X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-px0-f173.google.com ([209.85.216.173] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4178548 for flyrotary@lancaironline.net; Thu, 25 Mar 2010 13:20:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.173; envelope-from=wdleonard@gmail.com Received: by pxi3 with SMTP id 3so393553pxi.8 for ; Thu, 25 Mar 2010 10:19:45 -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=6ymHI0KHoFnTl2QEeBtRVIdx5bIX5RSJ1xiBtzGhr2E=; b=ll8bb1qLPX8oIEWv8wW387gpsmXwWAiLi6kZo0MTymiuN6lDF5z9s6KMiTh8stICMe gcV4GQg+gPAVBOTN5J3v65dDSooKUAK2Hka4yl08layiPULGuSUQpUclpNjbSuJzvXnY srvkbWLyODaoJI8yhHS9kkGyqcETwzVH3bfXE= 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=wRz3oal7vrdIKSo2g+a2JW0Wo3xTKfcdlzzTqrZiR3xw5XxqIR75vn4XThQ06xLUNR QzFvyVL276DjpfQtH8BycIErxAcP/6OONPkFmBXQPIGhYYQ/n8qQr1geTH2dKvdGet59 TARJh+t58lVEcj9qn0zvgFwWRTWj8eO7webbc= MIME-Version: 1.0 Received: by 10.140.55.10 with SMTP id d10mr10367816rva.247.1269537585582; Thu, 25 Mar 2010 10:19:45 -0700 (PDT) In-Reply-To: References: Date: Thu, 25 Mar 2010 10:19:45 -0700 Message-ID: <1c23473f1003251019y79086a9bje7e0b8cf237f506f@mail.gmail.com> Subject: Re: [FlyRotary] Adaptor plate rivets From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001636b1468dd185500482a340f5 --001636b1468dd185500482a340f5 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Thanks Al, will have to do that feel check. BTW, did you have visible smok= e trails? I don't. I wonder if there was some sort of change in the way the riveting was done. Early drives like Tracy, Ed, Bill Eslick(? havent heard), Todd Bartrim (havent heard), Chuck Dunlap (havent heard), Tommy James (havent heard) and I (so far) don't seem to have a problem while you and Mark who have slightly later versions are having loosening. (Have we heard from Joh= n Slade or Steve Brooks and I missed it?) Any other high-time re-drives that I left out?) - What about Tom Parks? (turbo 20B with Ross Drive). It's possible that power is the main issue (average torque), but it seems t= o 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 o= f us with turbo engines, and with 20B's you are are going to have lower torqu= e amplitude than even those with n.a. 13B's. Only your average torque is higher. Seems strange... that is why I am wondering about some sort of change to the later models of the gear drive. Tracy? --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Wed, Mar 24, 2010 at 11:25 PM, 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 > > > > > > > > > > > --001636b1468dd185500482a340f5 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
Thanks Al, will have to do that feel check.=A0 BTW, did you have visib= le smoke trails?=A0 I don't.=A0 I wonder if there was some sort of chan= ge in the way the riveting was done.=A0
=A0
Early drives like Tracy, Ed, Bill Eslick(? havent heard), Todd Bartrim= (havent heard), Chuck Dunlap (havent heard), Tommy James (havent heard)=A0= and I (so far) don't seem to have a problem while you and Mark who have= =A0slightly=A0later versions are having loosening.=A0 (Have we heard from J= ohn Slade=A0or Steve Brooks and=A0I missed it?)=A0 Any other high-time re-d= rives that I left out?)=A0 - What about Tom Parks? (turbo 20B with Ross Dri= ve).
=A0
It's possible that power is the main issue (average torque), but i= t seems to me that peak torque and torque=A0variation amplitude are=A0what= =A0are going to matter most.=A0 You and Mark are going to have lower peak t= orque than those of us with turbo engines, and with 20B's you are are g= oing to have lower torque amplitude than even those with n.a. 13B's.=A0= Only your average torque is higher.=A0 Seems strange... that is why I am w= ondering about some sort of change to the later models of the gear drive.= =A0 Tracy?
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
= http://RotaryRoster.= net


On Wed, Mar 24, 2010 at 11:25 PM, Al Gietzen <= ALVentures@cox.net> wrote:

=A0

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

=A0<= /font>

Dave= ; there is a way to check.<= /span>

=A0<= /font>

I went for = further checks on mine today =96 had to make the decision whether or not to= fly it to <= span style=3D"FONT-SIZE: 11pt; COLOR: blue; FONT-FAMILY: Verdana">Jean, NV, 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 t= o be deprived of my enjoyment before I had to fix itJ)=A0 I went to look for loose rivets, or to see is I could= detect any relative movement between the spline adapter flange and the alu= minum plate.

=A0<= /font>

No way to g= et 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 t= he plate, overlapping them onto the beveled edge of the flange; then pulled= a prop blade back and forth with the other hand. I could detect that there= was relative movement; however miniscule, as in maybe a few thousandths ma= x, but it was there. I could not detect it visually, but I could feel it.= =A0 So after some considerable deliberation, I decided that this should be = fixed before more flying.=A0

=A0<= /font>

I suspect i= f I done the same thing many flight hour= s ago it would have been similar, so a few more hours wouldn=92t really mat= ter, but I had to consider that aluminum rivets will work-harden, and becom= e brittle, and then at some point possibly subject to breaking, especially = if there is any operating regime where there could be torsional vibration w= ith force reversal.=A0 No way of knowing when that point would be reached.<= /span>

=A0<= /font>

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 is any relative movement it is definitel= y a cause for concern, and should be checked again after a few hours and se= e if you can detect a difference.

=A0<= /font>

I=92m plann= ing 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<= /font>

Al G=

=A0<= /font>

=A0<= /font>

=A0<= /font>

=A0<= /font>

=A0<= /font>


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