X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f183.google.com ([209.85.223.183] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4179013 for flyrotary@lancaironline.net; Thu, 25 Mar 2010 18:47:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.223.183; envelope-from=msteitle@gmail.com Received: by iwn13 with SMTP id 13so6390148iwn.14 for ; Thu, 25 Mar 2010 15:46:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=E7ddA1BQZILQElq7Cjf8e4O0FexrTEnU1nu9x5VLrTo=; b=wEzVnNOo40qDNnuRaPgfqDEbEx5i3ZTCdzhxt8MkMKhQEPWL48afkLgIfVjCcTUSeC Zv7JBJpNmMKCcVDSwT4umZS++UT8cuFQV73UYJeHereWnRmhzO04wOCrEdOXSv/utF5p g63SkIGWiCRLM7gyni5rVUlNHo3UG0i92u5oQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=hFgcW2AYIllBVVDz9+Z/w+74FuVfbD8CJCBnwaYriwt5E0K79qtkROpMHFhVahHVzp QL3/JwXO+gQ85p00hjjv35ACQTOzwkMkoh4jmaOU924Rhy9G99pCDdJX9857AJLJEmws OW2FauoDC+t3H5kjHp8r07r8PF/4Gsoi8Hf4k= MIME-Version: 1.0 Received: by 10.231.146.66 with SMTP id g2mr440542ibv.88.1269557210078; Thu, 25 Mar 2010 15:46:50 -0700 (PDT) In-Reply-To: References: Date: Thu, 25 Mar 2010 17:46:49 -0500 Message-ID: <5cf132c1003251546ye4abb48tddcbd23a09e17d1a@mail.gmail.com> Subject: Re: [FlyRotary] Re: Adaptor plate rivets From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e64980fe875ea30482a7d235 --0016e64980fe875ea30482a7d235 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable George, I didn't find any evidence of excessive heat, on my damper. But then my radiator is directly below the gearbox and flows slightly heated air directly over the flywheel/damper. Mark S. On Thu, Mar 25, 2010 at 4:30 PM, George Lendich wrote= : > No one has mentioned it yet but I'm wondering if heat could be a factor= , > one of them anyway. > George( down under) > > BTW, did you have visible smoke trails? I don't. I wonder if there was > some sort of change in the way the riveting was done. > > Dave; > > > > There were maybe a couple very slight trails on the flange side (toward t= he > re-drive). On the other side (I guess the head side of the rivets) where= I > could only see about 4-5 of them through the holes in the flywheel (ring > gear); all had distinct dark trails. > > > > It's possible that power is the main issue (average torque), but it seems > to me that peak torque and torque variation amplitude are what are going = to > matter most. You and Mark are going to have lower peak torque than those= of > us with turbo engines, and with 20B's you are are going to have lower tor= que > amplitude than even those with n.a. 13B's. > > One would think that is true; but you can=92t be sure. It is possible th= e > 20B may have some harmonics (resonance vibration) somewhere in the range = of > operation that the 13B doesn=92t have. Seems unlikely with the snubbers a= nd > the =91play=92 in the system, but . . . We need more feedback from all t= he > users with more than 150 hours, or so, to see what the pattern is. I=92m= not > aware of rivet changes =96 Tracy? > > Mark and I both have constant speed props and I think Al does also. Don't > see how it could make any difference but worth considering in the > investigation. Bobby > > I have a fixed pitch Catto. The mass of the prop would likely be a facto= r > =96 *if* there is some torsional vibration involved. My Catto only weigh= s > about 16 lbs; plus 3-4 for the extension and spinner. I have 180 hours an= d > barely detectable rivet wear; Mark apparently has more wear at about 150. > > Al > > > > --0016e64980fe875ea30482a7d235 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable George,=A0

I didn't find any evidence of excessive h= eat, on my damper. =A0But then my radiator is directly below the gearbox an= d flows slightly heated air directly over the flywheel/damper. =A0

Mark S.

On Thu, Mar 25, 2010 a= t 4:30 PM, George Lendich <lendich@aanet.com.au> wrote:
=A0No one has mentioned it yet but I&#= 39;m wondering=20 if heat could be a factor, one of them anyway.
George( down under)

BTW, did you have visibl= e smoke=20 trails?=A0 I don't.=A0 I wonder if there was some sort of change in t= he=20 way the riveting was done.=A0

<= span style=3D"font-size:11pt;color:blue;font-family:Verdana">Dave;

<= span style=3D"font-size:11pt;color:blue;font-family:Verdana">= =A0

<= span style=3D"font-size:11pt;color:blue;font-family:Verdana">There were may= be a=20 couple very slight trails on the flange side (toward the re-drive). =A0On= =20 the other side (I guess the head side of the rivets) where I could only s= ee=20 about 4-5 of them through the holes in the flywheel (ring gear); all had= =20 distinct dark trails.

=A0

It's possible that=20 power is the main issue (average torque), but it seems to me that peak to= rque=20 and torque=A0variation amplitude are=A0what=A0are going to matter=20 most.=A0 You and Mark are going to have lower peak torque than those of u= s=20 with turbo engines, and with 20B's you are are going to have lower to= rque=20 amplitude than even those with n.a. 13B's.=A0

One=20 would think that is true; but you can=92t be sure.=A0 It is possible the = 20B=20 may have some harmonics (resonance vibration) somewhere in the range of= =20 operation that the 13B doesn=92t have. Seems unlikely with the snubbers a= nd the=20 =91play=92 in the system, but . . . =A0We need more feedback from all the= users=20 with more than 150 hours, or so, to see what the pattern is. =A0I=92m not= =20 aware of rivet changes =96 Tracy?<= /p>

Mark and=20 I both have constant speed props and I think Al does also. Don't see = how it=20 could make any difference but worth considering in the investigation.=A0= =20 Bobby

I have=20 a fixed pitch Catto. =A0The mass of the prop would likely be a factor =96= =20 if there is some torsional= =20 vibration involved.=A0 My Catto only weighs about 16 lbs; plus 3-4 for th= e=20 extension and spinner. I have 180 hours and barely detectable rivet wear;= Mark=20 apparently has more wear at about 150.

Al

=A0


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