X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wproxy.gmail.com ([64.233.184.196] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 934743 for flyrotary@lancaironline.net; Fri, 20 Jan 2006 16:42:29 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.233.184.196; envelope-from=russell.duffy@gmail.com Received: by wproxy.gmail.com with SMTP id i22so584131wra for ; Fri, 20 Jan 2006 13:41:43 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:from:to:subject:date:message-id:mime-version:content-type:x-priority:x-msmail-priority:x-mailer:importance:in-reply-to:x-mimeole; b=cECplQB/ZGATTOSCMptcfcJ5nocEWCVbTqLSr4GvKxwV2sJ1wKasa6GaLWpLOmQFhi7XpDRD4K/BOHt8k2EqpBvK+TzEGqT+3LSnnczsQO4h5sADcWWZqH+2BSsmSwf3PCgopRXzrbKzqg3JKqOvgYiBmlOFLjEvu8gniNs7XS4= Received: by 10.54.152.5 with SMTP id z5mr2926546wrd; Fri, 20 Jan 2006 13:41:43 -0800 (PST) Return-Path: Received: from rd ( [65.6.194.9]) by mx.gmail.com with ESMTP id 9sm2338289wrl.2006.01.20.13.41.38; Fri, 20 Jan 2006 13:41:38 -0800 (PST) From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: flywheel weight? Date: Fri, 20 Jan 2006 15:41:37 -0600 Message-ID: <000201c61e0a$4bbc3690$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01C61DD8.0121C690" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_0003_01C61DD8.0121C690 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable 10lbs. That is about the weight of a rotor. But you'll be spinning it 3 times as fast, so it'll have 8 times the momentum (momentum is velocity squared, right?). The object is to keep the shaft from speeding up and slowing down, and I think increasing the momentum 8 times would accomplish that well. Hi Ernest, =20 All WAG's appreciated. I'm not sure the biggest problem is the missing = mass of the 2nd rotor, but rather the missing firing pulse. If we were to continue your momentum thought though, the flywheel advantage would be = even greater than you suggested. Remember that the center of the rotor mass = is traveling in a much smaller radius circle than the mass of the flywheel = ring that I proposed. Heck, maybe that 1.5 lbs of weight that I had before = would have made up for the missing rotor :-) =20 other ideas: Have the disc water/laser cut. And you don't need 4130, so have the cutter use whatever steel they have on hand. Have a brake shop turn the disc and balance it, or you might just be able to get a brake rotor that would bolt right into place with little or no modification. The heavy duty Matco rotors I just bought seem to be around those dimensions if memory serves. =20 Interesting thoughts. I'm still leaning toward trying to install 4 = separate weights, which makes it possible to do this without pulling the drive = off. It also makes balancing a simple matter of precisely weighing the added weights. I can buy 1/2" steel discs in various diameters from McMaster Carr, so I would just have to drill a hole in the middle, and bolt them = on. I wonder what the limit of a 7/16" bolt is for holding a couple pound = weight spinning at 8000 rpm. Probably don't want to have anything in the arc = of the flex plate the first time it was run up :-0 =20 Dale, =20 I thought about flywheels, but aren't they always manual trans = flywheels, made to install on the shaft itself? I need something that coexists = with the current auto balance weight, flex plate, and Tracy's dampener plate. = =20 =20 Thanks, Rusty (trying hopelessly to resist) =20 PS- Congrats to Joe! If this keeps up, people are going to think that rotaries can only fly backwards :-) ------=_NextPart_000_0003_01C61DD8.0121C690 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

10lbs.  That is about the weight of a = rotor.  But=20 you'll be spinning it
3 times as fast, so it'll have 8 times the = momentum=20 (momentum is
velocity squared, right?).  The object is to keep = the shaft=20 from
speeding up and slowing down, and I think increasing the = momentum=20 8
times would accomplish that well.

Hi=20 Ernest,
 
All = WAG's=20 appreciated.  I'm not sure the biggest problem is the missing mass = of the=20 2nd rotor, but rather the missing firing pulse.  If we were to = continue=20 your momentum thought though, the flywheel advantage would be even = greater=20 than you suggested.  Remember that the center of the=20 rotor mass is traveling in a much smaller radius circle than = the mass=20 of the flywheel ring that I proposed.  Heck, maybe that 1.5 lbs of = weight=20 that I had before would have made up for the missing rotor=20 :-)
 
other ideas:  Have the disc water/laser = cut.  And=20 you don't need 4130,
so have the cutter use whatever steel they have = on=20 hand.  Have a brake
shop turn the disc and balance it, or you = might just=20 be able to get a
brake rotor that would bolt right into place with = little or=20 no
modification.  The heavy duty Matco rotors I just bought seem = to=20 be
around those dimensions if memory serves.
 
Interesting=20 thoughts.  I'm still leaning toward trying to install 4 separate = weights,=20 which makes it possible to do this without pulling the drive off.  = It also=20 makes balancing a simple matter of precisely weighing the added = weights.  I=20 can buy 1/2" steel discs in various diameters from McMaster Carr, so I = would=20 just have to drill a hole in the middle, and bolt them on.  I = wonder what=20 the limit of a 7/16" bolt is for holding a couple pound weight = spinning at=20 8000 rpm.  Probably don't want to have anything in = the arc of the=20 flex plate the first time it was run up :-0
 
Dale,
 
I = thought about=20 flywheels, but aren't they always manual trans flywheels, made to = install on the=20 shaft itself?  I need something that coexists with the = current auto=20 balance weight, flex plate, and Tracy's dampener=20 plate.  
 
Thanks,
Rusty (trying hopelessly to=20 resist)
 
PS- Congrats to Joe!  If = this keeps up,=20 people are going to think that rotaries can only fly backwards=20 :-)
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