X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "Andrew Martin andrew@martinag.com.au" Received: from pmg.Logan.com ([207.170.160.161] verified) by logan.com (CommuniGate Pro SMTP 6.4.0) with ESMTPS id 3782633 for flyrotary@lancaironline.net; Fri, 10 Jan 2025 01:13:17 -0500 Received: from pmg.Logan.com (localhost [127.0.0.1]) by pmg.Logan.com (Proxmox) with ESMTP id 883332840E for ; Fri, 10 Jan 2025 01:13:17 -0500 (EST) Received-SPF: none (martinag.com.au: No applicable sender policy available) receiver=pmg.Logan.com; identity=mailfrom; envelope-from="andrew@martinag.com.au"; helo=mail-oi1-f172.google.com; client-ip=209.85.167.172 Received: from mail-oi1-f172.google.com (mail-oi1-f172.google.com [209.85.167.172]) by pmg.Logan.com (Proxmox) with ESMTPS for ; Fri, 10 Jan 2025 01:13:15 -0500 (EST) Received: by mail-oi1-f172.google.com with SMTP id 5614622812f47-3eb7ecc3c54so914861b6e.0 for ; Thu, 09 Jan 2025 22:13:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=martinag-com-au.20230601.gappssmtp.com; s=20230601; t=1736489594; x=1737094394; 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=yBjXfOEwTRmrwR4yWsT2xT1zJjv1Z1uPE4PCEQIJV/E=; b=lmCOISlwwRDF89ileolyGjiVCIqSG4uAx9P5Vej3Lp1ctatjOeG9gns9nsDWLNhyzK u817mkDwYVJ0BTpC7W2R7NxKC8D+mQkxTssG7S183lFKadgaaOSamVR5VBnvhll9f0fk e7HVkV1ZsRQ4+RNGuuLxhfNnGVeqs/J3fTfMMkVqygHo0/J2uLToJyGLc/1+547JRvzR rga6dpLIi9soLdaH/RGzH+6ISiG9hFZQtj04B095GJ5j3SavtJ0TKo4U0SWWCoEVDHyH i+H2jpb3mK+lBQ9vjEbkm2ZQ6rw8+It/i6tJ5CVRCe2QZWDUKC3H+bX3fUgHv5NGjVzB 7HjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736489594; x=1737094394; 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=yBjXfOEwTRmrwR4yWsT2xT1zJjv1Z1uPE4PCEQIJV/E=; b=Vchl8ekBssHkEdHc0FBsDC4LOKqAxfGePAsSQOWSlKx0WiTAUuCduAWjoVt9unHE1s XAqotTMo1eRRx0PQO/h1WH+PFqeyBHy2UlTUODK/+W9f5u2TL6iNhtZqZjOV99k9z7lZ 88GZ4a+RqVnyaw8nVNj0wdaZiFPqBbLJVFZ8qdhLQSeAZ/dBZ0/wD358hqOZ1CuxPZXE QwYyKQ4MKFMJum8SobIi5h16/pSHAuCEdH3y/xn/foNc7e1xDzpvujmsiHhJSgMkV+0r yLQdT9KcPR5AIGpn+/D4rqMA9J/1sPdSK/7fpqCgBb4iXmmjBGExw+ZOPMmCZRG1yQq9 RmGw== X-Gm-Message-State: AOJu0YwgxRQs7qt6lN9RmfTeyN6OjVToESk12DP0/c2wO82Nmxx8UQTx 4KCNquUDR5Wy8pt6hqm4f5R/wc+310Jm+jKaYmxWkdzgH97NVpOrh3rZ9Nq2LDzLTcJkDI+4Tdc dw2bxnYmjn8CfUVMRMBR0705n0iQROYhSIrXmV3Au1JwZJRQ= X-Gm-Gg: ASbGncvEYmqx+MOtWNA48lUc3FYfqgUprrkSiYpM6S4Vqfsnr6IVxKRLp2qJjnu6DzU IMQbvfp+6MXA3qzjtaWWNWOTrRC0c3uB5cqg= X-Google-Smtp-Source: AGHT+IFFVqwT5efJ22Z4b6dLHIMq8XOIFnmXbAk+Eyd/KZK9Jfb3BCyxe5s5NJR6s+l3llvJLgOPFaIVqKsWw6tiVBI= X-Received: by 2002:a05:6820:178f:b0:5f2:d964:b36b with SMTP id 006d021491bc7-5f730987b1dmr4815134eaf.5.1736488196527; Thu, 09 Jan 2025 21:49:56 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Date: Fri, 10 Jan 2025 13:49:19 +0800 X-Gm-Features: AbW1kvYWKoJ8zikuersUcX845onX_ARYYCVMu44udiXle9nzdA6s-JsxVQftDWI Message-ID: Subject: Re: [FlyRotary] Re: Flexplate cracks To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="0000000000001c7659062b53aa7d" X-SPAM-LEVEL: Spam detection results: 0 AWL -2.099 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 DMARC_MISSING 0.1 Missing DMARC policy HTML_MESSAGE 0.001 HTML included in message KAM_LINEPADDING 1.2 Spam that tries to get past blank line filters KAM_MXURI 1.5 URI begins with a mail exchange prefix, i.e. mx.[...] RCVD_IN_MSPIKE_H2 -0.001 Average reputation (+2) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_NONE 0.001 SPF: sender does not publish an SPF Record WEIRD_PORT 0.001 Uses non-standard port number for HTTP --0000000000001c7659062b53aa7d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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, particularly > for modified and higher horsepower engines. > > Since our engines are being used at a higher horsepower per unit time and > therefore higher stress (assumption) perhaps our setup could be likened t= o > 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 they > 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 th= ey 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. Sinc= e > then, I replaced the four rubber dampers with machined aluminum discs > giving a solid connection and then dynamically balanced the system. This > was done because maintaining a dynamic balance wasn=E2=80=99t possible wi= th 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 chan= ge. > >> > >> Steve Boese > >> > >>> On Jan 8, 2025, at 11:03=E2=80=AFPM, Stephen Izett stephen.izett@gmai= l.com < > flyrotary@lancaironline.net> wrote: > >>> > >>> =EF=BB=BF=E2=97=86 This message was sent from a non-UWYO address. Ple= ase 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 fle= x 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 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 > --0000000000001c7659062b53aa7d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Maybe some of the cracking flexplates are resulting f= rom starting issues, the starter motor can hammer the ring gear if not mesh= ing correctly or if engine misfires on start. may explain why so many flexp= lates come pre-cracked from the wreckers.

Andrew



=


On Fri, 10 Jan 2025 at 11:32, S= tephen Izett stephen.izett@gmail= .com <flyrotary@lanca= ironline.net> wrote:
Hi 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 <flyrotary@lancaironli= ne.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@lancaironlin= e.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 stephen.izett@gmail.com <fly= rotary@lancaironline.net> wrote:
>>>
>>> =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=A0ht= tp://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



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