X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "Stephen Izett stephen.izett@gmail.com" Received: from pmg.Logan.com ([207.170.160.161] verified) by logan.com (CommuniGate Pro SMTP 6.4.0) with ESMTPS id 3785959 for flyrotary@lancaironline.net; Sun, 12 Jan 2025 17:48:04 -0500 Received: from pmg.Logan.com (localhost [127.0.0.1]) by pmg.Logan.com (Proxmox) with ESMTP id F3489B163 for ; Sun, 12 Jan 2025 17:48:03 -0500 (EST) Received-SPF: pass (gmail.com ... _spf.google.com: Sender is authorized to use 'stephen.izett@gmail.com' in 'mfrom' identity (mechanism 'include:_netblocks.google.com' matched)) receiver=pmg.Logan.com; identity=mailfrom; envelope-from="stephen.izett@gmail.com"; helo=mail-pl1-f176.google.com; client-ip=209.85.214.176 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) by pmg.Logan.com (Proxmox) with ESMTPS for ; Sun, 12 Jan 2025 17:48:03 -0500 (EST) Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-2166360285dso62404415ad.1 for ; Sun, 12 Jan 2025 14:48:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1736722082; x=1737326882; darn=lancaironline.net; h=message-id:in-reply-to:to:references:date:subject:mime-version:from :from:to:cc:subject:date:message-id:reply-to; bh=iVy8+aIL6EpAIcjFXNbbBa3b3YUm4gHEIO3frXr9gRg=; b=T/giZ+m8dozvh1AFLOXqgOyb2m38d6SRf8Jeztai1RHje9f4DUpXrPIr08ecxqTSqW DTk8m4AgRMZo5l8CM9ULE7koBZZ4MY9LzRLMGA2zBuXzoqLYci6o/FswhAU5xBQnqfNo e1A0dSwMPiCNQZFSdfImI4UAU6oFtD35mR4Hc+UGC6xHwEPt44BhaBeKiSjM4ufNDA9A SH5iqzAcCPUYrAtyTd0iLU+dY7w6oKhnfg2pudNTs1AjBn+82kL4CjbCew4lWEEsP+Qh yiN5x+e50mrzLdIDnnFUCGygZwXalrjGUFPnnd89tLsmIr6CZtdYAVaPKx/qtt5A/jSo 8ZXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736722082; x=1737326882; h=message-id:in-reply-to:to:references:date:subject:mime-version:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=iVy8+aIL6EpAIcjFXNbbBa3b3YUm4gHEIO3frXr9gRg=; b=dMZpokbocBjy2ZmkYgaamAYMXy5NLbcU+77KPljggpJhpF9q62eGxc+is5hwY87Ov5 afKn5HiC+mFcU9rPJ95373Y0kRj3dpJysA25RHCDfaFQaBuvB1f7B96f/n5/DDoqIkia Y7sIyptpA8bYGNG0PqJZ5hBUGRMQEVQ3a1ycV63iFmcXA1QpyxkIZZnpyjP6OezOSWmF lYfw0hic5NGfGVjw0OtlinmzpmBbPF2Q1KrCpmKev9MObgeJJZAJnJoYuhd1LAvjOiwS bH8CRd3Zvm8GJ59MsLt3paOamVN8zLiccgom2Mq2X/3Vw5BmPeiE7+gkZ6hjM/tBdax5 /BCQ== X-Gm-Message-State: AOJu0YwHo7Qheyx/oX+RNu5qAzSiGvMzhm/FitY2jK4Cs9JJ66nLSLBs sKz2ONGfUKFaaZBKslm94dk7klSLIOl2x8gBNBG7cL4IfvbbKMwOXVyPPg== X-Gm-Gg: ASbGncuIkAL0wCwHUHnjPVRTqrmvuUlQOln4ifLXi+1ZCg85wlz6N50xe4DIsZRckeN yFjJFyGgXhzbQ92F7EhSKIRxS/6dIIuaj8AXrBvoLclfn/DpP1+5aaK+LQbIaWr3qY6xWsku4f+ qkSCWX3YCvvqf/EuXi1iHroSqJ545wV3HqhYgOzAchIdkOaITvULSGhpj9Owpxg5InaYCB2zVTJ 5U4yNxefGAJ8bmjBwszlZAygKSKn6cSMWqy0U5lyiPpqqyF602uGVkZRaLG1bBeSjTaMXdzKJ0Z aAMZRz67Fgql+26rRA== X-Google-Smtp-Source: AGHT+IFEZf1pbR4URk3rQ7JHUTShxkliYgpdDikKnlqWpf+pwQSg0ZSGPrpsKUX8ENONZyJxKiufLA== X-Received: by 2002:a17:902:d50d:b0:216:2abc:194f with SMTP id d9443c01a7336-21a83fb1563mr288613405ad.40.1736722081705; Sun, 12 Jan 2025 14:48:01 -0800 (PST) Received: from smtpclient.apple ([2001:8004:1080:9e9:e89e:19d0:2717:a9df]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21a9f256fe3sm42978805ad.243.2025.01.12.14.48.00 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 12 Jan 2025 14:48:01 -0800 (PST) Content-Type: multipart/alternative; boundary="Apple-Mail=_F8540CBF-780D-45C9-98E7-3DB2422AF827" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.200.121\)) Subject: Re: [FlyRotary] Flexplate cracks Date: Mon, 13 Jan 2025 06:47:47 +0800 References: To: Rotary motors in aircraft In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3826.200.121) X-SPAM-LEVEL: Spam detection results: 0 AWL 1.645 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% 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 FREEMAIL_REPLY 1 From and body contain different freemails HTML_MESSAGE 0.001 HTML included in message RCVD_IN_DNSWL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to DNSWL was blocked. 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See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [avcdn.net] --Apple-Mail=_F8540CBF-780D-45C9-98E7-3DB2422AF827 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Thanks Dave. I=E2=80=99ll have a look at what available. Steve Izett > On 13 Jan 2025, at 5:59=E2=80=AFam, David Leonard wdleonard@gmail.com = wrote: >=20 > I used a chromolloy flywheel. Inexpensive and not much more weight = than aluminum. >=20 > Dave Leonard=20 >=20 > On Sun, Jan 12, 2025, 1:53=E2=80=AFPM Charlie England = ceengland7@gmail.com = > = wrote: >> Thanks for those images. Looks like a larger AL disc could replace = part of the spacer's thickness and bolt to the holes where the damper = plate mounted. Does that look reasonable 'in person'? >>=20 >> If feasible, I'm thinking that it could serve two purposes; raise = resonant freq of the flexplate to a safe area, and add mass close to = what would be in an AL flywheel (they're getting hard to find used, and = new ones are really expensive). >>=20 >> I suspect the extra rotating mass on the Eshaft is needed (or at = least a good idea).=20 >>=20 >> Charlie >>=20 >> = Virus-free.www.avast.com = = >> On Sat, Jan 11, 2025 at 6:45=E2=80=AFPM Steven W. Boese = SBoese@uwyo.edu > wrote: >>> When the Flexplate is bolted to the eccentric shaft without the = damper plate it rings with frequencies of around 320 and 1340 Hz. It = doesn=E2=80=99t ring with the damper attached. >>> This gives the possibility that the Flexplate without the damper may = resonate being excited by the engine harmonics at rpm ranges normally = used in flight. Such resonance could accelerate Flexplate cracking. = For this reason, I would be reluctant to eliminate the damper while = retaining the Flexplate. Converting to Tracy=E2=80=99s recent solid = coupling design may best be done by also replacing the Flexplate with a = manual transmission flywheel. >>>=20 >>> The photo shows a couple of possibilities to convert to a solid = coupling while retaining the original splined input shaft. The = thickness of the aluminum spacer or the steel part can be adjusted to = accommodate the thickness of a flywheel. >>>=20 >>> Steve Boese=20 >>>=20 >>> --Apple-Mail=_F8540CBF-780D-45C9-98E7-3DB2422AF827 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Thanks = Dave.
I=E2=80=99ll have a look at what available.
Steve = Izett

On 13 Jan 2025, at 5:59=E2=80=AFam, David Leonard = wdleonard@gmail.com <flyrotary@lancaironline.net> wrote:

I used a = chromolloy flywheel.  Inexpensive and not much more weight than = aluminum.

Dave = Leonard 

On Sun, Jan = 12, 2025, 1:53=E2=80=AFPM Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:

3D""Virus-free.www.avast.com

On Sat, Jan = 11, 2025 at 6:45=E2=80=AFPM Steven W. Boese SBoese@uwyo.edu <flyrotary@lancaironline.net> = wrote:
When the Flexplate is bolted to the eccentric shaft without the damper = plate it rings with frequencies of around 320 and 1340 Hz.  It = doesn=E2=80=99t ring with the damper attached.
This gives the possibility that the Flexplate without the damper = may resonate being excited by the engine harmonics at rpm ranges = normally used in flight.  Such resonance could accelerate Flexplate = cracking.  For this reason, I would be reluctant to eliminate the damper while retaining the Flexplate.  Converting to Tracy=E2=80= =99s recent solid coupling design may best be done by also replacing the = Flexplate with a manual transmission flywheel.

The photo shows a couple of possibilities to convert to a solid = coupling while retaining the original splined input shaft.  The = thickness of the aluminum spacer or the steel part can be adjusted to = accommodate the thickness of a flywheel.

Steve Boese 

<image0.jpeg>

= --Apple-Mail=_F8540CBF-780D-45C9-98E7-3DB2422AF827--