X-Virus-Scanned: clean according to Sophos on Logan.com
Return-Path: <lehanover@gmail.com>
Received: from mail-bw0-f227.google.com ([209.85.218.227] verified)
  by logan.com (CommuniGate Pro SMTP 5.2.16)
  with ESMTP id 3878365 for flyrotary@lancaironline.net; Wed, 07 Oct 2009 20:55:12 -0400
Received-SPF: pass
 receiver=logan.com; client-ip=209.85.218.227; envelope-from=lehanover@gmail.com
Received: by bwz27 with SMTP id 27so4592498bwz.19
        for <flyrotary@lancaironline.net>; Wed, 07 Oct 2009 17:54:34 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:mime-version:received:date:message-id:subject
         :from:to:content-type;
        bh=lZufLIowlPThdf7NL+QvI0FOmLYvoTgt5pkJUpi8Bdg=;
        b=M09TzoI7z3m4MqP+ZewG8ZiAt2OL+/ndYL2cZ7x1tVoKLfGVN1lnsiAw37pK3bfL1Q
         1to/M4kXF7iQkKF/dVGPgSuhHi8B2Zw+Ehzn0HZF/hngLaa0osyq8fqxwl2sRKceZn57
         3tJEzQSfn0NcCSVK8YqJIk9+sBEKFeljYsoNw=
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:date:message-id:subject:from:to:content-type;
        b=YfqrZ8YKiGkpN05Otxmb9GdfOQyyWFGuRY6fVk8cZFy88jDs5/fs6wSRyaLlrMRSt8
         KKjD9TSrwEHQnH8SYviInQTGyKEUATFWJd7yXEdj2UH+xEK6L3WVL5/IWP04qMxuaY/9
         5Z/aXETC1ExRi+MoUKfL/wyQXeCpOzB/uoehA=
MIME-Version: 1.0
Received: by 10.204.10.20 with SMTP id n20mr465915bkn.161.1254963274699; Wed, 
	07 Oct 2009 17:54:34 -0700 (PDT)
Date: Wed, 7 Oct 2009 20:54:34 -0400
Message-ID: <1ab24f410910071754r7e60bda5n680e88e41dc045d4@mail.gmail.com>
Subject: Balls and Springs
From: Lynn Hanover <lehanover@gmail.com>
To: flyrotary@lancaironline.net
Content-Type: multipart/alternative; boundary=00032555a0d231d2c3047561e8eb

--00032555a0d231d2c3047561e8eb
Content-Type: text/plain; charset=ISO-8859-1

Lynn,
Thanks, I have spun up the rotor in a lathe and filled the rotor with
coolant from a spray bottle, being careful not to spill any and then
weighing the remainder and comparing it to the original weight (similar
system to what you suggest). I went the extra mile and then adjusted the
weight by comparing it to oil weight of the same volume.

I did speak to Richard Sohn at the time but at that stage he wasn't to
concerned with balancing to that extent with his demonstrator.

It has also been suggested that the apex seal and springs be excluded as
their weight is borne by the rotor housing.

Then again I've had people argue against those suggestions.

I thought any out of balance might exacerbate the negative torque pulses,
but your saying because their so large it's not  such a concern - which puts
my mind to rest.

I do like your suggestion of  'reverse engineering' the balancing process, I
think I will discuss that with a professional balancer.

George (down under)

 Lynn,
With balancing my single rotor, what would you suggest that I allow (
percentage wise) for oil weight in the rotor - it was suggested to me that I
should allow full rotor oil weight.
This discussion suggests otherwise.
George ( down under)

I think that is what we are happy with. I assume the rotor spining on its
own axis and orbiting will do two things in various degrees. The rotor
spinning provides a means for it to retain a quantity of oil even though it
is on its side.

And,

An amount of that oil will be forced out of the rotor because of centrifugal
force as the rotor orbits at crank shaft RPM.

And, some of the ejected oil will be replaced on the run by the oil jets.
The quantity of oil will be changing depending on aircraft attitude, and
engine oil pressure (RPM). Since the volume and weight will vary during
operation, any reasonable guess will be correct. It almost doesn't matter
because the oil is such a small percentage of the total rotor weight. If
forced to decide I would "Guess" 1/2 to 2/3 of the total volume.

The Apex seal, corner piece (if any) and spring are not included in balance
weight.

Lynn E. Hanover

--00032555a0d231d2c3047561e8eb
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div><font size=3D"2" face=3D"Arial">Lynn,</font></div>
<div><font size=3D"2" face=3D"Arial">Thanks, I have spun up the rotor in a =
lathe and filled the rotor with coolant from a spray bottle, being careful =
not to spill any and then weighing the remainder and comparing it to the or=
iginal weight (similar system to what you suggest). I went the extra mile a=
nd then adjusted the weight by comparing it to oil weight of the same volum=
e.</font></div>

<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">I did speak to Richard Sohn at the tim=
e but at that stage he wasn&#39;t to concerned with balancing to that exten=
t with his demonstrator.</font></div>
<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">It has also been suggested that the ap=
ex seal and springs be excluded=A0as their weight is borne by the rotor hou=
sing.</font></div>
<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">Then again I&#39;ve had people argue a=
gainst those suggestions.</font></div>
<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">I thought any out of balance might exa=
cerbate the negative torque pulses, but your saying because their so large =
it&#39;s not=A0 such a=A0concern - which puts my mind to rest.</font></div>
<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">I do like your suggestion of=A0 &#39;r=
everse engineering&#39; the balancing process, I think I will discuss that =
with a professional balancer.</font></div>
<div><font size=3D"2" face=3D"Arial"></font>=A0</div>
<div><font size=3D"2" face=3D"Arial">George (</font><font size=3D"2" face=
=3D"Arial">down under)</font></div>
<blockquote style=3D"BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PAD=
DING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px" dir=3D"ltr">
<div style=3D"FONT: 10pt arial">=A0Lynn,</div>
<div style=3D"FONT: 10pt arial">With balancing my single rotor, what would =
you suggest that I allow ( percentage wise) for oil weight in the rotor - i=
t was suggested to me that I should allow full rotor oil weight.</div>
<div style=3D"FONT: 10pt arial">This discussion suggests otherwise.</div>
<div style=3D"FONT: 10pt arial">George ( down under)</div>
<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">I think that is what we are happy with. I a=
ssume the rotor spining on its own axis and orbiting will do two things in =
various degrees. The rotor spinning provides a means for it to retain a qua=
ntity of oil even though it is on its side. </div>

<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">And,</div>
<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">An amount of that oil will be forced out of=
 the rotor because of centrifugal force as the rotor orbits at crank shaft =
RPM. </div>
<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">And, some of the ejected oil will be replac=
ed on the run by the oil jets. The quantity of oil will be changing dependi=
ng on aircraft attitude, and engine oil pressure (RPM). Since the volume an=
d weight will vary during operation, any reasonable guess will be correct. =
It almost doesn&#39;t matter because the oil is such a small percentage of =
the total rotor weight. If forced to decide I would &quot;Guess&quot; 1/2 t=
o 2/3 of the total volume. </div>

<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">The Apex seal, corner piece (if any) and sp=
ring are=A0not included in balance weight.=A0=A0</div>
<div style=3D"FONT: 10pt arial">=A0</div>
<div style=3D"FONT: 10pt arial">Lynn E. Hanover<font color=3D"navy" size=3D=
"2" face=3D"Arial"><span style=3D"FONT-FAMILY: Arial; COLOR: navy; FONT-SIZ=
E: 10pt"></span></font>=A0</div></blockquote>

--00032555a0d231d2c3047561e8eb--