X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 23 Feb 2011 09:09:33 -0500 Message-ID: X-Original-Return-Path: Received: from web81503.mail.mud.yahoo.com ([68.142.199.143] verified) by logan.com (CommuniGate Pro SMTP 5.4c2o) with SMTP id 4877947 for lml@lancaironline.net; Mon, 21 Feb 2011 15:24:58 -0500 Received-SPF: none receiver=logan.com; client-ip=68.142.199.143; envelope-from=slavaharlamor@sbcglobal.net Received: (qmail 45076 invoked by uid 60001); 21 Feb 2011 20:24:23 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=2EluWkk8G/Ve18ZqGbmMSuQJVbYV22k4XtKN8YZF93RkI9tiMNeidPQaS7KeBFzhC+FnC/nAwGgVjcDO8Qnz/KIG+zMFrbB8d6TSyTzwsvUpf4BE14YU+FAFivugsa8BDCmH/x8EORxDyJ55hOupDaI6CX+p55TpmWlhJwUqFEY=; X-Original-Message-ID: <975311.44445.qm@web81503.mail.mud.yahoo.com> X-YMail-OSG: V1ECTpYVM1n1AIEpa.wlIs9kne_g1QmRR8.d.ktDHWFedFL Fzs6C98BIVZdGv_MsgNsQKN2431RSGx4H0.5tv7TOZsaWLePhQOxOxJRgEMC XYG5omwf7lwcUA3HnK5O_dUl7symOe4f0myA1S.SyMCBLee.aobv8L.aK4Ay 9oBeFxVWp1LPIg07SCDsH1d9s6e8XFg_EwMZptVoqG1U_kZ8NJSXO9JhvoY1 W5JpuKtOz1_6ItZMSElQkB2tm58_zi_YTMBpsQVBTtcvavGEOD3JPhD4yorr aaTSx0Fg4RFoN_kRsuI7UpwbDyD_2.ndr6Tgi2.ZVTn_d0QKv3fcE7R2rzMy Lle_fPOzNa47PcGqsiSx0xNAbz7cMkxS91EVFY4zYmtbdcIq_BRUnuq.h3Av 37AkG0etGTw-- Received: from [99.33.43.1] by web81503.mail.mud.yahoo.com via HTTP; Mon, 21 Feb 2011 12:24:22 PST X-Mailer: YahooMailClassic/11.4.20 YahooMailWebService/0.8.109.292656 X-Original-Date: Mon, 21 Feb 2011 12:24:22 -0800 (PST) From: SLAVA HARLAMOR Subject: Re: [LML] Re: prop balance X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-978685939-1298319862=:44445" --0-978685939-1298319862=:44445 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello All, I have been in the background studying for my build project. Gra= yhawk, your information about the harmonic damper is an educational point o= f significance. I know nothing about dampers, is there a book that I can ge= t to learn about this subject. Does a damper have to be specific to an engi= ne or is the design universal to any recip? =A0 Thank you for any advice in advance, =A0 Sincerely, =A0 Mr. Slava Harlamor slavaharlamor@sbcglobal.net=20 =A0 --- On Mon, 2/21/11, Sky2high@aol.com wrote: From: Sky2high@aol.com Subject: [LML] Re: prop balance To: lml@lancaironline.net Date: Monday, February 21, 2011, 10:32 AM Jack, =A0 The 12 pound=A0harmonic damper is present to reduce negative torque between= power strokes.=A0 It has a steel ring suspended in silicone.=A0 It=A0does = not help balance the prop - it should be totally neutral with respect to ba= lance but not circular momentum.=A0 On fixed-pitch prop (likely wooden or c= omposite) driven engines, there is often a 100 rpm increase because of adde= d momentum and a reduction in the negative torque by damping it.=A0 Constan= t speed prop users may find it difficult to measure the effect.=A0 Another = benefit is to move the CG forward - usually a plus in the 320/360 series ai= rcraft. =A0 The person in Redmond is wrong.=A0 He is misinformed about the purpose of t= he damper. =A0 I have such a damper and I do balance my prop.=A0 Because I am in a=A0partn= ership=A0that owns=A0a simple balance device, I have no constraint on perfo= rming a balance or just checking the last balance to insure it has not chan= ged (it has not). =A0 Go balance that prop.=A0=A0Weights/longer bolts can be affixed where the da= mper is mounted to the starter ring.=A0 However, be careful that any large= =A0area washers=A0not stick out far enough to come in contact with the cowl= ing in dramatic + or - G maneuvers. =A0 Geeeeze! =A0 Grayhawk =A0 In a message dated 2/21/2011 7:26:04 A.M. Central Standard Time, jraddison@= msn.com writes: Question? On my LNC2-360 (BIB plus high comp pistons) there is an add-on "balancer" b= olted to the face of the starter ring gear. It is supposed to balance the engine with its internal weights that are sup= posed to arrange themselves to cancel or dampen our any sensed vibrations. The "balancer" is about 2 inches in debth and almost the diameter of the ri= ng gear; it is all self contained and you would have to take the prop off t= o get it off and take it apart if one was at least currious what was inside= of it. =A0 It's difficult to know if a 4 cyclynder Lycoming is as smooth as it can be,= because it's not a real smooth engine under the best of conditions. =A0 I inquired to a local experienced prop balance person in Redmond and they c= oncluded that because of the dynamic balancer on the ring gear, he would no= t attempt to balance the engine with his expensive balance work, as he thou= ght the attached dynamic balancer would change the internal weight at will. =A0 Does anyone have any experience with these dynamic balancers attached to th= e ring gear??? =A0 Cheers =A0 Jack Addison=A0 N360JS near Redmond, OR =3D --0-978685939-1298319862=:44445 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello All, I have been in the background= studying for my build project. Grayhawk, your information about the harmon= ic damper is an educational point of significance. I know nothing about dam= pers, is there a book that I can get to learn about this subject. Does a da= mper have to be specific to an engine or is the design universal to any rec= ip?
 
Thank you for any advice in advance,
 
Sincerely,
 
Mr. Slava Harlamor
 


--- On Mon, 2/21/11, Sky2high@aol.com <Sky2high@aol.c= om> wrote:

From: Sky2high@aol.com <Sky2high@aol.com>Subject: [LML] Re: prop balance
To: lml@lancaironline.net=
Date: Monday, February 21, 2011, 10:32 AM

Jack,
 
The 12 pound harmonic damper is present to reduce negative torque= between power strokes.  It has a steel ring suspended in silicone.&nb= sp; It does not help balance the prop - it should be totally neutral w= ith respect to balance but not circular momentum.  On fixed-pitch prop= (likely wooden or composite) driven engines, there is often a 100 rpm incr= ease because of added momentum and a reduction in the negative torque by da= mping it.  Constant speed prop users may find it difficult to measure = the effect.  Another benefit is to move the CG forward - usually a plu= s in the 320/360 series aircraft.
 
The person in Redmond is wrong.  He is misinformed about the purp= ose of the damper.
 
I have such a damper and I do balance my prop.  Because I am in a=  partnership that owns a simple balance device, I have no co= nstraint on performing a balance or just checking the last balance to insur= e it has not changed (it has not).
 
Go balance that prop.  Weights/longer bolts can be affixed w= here the damper is mounted to the starter ring.  However, be careful t= hat any large area washers not stick out far enough to come in co= ntact with the cowling in dramatic + or - G maneuvers.
 
Geeeeze!
 
Grayhawk
 
In a message dated 2/21/2011 7:26:04 A.M. Central Standard Time, jradd= ison@msn.com writes:
Question?
On my LNC2-360 (BIB plus high comp pisto= ns) there is an add-on "balancer" bolted to the face of the starter ring ge= ar.
It is supposed to balance the engine with its internal weights that = are supposed to arrange themselves to cancel or dampen our any sensed vibra= tions.
The "balancer" is about 2 inches in debth and almost the diameter= of the ring gear; it is all self contained and you would have to take the = prop off to get it off and take it apart if one was at least currious what = was inside of it.
 
It's difficult to know if a 4 cyclynder Lyco= ming is as smooth as it can be, because it's not a real smooth engine under= the best of conditions.
 
I inquired to a local experienced pro= p balance person in Redmond and they concluded that because of the dynamic balancer on the ring gear, he would not attempt to balance the engine with= his expensive balance work, as he thought the attached dynamic balancer wo= uld change the internal weight at will.
 
Does anyone have any e= xperience with these dynamic balancers attached to the ring gear???
&nbs= p;
Cheers
 
Jack Addison  N360JS
near Redmond, OR
= =3D
--0-978685939-1298319862=:44445--