X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from S1.cableone.net ([24.116.0.227] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1036980 for flyrotary@lancaironline.net; Fri, 17 Mar 2006 00:35:11 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.116.0.227; envelope-from=crayd@cableone.net Received: from chuckathlon (unverified [69.92.218.28]) by S1.cableone.net (CableOne SMTP Service S1) with ESMTP id 50129223 for ; Thu, 16 Mar 2006 22:34:59 -0700 Return-Path: From: "Chuck Dunlap" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Motor teardown results Date: Thu, 16 Mar 2006 22:36:03 -0700 Message-ID: <00ed01c64984$ae625b30$6501a8c0@chuckathlon> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00EE_01C6494A.02038330" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.3416 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2727.1300 In-Reply-To: Importance: Normal X-IP-stats: No info recorded yet X-External-IP: 69.92.218.28 X-Abuse-Info: Send abuse complaints to abuse@cableone.net This is a multi-part message in MIME format. ------=_NextPart_000_00EE_01C6494A.02038330 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable =20 Kelly, I use WalMart 2 stroke oil mixed 100:1 I used to use Conoco 2 stroke oil when it was available by the case here, cant get it anymore. Chuck =20 Chuck, As a clarification how do you lube your apex seals ? Do you mix with fuel or=20 use injection metering pump ? =20 -- Kelly Troyer=20 Dyke Delta/13B/RD1C/EC2=20 -------------- Original message from "Ed Anderson" : --------------=20 > Certainly, I don't feel we can rule anything out at this point, Doug.=20 > Degree of Lubrication could certainly play a role, but I personally doubt=20 > that it is the root cause - could be wrong about that, of course. I believe=20 > it may have to do with the amount of play in the rotor housing apex seal=20 > slots. I suspect that if the seals were pressing against the rotor housing=20 > wall in the manner they were designed to - the rounded top tangential to the=20 > surface of the housing - there is minimal drag and friction. As the slots=20 > wear the seals become able to "flop" from one side to the other of the > housing as its chamber undergoes the 4 cycles. When "flopped" the seal's=20 > rounded top is no longer in contact as designe d and the top edge=20 > (non-rounded part) of the seal may start to drag and cause unusual wear.=20 >=20 > If lubrication was sparse and this condition existed, I think it would > contribute to accelerated wear and chatter marks. But, just a hypothesis.=20 >=20 > Ed=20 >=20 > Ed Anderson=20 > Rv-6A N494BW Rotary Powered=20 > Matthews, NC=20 > eanderson@carolina.rr.com...........=20 >=20 >=20 > ----- Original Message -----=20 > From: "Doug Mueller"=20 > To: "Rotary motors in aircraft"=20 > Sent: Thursday, March 16, 2006 12:30 AM=20 > Subject: [FlyRotary] Re: Motor teardown results=20 >=20 >=20 > > Hi Chuck and Ed could there be any relationship to the lack of lubrication=20 > > to=20 > > these housings? The Lubrication increase could dampen any resonant=20 > > frequency causing chatter? What would your opinion be on that idea?=20 > > Anyone?=20 > >>=20 > >> From: "Ed Anderson"=20 > >> Date: 2006/03/16 Thu AM 12:21:11 EST=20 > >> To: "Rotary motors in aircraft"=20 > >> Subject: [FlyRotary] Re: Motor teardown results=20 > >>=20 > >> MessageThe chatter marks are certainly apparent, Chuck. Whoa! 150=20 > > hours is certainly not much out of a brand new housing. It could be as=20 > > you=20 > > suggest that the two piece seal played a role. However, I have another=20 > > suggestion. Measure the apex seal slot at the top (across the gap) and=20 > > see=20 > > what the distance is. Do it both on the good rotor and the damaged one if=20 > > you can find an undamaged spot. If like my rotor, the slots are worn, I=20 > > believe they may contribute to the chatter and breaking of the apex seal.=20 > >>=20 > >> Here's the theory. As the slot "V"s there is less support for the seal=20 > >> near=20 > > its top, the bottom is still fairly well constrained. As a consequence,=20 > > the top=20 > > portion of the seal is more able to be swayed back and forth by=20 > > combustion=20 > > and friction forces. In other words, instead of just rubbing on the rotor=20 > > housing wall with the smooth top of the seal, the edge of the seal starts=20 > > to=20 > > drag along the wall. The seal (with less support at the top) acts like a=20 > > stiff=20 > > spring (up to a limit) and "vibrates" as it slides along the housing wall=20 > > leaving=20 > > the chatter marks. At some point the forces become too much and the seal=20 > > breaks.=20 > >>=20 > >> It might be interesting to determine the vibration frequency of a seal=20 > > ( given its dimensions and composition) and then m easure the average=20 > > distance between the peaks (or valleys) of the chatter. Then given the=20 > > resonant frequency of the seal determine at what rotor rpm it would leave=20 > > chatter marks of the measured distance. {:>). No, I don't have a clue=20 > > about=20 > > how to do this, but I'll bet some mechanical engineer could come up with=20 > > something.=20 > >>=20 > >> Just a theory, of course, but if your apex slot tops are within the > > specifications called for by Mazda then that would discredit the theory.=20 > > If=20 > > they are worn then it might tend to give it support.=20 > >>=20 > >>=20 > >> When my seal broke it also caught the next seal down in is slot and > > smeared the top of the slot such that it could not come back up.=20 > >>=20 > >> You and I are apparently the only ones (that I know of ) that seem to=20 > >> have=20 > > had this failure mode of an apex seal disintegrating for no apparent > > reason.=20 > >>=20 > >> Thanks for sharing the photos and information.=20 > >>=20 > >> Are you going to try for Sun & Fun?=20 > >>=20 > >> Ed=20 > >>=20 > >>=20 > >> Ed Anderson=20 > >> Rv-6A N494BW Rotary Powered=20 > >> Matthews, NC=20 > >> eanderson@carolina.rr.com=20 > >>=20 > >> Ed=20 > >>=20 > >>=20 > >>=20 > >> ----- Original Message -----=20 > >> From: Chuck Dunlap=20 > >> To: Rotary motors in aircraft=20 > >> Sent: Wednesday, March 15, 2006 10:44 PM=20 > >> Subject: [FlyRotary] Motor teardown results=20 > >>=20 > >>=20 > >>=20 > >>=20 > >> I finally got time to get my failed 13b apart. The rear rotor was=20 > >> missing=20 > > one apex seal, the other 2 were intact but jammed due to the fragments of=20 > > the broken one. The rotor housing has the classic chatter marks all=20 > > around.=20 > > Doing a Google of "13B apex seal chatter" results in plenty of examples of=20 > > this failure mode. Apparently the chatter is from the natural resonant=20 > > frequency of the seal, it eventually fatigues the seal causing failure.=20 > >> The front rotor was in good shape, but the housing had the same chatter=20 > > marks, but not as severe as the rear rotor. The front rotor housing was=20 > > brand=20 > > new 150 hours ago when I rebuilt this motor after the Grand Canyon forced=20 > > landing. At that time the good rotor housing had slight chatter marks but=20 > > I=20 > > reused it. The front rotor was destroyed at that time due to foreign > > object=20 > & gt; entering the rotor.=20 > >> Both rotors were missing the corner seal rubber plugs on the side with=20 > > the short apex seal segment. Perhaps the small segment vibrated more,=20 > > disintegrating the rubber seals?=20 > >> The first 260 hours of flying my rotary bird was with stock 3-piece > >> seals,=20 > > and I never saw any chatter marks. The last 250 hours has been flown with=20 > > 2=20 > > piece seals and now I have chatter marks .=20 > >> I now have Tracy's 2 piece apex seals and I wonder how they will=20 > >> perform,=20 > > it appears that the heavier weight of the 2 piece seals puts the resonant=20 > > frequency in the cruising range of 6000RPM?=20 > >>=20 > >> Chuck Dunlap=20 > >> RV6 13B=20 > >>=20 > >>=20 > >>=20 > > -----------------------------------------------------------------=20 > > - ------------=20 > >>=20 > >>=20 > >> --=20 > >> Homepage: http://www.flyrotary.com/=20 > >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/=20 > >>=20 > >>=20 > >=20 > > Doug Mueller=20 > > RX-6 13BT=20 > > N900DM=20 > > Boulder City(61B),Nevada=20 > >=20 > >=20 > > --=20 > > Homepage: http://www.flyrotary.com/=20 > > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/=20 > >=20 >=20 >=20 >=20 > --=20 > Homepage: http://www.flyrotary.com/=20 > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/=20 ------=_NextPart_000_00EE_01C6494A.02038330 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message
 
Kelly, I = use WalMart 2=20 stroke oil mixed 100:1 I used to use Conoco 2 stroke oil when it = was=20 available by the case here, cant get it=20 anymore.
Chuck
  
Chuck,
   As a clarification how do you lube your apex = seals ? Do=20 you mix with fuel or
use injection metering pump ?
    
--
Kelly Troyer
Dyke=20 Delta/13B/RD1C/EC2




--------------=20 Original message from "Ed Anderson" = <eanderson@carolina.rr.com>:=20 --------------


> Certainly, I don't feel we can rule = anything=20 out at this point, Doug.
> Degree of Lubrication could = certainly play=20 a role, but I personally doubt
> that it is the root cause - = could be=20 wrong about that, of course. I believe
> it may have to do = with the=20 amount of play in the rotor housing apex seal
> slots. I = suspect that=20 if the seals were pressing against the rotor housing
> wall = in the=20 manner they were designed to - the rounded top tangential to the =
>=20 surface of the housing - there is minimal drag and friction. As the = slots=20
> wear the seals become able to "flop" from one side to the = other of=20 the
> housing as its chamber undergoes the 4 cycles. When = "flopped"=20 the seal's
> rounded top is no longer in contact as designe d = and the=20 top edge
> (non-rounded part) of the seal may start to drag = and cause=20 unusual wear.
>
> If lubrication was sparse and this = condition=20 existed, I think it would
> contribute to accelerated wear = and=20 chatter marks. But, just a hypothesis.
>
> Ed
> =
> Ed Anderson
> Rv-6A N494BW Rotary Powered
> = Matthews,=20 NC
> eanderson@carolina.rr.com...........
>
> =
>=20 ----- Original Message -----
> From: "Doug Mueller"=20
> To: "Rotary motors in aircraft"=20
> Sent: Thursday, March 16, 2006 = 12:30=20 AM
> Subject: [FlyRotary] Re: Motor teardown results
> =
>
> > Hi Chuck and Ed could there be any = relationship to=20 the lack of lubrication
> > to
> > these = housings? The=20 Lubrication increase could dampen any resonant
> > = frequency=20 causing chatter? What would your opinion be on that idea?
> = >=20 Anyone?
> >>
> >> From: "Ed Anderson"=20
> >> Date: 2006/03/16 Thu AM = 12:21:11 EST
> >> To: "Rotary motors in aircraft"=20
> >> Subject: [FlyRotary] = Re:=20 Motor teardown results
> >>
> >> = MessageThe=20 chatter marks are certainly apparent, Chuck. Whoa! 150
> > = hours=20 is certainly not much out of a brand new housing. It could be as =
>=20 > you
> > suggest that the two piece seal played a = role.=20 However, I have another
> > suggestion. Measure the apex = seal slot=20 at the top (across the gap) and
> > see
> > what = the=20 distance is. Do it both on the good rotor and the damaged one if =
>=20 > you can find an undamaged spot. If like my rotor, the slots are = worn, I=20
> > believe they may contribute to the chatter and = breaking of the=20 apex seal.
> >>
> >> Here's the theory. As = the=20 slot "V"s there is less support for the seal
> >> near =
>=20 > its top, the bottom is still fairly well constrained. As a = consequence,=20
> > the top
> > portion of the seal is more able = to be=20 swayed back and forth by
> > combustion
> > and = friction=20 forces. In other words, instead of just rubbing on the rotor =
> >=20 housing wall with the smooth top of the seal, the edge of the seal = starts=20
> > to
> > drag along the wall. The seal (with = less=20 support at the top) acts like a
> > stiff
> > = spring (up=20 to a limit) and "vibrates" as it slides along the housing wall =
> >=20 leaving
> > the chatter marks. At some point the forces = become too=20 much and the seal
> > breaks.
> >>
> = >>=20 It might be interesting to determine the vibration frequency of a = seal=20
> > ( given its dimensions and composition) and then m = easure the=20 average
> > distance between the peaks (or valleys) of the = chatter. Then given the
> > resonant frequency of the seal = determine at what rotor rpm it would leave
> > chatter = marks of=20 the measured distance. {:>). No, I don't have a clue
> = > about=20
> > how to do this, but I'll bet some mechanical engineer = could=20 come up with
> > something.
> >>
> = >>=20 Just a theory, of course, but if your apex slot tops are within the =
>=20 > specifications called for by Mazda then that would discredit = the=20 theory.
> > If
> > they are worn then it might = tend to=20 give it support.
> >>
> >>
> = >> When=20 my seal broke it also caught the next seal down in is slot and =
> >=20 smeared the top of the slot such that it could not come back up. =
>=20 >>
> >> You and I are apparently the only ones = (that I=20 know of ) that seem to
> >> have
> > had this = failure=20 mode of an apex seal disintegrating for no apparent
> > = reason.=20
> >>
> >> Thanks for sharing the photos = and=20 information.
> >>
> >> Are you going to = try for=20 Sun & Fun?
> >>
> >> Ed
> = >>=20
> >>
> >> Ed Anderson
> >> = Rv-6A=20 N494BW Rotary Powered
> >> Matthews, NC
> = >>=20 eanderson@carolina.rr.com
> >>
> >> Ed =
>=20 >>
> >>
> >>
> >> ----- = Original Message -----
> >> From: Chuck Dunlap
> = >> To: Rotary motors in aircraft
> >> Sent: = Wednesday,=20 March 15, 2006 10:44 PM
> >> Subject: [FlyRotary] Motor = teardown results
> >>
> >>
> = >>=20
> >>
> >> I finally got time to get my = failed 13b=20 apart. The rear rotor was
> >> missing
> > = one apex=20 seal, the other 2 were intact but jammed due to the fragments of =
>=20 > the broken one. The rotor housing has the classic chatter marks = all=20
> > around.
> > Doing a Google of "13B apex seal = chatter" results in plenty of examples of
> > this failure = mode.=20 Apparently the chatter is from the natural resonant
> > = frequency=20 of the seal, it eventually fatigues the seal causing failure. =
>=20 >> The front rotor was in good shape, but the housing had the = same=20 chatter
> > marks, but not as severe as the rear rotor. = The front=20 rotor housing was
> > brand
> > new 150 hours = ago when I=20 rebuilt this motor after the Grand Canyon forced
> > = landing. At=20 that time the good rotor housing had slight chatter marks but =
> >=20 I
> > reused it. The front rotor was destroyed at that = time due to=20 foreign
> > object
> & gt; entering the rotor. =
>=20 >> Both rotors were missing the corner seal rubber plugs on = the side=20 with
> > the short apex seal segment. Perhaps the small = segment=20 vibrated more,
> > disintegrating the rubber seals? =
>=20 >> The first 260 hours of flying my rotary bird was with stock = 3-piece=20
> >> seals,
> > and I never saw any chatter = marks.=20 The last 250 hours has been flown with
> > 2
> > = piece=20 seals and now I have chatter marks .
> >> I now have = Tracy's 2=20 piece apex seals and I wonder how they will
> >> = perform,=20
> > it appears that the heavier weight of the 2 piece = seals puts=20 the resonant
> > frequency in the cruising range of = 6000RPM?=20
> >>
> >> Chuck Dunlap
> >> = RV6 13B=20
> >>
> >>
> >>
> >=20 ----------------------------------------------------------------- =
>=20 > - ------------
> >>
> >>
> = >> --=20
> >> Homepage: http://www.flyrotary.com/
> = >>=20 Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ =
>=20 >>
> >>
> >
> > Doug Mueller =
>=20 > RX-6 13BT
> > N900DM
> > Boulder = City(61B),Nevada=20
> >
> >
> > --
> > Homepage: = http://www.flyrotary.com/
> > Archive and UnSub:=20 http://mail.lancaironline.net/lists/flyrotary/
> > =
>=20
>
>
> --
> Homepage: = http://www.flyrotary.com/=20
> Archive and UnSub: = http://mail.lancaironline.net/lists/flyrotary/=20
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