X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) From: "Le Roux Breytenbach breytenbachleroux@gmail.com" Received: from mail-ed1-f44.google.com ([209.85.208.44] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 1016268 for flyrotary@lancaironline.net; Mon, 07 Dec 2020 06:49:43 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.208.44; envelope-from=breytenbachleroux@gmail.com Received: by mail-ed1-f44.google.com with SMTP id cm17so13408469edb.4 for ; Mon, 07 Dec 2020 03:49:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:in-reply-to:to; bh=Ref0q1G+g2eX37P7aFVs86IqHp1SiB7l//nFtgCpEUQ=; b=HPS9Y/elXhkfBIjALoJzRjkSF/PcgcMisl3+w/FSW5L723eLiq0DLweyS9jTbb+52P Kp3hWD0i4xcQOW5KuDWTNA47f6GTqd3Dgf3ZExd1h+A7tRCop3DOtdvKSoURe9cOPFtI u5HyIqeAuryMZBctKuQU97DGbzJeaBpxvhuCeuz6hZBjwS2Xz3LfAq9Pr6zKjIQcLDQt bOgawg/Kn9uT0OboBHqlPP5P1pG+XBunDOucpvo6w/7mzcNNHY/Ftz+B2B8r5giTJojR U1HH6jmQ4Nr0mpdoeg76Kpj8Lngwl1usfkf9E8vKMgJtNvVdM+VfDrs4jQPPMrJVmUKm ZF+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:in-reply-to:to; bh=Ref0q1G+g2eX37P7aFVs86IqHp1SiB7l//nFtgCpEUQ=; b=udm8IcVz+PdV48EOv5hi4w5wyIjggsTJurzgZwBt7ebENsBg3kZL5qVOBX+JwRuZJK qWYQ1Wv8Aot3GBtRIU7q5Ay92MXPj9verlWODU82fGCQZgxpkwdEi3BgyD6HMM/2bfgn dboT6r0co0ZWzvk13agqjDugbiyx+9A91gT3WWQXbT2ybpANxAkKpyQkwdLkClWgxFsG C39gfCk0vsj7Zim9OUcvnu5fXAoQernmMoNW4HYLrC+2U5JJcb0gG5BHTX4bK48T74uy Q2CYyljfy0xYB6nWEId3G7lej7U63oTIFToToO5qZyqK246TUGQiq9hMMjKs8w2/wfZE D7ig== X-Gm-Message-State: AOAM531pMjEcxR430ELPM/uG7PIgdUvml86yF3jVWZcTvl6INu7SKPuv SiM92L4XA/KGZIBWbF0W+VF+dF9QvlU= X-Google-Smtp-Source: ABdhPJz+KG/I8BpJgCiso/JBPd5POnfN5aCUIi7RW23yeca/p2JdPX5YuxxIb0pqna/di1nMCL3NKA== X-Received: by 2002:a50:ccc8:: with SMTP id b8mr19604293edj.152.1607341764529; Mon, 07 Dec 2020 03:49:24 -0800 (PST) Return-Path: Received: from [192.168.0.51] ([160.226.128.22]) by smtp.gmail.com with ESMTPSA id dk16sm5515041ejb.85.2020.12.07.03.49.22 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Dec 2020 03:49:23 -0800 (PST) Content-Type: multipart/alternative; boundary=Apple-Mail-37367DC4-98BC-4513-A8F5-43DE82A1B00C Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) Subject: Re: [FlyRotary] Re: RD1-C damper Date: Mon, 7 Dec 2020 13:49:20 +0200 Message-Id: References: In-Reply-To: To: Rotary motors in aircraft X-Mailer: iPhone Mail (17H35) --Apple-Mail-37367DC4-98BC-4513-A8F5-43DE82A1B00C Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Yes your right there Lynn just forget to mentioned it. Thanks for the =E2=80=9Crecap=E2=80=9D Sent from my iPhone Le Roux Breytenbach=20 > On 07 Dec 2020, at 13:34, lehanover lehanover@aol.com wrote: >=20 > =EF=BB=BF > Carbon fiber directly against steel may be poor practice. Typically fiberg= lass is used against steel and then carbon fiber over the fiberglass. Carbon= fiber is conductive and can corrode steel. Lynn E. Hanover=20 > =20 > In a message dated 12/7/2020 5:29:23 AM Eastern Standard Time, flyrotary@l= ancaironline.net writes: > =20 > =20 > Hi : It was mentioned on P.L. newsletter a couple of years ago - what if t= he flexplate center are reinforced with say 6 layers of carbonfiber on both s= ides ? > The carbonfiber can be vacumebag and really good cured if doiing it from b= oth sides. > The carbonfiber will lock from both sides face to face threw the bigger ho= les and will secure more than just on the metal itself. > Doiing the flexplate as a complete unit and then just cut and machine the h= oles. > It will be ridged and light as well and counter the gyroscopic forces ect.= that leads to cracks from the holes > Then the rubber dampener could still be put in place. > I am goiing to replace the center on this clutchplate with a rubber dampen= er >=20 >=20 >=20 > Regards Le Roux >=20 >=20 > Sent from my iPhone > Le Roux Breytenbach=20 >=20 > > On 07 Dec 2020, at 09:07, Stephen Izett stephen.izett@gmail.com wrote: > >=20 > > See below what Tracy wrote in Feb 2012. > > Also found a note in the archive where Tracy mentions only producing a f= ew of the RD-2 boxes before retiring. > > So how many hours does Tracy=E2=80=99s RV4 with the damper removed now h= ave on it.=20 > > Sounds from what some have said that he may have installed this mod to h= is 20B RV8 which may have more time, however thats a 3 rotor. What differenc= e would that make I wonder?=20 > > I take it the torque reversal and pulses will be the same magnitude but t= he sum of those pulses may have a different outcome for anything connected. > >=20 > > Cheers > >=20 > > Steve Izett > >=20 > >=20 > > email from Tracy back in Feb 2012 - > > "Finally got around to flight testing the aftermarket flywheel setup for= the RWS redrive.=20 > >=20 > > The cracked flexplate issue some builders experienced came up at the sam= e time as my CNC source for input shafts lost the ability to make them anymo= re due to loss of specialized spline making machinery. Since I had to line u= p a new source I took this opportunity to review the design from the input s= haft back to the engine. Because the damper has been such an expensive and l= abor intensive part, it was looked at as well. As a result, there have been= enough changes to warrant a change in the name so the new drives will be RD= -2B & RD-2C. > >=20 > > In rethinking the drive I had the thought that since the relatively low f= requency primary resonance range of the drive train is taken care of by the s= ystem lash, that left only the high frequency harmonics that the damper is r= esponsible for. This high range is the factor that creates the red zone in r= pm ranges found on some certified engines and metal prop combinations. As f= ar as I know, no one has used a metal prop on an RD-1x drive so I decided th= at it was an unneeded requirement. The new design has no damper at all and c= onsequently it has a "No Metal Propeller" restriction. > >=20 > > Replacing the damper is a flanged spline that is bolted directly to the f= lywheel using the same bolts (longer bolts required) that attach the flywhee= l to the counterweight. The spline is a different spec (15 splines instead o= f 30) so it is not compatible with the RD-1 damper but the new shaft itself i= s backward compatible with the remainder of the drive. I retrofitted the sa= me RD-1C that was on my RV-4 for these tests. > >=20 > > The flywheel was an aluminum racing flywheel with the replaceable iron f= riction surface unbolted and removed. Really looks pretty and professional c= ompared to the flexplate. Any of the aftermarket RX-7 & RX-8 racing flywhee= ls (steel or aluminum) that utilize the auto counterweight may be used.=20 > >=20 > > As David Leonard found, these flywheels place the ring gear about .2" cl= oser to the engine than the flexplate. To compensate, I milled .2" off the f= ront surface of the adapter plate where the starter mounts. No changes were= needed to the starter itself. I did not bother to grind the lead-in bevel o= n the ring gear teeth as discussed earlier. Starter engagement was smooth a= nyway. > >=20 > > The RV-4 drive had over 700 hours on it and everything looked beautiful i= nside. No signs of wear other than a shallow groove (~.002") on the input s= haft where the 1mm thrust bearing race between the two needle bearings rides= . Others have reported more than this in fewer hours so this is an area to i= nspect carefully. The new input shaft is a harder alloy (post machining thr= ough hardened 4340) than the the RD-1 which was pre hardened 4140. This sho= uld reduce the wear in this area. The old flexplate with over 1000 hours wa= s still crack free. The input shaft oil seal still looked and felt new so i= t was not replaced as planed. Others have reported these leaking in much fe= wer hours. Don't know the reason but I suspect that oil temperatures out of= range may be a factor. NEVER allow oil temps to exceed redline. If they g= o higher, back off the power then land and correct the cooling system. > >=20 > > Only 1 hour of flight testing so far but all indications were good. Ope= rated the engine through the full range of rpm up to 7100 looking for tell-t= ale signs of resonance. I was sort of expecting to feel, sense or hear some= indication of increased harshness in the drive with no rubber anywhere in t= he system but if anything, it felt smoother. There was none of the 'Waaa --= - Waaa' warbling sound (like a twin engine with the engines out of sync) tha= t I had with the Ross drive years ago. So far I'm very satisfied with the r= esults but it's still early in the tests.=E2=80=9D > >=20 > >=20 > >=20 > >=20 > >=20 > >> On 7 Dec 2020, at 9:47 am, Stephen Izett stephen.izett@gmail.com wrote: > >>=20 > >> Thanks Lynn. > >>=20 > >> Steve > >>=20 > >>=20 > >>>> On 7 Dec 2020, at 9:04 am, lehanover lehanover@aol.com wrote: > >>>=20 > >>> If you have picked up a stock manual transmission flywheel for a rotar= y, you must know that "Houston we have a problem". So the worst pick for a c= ar engine becomes the best pick for smoothness at idle. That flywheel is the= answer. The less flywheel effect available the more powerful the reversals n= ear idle. The more powerful the reversals the shorter the flex plate life. T= he flex plate drives the car through a hydraulic damper. So it is with the a= ircraft. No damper, short life. There are companies who make little tiny sho= ck absorbers. I thought that 4 such shocks on a racing flywheel pushing a dr= iven disc should do the job. Even stock flex plates from piston powered cars= get cracks. Few fail completely. > >>>=20 > >>> I think Tracy's pucks are adequate. Just double up the flex plate to j= ust outboard of the puck housings. No welding. Use nuts and bolts. It also a= dds actual flywheel effect which reduces the stress. =20 > >>> For the racer I made a steel button flywheel. Just large enough to sup= port a 2 disc 5 1/4" clutch. I bolted this on over the stock flex plate. The= flex plate was just used to start the engine and nothing else. I turned dow= n the face of the counter weight so as to provide a taller spigot to locate t= he flex plate and the flywheel. Piece of cake.=20 > >>>=20 > >>> The racer used a straight cut gear dog ring style gear box from Saenz i= n Argentina. The gears had enough clearance so as to agree with various RPMs= . As on start up form a stand still the RPMs would drop below 2,200 and the c= ar sounded like a Brush Hog running over a pile of hammer heads. That is wha= t you want to avoid.=20 > >>>=20 > >>> Also when unloaded even at higher RPM. The same thing. So when feather= ing the throttle like in third gear. When the engine is not driving the whee= ls and the wheels are not driving the engine. Maybe as on final you might ge= t into this situation. So a bit more power, or, a bit less power will save t= he day. > >>>=20 > >>> The teem had a very competent engineer. My hands are still dirty......= ......... Lynn E. Hanover =20 > >>>=20 > >>> In a message dated 12/6/2020 5:28:22 PM Eastern Standard Time, flyrota= ry@lancaironline.net writes: > >>>=20 > >>> Thanks Dave. > >>>=20 > >>> Did you do away with your damper after your flax plate disintegrated/f= ailed over time, or was this still before Tracy changed his mind about the n= eed for the "higher frequency=E2=80=9D isolation provided by the damper? > >>>=20 > >>> I was trying to think about the forces at work on that thin steel plat= e apart from the torque of your boosted 300 hp. > >>> I was wondering about the gyroscopic (is that the right word) force cr= eated by that extra mass bolted to it, travelling at much higher velocity, a= nd then being asked to change direction with the subsequent =E2=80=9Cflexing= =E2=80=9D forces at play. > >>> Steve Boese=E2=80=99 science/engineering mind or Lynn Hanover=E2=80=99= s hands dirty experience appreciated at this point! > >>>=20 > >>> Thanks also to Dave Leonard for what we have learnt from your need for= speed, and Neil Unger=E2=80=99s relentless work on gearboxes. > >>>=20 > >>> So there being evidence of failure outside of aircraft use, I'll look i= nto another stronger starter ring gear. > >>>=20 > >>> BUT more to the point. what experience do we now have of removing the d= amper altogether? > >>> I thought this was the important question, because if not required, ap= pears to save significant: weight, cost, and maintenance. > >>>=20 > >>> Has there been further word from Tracy or anyone else flying the RD2 o= r other no-isolator setups? > >>> Tracy=E2=80=99s initial testing appeared promising but thats now some y= ears back. > >>>=20 > >>> Thanks heaps everyone. Couldn't have got this far without your brains,= pain, cheque book, experience etc. > >>>=20 > >>> Cheers > >>>=20 > >>> Steve Izett > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>=20 > >>>> On 7 Dec 2020, at 12:52 am, David Leonard wdleonard@gmail.com wrote: > >>>>=20 > >>>> Steve, you are right. The Issue is cracking og the auto-tranny flex p= late. Mine failed entirely. I highly recommend making the change sooner ra= ther than later. > >>>>=20 > >>>> Dave Leonard > >>>>=20 > >>>> On Sun, Dec 6, 2020, 12:48 AM Stephen Izett stephen.izett@gmail.com <= flyrotary@lancaironline.net> wrote: > >>>> Hi Charlie > >>>>=20 > >>>> I thought people moved to the race flywheels because the flex plates w= ere cracking. > >>>> I hadn=E2=80=99t heard of the Engine/Drive/Prop needing a flywheel ma= ss. > >>>> I found some info on the forum archive but nothing to draw it all tog= ether. > >>>> I=E2=80=99ll have a good look at the flexplate when I pull the drive a= nd check for cracking, but unless I hear otherwise I plan to reuse the flex p= late. > >>>>=20 > >>>> Thanks > >>>>=20 > >>>> Steve > >>>>=20 > >>>>=20 > >>>>=20 > >>>>=20 > >>>>=20 > >>>>=20 > >>>>> On 6 Dec 2020, at 8:58 am, Charlie England ceengland7@gmail.com wrote: > >>>>>=20 > >>>>> On 12/5/2020 6:35 PM, Stephen Izett stephen.izett@gmail.com wrote: > >>>>>> Hi team > >>>>>>=20 > >>>>>> Having completed phase #1 testing of the Glasair Super IIRG power b= y Renesis and RD1-C redrive, I=E2=80=99re going to pull the redrive for its 2= 5 hourly initial inspection. > >>>>>>=20 > >>>>>> Tracy deleted the damper assembly from the last rendition of his de= sign and I=E2=80=99m considering removing ours by creating a new adapter pla= te from the existing splined > >>>>>> part that is currently riveted to the damper and adding some longer= bolts and spacers. > >>>>>>=20 > >>>>>> Has anyone heard anything further in regard to RD receives with the= damper removed? > >>>>>> Has Tracy given any further updatess? > >>>>>> All I have read was after initial tests some years ago. > >>>>>>=20 > >>>>>> Cheers > >>>>>>=20 > >>>>>> Steve. > >>>>> Best I remember is that you need either an aluminum or steel racing f= lywheel, to get more mass on the engine side of the system. IIRC, it's also= limited to low mass (wood, etc) propellers. The ones he sold had a differen= t input shaft, but I think Dave Leonard modified his RD1-C & to use a steel r= acing flywheel which was only slightly heavier than the aluminum version. Se= arch for Dave's posts, if he doesn't chime in. I've been wondering if Guibo/= Rototflex couplers could be a viable alternative to the aluminum plate/rubbe= r discs. Probably would weigh more, and definitely cost more. > >>>>>=20 > >>>>> Charlie > >>>>>=20 > >>>>> -- > >>>>> This email has been checked for viruses by Avast antivirus software.= > >>>>> https://www.avast.com/antivirus > >>>>>=20 > >>>>>=20 > >>>>> -- > >>>>> Homepage: http://www.flyrotary.com/ > >>>>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary= /List.html > >>>>=20 > >>>>=20 > >>>> -- > >>>> Homepage: http://www.flyrotary.com/ > >>>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/= List.html > >>>=20 > >>>=20 > >>> -- > >>> Homepage: http://www.flyrotary.com/ > >>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/L= ist.html > >>=20 > >>=20 > >> -- > >> Homepage: http://www.flyrotary.com/ > >> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/Li= st.html > >=20 > >=20 > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/Lis= t.html-- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.= html --Apple-Mail-37367DC4-98BC-4513-A8F5-43DE82A1B00C Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable Yes your right there Lynn just forget to me= ntioned it.

Thanks for the =E2=80=9Crecap=E2=80=9D
<= div>



Sent from my iPhoneLe Roux Breytenbach 

On 07 Dec 2020, at 13:34, lehanover lehanover@aol.com <flyrotary@l= ancaironline.net> wrote:

=EF=BB=BF
Carbon fiber directly against steel may be poor practic= e. Typically fiberglass is used against steel and then carbon fiber over the= fiberglass. Carbon fiber is conductive and can corrode steel.  Lynn E.= Hanover 
 
In a message dated 12/7/2020 5:29:23 AM Eastern Standard Time, flyrotary@lan= caironline.net writes:
 
 
Hi : It was mentioned on P.L. newsletter a couple of years a= go - what if the flexplate center are reinforced with say 6 layers of carbon= fiber on both sides ?
The carbonfiber can be vacumebag and really good cured if d= oiing it from both sides.
The carbonfiber will lock from both sides face to face thre= w the bigger holes and will secure more than just on the metal itself.
=
Doiing the flexplate as a complete unit and then just cut a= nd machine the holes.
It will be ridged and light as well and counter the gyrosco= pic forces ect.that leads to cracks from the holes
Then the rubber dampener could still be put in place.
=
I am goiing to replace the center on this clutchplate with a= rubber dampener



Regards Le Roux


Sent from my= iPhone
Le Roux Breytenbach

> On 07 Dec 2020, at 09:07, Stephe= n Izett stephen.izett@gmail.com <flyrotary@lancaironlin= e.net> wrote:
>
> See below what Tracy wrote in Feb 2012= .
> Also found a note in the archive where Tracy mentions only produci= ng a few of the RD-2 boxes before retiring.
> So how many hours does T= racy=E2=80=99s RV4 with the damper removed now have on it.
> Sounds f= rom what some have said that he may have installed this mod to his 20B RV8 w= hich may have more time, however thats a 3 rotor. What difference would that= make I wonder?
> I take it the torque reversal and pulses will be th= e same magnitude but the sum of those pulses may have a different outcome fo= r anything connected.
>
> Cheers
>
> Steve Izett>
>
> email from Tracy back in Feb 2012 -
> "Finall= y got around to flight testing the aftermarket flywheel setup for the RWS re= drive.
>
> The cracked flexplate issue some builders experienc= ed came up at the same time as my CNC source for input shafts lost the abili= ty to make them anymore due to loss of specialized spline making machinery.&= nbsp; Since I had to line up a new source I took this opportunity to review t= he design from the input shaft back to the engine.  Because the damper h= as been such an expensive and labor intensive part, it was looked at as well= .  As a result, there have been enough changes to warrant a change in t= he name so the new drives will be RD-2B & RD-2C.
>
> In ret= hinking the drive I had the thought that since the relatively low frequency p= rimary resonance range of the drive train is taken care of by the system las= h, that left only the high frequency harmonics that the damper is responsibl= e for.  This high range is the factor that creates the red zone in rpm r= anges found on some certified engines and metal prop combinations.  As f= ar as I know, no one has used a metal prop on an RD-1x drive so I decided th= at it was an unneeded requirement.  The new design has no damper at all= and consequently it has a "No Metal Propeller" restriction.
>
>= ; Replacing the damper is a flanged spline that is bolted directly to the fl= ywheel using the same bolts (longer bolts required) that attach the flywheel= to the counterweight.  The spline is a different spec (15 splines inst= ead of 30) so it is not compatible with the RD-1 damper but the new shaft it= self is backward compatible with the remainder of the drive.  I retrofi= tted the same RD-1C that was on my RV-4 for these tests.
>
> Th= e flywheel was an aluminum racing flywheel with the replaceable iron frictio= n surface unbolted and removed.  Really looks pretty and professional c= ompared to the flexplate.  Any of the aftermarket RX-7 & RX-8 racin= g flywheels (steel or aluminum) that utilize the auto counterweight may be u= sed.
>
> As David Leonard found, these flywheels place the rin= g gear about .2" closer to the engine than the flexplate.  To compensat= e, I milled .2" off the front surface of the adapter plate where the starter= mounts.  No changes were needed to the starter itself.  I did not= bother to grind the lead-in bevel on the ring gear teeth as discussed earli= er.  Starter engagement was smooth anyway.
>
> The RV-4 dr= ive had over 700 hours on it and everything looked beautiful inside.  N= o signs of wear other than a shallow groove (~.002") on the input shaft wher= e the 1mm thrust bearing race between the two needle bearings rides.  O= thers have reported more than this in fewer hours so this is an area to insp= ect carefully.  The new input shaft is a harder alloy (post machining t= hrough hardened 4340) than the the RD-1 which was pre hardened 4140.  T= his should reduce the wear in this area.  The old flexplate with over 1= 000 hours was still crack free.  The input shaft oil seal still looked a= nd felt new so it was not replaced as planed.  Others have reported the= se leaking in much fewer hours.  Don't know the reason but I suspect th= at oil temperatures out of range may be a factor.  NEVER allow oil temp= s to exceed redline.  If they go higher, back off the power then land a= nd correct the cooling system.
>
> Only 1 hour of flight testin= g so far but all indications were good.  Operated the engine through th= e full range of rpm up to 7100 looking for tell-tale signs of resonance.&nbs= p; I was sort of expecting to feel, sense or hear some indication of increas= ed harshness in the drive with no rubber anywhere in the system but if anyth= ing, it felt smoother.  There was none of the 'Waaa --- Waaa' warbling s= ound (like a twin engine with the engines out of sync) that I had with the R= oss drive years ago.  So far I'm very satisfied with the results but it= 's still early in the tests.=E2=80=9D
>
>
>
> >
>> On 7 Dec 2020, at 9:47 am, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
= >>
>> Thanks Lynn.
>>
>> Steve
>>= ;
>>
>>>> On 7 Dec 2020, at 9:04 am, lehanover lehanover@aol.com <flyrotary@lancaironline.net> wrote:
= >>>
>>> If you have picked up a stock manual transmiss= ion flywheel for a rotary, you must know that "Houston we have a problem". S= o the worst pick for a car engine becomes the best pick for smoothness at id= le. That flywheel is the answer. The less flywheel effect available the more= powerful the reversals near idle. The more powerful the reversals the short= er the flex plate life. The flex plate drives the car through a hydraulic da= mper. So it is with the aircraft. No damper, short life. There are companies= who make little tiny shock absorbers. I thought that 4 such shocks on a rac= ing flywheel pushing a driven disc should do the job. Even stock flex plates= from piston powered cars get cracks. Few fail completely.
>>> <= br>>>> I think Tracy's pucks are adequate. Just double up the flex p= late to just outboard of the puck housings. No welding. Use nuts and bolts.&= nbsp; It also adds actual flywheel effect which reduces the stress.  >>> For the racer I made a steel button flywheel. Just large enou= gh to support a 2 disc 5 1/4" clutch. I bolted this on over the stock flex p= late. The flex plate was just used to start the engine and nothing else. I t= urned down the face of the counter weight so as to provide a taller spigot t= o locate the flex plate and the flywheel. Piece of cake.
>>> >>> The racer used a straight cut gear dog ring style gear box fr= om Saenz in Argentina. The gears had enough clearance so as to agree with va= rious RPMs. As on start up form a stand still the RPMs would drop below 2,20= 0 and the car sounded like a Brush Hog running over a pile of hammer heads. T= hat is what you want to avoid.
>>>
>>> Also when u= nloaded even at higher RPM. The same thing. So when feathering the throttle l= ike in third gear. When the engine is not driving the wheels and the wheels a= re not driving the engine. Maybe as on final you might get into this situati= on. So a bit more power, or, a bit less power will save the day.
>>= >
>>> The teem had a very competent engineer. My hands are s= till dirty............... Lynn E. Hanover 
>>>
>>= ;> In a message dated 12/6/2020 5:28:22 PM Eastern Standard Time, flyrotary@lancaironline.net writ= es:
>>>
>>> Thanks Dave.
>>>
>&g= t;> Did you do away with your damper after your flax plate disintegrated/= failed over time, or was this still before Tracy changed his mind about the n= eed for the "higher frequency=E2=80=9D isolation provided by the damper?
= >>>
>>> I was trying to think about the forces at work= on that thin steel plate apart from the torque of your boosted 300 hp.
&= gt;>> I was wondering about the gyroscopic (is that the right word) fo= rce created by that extra mass bolted to it, travelling at much higher veloc= ity, and then being asked to change direction with the subsequent =E2=80=9Cf= lexing=E2=80=9D forces at play.
>>> Steve Boese=E2=80=99 science= /engineering mind or Lynn Hanover=E2=80=99s hands dirty experience appreciat= ed at this point!
>>>
>>> Thanks also to Dave Leona= rd for what we have learnt from your need for speed, and Neil Unger=E2=80=99= s relentless work on gearboxes.
>>>
>>> So there be= ing evidence of failure outside of aircraft use, I'll look into another stro= nger starter ring gear.
>>>
>>> BUT more to the poi= nt. what experience do we now have of removing the damper altogether?
>= ;>> I thought this was the important question, because if not required= , appears to save significant: weight, cost, and maintenance.
>>>= ;
>>> Has there been further word from Tracy or anyone else fly= ing the RD2 or other no-isolator setups?
>>> Tracy=E2=80=99s ini= tial testing appeared promising but thats now some years back.
>>&g= t;
>>> Thanks heaps everyone. Couldn't have got this far withou= t your brains, pain, cheque book, experience etc.
>>>
>&g= t;> Cheers
>>>
>>> Steve Izett
>>> <= br>>>>
>>>
>>>
>>>
>&= gt;>
>>>
>>>
>>>
>>>&= gt; On 7 Dec 2020, at 12:52 am, David Leonard wdleonard@gmail.com <flyrotary@lancaironline.net> wrote:
>>>>
&= gt;>>> Steve, you are right.  The Issue is cracking og the aut= o-tranny flex plate.  Mine failed entirely.  I highly recommend ma= king the change sooner rather than later.
>>>>
>>&g= t;> Dave Leonard
>>>>
>>>> On Sun, Dec 6, 2= 020, 12:48 AM Stephen Izett steph= en.izett@gmail.com <fl= yrotary@lancaironline.net> wrote:
>>>> Hi Charlie
&= gt;>>>
>>>> I thought people moved to the race flyw= heels because the flex plates were cracking.
>>>> I hadn=E2=80= =99t heard of the Engine/Drive/Prop needing a flywheel mass.
>>>= > I found some info on the forum archive but nothing to draw it all toget= her.
>>>> I=E2=80=99ll have a good look at the flexplate when= I pull the drive and check for cracking, but unless I hear otherwise I plan= to reuse the flex plate.
>>>>
>>>> Thanks>>>>
>>>> Steve
>>>>
>>= ;>>
>>>>
>>>>
>>>> >>>>
>>>>> On 6 Dec 2020, at 8:58 am, Charli= e England ceengland7@gmail.com &= lt;flyrotary@lancaironline.ne= t> wrote:
>>>>>
>>>>> On 12/5/20= 20 6:35 PM, Stephen Izett stephen= .izett@gmail.com wrote:
>>>>>> Hi team
>>&= gt;>>>
>>>>>> Having completed phase #1 testi= ng of the Glasair Super IIRG power by Renesis and RD1-C redrive, I=E2=80=99r= e going to pull the redrive for its 25 hourly initial inspection.
>>= ;>>>>
>>>>>> Tracy deleted the damper asse= mbly from the last rendition of his design and I=E2=80=99m considering remov= ing ours by creating a new adapter plate from the existing splined
>&g= t;>>>> part that is currently riveted to the damper and adding s= ome longer bolts and spacers.
>>>>>>
>>>&g= t;>> Has anyone heard anything further in regard to RD receives with t= he damper removed?
>>>>>> Has Tracy given any further u= pdatess?
>>>>>> All I have read was after initial tests= some years ago.
>>>>>>
>>>>>> Ch= eers
>>>>>>
>>>>>> Steve.
>= >>>> Best I remember is that you need either an aluminum or stee= l racing flywheel, to get more mass on the engine side of the system.  I= IRC, it's also limited to low mass (wood, etc) propellers. The ones he sold h= ad a different input shaft, but I think Dave Leonard modified his RD1-C &= ; to use a steel racing flywheel which was only slightly heavier than the al= uminum version. Search for Dave's posts, if he doesn't chime in. I've been w= ondering if Guibo/Rototflex couplers could be a viable alternative to the al= uminum plate/rubber discs. Probably would weigh more, and definitely cost mo= re.
>>>>>
>>>>> Charlie
>>>= >>
>>>>> --
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>>>>>
>>= >>>
>>>>> --
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>>>>
>>>>
>>&g= t;> --
>>>> Homepage:  http://www.flyrotary.com/
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>>> <= br>>>>
>>> --
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&g= t;
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