X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f180.google.com ([209.85.214.180] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTPS id 5053711 for flyrotary@lancaironline.net; Sat, 16 Jul 2011 08:38:46 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.180; envelope-from=rwstracy@gmail.com Received: by iwn9 with SMTP id 9so1707171iwn.25 for ; Sat, 16 Jul 2011 05:38:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=27sO1QP3FzzWr2oqOHxk4CjSpgTlba19qYSjmA7eAH4=; b=uRi4QM6G5ndbx/LH2IfBDthEDKRF7qHp2t01/GfiDYk8ijo23u1NoRwS0dGLWm40K+ J/XWDkXNF7lTTPlHTz+QxrdkRjNzao+SGWWpryWXRx2Xn+uk3/H1Tr99xk1YoS22Mw1S VLgnjsCIsxk9xCCVHdv4D++CBuzho9BhKcAo4= Received: by 10.42.209.199 with SMTP id gh7mr4429506icb.480.1310819890267; Sat, 16 Jul 2011 05:38:10 -0700 (PDT) Return-Path: Received: from [10.0.1.3] (99-197-145-127.cust.wildblue.net [99.197.145.127]) by mx.google.com with ESMTPS id a9sm2610102icy.18.2011.07.16.05.38.02 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 16 Jul 2011 05:38:08 -0700 (PDT) Subject: Re: [FlyRotary] Re: Flex Plate Failure - Improvements References: From: Tracy Content-Type: multipart/alternative; boundary=Apple-Mail-16--347283863 X-Mailer: iPad Mail (8F191) In-Reply-To: Message-Id: Date: Sat, 16 Jul 2011 08:37:46 -0400 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (iPad Mail 8F191) --Apple-Mail-16--347283863 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Interesting ! The failure might have been the same as on the Blanton V6 dr= ives where the flex plate is used only for the ring gear & starter. That i= s apparently the worst case scenario for flex plates, I.e., no load (or damp= ing of any kind) at all. They apparently flutter and self destruct. Tracy Sent from my iPad On Jul 15, 2011, at 11:55 PM, Lehanover@aol.com wrote: > I made up a small steel flywheel to fit the counter-weight, but only big e= nough to bolt on a 5 1/2" Tilton dual disc clutch pack. I used a flex plate o= nly to carry the starter ring. It did not occur to me to try to transmit tor= que through the flex plate. I had one of my drivers miss a shift and reved t= o the moon. The conical shape of the flex plate went dead flat. Bits of ring= gear around the welds hug on and nearly cut the bell housing into two piece= s. The remaining pieces were dribbled out onto the track for others to deal w= ith. The flange the ring gear sat on was turned to 45 degrees. After that I T= IGed the whole gear to the flex plate. They do fail in cars, that is why you= can buy one with the cracks already installed. There used to be a doubler p= late on top of the bolt circle to spread out the strain of the mounting bolt= s and reduce cracking. Are those still being used? > =20 > Probably not a problem for airplanes, but I would not transfer torque with= one. > =20 > Lynn E. Hanover > =20 > =20 > =20 > In a message dated 7/15/2011 2:42:02 P.M. Paraguay Standard Time, rwstracy= @gmail.com writes: > I'm still in analysis mode on this myself. >=20 > So far the possibilities are: >=20 > 1. The flex plate may have been warped when installed ( I bought several t= hat were) I think the standard should be close to zero runout or wobble on t= he flexplate in view of this failure. >=20 --Apple-Mail-16--347283863 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=utf-8

Interesting ! The failure might have been the same as on the Blanton V6 drives where the flex plate is used only for the ring gear & starter. That is apparently the worst case scenario for flex plates, I.e., no load (or damping of any kind) at all. They apparently flutter and self destruct.

Tracy

Sent from my iPad

On Jul 15, 2011, at 11:55 PM, Lehanover@aol.com wrote:

I made up a small steel flywheel to fit the counter-weight, but only big enough to bolt on a 5 1/2" Tilton dual disc clutch pack. I used a flex plate only to carry the starter ring. It did not occur to me to try to transmit torque through the flex plate. I had one of my drivers miss a shift and reved to the moon. The conical shape of the flex plate went dead flat. Bits of ring gear around the welds hug on and nearly cut the bell housing into two pieces. The remaining pieces were dribbled out onto the track for others to deal with. The flange the ring gear sat on was turned to 45 degrees. After that I TIGed the whole gear to the flex plate. They do fail in cars, that is why you can buy one with the cracks already installed. There used to be a doubler plate on top of the bolt circle to spread out the strain of the mounting bolts and reduce cracking. Are those still being used?

Probably not a problem for airplanes, but I would not transfer torque with one.

Lynn E. Hanover

In a message dated 7/15/2011 2:42:02 P.M. Paraguay Standard Time, rwstracy@gmail.com writes:

I'm still in analysis mode on this myself.

So far the possibilities are:

1. The flex plate may have been warped when installed ( I bought several that were) I think the standard should be close to zero runout or wobble on the flexplate in view of this failure.

--Apple-Mail-16--347283863--