X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f174.google.com ([209.85.223.174] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4178151 for flyrotary@lancaironline.net; Thu, 25 Mar 2010 06:11:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.223.174; envelope-from=msteitle@gmail.com Received: by iwn4 with SMTP id 4so192185iwn.3 for ; Thu, 25 Mar 2010 03:10:55 -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=mYio2nFfb5otYGg1va5Qgl9iVmRqx9ddP1keZDP20W8=; b=L5a+X/Ye5jBA2vI2/+quME3Y3s4WINWHo//so6dftexsz1WuJ48QNYAF8ciLP15A7o Rn9bbm4S+WEiOmKrApmCA1UwMiyIjmFxUSubS1lFpPEl+BMUsqxjoPYFq9aNh1UG7rt3 TlPpXyJoKLerK467a9Sm2lyEOovOsy7uAz7qQ= 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=s93+cTweec1bTJRH9z33EK7qMMcwE3lm5U/sD/q/mwpJ3hMpYr3VP+El/MTEgts+CO LRosNJ4TZJCGzote6uSd8nYrw4O+2cLW9J+BPYIAwnB7XvV/xuvSBaEnBcNpnj1JNiTq +TB56k9Ib5Z3pkjh3oJofOM6shXvYlsZ3eFcE= MIME-Version: 1.0 Received: by 10.231.152.75 with SMTP id f11mr446479ibw.50.1269511855619; Thu, 25 Mar 2010 03:10:55 -0700 (PDT) In-Reply-To: References: Date: Thu, 25 Mar 2010 05:10:55 -0500 Message-ID: <5cf132c1003250310r3d806f23v62392de139cbbbb7@mail.gmail.com> Subject: Re: [FlyRotary] Adaptor plate rivets From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e6d26cac313ef704829d438e --0016e6d26cac313ef704829d438e Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Al, Good tip on checking for "relative movement" on the damper assy. I didn't do that, but then I had visual evidence of movement. To answer your question about the washers, I used thick washers on both sides. But I'll have to remove them all in order to replace the AN-6A bolt= s with AN173-6A's. I'm hoping the bolts arrive by this weekend so I can star= t putting everything back together. Mark S. On Thu, Mar 25, 2010 at 1:25 AM, Al Gietzen wrote: > > > I tried to check my plate for smoking rivets today, but the shop head is > against the flywheel and I can't see a thing. The round heads all seem > fine. Couldn't detect any that seem loose or smoking or anything. Will > just have to keep an eye on it. David Leonard > > > > Dave; there is a way to check. > > > > I went for further checks on mine today =96 had to make the decision whet= her > or not to fly it to Jean, NV, on Saturday for the CONTACT! Alternative > Engine Fly-in. (First I went flying for about an hour just to make sure = I > wasn=92t going to be deprived of my enjoyment before I had to fix itJ) I > went to look for loose rivets, or to see is I could detect any relative > movement between the spline adapter flange and the aluminum plate. > > > > No way to get at the heads of the rivets without disassembly, and > everything =91looked=92 fine on the front side of the flange. So I presse= d my > fingertips onto the plate, overlapping them onto the beveled edge of the > flange; then pulled a prop blade back and forth with the other hand. I co= uld > detect that there was relative movement; however miniscule, as in maybe a > few thousandths max, but it was there. I could not detect it visually, bu= t I > could feel it. So after some considerable deliberation, I decided that t= his > should be fixed before more flying. > > > > I suspect if I done the same thing many flight hours ago it would have > been similar, so a few more hours wouldn=92t really matter, but I had to > consider that aluminum rivets will work-harden, and become brittle, and t= hen > at some point possibly subject to breaking, especially if there is any > operating regime where there could be torsional vibration with force > reversal. No way of knowing when that point would be reached. > > > > So I think you should give it the =91sensitive fingers=92 check, and feel= for > relative movement. Not that you necessarily have to replace the rivets ri= ght > away, but if you are quite certain there is any relative movement it is > definitely a cause for concern, and should be checked again after a few > hours and see if you can detect a difference. > > > > I=92m planning on replacing the rivets with AN173-6A bolts, with MS21042-= 3 > metal lock nuts over AN960-10L washers. Maybe Mark can tell us if the thi= n > washers are enough to sure the threads don=92t bottom out. About 4 or 5 o= f > these bolts would be as strong as 20 aluminum rivets, but I guess all 20 > would be good to distribute the stress in the aluminum plate. > > > > Al G > > > > > > > > > > > --0016e6d26cac313ef704829d438e Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Al,

Good tip on checking for "relative movement&quo= t; on the damper assy. =A0I didn't do that, but then I had visual evide= nce of movement.=A0

To answer your question about = the washers, I used thick washers on both sides. =A0But I'll have to re= move them all in order to replace the AN-6A bolts with AN173-6A's. =A0I= 'm hoping the bolts arrive by this weekend so I can start putting every= thing back together. =A0

Mark S.

On Thu, Mar 2= 5, 2010 at 1:25 AM, Al Gietzen <ALVentures@cox.net> wrote:

=A0

I tried to check my plate= for smoking rivets today, but the shop head is against the flywheel and I can't see a thing.=A0 T= he round heads all seem fine.=A0 Couldn't detect any that seem loose or sm= oking or anything.=A0 Will just have to keep an eye on it.=A0=A0 David Leonard

=A0

Dave; there is a way to check.=

=A0

I went for fur= ther checks on mine today =96 had to make the decision whether or not to fly it to Jean, NV<= /font>, on Saturday for the CONTACT! Alternative Engine Fly-in.=A0 (First I went flying for about an hour just to make sure I wasn=92t going to be deprived of my enjoyment befo= re I had to fix itJ)=A0 I went to look for lo= ose rivets, or to see is I could detect any relative movement between the spline adapter flange and the alum= inum plate.

=A0

No way to get = at the heads of the rivets without disassembly, and everything =91looked=92 fine on the front side of the flange. So I pressed my fingertips onto the plate, overlapping them = onto the beveled edge of the flange; then pulled a prop blade back and forth wit= h the other hand. I could detect that there was relative movement; however miniscule, as in maybe a few thousandths max, but it was there. I could not detect it visually, but I could feel it.=A0 So after some considerable deli= beration, I decided that this should be fixed before more flying.=A0

=A0

I suspect if I= done the same thing many flight hours ago it would have been similar, so a few more hours wouldn=92t really matter, but I had to consider that aluminum rivets will work-harden, and be= come brittle, and then at some point possibly subject to breaking, especially if there is any operating regime where there could be torsional vibration with force reversal.=A0 No way of knowing when that point would be reached.

=A0

So I think you= should give it the =91sensitive fingers=92 check, and feel for relative movement. Not that you necessarily have to replace the rivets right away, but if you are quite certain there i= s any relative movement it is definitely a cause for concern, and should be checked again after a few hours and see if you can detect a difference.

=A0

I=92m planning= on replacing the rivets with AN173-6A bolts, with MS21042-3 metal lock nuts over AN960-10L washers. Maybe Mark can tell us if the thin washers are enough to sure the threads don=92t bottom out. About 4 or 5 of these bolts would be as strong as 20 aluminum rivets, but I guess all 20 would be good to distribute the stress in the aluminum plate.

=A0

Al G

=A0

=A0

=A0

=A0

=A0


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