X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=cpHlbGwi c=1 sm=1 tr=0 a=PnbjpSU/03CrHefOPWZnMg==:117 a=x7bEGLp0ZPQA:10 a=Cs6MGpLMSVwA:10 a=3JhidrIBZZsA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=UKPAHat8AAAA:8 a=RZgt-dW0AHFRPoCB8RwA:9 a=nzKkuV-CCuY0ifXr:21 a=olezCTvegECp-ciY:21 a=QEXdDO2ut3YA:10 a=UH56FRssisUdLDdCahsA:9 a=zxhdxLzBH6sLLbZE:21 a=kQj2FNcNnSeoFzSX:21 a=6NDMZAh2JptthSvy:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=Fc6xXSS-RxGHxrvp76Qp:22 From: "Max maxfly55@gmail.com" Received: from mail-ot1-f44.google.com ([209.85.210.44] verified) by logan.com (CommuniGate Pro SMTP 6.2.10) with ESMTPS id 12118488 for flyrotary@lancaironline.net; Fri, 18 Jan 2019 21:04:22 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.210.44; envelope-from=maxfly55@gmail.com Received: by mail-ot1-f44.google.com with SMTP id w25so16092889otm.13 for ; Fri, 18 Jan 2019 18:04:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=D0C4Z6wa4aq1a4q1nXbBhEh8JyVid4yMUmIo3ihuZkc=; b=nO6ahWX36uJwUD4aNKnaJoa7P72ovBKKsLyaHPBeyycvcjWbx3AZKuK30N2ez2GA4x aEUFNc1wW/n5Kh+PTPa14KjBd0rmef3F/3zZnojdkH+XwPmuT3ZIlHL3FdZLS83qabFb EEwhLJg9Ehp1qUmGtaL2OChSoO1DUh4R2RZfd9xRh35qfVVwTkNm0iTCQwYIRNoH+gJd SUZnPZ2tDNBFFmzDIcvIQMW1u6iAtmlwcW1ofgQ5ScYQRwGrvRIQWhKN8pXQx3OaVTcA +aGxljHE+LMMYbS3e/q64cqDV/O6sIAFqrC+nStl5PKUaCjEjk6ihseOhgaUqXfsqCK3 TyXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=D0C4Z6wa4aq1a4q1nXbBhEh8JyVid4yMUmIo3ihuZkc=; b=KcaQ85uH6tWK5vKY7dmFgfZU7b29JEn/k12wXA8UyUwTNWYYa8s49iaOeCavu9P054 dB5i8mhUqW0OYkVQ1lwqPZMnLP72GZalPLCanDmcBtqUgMT4XC4VmZ2NDf9HchGbz4aH AXJVHM/qpZe4Qq8oenfzrU8I5fUWXJebSlUNEo/Y3jVX0QxfdHpT7UiemivzS8BhPfKJ /g/CStpLGq3eprLayegZB44C88gnMTCnapfvx57pCul8cBgM7QQ9O0ZBrOXgvKGIwkn2 cfaRDSzrCuk6FEZvteWWRumH8tfrN/C9fEgIyZRG9nWG+6SzHCtEGEsFrbwX3CxntNxn U0Ow== X-Gm-Message-State: AJcUukfyWhPXOwFZdhJuS3xR9T06gl6CeTFV4IW5ICBKktshVEXWGFdW 9Fo+QWH9/EZtrUtysXGuCUbJV3Yi+9RxfkIG1RNIwA== X-Google-Smtp-Source: ALg8bN6gWvHKj01HlzMqhF+FGLgbLtD8dvA/gwE8DNSe/8B8zK5fOCWIWJtvxThU9W6N2Hw2wOH9iNRhf2TPmfCsk5k= X-Received: by 2002:a9d:f05:: with SMTP id 5mr13519684ott.123.1547863445168; Fri, 18 Jan 2019 18:04:05 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Date: Fri, 18 Jan 2019 21:03:53 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Rubber Damper To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="000000000000cf692d057fc60af4" --000000000000cf692d057fc60af4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello, please remove maxfly55@gmail.com from this mailing list. Thank you. On Fri, Jan 18, 2019, 3:49 PM Steven W. Boese SBoese@uwyo.edu < flyrotary@lancaironline.net wrote: > Bobby, > > My guess is that weight probably was not the reason for the "no metal > prop" restriction. Metal props have the potential to develop destructive > harmonic vibrations since they have little damping capability compared to= a > wood or composite prop. Carbon fiber props are so stiff that they may no= t > provide much damping of torsional resonance but I have no proof of that. > The rubber dampers should provide some isolation between the engine and t= he > rest of the drive train making it less likely to excite those harmonics. > > When I replaced the test stand rubber dampers with solid metal ones, I wa= s > trying to get a baseline for the engine side of the system without > disassembling the plane. There was about 0.020" of clearance between the > test stand damper plate and the ID of the flex plate. Without the reducti= on > drive input shaft, the damper plate could become off center until > constrained by the flex plate. The damper plate apparently did not becom= e > off center to the same location from one run to the next, thus preventing > achieving a balance solution. The solid metal parts fixed the position = of > the damper plate on the flex plate allowing the assembly to be balanced. > This was completely separate from torsional and prop harmonic > considerations. > > I would be interested in purchasing a supply of rubber dampers. > > > Steve Boese > > On Jan 18, 2019, at 10:33 AM, Bobby J. Hughes bhughes@qnsi.net < > flyrotary@lancaironline.net> wrote: > > Steve, > > > > Tracy had a =E2=80=9Cno metal prop=E2=80=9D exception for the rigid coupl= ed drives. Was > this due to weight or some other concern? My MT prop weights about 39#=E2= =80=99s. > I personally like the rubber dampers but I believe they should be > considered a consumable item. Flat spots on the 45 durometer appear with > less than 100 hours. May be as few as 50 hours. They are cheap but the > minimum order is 600 units. I have a quote and plan to try and get a grou= p > buy together. If a group buy is possible I plan to buy 40 units and chang= e > every 50- 100 hours. A firmer material may last longer. Thinking about a = 60 > =E2=80=93 65 durometer. I=E2=80=99ll put the group buy information out to= the group when I > have time. > > > > Bobby > > > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net > ] > *Sent:* Tuesday, January 15, 2019 2:56 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Rubber Damper > > > > Bobby, > > > > When I was performing a dynamic balance of the turbo Renesis on the test > stand with only the flex plate and damper plate installed, I was unable t= o > achieve a solution due to the angular position of the heavy spot changing > from one run to the next without attaching weights. Solid aluminum > replacements for the dampers were made and installed. A dynamic balance > solution was then achieved. It may be that the solid damper replacements > would result in a setup very similar to the rigid coupling described as > used in Tracy's latest drives. This was only done on the test stand and = I > have not installed the solid parts in the plane. > > Steve Boese > > > On Jan 15, 2019, at 11:59 AM, Bobby J. Hughes bhughes@qnsi.net < > flyrotary@lancaironline.net> wrote: > > =E2=97=86 This message was sent from a non-UWYO address. Please exercise = caution > when clicking links or opening attachments from external sources. > > > > Tracy, > > > > Service Rubber located the part number. It was actually a 45 durometer. > They are providing a quote with minimum quantity. > > > > Thanks, > > > > Bobby > > > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net > ] > *Sent:* Tuesday, January 15, 2019 12:29 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Rubber Damper > > > > Tracy, > > > > I=E2=80=99m exploring the possibility of have a batch of dampers made. Me= asuring > the worn units is difficult. I found some information in the archives but > need to confirm the measurements. > > > > Supplier was Service Rubber in Texas. They have changed accounting system= s > and can=E2=80=99t located the part number. If you have the part number th= at would > be most helpful. > > > > OD 1.374=E2=80=9D > > ID 0.75=E2=80=9D > > Height --? > > > > Durometer of 50. Looking at increasing to 65. Service Rubber recommended > neoprene. > > > > Depending on minimum quantity and price it will likely take a group buy. > My 50 durometer develop flat spots very fast. I have been rotating them t= o > move the flat spot to the opposite side. I think they need to be change > every 50 =E2=80=93 100 hours. Harder material may survive longer. > > > > Thanks, > > > > Bobby > > > > > > --000000000000cf692d057fc60af4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hello, please remove maxfly55@gmail.com from this mailing list. Thank you.=C2=A0


O= n Fri, Jan 18, 2019, 3:49 PM Steven W. Boese SBoese@uwyo.edu <flyrotary@lancaironline.net wrote:
Bobby,

My guess is that weight= probably was not the reason for the "no metal prop" restriction.= =C2=A0 Metal props have the potential to develop destructive harmonic vibra= tions since they have little damping capability compared to a wood or composite prop.=C2=A0 Carbon fiber props are so stiff that they may not pr= ovide much damping of torsional resonance but I have no proof of that.=C2= =A0 The rubber dampers should provide some isolation between the engine and= the rest of the drive train making it less likely to excite those harmonics.

When I replaced the tes= t stand rubber dampers with solid metal ones, I was trying to get a baselin= e for the engine side of the system without disassembling the plane.=C2=A0 = There was about 0.020" of clearance between the test stand damper plate and the ID of the flex plate. Without the reduction drive input shaf= t, the damper plate could become off center until constrained by the flex p= late.=C2=A0 The damper plate apparently did not become off center to the sa= me location from one run to the next, thus preventing achieving a balance solution.=C2=A0 The solid metal parts = fixed the =C2=A0position of the damper plate on the flex plate allowing the= assembly to be balanced.=C2=A0 This was completely separate from torsional= and prop harmonic considerations.

I would be interested i= n purchasing a supply of rubber dampers.


Steve Boese

On Jan 18, 2019, at 10:33 AM, Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:

Steve,

=C2=A0

Tracy had a =E2=80=9Cn= o metal prop=E2=80=9D exception for the rigid coupled drives. Was this due = to weight or some other concern? My MT prop weights about 39#=E2=80=99s.=C2= =A0 I personally like the rubber dampers but I believe they should be considered a consumable item. Flat spots on the 45 durometer appear wit= h less than 100 hours. May be as few as 50 hours. They are cheap but the mi= nimum order is 600 units. I have a quote and plan to try and get a group bu= y together. If a group buy is possible I plan to buy 40 units and change every 50- 100 hours. A firmer material m= ay last longer. Thinking about a 60 =E2=80=93 65 durometer. I=E2=80=99ll pu= t the group buy information out to the group when I have time.

=C2=A0

Bobby

=C2=A0

From: Rotary m= otors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Tuesday, January 15, 2019 2:56 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Rubber Damper

=C2=A0

Bobby,

=C2=A0

When I was performing a dynamic balance of the turbo= Renesis on the test stand with only the flex plate and damper plate instal= led, I was unable to achieve a solution due to the angular position of the = heavy spot changing from one run to the next without attaching weights.=C2=A0 Solid aluminum replacements for = the dampers were made and installed.=C2=A0 A dynamic balance solution was t= hen achieved.=C2=A0 It may be that the solid damper replacements would resu= lt in a setup very similar to the rigid coupling described as used in Tracy's latest drives.=C2=A0 This was only done o= n the test stand and I have not installed the solid parts in the plane.

Steve Boese


On Jan 15, 2019, at 11:59 AM, Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:

=E2=97=86 This message was sent from a n= on-UWYO address. Please exercise caution when clicking links or opening att= achments from external sources.

=C2=A0

Tracy,

=C2=A0

Service Rubber located= the part number. It was actually a 45 durometer. They are providing a quot= e with minimum quantity.

=C2=A0

Thanks,<= u>

=C2=A0

Bobby=

=C2=A0

From: Rotary m= otors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Tuesday, January 15, 2019 12:29 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Rubber Damper

=C2=A0

Tracy,

=C2=A0

I=E2=80=99m exploring the possibility of have a batc= h of dampers made. Measuring the worn units is difficult. I found some info= rmation in the archives but need to confirm the measurements.

=C2=A0

Supplier was Service Rubber in Texas. They have chan= ged accounting systems and can=E2=80=99t located the part number. If you ha= ve the part number that would be most helpful.

=C2=A0

OD =C2=A01.374=E2=80=9D

ID 0.75=E2=80=9D

Height --?

=C2=A0

Durometer of 50. Looking at increasing to 65. Servic= e Rubber recommended neoprene.

=C2=A0

Depending on minimum quantity and price it will like= ly take a group buy. My 50 durometer develop flat spots very fast. I have b= een rotating them to move the flat spot to the opposite side. I think they = need to be change every 50 =E2=80=93 100 hours. Harder material may survive longer.

=C2=A0

Thanks,

=C2=A0

Bobby

=C2=A0

=C2=A0

--000000000000cf692d057fc60af4--