X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 27 Jul 2013 18:36:27 -0400 Message-ID: X-Original-Return-Path: Received: from omr-d07.mx.aol.com ([205.188.109.204] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with ESMTPS id 6393582 for lml@lancaironline.net; Sat, 27 Jul 2013 17:38:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.109.204; envelope-from=vtailjeff@aol.com Received: from mtaout-db01.r1000.mx.aol.com (mtaout-db01.r1000.mx.aol.com [172.29.51.193]) by omr-d07.mx.aol.com (Outbound Mail Relay) with ESMTP id 37605700000A7 for ; Sat, 27 Jul 2013 17:38:09 -0400 (EDT) Received: from [192.168.1.119] (24-107-98-233.dhcp.stls.mo.charter.com [24.107.98.233]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mtaout-db01.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id A7733E0000BD; Sat, 27 Jul 2013 17:38:08 -0400 (EDT) References: In-Reply-To: Mime-Version: 1.0 (1.0) Content-Type: multipart/alternative; boundary=Apple-Mail-6FD9EFD1-EC62-457A-8133-752E05D1D3B2 X-Original-Message-Id: Content-Transfer-Encoding: 7bit X-Mailer: iPad Mail (9B206) From: vtailjeff@aol.com Subject: Re: [LML] Re: Potential Problem-Engine Vibration X-Original-Date: Sat, 27 Jul 2013 16:38:09 -0500 X-Original-To: Lancair Mailing List x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:461448992:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33c151f43dc0446d X-AOL-IP: 24.107.98.233 --Apple-Mail-6FD9EFD1-EC62-457A-8133-752E05D1D3B2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii How is that mechanically possible? All blades are attached to the same pitch= change mechanism. J Sent from my iPad On Jul 27, 2013, at 12:34 PM, Steve Colwell wrote: > That is a possibility I had not considered, I will ask Hartzell about it. = Another possibility is the movable crankshaft counter weights failing to po= sition correctly. >=20 > Steve Colwell =20 >=20 >=20 > From: Craig Schulze > To: Steve Colwell =20 > Cc: "lml@lancaironline.net" =20 > Sent: Friday, July 26, 2013 7:42 AM > Subject: Re: Potential Problem-Engine Vibration >=20 > It sounds to me that you may have an issue with your prop hub not changing= the pitch exactly the same on all the blades. The vibration you are feeli= ng is one blade taking a larger bite of air and then causing everything to w= obble. It settles in sometimes but when you change the power setting the pi= tch on the prop is adjusted by the hub unevenly. =20 >=20 > Blue Skies, > Craig Schulze > Lancair N73S >=20 >=20 > On Jul 25, 2013, at 1:22 PM, "Steve Colwell" wrote:= >=20 > In the first 40 hours I had vibration so severe it caused stick shake. Th= is > has continued intermittently more or less for almost 400 hours. >=20 > First I found and fixed several Cowl Interference locations, then adjusted= > and notched the hat section of the nose gear door. >=20 > At about 50 hours I paid Barrett to tear down the engine to replace the > Performance pistons (prematurely worn top rings) with stock ECI pistons. > Also found a cracked case. >=20 > We had the Kelly Alternator balanced and rebuilt at a shop recommended by > Bill Bainbridge of B & C. Sorry I can't remember the name, the Legacy fil= e > is in Texas.=20 >=20 > I rounded the leading edges of the elevator counter weights when building s= o > I temporarily squared them off to go back to the stock shape for testing. >=20 > All gear doors were checked in flight with video camera.=20 >=20 > The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web > page. >=20 > Along the way the prop was balanced twice. >=20 > I could not get more that the usual vibration (which always seemed to be t= oo > much) on test flights. Then, unpredictably, vibration magnitude would > increase with power reduction on some later flight. I say unpredictably > because I could not get increased vibration by attempting to duplicate > previous conditions. Let's hope a solution surfaces at Airventure. >=20 > Steve Colwell Legacy RG IO550-N with Hartzell 3 Blade >=20 >=20 >=20 > -----Original Message----- > From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Pau= l > Miller > Sent: Thursday, July 25, 2013 7:22 AM > To: lml@lancaironline.net > Subject: [LML] Re: Potential Problem-Engine Vibration >=20 > Ed Martin's legacy is smooth. Mine has had a lot of annoying vibes as you= > describe but virtually all have been removed with lots of cowling > interference fixes and plug change. Many pilots forget the alternator can= > be a wicked source of vibration and it is almost in the same plane as the > prop. >=20 > The problems I had originally were in that freq range and visible at the > wingtip also. >=20 > Paul >=20 >=20 >=20 --Apple-Mail-6FD9EFD1-EC62-457A-8133-752E05D1D3B2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
How is that mechanically p= ossible? All blades are attached to the same pitch change mechanism.

J

Sent from my iPad

On Jul 27, 2013, a= t 12:34 PM, Steve Colwell <mcmess= 1919@yahoo.com> wrote:

That is a possibility I had= not considered, I will ask Hartzell about it.  Another possibility is t= he movable crankshaft counter weights failing to position correctly.

= Steve Colwell 


From: Craig Schulze <= ;craig@skybolt.net>
To: Steve Colwell <mcmess1919@yahoo.com>
Cc: "lml@lancaironline.net" <lm= l@lancaironline.net>
Sent:= Friday, July 26, 2013 7:42 AM
Sub= ject: Re: Potential Problem-Engine Vibration
<= div class=3D"y_msg_container">
It sounds to me that you may have an issue= with your prop hub not changing the pitch exactly the  same on all the= blades.  The vibration you are feeling is one blade taking a larger bi= te of air and then causing everything to wobble.  It settles in sometim= es but when you change the power setting the pitch on the prop is adjusted b= y the hub unevenly. 

Blue Skies,
Craig Schulze
Lancair N7= 3S


On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess191= 9@yahoo.com> wrote:

In the first 40 hours I had vibration so s= evere it caused stick shake.  This
has continued intermittently more= or less for almost 400 hours.

First I found and fixed several Cowl Interference locations, then adjusted
and notched the hat s= ection of the nose gear door.

At about 50 hours I paid Barrett to tea= r down the engine to replace the
Performance pistons (prematurely worn to= p rings) with stock ECI pistons.
Also found a cracked case.

We had= the Kelly Alternator balanced and rebuilt at a shop recommended by
Bill B= ainbridge of B & C.  Sorry I can't remember the name, the Legacy fi= le
is in Texas.

I rounded the leading edges of the elevator count= er weights when building so
I temporarily squared them off to go back to t= he stock shape for testing.

All gear doors were checked in flight wit= h video camera.

The pitch trim hinge pin had play, I replaced it per= Chris Zavatson's web
page.

Along the way the prop was balanced tw= ice.

I could not get more that the usual vibration (which always seem= ed to be too
much) on test flights.  Then, unpredictably, vibration magnitude would
increase with power reduction o= n some later flight.  I say unpredictably
because I could not get in= creased vibration by attempting to duplicate
previous conditions.  L= et's hope a solution surfaces at Airventure.

Steve Colwell  Lega= cy RG IO550-N with Hartzell 3 Blade



-----Original Message----= -
From: Lancair Mailing List [mailto:lml@lancaironline.net] On B= ehalf Of Paul
Miller
Sent: Thursday, July 25, 2013 7:22 AM
To: lml@lancaironline.net
Subject: [LML] Re: Potential Problem-Engine V= ibration

Ed Martin's legacy is smooth.  Mine has had a lot of an= noying vibes as you
describe but virtually all have been removed with lot= s of cowling
interference fixes and plug change.  Many pilots forget the alternator can
be a wicked source of vibration and it i= s almost in the same plane as the
prop.

The problems I had origina= lly were in that freq range and visible at the
wingtip also.

Paul<= br>


= --Apple-Mail-6FD9EFD1-EC62-457A-8133-752E05D1D3B2--