X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 21 Nov 2011 08:29:02 -0500 Message-ID: X-Original-Return-Path: Received: from nm7-vm4.bullet.mail.ne1.yahoo.com ([98.138.91.167] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with SMTP id 5207869 for lml@lancaironline.net; Sun, 20 Nov 2011 20:34:30 -0500 Received-SPF: none receiver=logan.com; client-ip=98.138.91.167; envelope-from=randylsnarr@yahoo.com Received: from [98.138.90.56] by nm7.bullet.mail.ne1.yahoo.com with NNFMP; 21 Nov 2011 01:33:54 -0000 Received: from [98.138.88.234] by tm9.bullet.mail.ne1.yahoo.com with NNFMP; 21 Nov 2011 01:33:54 -0000 Received: from [127.0.0.1] by omp1034.mail.ne1.yahoo.com with NNFMP; 21 Nov 2011 01:33:54 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 64912.97745.bm@omp1034.mail.ne1.yahoo.com Received: (qmail 70732 invoked by uid 60001); 21 Nov 2011 01:33:53 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=JXBjVMMo3o7azZ2zuS0hp3YWdo15vFZ0stWouiw1PIVLjwv8hai2hJnpQZYF7A281r9H3M0x0sf/Fazq9DIy5Jbt/PXl80OzoforZIrGFyu0xJdmz/q4AFSrE9z/QF1jGONB0Net9P8K5wiIVhigH60SY6iR8l4K8rV8xZ2t3Rk=; X-YMail-OSG: yNexEIQVM1krRQwFd4pqLj6QSOdlXyYYfChAcbh1PZj.BK8 Jd4DvRD22eStPQtAvCy_YtAXbiZnMT9cNEYo7iMDB7uE7H1L2uZxo.C1UUSZ QN5z4MPlTbnkuFHyV83KslAq76XXhmijYI.V0q_OZrToW6X5JrjEXRtBwpbq fVlrYc2x9BgAMFahFi0sS6rltuoLwBJFNlraysZWHBwtNp6Sx0BJ_BApURQd wbnXmPkg_JfhfvIwL8htWiPL6jkAA3gzvIzdJqmsc4Ul9Dbc67Ynvw8IaolS hdGZPv_QKoj3CQSIhk9_3gV7MWQRP3LIs_gOgsxYCjnKr.aZkljFPGg62Ydr JL7p0e0aEEcoPF.jQ4oWUCfmya2ovmzA_bJKLNWG87jxFBvKhVEv_G.TEP_2 avvnJ2E9TOMiWyq.qgjVnWf49amBSIOVGfxrC_v31hF911V.TVWqtWgjk3m7 4M42IPBPXmMMWD6_Zs56n4x7DasEdzKB4eY2MgD9vy2_L_dbZVzX5V4TSdhJ EyVESVNOua9zN3vOIj4ZtczQ4DkUxo5lCb3BrP9h9txxsBAVmGSoZHARHQy9 zB3qr.A4oz7A5OsZE_kw- Received: from [76.8.220.20] by web111411.mail.gq1.yahoo.com via HTTP; Sun, 20 Nov 2011 17:33:52 PST X-Mailer: YahooMailWebService/0.8.115.325013 References: X-Original-Message-ID: <1321839232.69236.YahooMailNeo@web111411.mail.gq1.yahoo.com> X-Original-Date: Sun, 20 Nov 2011 17:33:52 -0800 (PST) From: randy snarr Reply-To: randy snarr Subject: Re: [LML] Legacy vibrations resolved X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="640426125-297581477-1321839232=:69236" --640426125-297581477-1321839232=:69236 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Steve,=0AAs a side note, I had a legacy driver stop by my hangar a few year= s ago. When he shut down, there was a definite metal on metal rattle in the= tail as the blades came to a stop. I started inspecting the back of his pl= ane before he got out. He had the same play in the hinges. Especially the o= uter hinge pilot side.=0AWith the airplane idling, the hinges rattled prett= y bad but with the engine running you could not hear it but it was defintel= y there at shut down. The tell tale gray trails were there as well. =0A=0A= =0AFWIW..=0ARandy.=0A=0A=C2=A0=0A"Flight by machines heavier than air is un= practical and insignificant, if not utterly impossible"=0A-Simon Newcomb, 1= 902=0A=0A=0A________________________________=0A From: Steve Colwell =0ATo: lml@lancaironline.net =0ASent: Sunday, November 20, 2= 011 7:48 AM=0ASubject: [LML] Legacy vibrations resolved=0A =0A=0AOur Legacy= has had a pitch vibration in the stick that comes and goes.=C2=A0 It seems= to be related to about 50% fuel load or less and reduced but stable power.= =C2=A0 The plane has about 275 hours and this has been going on since the f= irst 40 hours.=C2=A0 When it is vibrating in level flight (approximately 2 = cycles per second and the stick is visibly moving in a pronounced shake) it= will continue to vibrate when pitched up at about 1.5 G.=C2=A0 After the p= itch up, when pitched down to less than 1 G, the vibration will quit.=C2=A0= =C2=A0 After working thru many of the same contact points firewall forward = and the gear doors Paul Miller had, I still had the vibration. All the whil= e, I'm thinking, this is a great way to initiate flutter.=C2=A0 I might add= , I very carefully rebalanced the control surfaces after painting. =0A=C2= =A0=0AI mentioned the problem to Chris Zavatson at the Lancair Breakfast Fl= y-In at Willows, CA..=C2=A0 Chris asked if I had checked the control and tr= im hinges for play.=C2=A0 That was easy, I check them every pre-flight.=C2= =A0 Only not the way Chris checks them. He pushes and pulls looking at the = hinge.=C2=A0 See video=C2=A0 http://www.n91cz.com/HingePlay/hinges.htm =0A= =C2=A0=0AI replaced the Pitch Trim Hinge Pin with Stainless Steel (3/32=E2= =80=9D - .09375) welding wire.=C2=A0 Now, no play can be seen in the push p= ull test.=C2=A0 We have put 20+ hours on with the new SS hinge pin and no m= ore stick shake.=C2=A0 I included Paul=E2=80=99s post of problem areas (see= below) since I had some of them too. =C2=A0=0A=C2=A0=0ASteve Colwell=C2=A0= Legacy RG 310 hours=0A=C2=A0=0A=0ASent: Monday, April 12, 2010 6:47 AM=0AT= o: lml@lancaironline.net=0ASubject: [LML] Legacy vibrations resolved=0A=C2= =A0=0AI had written about vibrations in the 300 hour Legacy engine =0Acompa= rtment.=C2=A0 Many wrote about their fixes.=C2=A0=C2=A0 I am happy to repor= t that =0Athe following worked for me:=0A=C2=A0=0A1) Changed engine isolato= rs last year (no difference)=0A2) enlarged cutout on nose gear door stiffen= er.=C2=A0 After repeatedly seeing new witness marks I did a retraction test= and saw the interference is much larger than I expected.=C2=A0 I trimmed a= nother 1/8 inch from the cutout.=C2=A0 This cutout prevents interference fr= om the bolt attaching the linkage to the nose gear on both sides.=C2=A0 The= co-pilot side needed a larger cutout.=C2=A0 White primer was used to show = the marks after each flight.=C2=A0 I think this was transmitting a lot of c= owl vibration.=0A3) I sprayed white primer on the areas contacting the baff= ling.=C2=A0=C2=A0 I =0Afound three hard hit areas and this is using the fac= tory white powder coated baffling.=C2=A0 Two areas at the front of the #5 c= ylinder needed bending away from the cowl.=C2=A0 Another area just above th= e oil cooler on the top side of the cowl was hitting.=C2=A0 The #5 EGT prob= e was hitting.=C2=A0 =0AThe #5 forward rocker cover was hitting on the bott= om and was peened about a 1/4 to match the form of the cowl.=C2=A0 I remove= d the rocker cover to check for clearance with the rocker arm.=0A4) Bafflin= g repairs were made to areas that were not tight against the =0Acowl.=C2=A0= =C2=A0 This significantly reduced the CHTs.=C2=A0 I used the cooling and = =0Adrag reduction data on lml from owners to help make small but helpful ch= anges in the baffling.=0A5) The prop governor cable was a hard hit on the m= etal baffling and was trimmed.=0A6) The nose gear doors had a slight overla= p which was trimmed so they close tight with no gaps.=0A7) Both main gear i= nner and outer doors were adjusted to be flush and tight when retracted.=C2= =A0 This took a significant amount of time involving small hinge adjustment= s and testing of each individual attachment link on the outer doors to get = the right length before attaching both links for the final test.=C2=A0 I sa= y this because the two links are slightly different in length and geometry.= =C2=A0 I found one was a little longer than required and actually twisted t= he door slightly open when both links were attached.=C2=A0 This was not evi= dent until I retracted the gear using only single links.=0A8) the large cir= cular baffle behind the prop is cracked in two places and remains that way = until a fix can be made.=C2=A0 This appears to be from a tight fit and need= s to be measured for a new smaller piece.=C2=A0 This is a large crack that = could easily be flopping around in flight and somehow interfering with the = cooling process.=0A9) removed the quick drain for oil and replaced with the= factory plug.=C2=A0 =0AI have lots of clearance and may put the quick drai= n back in.=0A=C2=A0=0AThe net result is now I have a smooth engine compartm= ent.=C2=A0=C2=A0 My symptoms =0Aincluded a difficult propeller balancing as= we could never exactly home in on a solution.=C2=A0 The vibration was smal= l at 2700 rpm and takeoff but increased significantly with rpm reduction.= =C2=A0 I attribute that to the higher torque twisting the engine closer to = the left side of the baffling.=C2=A0 The vibration was evident in the cockp= it, cowling and when looking at the wings.=C2=A0 The next project will be t= o replace the silicone baffle with new material and replace the circular ba= ffle plate behind the prop and replace the left side metal baffle to better= fit the cowl line near the #5 cylinder.=C2=A0 Many thanks to all the sugge= stions that made this easier to do.=0A=C2=A0=0APaul Miller=0AN357V Legacy R= G --640426125-297581477-1321839232=:69236 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Steve,
As a side note, I had a legacy driver stop by my hangar= a few years ago. When he shut down, there was a definite metal on metal ra= ttle in the tail as the blades came to a stop. I started inspecting the bac= k of his plane before he got out. He had the same play in the hinges. Espec= ially the outer hinge pilot side.
With the airplane idling, the hinges r= attled pretty bad but with the engine running you could not hear it but it = was defintely there at shut down. The tell tale gray trails were there as w= ell.

FWIW..
Rand= y.
 
"Fl= ight by machines heavier than air is unpractical and insignificant, if not = utterly impossible"
-Simon Newcomb, 1902
From: Steve Colwell <mcmess19= 19@yahoo.com>
To: l= ml@lancaironline.net
Sent: Sunday, November 20, 2011 7:48 AM
Subject: [LML] Legacy vibrations resolved
 =0A
Our Legacy has had a pitch vib= ration in the stick that comes and goes.  It seems to be related to ab= out 50% fuel load or less and reduced but stable power.  The plane has= about 275 hours and this has been going on since the first 40 hours. = When it is vibrating in level flight (approximately 2 cycles per second an= d the stick is visibly moving in a pronounced shake) it will continue to vi= brate when pitched up at about 1.5 G.  After the pitch up, when pitche= d down to less than 1 G, the vibration will quit.   After working= thru many of the same contact points firewall forward and the gear doors P= aul Miller had, I still had the vibration. All the while, I'm thinking, thi= s is a great way to initiate flutter.  I might add, I very carefully r= ebalanced the control surfaces after painting.
 
I mentioned the proble= m to Chris Zavatson at the Lancair Breakfast Fly-In at Willows, CA..  = Chris asked if I had checked the control and trim hinges for play.  Th= at was easy, I check them every pre-flight.  Only not the way Chris ch= ecks them. He pushes and pulls looking at the hinge.  See video  = http://www.n91cz.com/HingePlay/hinges.htm
 
I replace= d the Pitch Trim Hinge Pin with Stainless Steel (3/32=E2=80=9D - .09375) we= lding wire.  Now, no play can be seen in the push pull test.  We = have put 20+ hours on with the new SS hinge pin and no more stick shake.&nb= sp; I included Paul=E2=80=99s post of problem areas (see below) since I had= some of them too.  
&nb= sp;
Steve Colwell  Legacy= RG 310 hours
 

Sent: Monday, April 12, 2010 6:47 AM
T= o: lml@lancaironline.net
Subject: [LML] Legacy vibrations resolved
=
 
I had written about vibrations in the 300 hour Legacy eng= ine
compartment.  Many w= rote about their fixes.   I am happy to report that
the following worked for me:
 
1) Changed engine isolators last year (no difference)
2) enlarged cutout on nose gear door stif= fener.  After repeatedly seeing new witness marks I did a retraction t= est and saw the interference is much larger than I expected.  I trimme= d another 1/8 inch from the cutout.  This cutout prevents interference from the= bolt attaching the linkage to the nose gear on both sides.  The co-pi= lot side needed a larger cutout.  White primer was used to show the ma= rks after each flight.  I think this was transmitting a lot of cowl vi= bration.
3) I sprayed white pr= imer on the areas contacting the baffling.   I
found three hard hit areas and this is using = the factory white powder coated baffling.  Two areas at the front of t= he #5 cylinder needed bending away from the cowl.  Another area just a= bove the oil cooler on the top side of the cowl was hitting.  The #5 E= GT probe was hitting. 
T= he #5 forward rocker cover was hitting on the bottom and was peened about a= 1/4 to match the form of the cowl.  I removed the rocker cover to check for clearance with the rocker arm.
4) Baffling repairs were made to areas that were not tight agai= nst the
cowl.   Thi= s significantly reduced the CHTs.  I used the cooling and
drag reduction data on lml from owners to= help make small but helpful changes in the baffling.
5) The prop governor cable was a hard hit on the me= tal baffling and was trimmed.
= 6) The nose gear doors had a slight overlap which was trimmed so they close= tight with no gaps.
7) Both m= ain gear inner and outer doors were adjusted to be flush and tight when ret= racted.  This took a significant amount of time involving small hinge = adjustments and testing of each individual attachment link on the outer doo= rs to get the right length before attaching both links for the final test. = I say this because the two links are slightly different in length and geom= etry.  I found one was a little longer than required and actually twis= ted the door slightly open when both links were attached.  This was no= t evident until I retracted the gear using only single links.
8) the large circular baffle behind the pro= p is cracked in two places and remains that way until a fix can be made.&nb= sp; This appears to be from a tight fit and needs to be measured for a new = smaller piece.  This is a large crack that could easily be flopping ar= ound in flight and somehow interfering with the cooling process.
9) removed the quick drain for oil and r= eplaced with the factory plug. 
I have lots of clearance and may put the quick drain back in.
 
The net result is now I have a smooth engine = compartment.   My symptoms
included a difficult propeller balancing as we could never exactly = home in on a solution.  The vibration was small at 2700 rpm and takeof= f but increased significantly with rpm reduction.  I attribute that to= the higher torque twisting the engine closer to the left side of the baffl= ing.  The vibration was evident in the cockpit, cowling and when looki= ng at the wings.  The next project will be to replace the silicone baf= fle with new material and replace the circular baffle plate behind the prop= and replace the left side metal baffle to better fit the cowl line near th= e #5 cylinder.  Many thanks to all the suggestions that made this easi= er to do.
 
Paul Miller
N357V Legacy RG


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