X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "David Leonard wdleonard@gmail.com" Received: from pmg.Logan.com ([207.170.160.161] verified) by logan.com (CommuniGate Pro SMTP 6.4.0) with ESMTPS id 3784038 for flyrotary@lancaironline.net; Fri, 10 Jan 2025 20:35:36 -0500 Received: from pmg.Logan.com (localhost [127.0.0.1]) by pmg.Logan.com (Proxmox) with ESMTP id 0B88A2F621 for ; Fri, 10 Jan 2025 20:35:36 -0500 (EST) Received-SPF: pass (gmail.com ... _spf.google.com: Sender is authorized to use 'wdleonard@gmail.com' in 'mfrom' identity (mechanism 'include:_netblocks.google.com' matched)) receiver=pmg.Logan.com; identity=mailfrom; envelope-from="wdleonard@gmail.com"; helo=mail-pj1-f44.google.com; client-ip=209.85.216.44 Received: from mail-pj1-f44.google.com (mail-pj1-f44.google.com [209.85.216.44]) by pmg.Logan.com (Proxmox) with ESMTPS for ; Fri, 10 Jan 2025 20:35:35 -0500 (EST) Received: by mail-pj1-f44.google.com with SMTP id 98e67ed59e1d1-2ef72924e53so4390489a91.3 for ; Fri, 10 Jan 2025 17:35:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1736559328; x=1737164128; darn=lancaironline.net; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=bJxr7l9KTNzJ9mxbC+N/VcOrf3aOGXH037LRDiGHRyU=; b=OHkkn7c3waSJfevEwxwWAwR6jGoFbW4xhXIRFy9CaI6jpcmkZ59b4wjEFGl6y1fkHp HEcd75TDYl5Wv5A1jrnnaFKDUiek3hbvJ/olxlhl1XiQB15OfBtacu09sSjhhMWlACsV Uv7Adk1jACpJsHv0boFpEpFXqn0zwfNTnKdNLQSLxOUn+0IN5g1oBcPdWnYyUg/a4JCq EcJlG/romzR5tDKpPgr2U0CQhN53Vt/ejlQ6uYHXRP4EF4Zbd2+v7+7Z/2YHKrT9CHIL KGRQJguOZJcKuXs9vBM7tX02kQfKlztxEpeB+kWIGCSAaW2w39JdFnoeKgjv8LjWPaRc lDhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736559328; x=1737164128; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=bJxr7l9KTNzJ9mxbC+N/VcOrf3aOGXH037LRDiGHRyU=; b=BWDrkfj5uoDohWDuIvkqXDfPvR1Uk0FjMXPsXOdLmg6Id4g9yBPUdnL9eJ4JkVKeVB Fe71RcF/RwTDtW1sIqjDEPDsMfOp4AZH3Qo6f2VNI2KSOkVoax2Fa9IPS3f5wpp1ZZEu jw5JDZhmHCRcy0lagLVJVkC1XRCEc+PXBqtxu0MmL2oEF+UnB4ekq1ZuUq9fNOe3tgjk ytLCCkdvFsY5T0f2spyJqC17c5P5zmHsZ8WDmMb6C1xyQNqDknSKakiSPnxmUbjLv/T5 3k96cvlJPHnG64+vfh/e63Zb5FdpvBafTS28fYyb069ilyc44VcJuzVNRfDaxErXuO9D aFsA== X-Gm-Message-State: AOJu0Yzik+Kc7ulA+QVF0+aTJWxKa89O/sKTxPgyZxCkHkSXbVPv0Q6A ibh7a+ioPILJ2gcYafzG5y8v5y7wdw0Kp2GDfxcYep1wrXV7S0e0Dd3aISRlH2ocxRYaaslTfFE l1c7RfIvLvWLmaohbiWg7ukgj7lFYiQ== X-Gm-Gg: ASbGnctrbd99kJuFHwQjF+1uQ5K/GWjP2QzBMyOHiMDkUaAYkQmKZuCFvp+wH3C5k0M 6oQYu/C8tZ+cF+PNW6k8WnugL2YM6lZGNzrP28/9h5Zka1k2HjrUNK4Nfe2OvAOE= X-Google-Smtp-Source: AGHT+IFcMCCCkM3N1xhF+iBDOgvU0L74IluY1jb/l/wSBrKdxs4JNPD9ySD4KsZ7xeMqgS9tfArSHELUT2dkFArhKME= X-Received: by 2002:a17:90b:4ed0:b0:2ee:6736:8512 with SMTP id 98e67ed59e1d1-2f548eb3229mr22726717a91.12.1736559327709; Fri, 10 Jan 2025 17:35:27 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Date: Fri, 10 Jan 2025 17:35:16 -0800 X-Gm-Features: AbW1kvZez5kBZxE4QzOLImn_LmPk_BSqbMr5c-agzRWRVBM9GJDLh4Zt6uStHBM Message-ID: Subject: Re: [FlyRotary] Re: Flexplate cracks To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="000000000000dc1039062b643987" X-SPAM-LEVEL: Spam detection results: 0 AWL -0.860 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% CBJ_GiveMeABreak 1.75 Messages with consecutive break characters DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature DKIM_VALID_AU -0.1 Message has a valid DKIM or DK signature from author's domain DKIM_VALID_EF -0.1 Message has a valid DKIM or DK signature from envelope-from domain DMARC_PASS -0.1 DMARC pass policy FREEMAIL_FROM 0.001 Sender email is commonly abused enduser mail provider HTML_MESSAGE 0.001 HTML included in message KAM_MXURI 1.5 URI begins with a mail exchange prefix, i.e. mx.[...] RCVD_IN_DNSWL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to DNSWL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#DnsBlocklists-dnsbl-block for more information. RCVD_IN_MSPIKE_H3 0.001 Good reputation (+3) RCVD_IN_MSPIKE_WL 0.001 Mailspike good senders RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [flyrotary.com,lancaironline.net] WEIRD_PORT 0.001 Uses non-standard port number for HTTP --000000000000dc1039062b643987 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable in the car, the flex plates are only used to carry the torque from the starter and are not designed to transmit the output of the engine. in our setups. We have adapted this flex plate to transmit the entire output of the engine which it apparently is not up to. I had my rd1-b seize up a bearing during a race at Reno which may have been due to gyroscopic forces, but I think the flex plate issue just needs to be fixed by replacing all the flex plates with proper flywheels. Dave Leonard On Fri, Jan 10, 2025, 1:45=E2=80=AFAM Le Roux Breytenbach breytenbachleroux@gmail.com wrote: > What i can rember was this also a topic on the late Paul L group > discussion. > Maybe Dave Leonard can chime in - think more that it was gyroscopic force= s > that craked the plates > Maybe i can find the photos and topic in my old mails > > Sent from my iPhone > Le Roux Breytenbach > > On 10 Jan 2025, at 08:13, Andrew Martin andrew@martinag.com.au < > flyrotary@lancaironline.net> wrote: > > =EF=BB=BF > Maybe some of the cracking flexplates are resulting from starting issues, > the starter motor can hammer the ring gear if not meshing correctly or if > engine misfires on start. may explain why so many flexplates come > pre-cracked from the wreckers. > > Andrew > > > > > > On Fri, 10 Jan 2025 at 11:32, Stephen Izett stephen.izett@gmail.com < > flyrotary@lancaironline.net> wrote: > >> Hi M >> >> I was wondering the same thing. >> >> What I discovered first of all was that flex plates are designed to flex >> (funny that) and cracking is not limited to our setup. >> There are companies that specialise in stronger flex plates, particularl= y >> for modified and higher horsepower engines. >> >> Since our engines are being used at a higher horsepower per unit time an= d >> therefore higher stress (assumption) perhaps our setup could be likened = to >> race applications. >> But then our hours of use would be significantly lower (assumption) than >> an average vehicle, but perhaps not a race application. >> Is the cracking we are seeing consistent with race applications? But the= y >> dont race automatics, do they? >> >> So my take on this is that perhaps the flexing of the plate in our setup >> is to some extent higher than OEM. >> >> Our options seem to be: >> 1. Replacing the OEM flex plate with a stronger part. Steve B being the >> latest going down that track and in his case also removing the rubber >> isolation in the process. >> 2. Connect direct to the eccentric shaft and therefore taking the stress >> off the Flex Plate doing away with the damping mechanism which Tracy did= , >> and perhaps is still doing. Would be real nice to know. >> >> Like M, I would appreciate hearing what others know or are thinking or >> doing. >> >> Steve Izett >> >> >> >> >> >> >> >> >> >> >> >> >> > On 10 Jan 2025, at 2:15=E2=80=AFam, Marc Wiese cardmarc@charter.net < >> flyrotary@lancaironline.net> wrote: >> > >> > Has the cause of these cracks been uncovered, and if so, what is the >> current thinking on it? An AL racing plate? >> > M >> > Sent from my iPhone >> > >> >> On Jan 9, 2025, at 1:31=E2=80=AFAM, Steven W. Boese SBoese@uwyo.edu < >> flyrotary@lancaironline.net> wrote: >> >> >> >> =EF=BB=BFSteve, >> >> >> >> I didn=E2=80=99t see the cracks prior to disassembly and doubt that t= hey could >> have been seen on the counterweight side very well -if at all- when >> assembled. >> >> >> >> I replaced the Flexplate with a steel flywheel about a year ago. >> Since then, I replaced the four rubber dampers with machined aluminum di= scs >> giving a solid connection and then dynamically balanced the system. Thi= s >> was done because maintaining a dynamic balance wasn=E2=80=99t possible w= ith the >> dampers. Only a few hours of flight have occurred in this configuration= so >> far and there has been no indication of problems resulting from this cha= nge. >> >> >> >> Steve Boese >> >> >> >>> On Jan 8, 2025, at 11:03=E2=80=AFPM, Stephen Izett stephen.izett@gma= il.com < >> flyrotary@lancaironline.net> wrote: >> >>> >> >>> =EF=BB=BF=E2=97=86 This message was sent from a non-UWYO address. Pl= ease exercise >> caution when clicking links or opening attachments from external sources= . >> >>> >> >>> >> >>> Hi Steve >> >>> >> >>> Is this recent then? >> >>> >> >>> I=E2=80=99m not able to get to my aircraft at present to check my fl= ex plate >> which has probably seen 50 hours of service. >> >>> >> >>> Was it possible to see these cracks assembled? >> >>> >> >>> I would appreciate your reflections on Tracys latter choice to remov= e >> the damper, and particularly when using a timber/glass prop such as an M= T. >> >>> >> >>> It would be great to have an update and current info from Tracy >> regarding his no damper hours if anyone can contact him. >> >>> >> >>> Very helpful, thanks again Steve >> >>> >> >>> Steve >> >> >> >> -- >> >> Homepage: http://www.flyrotary.com/ >> >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> > >> > >> > >> > -- >> > Homepage: http://www.flyrotary.com/ >> > Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> >> >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> > --000000000000dc1039062b643987 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
in the car, the flex plates are only used to carry the to= rque from the starter and are not designed to transmit the output of the en= gine. in our setups. We have adapted this flex plate to transmit the entire= output of the engine which it apparently is not up to.=C2=A0

I had my rd1-b seize up a bearing during a = race at Reno which may have been due to gyroscopic forces, but I think the = flex plate issue just needs to be fixed by replacing all the flex plates wi= th proper flywheels.=C2=A0

Dave Leonard=C2=A0

On Fri, Jan 10, 2025, 1:45= =E2=80=AFAM Le Roux Breytenbach breytenbachleroux@gmail.com <flyrotary@lancaironline.net> wrote:
What i can rember was this also a top= ic on the late Paul L group discussion.
Maybe Dave Leonard can chime in= - think more that it was gyroscopic forces that craked the plates
Maybe i can find the photos and topic in my old mails

Sen= t from my iPhone
Le Roux Breytenbach=C2=A0
=
On 10 Jan 2025, at 08:13, Andrew Martin a= ndrew@martinag.com.au <flyrotary@lancaironline.net> = wrote:

=EF=BB=BF
Maybe some of the cracking flexplates are r= esulting from starting issues, the starter motor can hammer the ring gear i= f not meshing correctly or if engine misfires on start. may explain why so = many flexplates come pre-cracked from the wreckers.

Andrew





On Fri, 10 Jan 2025 at 11:32, Stephen Izett= stephen.izett@gmail.com <flyrotary@lancaironline.net<= /a>> wrote:
H= i M

I was wondering the same thing.

What I discovered first of all was that flex plates are designed to flex (f= unny that) and cracking is not limited to our setup.
There are companies that specialise in stronger flex plates, particularly f= or modified and higher horsepower engines.

Since our engines are being used at a higher horsepower per unit time and t= herefore higher stress (assumption) perhaps our setup could be likened to r= ace applications.
But then our hours of use would be significantly lower (assumption) than an= average vehicle, but perhaps not a race application.
Is the cracking we are seeing consistent with race applications? But they d= ont race automatics, do they?

So my take on this is that perhaps the flexing of the plate in our setup is= to some extent higher than OEM.

Our options seem to be:
1. Replacing the OEM flex plate with a stronger part. Steve B being the lat= est going down that track and in his case also removing the rubber isolatio= n in the process.
2. Connect direct to the eccentric shaft and therefore taking the stress of= f the Flex Plate doing away with the damping mechanism which Tracy did, and= perhaps is still doing. Would be real nice to know.

Like M, I would appreciate hearing what others know or are thinking or doin= g.

Steve Izett












> On 10 Jan 2025, at 2:15=E2=80=AFam, Marc Wiese cardmarc@charter.net<= /a> <flyrotary@lancaironline.net> wrote:
>
> Has the cause of these cracks been uncovered, and if so, what is the c= urrent thinking on it? An AL racing plate?
> M
> Sent from my iPhone
>
>> On Jan 9, 2025, at 1:31=E2=80=AFAM, Steven W. Boese SBoese@uwyo.edu <flyrotary@lancaironline.net> wrote:
>>
>> =EF=BB=BFSteve,
>>
>> I didn=E2=80=99t see the cracks prior to disassembly and doubt tha= t they could have been seen on the counterweight side very well -if at all-= when assembled.
>>
>> I replaced the Flexplate with a steel flywheel about a year ago.= =C2=A0 Since then, I replaced the four rubber dampers with machined aluminu= m discs giving a solid connection and then dynamically balanced the system.= =C2=A0 This was done because maintaining a dynamic balance wasn=E2=80=99t p= ossible with the dampers.=C2=A0 Only a few hours of flight have occurred in= this configuration so far and there has been no indication of problems res= ulting from this change.
>>
>> Steve Boese
>>
>>> On Jan 8, 2025, at 11:03=E2=80=AFPM, Stephen Izett stephe= n.izett@gmail.com <flyrotary@lancaironline.net> wrot= e:
>>>
>>> =EF=BB=BF=E2=97=86 This message was sent from a non-UWYO addre= ss. Please exercise caution when clicking links or opening attachments from= external sources.
>>>
>>>
>>> Hi Steve
>>>
>>> Is this recent then?
>>>
>>> I=E2=80=99m not able to get to my aircraft at present to check= my flex plate which has probably seen 50 hours of service.
>>>
>>> Was it possible to see these cracks assembled?
>>>
>>> I would appreciate your reflections on Tracys latter choice to= remove the damper, and particularly when using a timber/glass prop such as= an MT.
>>>
>>> It would be great to have an update and current info from Trac= y regarding his no damper hours if anyone can contact him.
>>>
>>> Very helpful, thanks again Steve
>>>
>>> Steve
>>
>> --
>> Homepage:=C2=A0 http://www.flyrotary.com/
>> Archive and UnSub:=C2=A0 =C2=A0http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
>
> --
> Homepage:=C2=A0 http://www.flyrotary.com/
> Archive and UnSub:=C2=A0 =C2=A0http://mail.lancaironline.net:81/lists/flyrotary/List.html



--
Homepage:=C2=A0 http://www.flyrotary.com/
Archive and UnSub:=C2=A0 =C2=A0= http://mail.lancaironline.net:81/lists/flyrotary/List.html
--000000000000dc1039062b643987--