X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3878630 for flyrotary@lancaironline.net; Thu, 08 Oct 2009 03:59:39 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id DEC391739D1 for ; Thu, 8 Oct 2009 15:58:57 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 8608DBEC010 for ; Thu, 8 Oct 2009 15:58:52 +0800 (WST) Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Balls and Springs Date: Thu, 8 Oct 2009 17:58:54 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01CA4840.FFF4A390" 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 X-Antivirus: avast! (VPS 091007-0, 10/07/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0013_01CA4840.FFF4A390 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Richard, Yep! saw your response but couldn't quite understand it ( my problem, = not yours). I did have to laugh about the balancer's comments - but I do like the = reverse engineering of Lynn's suggestion. I'm glad you got yours right though. George ( down under) Hi George, did you get my response to Lynn's comment at about 10:99this morning? = It is located down after what Lynn wrote. Sorry, some do it one way and = others the other way.=20 Richard Sohn N2071U ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 07, 2009 4:04 PM Subject: [FlyRotary] Re: Balls and Springs 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) 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 -------------------------------------------------------------------------= --- No virus found in this incoming message. Checked by AVG - www.avg.com=20 Version: 8.5.421 / Virus Database: 270.14.5/2419 - Release Date: = 10/07/09 05:18:00 ------=_NextPart_000_0013_01CA4840.FFF4A390 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 Richard,
Yep! saw your response but couldn't = quite=20 understand it ( my problem, not yours).
I did have to laugh about the = balancer's=20 comments - but I do like the reverse engineering of Lynn's = suggestion.
I'm glad you got yours right = though.
George ( down under)
 
Hi George,
 
did you get my response to Lynn's = comment at=20 about 10:99this morning? It is located down after what Lynn wrote. = Sorry, some=20 do it one way and others the other way.
 
Richard Sohn
N2071U
----- Original Message -----
From:=20 George=20 Lendich
To: Rotary motors in = aircraft=20
Sent: Wednesday, October 07, = 2009 4:04=20 PM
Subject: [FlyRotary] Re: = Balls and=20 Springs

Lynn,
Thanks, I have spun up the rotor in = a lathe and=20 filled the rotor with coolant from a spray bottle, being careful not = to=20 spill any and then weighing the remainder and comparing it to the = original=20 weight (similar system to what you suggest). I went the extra mile = and then=20 adjusted the weight by comparing it to oil weight of the same=20 volume.
 
I did speak to Richard Sohn at the = time but at=20 that stage he wasn't to concerned with balancing to that extent with = his=20 demonstrator.
 
It has also been suggested that the = apex seal=20 and springs be excluded as their weight is borne by the rotor=20 housing.
 
Then again I've had people argue = against those=20 suggestions.
 
I thought any out of balance might = exacerbate=20 the negative torque pulses, but your saying because their so large = it's=20 not  such a concern - which puts my mind to = rest.
 
I do like your suggestion of  = 'reverse=20 engineering' the balancing process, I think I will discuss that with = a=20 professional balancer.
 
George (down=20 under)
 Lynn,
With balancing my single rotor, = what would=20 you suggest that I allow ( percentage wise) for oil weight in the = rotor -=20 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=20 on the internet came from Down there. A rotor is spun up in the = lathe with=20 a 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)=20 The weights are close enough. Then the rotor is laid on a grill on = the pan=20 and allowed to drain. Then weigh the liquid in the pan. I bet the=20 balancing people just have a number on the wall for rotaries that = is close=20 to that weight. A balancer could do it backwards by spinning the = shaft=20 from a 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=20 start out with the balance correct. I have thought about singles = and=20 decided that as big a diameter flywheel that you can fit but = weighted only=20 at the outer edge. Like 4 sets of starter rings tiged to a flex = plate.=20 Even Mazda builds with pieces two weight ranges apart. They have = stamped=20 the weights on rotors, and have used colored paint dots. Of course = the=20 paint dots are gone when we see a used rotor.
 
Richard = Sohn can=20 tell you. He seems to be doing well with his.
 
Lynn E. = Hanover
 


No virus found in this incoming message.
Checked by = AVG -=20 www.avg.com
Version: 8.5.421 / Virus Database: 270.14.5/2419 - = Release=20 Date: 10/07/09 05:18:00
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