X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp1.av-mx.com ([137.118.16.57] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3877835 for flyrotary@lancaironline.net; Wed, 07 Oct 2009 11:44:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.57; envelope-from=res12@fairpoint.net Received: from main (unknown [66.243.229.194]) (Authenticated sender: res12@fairpoint.net) by smtp1.av-mx.com (Postfix) with ESMTP id 7F7F4290BCB for ; Wed, 7 Oct 2009 11:44:22 -0400 (EDT) Message-ID: <21008E763B1F4DBE9D7EEC86A67F21D5@main> From: "Richard Sohn" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Balls and Springs Date: Wed, 7 Oct 2009 10:44:25 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00F0_01CA473B.237FEFB0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_00F0_01CA473B.237FEFB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Typo!!! Should read "cmgram" not cmkg. Sorry, even happens to a full blood metric person. Richard Sohn N2071U ----- Original Message -----=20 From: Richard Sohn=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 07, 2009 8:59 AM Subject: [FlyRotary] Re: Balls and Springs ----- Original Message -----=20 From: Lynn Hanover=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 07, 2009 6:28 AM Subject: [FlyRotary] Balls and Springs 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) George, The process I saw on the internet came from Down there. A rotor is = spun up in the lathe with a plastic shield around the outside. Oil is = squirted in until it starts spilling out. A pan is slipped under the = rotor and the lathe stopped. (if your lathe has a coolant system that = would work as well with less mess) The weights are close enough. Then = the rotor is laid on a grill on the pan and allowed to drain. Then weigh = the liquid in the pan. I bet the balancing people just have a number on = the wall for rotaries that is close to that weight. A balancer could do = it backwards by spinning the shaft from a factory built engine, with the = counterweights mounted, and then add bobweight until he gets a balance. = Then subtract the rotor weight from the bobweight and that difference = would be the oil allowance.=20 The big name builders all balance to a gnats butt weight, but I just = get the rotor weights the same. Never a problem. The single pulse per = revolution will be so big that a small balance error will go unoticed. = But, its no sin to start out with the balance correct. I have thought = about singles and decided that as big a diameter flywheel that you can = fit but weighted only at the outer edge. Like 4 sets of starter rings = tiged to a flex plate. Even Mazda builds with pieces two weight ranges = apart. They have stamped the weights on rotors, and have used colored = paint dots. Of course the paint dots are gone when we see a used rotor.=20 Richard Sohn can tell you. He seems to be doing well with his. Lynn E. Hanover Thanks for the comment Lynn.=20 For the 12A rotor I am using 360 grams, that is on the analytical = balancing. When my first engine went on the balancer at Racing Beat, the = first question was "who did the first balancing on that?" . I think that = only supports your comments on the sensitivity.=20 Here is the way I am doing it:=20 First I measure the moment of the rotor and the e-shaft.=20 Next is calculating the moment required for the fly wheel and the = counter weight. When the fly wheel fabricated I trim it to the calculated moment. next is measuring the moment on the counter weight and calculating = the correction. Next trimming the counter weight to the calculated moment. The resolution I achieve on each component is +- 15cmkg at a total = of 5000cmkg.=20 I have not done any nrs with the 13B setup. FWIW Richard Sohn N2071U -------------------------------------------------------------------------= --- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.420 / Virus Database: 270.14.5/2418 - Release Date: = 10/06/09 18:34:00 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.420 / Virus Database: 270.14.5/2418 - Release Date: = 10/06/09 18:34:00 ------=_NextPart_000_00F0_01CA473B.237FEFB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Typo!!!
 
Should read "cmgram" not = cmkg.
 
Sorry, even happens to a full blood = metric=20 person.
 
Richard Sohn
N2071U
----- Original Message -----
From:=20 Richard=20 Sohn
Sent: Wednesday, October 07, = 2009 8:59=20 AM
Subject: [FlyRotary] Re: Balls = and=20 Springs

 
----- Original Message -----
From:=20 Lynn=20 Hanover
To: Rotary motors in = aircraft=20
Sent: Wednesday, October 07, = 2009 6:28=20 AM
Subject: [FlyRotary] Balls = and=20 Springs

 Lynn,
With balancing my single rotor, what = would you=20 suggest that I allow ( percentage wise) for oil weight in the rotor = - it was=20 suggested to me that I should allow full rotor oil weight.
This discussion suggests = otherwise.
George ( down under)
 
George,
 
The = process I saw=20 on the internet came from Down there. A rotor is spun up in the = lathe with a=20 plastic shield around the outside. Oil is squirted in until it = starts=20 spilling out. A pan is slipped under the rotor and the lathe = stopped. (if=20 your lathe has a coolant system that would work as well with less = mess) The=20 weights are close enough. Then the rotor is laid on a grill on the = pan and=20 allowed to drain. Then weigh the liquid in the pan. I bet the = balancing=20 people just have a number on the wall for rotaries that is close to = that=20 weight. A balancer could do it backwards by spinning the shaft from = a=20 factory built engine, with the counterweights mounted, and then add=20 bobweight until he gets a balance. Then subtract the rotor weight = from the=20 bobweight and that difference would be the oil allowance.=20
 
The big = name=20 builders all balance to a gnats butt weight, but I just get the = rotor=20 weights the same. Never a problem. The single pulse per revolution = will be=20 so big that a small balance error will go unoticed. But, its no sin = to start=20 out with the balance correct. I have thought about singles and = decided that=20 as big a diameter flywheel that you can fit but weighted only at the = outer=20 edge. Like 4 sets of starter rings tiged to a flex plate. Even Mazda = builds=20 with pieces two weight ranges apart. They have stamped the weights = on=20 rotors, and have used colored paint dots. Of course the paint dots = are gone=20 when we see a used rotor.
 
Richard = Sohn can=20 tell you. He seems to be doing well with his.
 
Lynn E.=20 Hanover
 
Thanks for the comment Lynn. =
For the 12A rotor I am using 360 grams, that is on = the=20 analytical balancing. When my first engine went on the balancer at = Racing=20 Beat, the first question was "who did the first balancing on that?" = . I=20 think that only supports your comments on the sensitivity.=20
Here is the way I am doing it: =
First I measure the moment of the rotor and the=20 e-shaft.
Next is calculating the moment required for the fly = wheel and=20 the counter weight.
When the fly wheel fabricated I trim it to the = calculated=20 moment.
next is measuring the moment on the counter weight = and=20 calculating the correction.
Next trimming the counter weight to the calculated=20 moment.
The resolution I=20 achieve on each component is  +- 15cmkg at a total of 5000cmkg. =
 
I have not=20 done any nrs with the 13B setup.
 
FWIW
 
Richard=20 Sohn
N2071U
 
 


No virus found in this incoming message.
Checked by = AVG -=20 www.avg.com
Version: 8.5.420 / Virus Database: 270.14.5/2418 - = Release=20 Date: 10/06/09 18:34:00

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html


No virus found in this incoming message.
Checked by AVG = -=20 www.avg.com
Version: 8.5.420 / Virus Database: 270.14.5/2418 - = Release=20 Date: 10/06/09 18:34:00
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