as a flywheel - At least you eleiminate ANY ( if there is...) stall issues at the tips.... FWIW You might give some thought to adding mass to the engine. This might be a situation where you could be adding weight to the wrong end of the vibration problem. Adding mass would be like adding a heavy flywheel, or the missing rotor, but I'm not sure I follow how it could be adding weight to the "wrong end of the vibration problem." And why don't you have that brandnew, easy to work with, etc. ACES on the machine, yet?? If I am not wrong you can measure any and everything with it! Even ceiling fans! Mine is down to 0.02 IPS :)) There is also a "spectrum" feature on it, to give you any resonante frequencies... Vibrations are a bitch (on aircraft at least......), you might guess to the source based on what you "feel" - it might turn out to be a different source alltogether - the spectrum will help you chase the source. You also can set up to measure imbalance of the engine alone - Check wether you have all your counterweights clocked correctly... What I say is: You HAVE a vibration analysis tool - and an easy to use one! Try it! Props is just one ofthe many uses! I like the weather station, for some reason I thought it would be warmer in Florida :>) Despite what many people believe, not all of Florida is in Miami. It's a big state, and we hide the best part in the panhandle. Shhhh, don't tell anyone :-) 21:56 1/15/06 I see you're with Bellsouth too :-) Cheers, Rusty Thomas J. ------=_NextPart_000_004B_01C61AB9.BA5E9330 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message=
Hi Rusty,
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Monday, January 16, 2006 = 12:58=20 AM
Subject: [FlyRotary] Re: shake, = rattle=20 and hum

You=20 had made mention of the prop being set at a high pitch angle, and that = you=20 were going to reduce the pitch thinking that was part of the prop = oscillation=20 problem.  Did you reset the pitch angle?  If you did then = apparently=20 that was not the problem. 
 
Hi=20 Bob,
 
Yep, I changed the = pitch from 15=20 degrees at the tip, to 10 degrees, and it made no=20 difference.  
Why not reduce more, go all the way to = nearly flat=20 pitch, from what I remember that prop is a little on the big side for = the=20 Kolb, isn't it.
Even if it doesn't produce any thrust (flat = pitch),=20 it works as a flywheel - At least you eleiminate ANY ( if there is...) = stall=20 issues at the tips....
FWIW=20 You might give some thought to adding mass to the engine.  This = might be=20 a situation where you could be adding weight to the wrong end of the = vibration=20 problem.  
 
Adding mass would be = like adding=20 a heavy flywheel, or the missing rotor, but I'm not sure I follow = how it could be adding weight to the "wrong end=20 of the vibration=20 problem." 
And why don't you = have that=20 brandnew, easy to work with, etc. ACES on the machine,=20 yet??
If I am not wrong you = can measure=20 any and everything with it! Even ceiling fans! Mine is down to 0.02 = IPS=20 :))
There is also a = "spectrum"=20 feature on it, to give you any resonante=20 frequencies...
Vibrations are a = bitch (on=20 aircraft at least......), you might guess to the source based on what = you=20 "feel"  = - it might=20 turn out to be a different source alltogether - the spectrum will help = you=20 chase the source. You also can set up to measure imbalance of the = engine alone=20 - Check wether you have all your counterweights clocked=20 correctly...
What I say is: You = HAVE a=20 vibration analysis tool - and an easy to use one! Try it! Props is = just one=20 ofthe many uses!
 
I=20 like the weather station,  for some reason I thought it would be = warmer=20 in Florida :>) 
 
Despite what many = people believe,=20 not all of Florida is in Miami.  It's a big state, and we hide = the best=20 part in the panhandle.  Shhhh, don't tell anyone=20  :-)   
 
21:56=20 1/15/06 
 
I see you're with = Bellsouth too=20 :-)
 
Cheers,
Rusty=20
 
Thomas J.
 
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