X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) From: "Ernest Christley echristley@att.net" Received: from sonic310-24.consmr.mail.gq1.yahoo.com ([98.137.69.150] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 1016699 for flyrotary@lancaironline.net; Mon, 07 Dec 2020 09:20:27 -0500 Received-SPF: none receiver=logan.com; client-ip=98.137.69.150; envelope-from=echristley@att.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1607350809; bh=ezflQA3RlbMfG0Hg9rmjQFiozZ0JqS10Z80Is5ZSh2g=; h=Date:From:To:In-Reply-To:References:Subject:From:Subject; b=ajtdjQ4nf4MFuWtmiRYCaoU6+dp6ys4HBBgHs8CEn3UapsGl9j+JSYTrlRsCNrjz5uQ/zlJAAueSNK/x3VVJn72U+bCZ61omOHhWbvs65KG7fK1TLfPXUZYBamXNhe2Fm15G/8GOw1SJG1EZQyoJmwBZ7xm2ha+hLDj94SsVwb4= X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1607350809; bh=rnpEByQN4qZzWuLdy1DKtCi2GY4upvLyg3RT3SeMLpK=; h=Date:From:To:Subject:From:Subject; b=aE2PBLKQkM5xqoYQwlaLUiJDkwuBARiF3prQ4l4lEdLk8/+6aDrq8ZRX1lU2aAiLT1XRC2GYNx9HEvEljYT+4XZnnW65CWv/mOOh7rinGE1xDKPRXjKvIdPZFRiaQTzc63pWehVPrqQAADayxIgOh8CNIDcwRflloqJFn/Rh2aGGL28Y/I1u+wBYYv0M5Cf/i8ASd+Ig8nQKBhgEYj92lqU0BvYRSlBACrMiNSZCkWr2oXkSNJYkejJKgdt341uMr1srIfUMScUuJjC6mxmQDAYcp3+BRtH3RBRMfhkF2WNzUdkDz4b5CcXcqx2HmguoeguzsFzh/MVlSRDkTdk4UQ== X-YMail-OSG: dQn.3xIVM1lB2e4gQJojKwiXX8FC6yGTkba0youdErfUqIQG_jES1zlEFNNV.zu VEbaRp8hpdFl3Rs71_1nTMs0sPAzb1WhV3HC56Uva0pB4Ix23XtaMKDO4qnIGvtCWOVrnIotuiyb _Oo._o6_reazMrDFGogAHsW2KQ5CPHC13p.Lt2NExUsqZnyr1WvqxfMAJjS.AImydQzhM_oM2cdM jXzrvPp4IDb9iFcRtZ0oEyDrYeLAUEeixwuzUKkACJaC4KIO6ncgBOEKh5fJMpslnQI430BTqxaC RsbiCB_a9SiW6DRLtbBJm2koq8KAjwit2c9YRnUk6N65fxOQhZVw3.4wY.kYQtvQ1lQl0JaCOD5z t_WfxVnKiRPuIy4EZo5bQacDSyjoD4rvOJT6tDe1QYpFslWKVH1tScbigGtJNhX7Ainftd817kj6 TDN2KVYhKthwlOeyqsvvbnQ0Rn31RD1ZbFBoD4taH_h8yvUnmcFtpKjwrHoi5j4z7KROY7cPYW.0 QJHEQMEVEGlDHOjtUkhiQ6ROQ5KcIMNox5lrukvjNLJrW9244woeb2JU1tKRmFw2knXH1nBhz7cd HGHFZlRLH4u7Ky8CqcOrqw36zRkeG8EV3hNfI4yTBd9aIH3HUP7S3Uh_s11_YU8JEay95hcWsWxO mvGqpTVN3a14Z74KIlNe.Xyls3bwzBMoc09AMbKD.LhNDZxtgFLa40uVSCdVTL5u6lrHtouA6VXt DvGDs1X9aXiXxTmCk8KoSJEDhjB47UTZVj5QtX3OnJajO_QJNJCEbUk_Bk9HkwrXfskMalY4J3Vc O9bmjjyUcJaa48ADf4e7CLiOziPZF2DVGXvBn7T9zaCeW5l.ZC1YqbewAii4toFZCDCKRBO155TP OnshEwVeLh98Uj3g.N.WK1ZbRvTGq.Ays9I9fHdWvaKFJGHpsCq8Cr_g_gxRweMkjy6F1QJ1AkvS Kbuy9OcfTJqm20lxMp_tMqW1PAAFXM7qGQSlxiorx6VSlhgrrmkxJH0_oyFaZSghGuuXuctcKrAi F6FRfwHJRJxAX1YJvw9J_eMwzV868CYHcNcs_simuWdjZmf6yQnzjN9LRUGTT6jxy8AQqMHYvXkV o0bX4_8JEb9l81YL1i71cKmTPUOC08YwCOBcn6sTPrZYSdJpyAluwmYNbOsiD4qwzWWvxgnW3XIX p.KsTypjkrMkmDpD60_b.GcoeaXZG323x1nAnUSHu9sqKS8y_8na2S_AMDr1NX6Myj4jgmzfHKVE nhGKzv3ZEnGRkGSFpDFXoh4yq33uNlqfeQrocWg5pKiPbrT52DX4rsLoW51kkI44KcX1U58yrkKa 7YF.s9bmV1KBhSNIidPJ9ly8CLyGC3dZIyG9.zep7.GhvLBL9SQ17EiwBXiTx5woRvXq8MmFfKjB 7w0rHAMlYdgTrRBuInEM5oU50coinjlAh05f.6OUM88XkQOuRLLpE0V_8c29mIn.2T4r82XD7i_w UWqXBGStQaDqCZ0zodO64RJj8CtNnobIWbX_m59Cr87e9BAafGtYMCTx_tcHtwj_AtH2off2DyPW DCjyo_vNfgo9KQ1wK7vqhJgyPwJ_yjB_8DEQHPO8umzDmxUTQaOVgvgdVDhc0Zg.h1.4SA.wDH_u xsV.1uoeGsB7cjjzqDai21GmFtxD.QjSb54hsV_clwU262sX7HxAQTZeJVdEJAisZ07vn1YgDknz RxvK_HLoQczkr2seojdL648NKElaLzSSDr9er2RAXFBaJj6_WZkPXNxUHTiXolG5Wao0G9hP6rqE _mu4wHwYz41an5WiALaX3QbyXq2EusQnTX065rjLkdHIT.K9pG20p5rSxYYZ30eP4F3ElgUjFMGX z9BwVUS.KGfJQ3O9VMTUjuU3jcZZDaQefBy2NSOM921bsw9lGGjlUA5xJrTfL4YMD83qrqi9GpjD jib.BRiLGh8C9d5FSEzZMhUh2.VHy7Tl3TauRxQMaSfw6IMk1GI0UxG8CJL_fNCQQtziQU5q6dZe MwRkJqYUQnmDuUcpzYzWv1rUtUQDB9buircjgbDy9k2EIgqJyiykGTEKiY97Nd7t.KMQPxu.jgn. Pb1JyvdMi.VqsXVf2UFsK0dukGrKgevkKVU3WNIgxnTphKTc039CzbwXvmexQEpvfa_QX9GwU..r TEH7Zlsv5g3ym8qPQ1t6Pf_Cmmff9.bvm5IChv1i3R9IWR2vJhfTZ_9gwf6KoiG4hpuh393kn_tZ RqptHRLXsBLUvvYc196Eaa17lf8TWxv91xa3irKrYVEQ5_tbTJZyyClxHzKcZ4vpXTQbJeD4bVCe 2gECh0RPjjdnSXSR_gA8yFmBk._2w4uqfRVDzzVrjUHkB3UyOD30vVVNHQJ5llbZ_O5dEBhEl3nx HNNdtQHjS9aN9_FyOsDKfS1uX9YlQ.m6PLucKN0sA0R8ryd1ob4FIfrpqhjm0 Received: from sonic.gate.mail.ne1.yahoo.com by sonic310.consmr.mail.gq1.yahoo.com with HTTP; Mon, 7 Dec 2020 14:20:09 +0000 Date: Mon, 7 Dec 2020 14:20:05 +0000 (UTC) To: "Le Roux Breytenbach breytenbachleroux@gmail.com" Message-ID: <504549755.4478317.1607350805101@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: RD1-C damper MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_4478316_378153556.1607350805094" X-Mailer: WebService/1.1.17111 YMailNorrin Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:83.0) Gecko/20100101 Firefox/83.0 Content-Length: 33563 ------=_Part_4478316_378153556.1607350805094 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable The temperature in that area will range from around 180F to well below fre= ezing on a cold night, resulting in a lot of differential expansion.=C2=A0 = Epoxy is basically plastic.=C2=A0 It is going to soften in use, when its st= rength is needed most. This is something I'd probably try, but I wouldn't bet money that it would = work. On Monday, December 7, 2020, 5:29:25 AM EST, Le Roux Breytenbach breyte= nbachleroux@gmail.com wrote: =20 =20 =20 Hi : It was mentioned on P.L. newsletter a couple of years ago - what if th= e flexplate center are reinforced with say 6 layers of carbonfiber on both = sides ? The carbonfiber can be vacumebag and really good cured if doiing it from bo= th sides. The carbonfiber will lock from both sides face to face threw the bigger hol= es 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.t= hat leads to cracks from the holes=20 Then the rubber dampener could still be put in place. I am goiing to replace the center on this clutchplate with a rubber dampene= r Regards Le Roux Sent from my iPhone Le Roux Breytenbach=20 > On 07 Dec 2020, at 09:07, Stephen Izett stephen.izett@gmail.com wrote: >=20 > =EF=BB=BFSee below what Tracy wrote in Feb 2012. > Also found a note in the archive where Tracy mentions only producing a fe= w of the RD-2 boxes before retiring. > So how many hours does Tracy=E2=80=99s RV4 with the damper removed now ha= ve on it.=20 > Sounds from what some have said that he may have installed this mod to hi= s 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 same= time as my CNC source for input shafts lost the ability to make them anymo= re due to loss of specialized spline making machinery.=C2=A0 Since I had to= line up a new source I took this opportunity to review the design from the= input shaft back to the engine.=C2=A0 Because the damper has been such an = expensive and labor intensive part, it was looked at as well.=C2=A0 As a re= sult, 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= system lash, that left only the high frequency harmonics that the damper i= s responsible for.=C2=A0 This high range is the factor that creates the red= zone in rpm ranges found on some certified engines and metal prop combinat= ions.=C2=A0 As far as I know, no one has used a metal prop on an RD-1x driv= e so I decided that it was an unneeded requirement.=C2=A0 The new design ha= s no damper at all and consequently it has a "No Metal Propeller" restricti= on. >=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 flywhe= el to the counterweight.=C2=A0 The spline is a different spec (15 splines i= nstead of 30) so it is not compatible with the RD-1 damper but the new shaf= t itself is backward compatible with the remainder of the drive.=C2=A0 I re= trofitted the same RD-1C that was on my RV-4 for these tests. >=20 > The flywheel was an aluminum racing flywheel with the replaceable iron fr= iction surface unbolted and removed.=C2=A0 Really looks pretty and professi= onal compared to the flexplate.=C2=A0 Any of the aftermarket RX-7 & RX-8 ra= cing flywheels (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" clo= ser to the engine than the flexplate.=C2=A0 To compensate, I milled .2" off= the front surface of the adapter plate where the starter mounts.=C2=A0 No = changes were needed to the starter itself.=C2=A0 I did not bother to grind = the lead-in bevel on the ring gear teeth as discussed earlier.=C2=A0 Starte= r engagement was smooth anyway. >=20 > The RV-4 drive had over 700 hours on it and everything looked beautiful i= nside.=C2=A0 No signs of wear other than a shallow groove (~.002") on the i= nput shaft where the 1mm thrust bearing race between the two needle bearing= s rides.=C2=A0 Others have reported more than this in fewer hours so this i= s an area to inspect carefully.=C2=A0 The new input shaft is a harder alloy= (post machining through hardened 4340) than the the RD-1 which was pre har= dened 4140.=C2=A0 This should reduce the wear in this area.=C2=A0 The old f= lexplate with over 1000 hours was still crack free.=C2=A0 The input shaft o= il seal still looked and felt new so it was not replaced as planed.=C2=A0 O= thers have reported these leaking in much fewer hours.=C2=A0 Don't know the= reason but I suspect that oil temperatures out of range may be a factor.= =C2=A0 NEVER allow oil temps to exceed redline.=C2=A0 If they go higher, ba= ck off the power then land and correct the cooling system. >=20 > Only 1 hour of flight testing so far but all indications were good.=C2=A0= Operated the engine through the full range of rpm up to 7100 looking for t= ell-tale signs of resonance.=C2=A0 I was sort of expecting to feel, sense o= r hear some indication of increased harshness in the drive with no rubber a= nywhere in the system but if anything, it felt smoother.=C2=A0 There was no= ne of the 'Waaa --- Waaa' warbling sound (like a twin engine with the engin= es out of sync) that I had with the Ross drive years ago.=C2=A0 So far I'm = very satisfied with the results 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 rotary= , 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 th= e answer. The less flywheel effect available the more powerful the reversal= s near idle. The more powerful the reversals the shorter the flex plate lif= e. The flex plate drives the car through a hydraulic damper. So it is with = the aircraft. No damper, short life. There are companies who make little ti= ny shock absorbers. I thought that 4 such shocks on a racing flywheel pushi= ng a driven disc should do the job. Even stock flex plates from piston powe= red cars get cracks. Few fail completely. >>>=20 >>> I think Tracy's pucks are adequate. Just double up the flex plate to ju= st outboard of the puck housings. No welding. Use nuts and bolts.=C2=A0 It = also adds actual flywheel effect which reduces the stress.=C2=A0=20 >>> For the racer I made a steel button flywheel. Just large enough to supp= ort 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 do= wn the face of the counter weight so as to provide a taller spigot to locat= e the 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 RPM= s. As on start up form a stand still the RPMs would drop below 2,200 and th= e car sounded like a Brush Hog running over a pile of hammer heads. That is= what you want to avoid.=20 >>>=20 >>> Also when unloaded even at higher RPM. The same thing. So when featheri= ng 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 g= et into this situation. So a bit more power, or, a bit less power will save= the day. >>>=20 >>> The teem had a very competent engineer. My hands are still dirty.......= ........ Lynn E. Hanover=C2=A0=20 >>>=20 >>> In a message dated 12/6/2020 5:28:22 PM Eastern Standard Time, flyrotar= y@lancaironline.net writes: >>>=20 >>> Thanks Dave. >>>=20 >>> Did you do away with your damper after your flax plate disintegrated/fa= iled 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 plate= apart from the torque of your boosted 300 hp. >>> I was wondering about the gyroscopic (is that the right word) force cre= ated 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=9Cflexin= g=E2=80=9D forces at play. >>> Steve Boese=E2=80=99 science/engineering mind or Lynn Hanover=E2=80=99s= 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, app= ears to save significant: weight, cost, and maintenance. >>>=20 >>> Has there been further word from Tracy or anyone else flying the RD2 or= 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.=C2=A0 The Issue is cracking og the auto-tranny f= lex plate.=C2=A0 Mine failed entirely.=C2=A0 I highly recommend making the = change sooner rather than later. >>>>=20 >>>> Dave Leonard >>>>=20 >>>> On Sun, Dec 6, 2020, 12:48 AM Stephen Izett stephen.izett@gmail.com 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 mas= s. >>>> I found some info on the forum archive but nothing to draw it all toge= ther. >>>> 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= plate. >>>>=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 by= Renesis and RD1-C redrive, I=E2=80=99re going to pull the redrive for its = 25 hourly initial inspection. >>>>>>=20 >>>>>> Tracy deleted the damper assembly from the last rendition of his des= ign 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.=C2=A0 IIRC, it'= s also limited to low mass (wood, etc) propellers. The ones he sold had a d= ifferent input shaft, but I think Dave Leonard modified his RD1-C & to use = a steel racing flywheel which was only slightly heavier than the aluminum v= ersion. Search for Dave's posts, if he doesn't chime in. I've been wonderin= g if Guibo/Rototflex couplers could be a viable alternative to the aluminum= plate/rubber 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:=C2=A0 http://www.flyrotary.com/ >>>>> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyro= tary/List.html >>>>=20 >>>>=20 >>>> -- >>>> Homepage:=C2=A0 http://www.flyrotary.com/ >>>> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrot= ary/List.html >>>=20 >>>=20 >>> -- >>> Homepage:=C2=A0 http://www.flyrotary.com/ >>> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrota= ry/List.html >>=20 >>=20 >> -- >> Homepage:=C2=A0 http://www.flyrotary.com/ >> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrotar= y/List.html >=20 >=20 > -- > Homepage:=C2=A0 http://www.flyrotary.com/ > Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrotary= /List.html-- Homepage:=C2=A0 http://www.flyrotary.com/ Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/flyrotary/L= ist.html =20 ------=_Part_4478316_378153556.1607350805094 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The temperature in that area= will range from around 180F to well below freezing on a cold night, result= ing in a lot of differential expansion.  Epoxy is basically plastic.&n= bsp; It is going to soften in use, when its strength is needed most.
<= div dir=3D"ltr" data-setdir=3D"false">
This is something I'd probably try, but I wouldn't bet money th= at it would work.

=20
=20
On Monday, December 7, 2020, 5:29:25 AM EST, Le Roux Br= eytenbach breytenbachleroux@gmail.com <flyrotary@lancaironline.net> w= rote:



Hi : It wa= s mentioned on P.L. newsletter a couple of years ago - what if the flexplat= e center are reinforced with say 6 layers of carbonfiber on both sides ?
The carbonfiber can be vacumebag and really good cu= red if doiing it from both sides.
The carbonfiber= will lock from both sides face to face threw the bigger holes and will sec= ure more than just on the metal itself.
Doiing th= e flexplate as a complete unit and then just cut and machine the holes.
=
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 dampener



Regards Le Roux


Sent from my i= Phone
Le Roux Breytenbach

> On 07 Dec 2020, at 09:07, Stephen= Izett stephen.izett@gmail.com <flyrot= ary@lancaironline.net> wrote:
>
> =EF=BB=BFSee below wh= at Tracy wrote in Feb 2012.
> Also found a note in the archive where = Tracy mentions only producing a few of the RD-2 boxes before retiring.
&= gt; So how many hours does Tracy=E2=80=99s RV4 with the damper removed now = have on it.
> Sounds from what some have said that he may have insta= lled this mod to his 20B RV8 which may have more time, however thats a 3 ro= tor. What difference would that make I wonder?
> I take it the torqu= e reversal and pulses will be the same magnitude but the sum of those pulse= s may have a different outcome for anything connected.
>
> Che= ers
>
> Steve Izett
>
>
> email from Tracy= back in Feb 2012 -
> "Finally got around to flight testing the after= market flywheel setup for the RWS redrive.
>
> The cracked fl= explate issue some builders experienced came up at the same time as my CNC = source for input shafts lost the ability to make them anymore due to loss o= f specialized spline making machinery.  Since I had to line up a new s= ource I took this opportunity to review the design from the input shaft bac= k 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 ha= ve been enough changes to warrant a change in the name so the new drives wi= ll be RD-2B & RD-2C.
>
> In rethinking the drive I had the= thought that since the relatively low frequency primary resonance range of= the drive train is taken care of by the system lash, that left only the hi= gh frequency harmonics that the damper is responsible for.  This high = range is the factor that creates the red zone in rpm ranges found on some c= ertified engines and metal prop combinations.  As far as I know, no o= ne has used a metal prop on an RD-1x drive so I decided that it was an unne= eded requirement.  The new design has no damper at all and consequentl= y it has a "No Metal Propeller" restriction.
>
> Replacing the= damper is a flanged spline that is bolted directly to the flywheel using t= he same bolts (longer bolts required) that attach the flywheel to the count= erweight.  The spline is a different spec (15 splines instead of 30) s= o it is not compatible with the RD-1 damper but the new shaft itself is bac= kward compatible with the remainder of the drive.  I retrofitted the s= ame RD-1C that was on my RV-4 for these tests.
>
> The flywhee= l was an aluminum racing flywheel with the replaceable iron friction surfac= e unbolted and removed.  Really looks pretty and professional compared= to the flexplate.  Any of the aftermarket RX-7 & RX-8 racing flyw= heels (steel or aluminum) that utilize the auto counterweight may be used. =
>
> As David Leonard found, these flywheels place the ring ge= ar about .2" closer to the engine than the flexplate.  To compensate, = I milled .2" off the front surface of the adapter plate where the starter m= ounts.  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 earl= ier.  Starter engagement was smooth anyway.
>
> The RV-4= drive had over 700 hours on it and everything looked beautiful inside.&nbs= p; No signs of wear other than a shallow groove (~.002") on the input shaft= where the 1mm thrust bearing race between the two needle bearings rides.&n= bsp; Others have reported more than this in fewer hours so this is an area = to inspect carefully.  The new input shaft is a harder alloy (post mac= hining through hardened 4340) than the the RD-1 which was pre hardened 4140= .  This should reduce the wear in this area.  The old flexplate = with over 1000 hours was still crack free.  The input shaft oil seal = still looked and felt new so it was not replaced as planed.  Others ha= ve reported these leaking in much fewer hours.  Don't know the reason = but I suspect that oil temperatures out of range may be a factor.  NEV= ER allow oil temps to exceed redline.  If they go higher, back off the= power then land and correct the cooling system.
>
> Only 1 ho= ur of flight testing so far but all indications were good.  Operated t= he engine through the full range of rpm up to 7100 looking for tell-tale si= gns of resonance.  I was sort of expecting to feel, sense or hear som= e indication of increased harshness in the drive with no rubber anywhere in= the 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) that I had with the Ross drive years ago.  So far I'm very satis= fied with the results but it's still early in the tests.=E2=80=9D
> <= br>>
>
>
>
>> 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:
>>> <= br>>>> If you have picked up a stock manual transmission flywheel = for a rotary, you must know that "Houston we have a problem". So the worst = pick for a car engine becomes the best pick for smoothness at idle. That fl= ywheel is the answer. The less flywheel effect available the more powerful = the reversals near idle. The more powerful the reversals the shorter the fl= ex plate life. The flex plate drives the car through a hydraulic damper. So= it is with the aircraft. No damper, short life. There are companies who ma= ke little tiny shock absorbers. I thought that 4 such shocks on a racing fl= ywheel pushing a driven disc should do the job. Even stock flex plates from= piston powered cars get cracks. Few fail completely.
>>>
&= gt;>> I think Tracy's pucks are adequate. Just double up the flex pla= te to just outboard of the puck housings. No welding. Use nuts and bolts.&n= bsp; It also adds actual flywheel effect which reduces the stress.  >>> For the racer I made a steel button flywheel. Just large eno= ugh to support 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 down the face of the counter weight so as to provide a taller spig= ot to locate the flex plate and the flywheel. Piece of cake.
>>&g= t;
>>> The racer used a straight cut gear dog ring style gear = box from Saenz in 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 be= low 2,200 and the car sounded like a Brush Hog running over a pile of hamme= r heads. That is what you want to avoid.
>>>
>>> = Also when unloaded even at higher RPM. The same thing. So when feathering t= he throttle like in third gear. When the engine is not driving the wheels a= nd the wheels are not driving the engine. Maybe as on final you might get i= nto this situation. So a bit more power, or, a bit less power will save the= day.
>>>
>>> The teem had a very competent engine= er. My hands are still dirty............... Lynn E. Hanover 
>&= gt;>
>>> In a message dated 12/6/2020 5:28:22 PM Eastern St= andard Time, flyrotary@lancaironline.net writes:
= >>>
>>> Thanks Dave.
>>>
>>>= Did you do away with your damper after your flax plate disintegrated/faile= d over time, or was this still before Tracy changed his mind about the need= for the "higher frequency=E2=80=9D isolation provided by the damper?
&g= t;>>
>>> 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) f= orce created by that extra mass bolted to it, travelling at much higher vel= ocity, and then being asked to change direction with the subsequent =E2=80= =9Cflexing=E2=80=9D forces at play.
>>> Steve Boese=E2=80=99 sc= ience/engineering mind or Lynn Hanover=E2=80=99s hands dirty experience app= reciated at this point!
>>>
>>> Thanks also to Dav= e Leonard for what we have learnt from your need for speed, and Neil Unger= =E2=80=99s relentless work on gearboxes.
>>>
>>> S= o there being evidence of failure outside of aircraft use, I'll look into a= nother stronger starter ring gear.
>>>
>>> BUT mor= e to the point. what experience do we now have of removing the damper altog= ether?
>>> I thought this was the important question, because i= f not required, appears to save significant: weight, cost, and maintenance.=
>>>
>>> Has there been further word from Tracy or= anyone else flying the RD2 or other no-isolator setups?
>>> Tr= acy=E2=80=99s initial testing appeared promising but thats now some years b= ack.
>>>
>>> Thanks heaps everyone. Couldn't have = got this far without your brains, pain, cheque book, experience etc.
>= ;>>
>>> Cheers
>>>
>>> Steve Iz= ett
>>>
>>>
>>>
>>>
= >>>
>>>
>>>
>>>
>>= ;>
>>>> On 7 Dec 2020, at 12:52 am, David Leonard wdl= eonard@gmail.com <flyrotary@lancaironline.net= > wrote:
>>>>
>>>> Steve, you are right.&= nbsp; The Issue is cracking og the auto-tranny flex plate.  Mine faile= d entirely.  I highly recommend making the change sooner rather than l= ater.
>>>>
>>>> Dave Leonard
>>>= >
>>>> On Sun, Dec 6, 2020, 12:48 AM Stephen Izett stephen.izett@gmail.com <flyrotary@lancairo= nline.net> wrote:
>>>> Hi Charlie
>>>>=
>>>> I thought people moved to the race flywheels because = the flex plates were cracking.
>>>> I hadn=E2=80=99t heard o= f the Engine/Drive/Prop needing a flywheel mass.
>>>> I foun= d some info on the forum archive but nothing to draw it all together.
&g= t;>>> I=E2=80=99ll have a good look at the flexplate when I pull t= he drive and check for cracking, but unless I hear otherwise I plan to reus= e the flex plate.
>>>>
>>>> Thanks
>&g= t;>>
>>>> Steve
>>>>
>>>&= gt;
>>>>
>>>>
>>>>
>= >>>
>>>>> On 6 Dec 2020, at 8:58 am, Charlie En= gland ceengland7@gmail.com <flyrotary@lancai= ronline.net> wrote:
>>>>>
>>>>>= On 12/5/2020 6:35 PM, Stephen Izett stephen.izett@gmail.com= wrote:
>>>>>> Hi team
>>>>>> >>>>>> Having completed phase #1 testing of the Glasair = Super IIRG power by Renesis and RD1-C redrive, I=E2=80=99re going to pull t= he redrive for its 25 hourly initial inspection.
>>>>>>= ;
>>>>>> Tracy deleted the damper assembly from the l= ast rendition of his design and I=E2=80=99m considering removing ours by cr= eating a new adapter plate from the existing splined
>>>>>= ;> part that is currently riveted to the damper and adding some longer b= olts and spacers.
>>>>>>
>>>>>> = Has anyone heard anything further in regard to RD receives with the damper = removed?
>>>>>> Has Tracy given any further updatess?<= br>>>>>>> All I have read was after initial tests some ye= ars ago.
>>>>>>
>>>>>> Cheers>>>>>>
>>>>>> Steve.
>>&g= t;>> Best I remember is that you need either an aluminum or steel rac= ing flywheel, 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 ha= d 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 a= luminum version. Search 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/rubber discs. Probably would weigh more, and definitely cos= t more.
>>>>>
>>>>> Charlie
>>= ;>>>
>>>>> --
>>>>> This emai= l has been checked for viruses by Avast antivirus software.
>>>= >> http= s://www.avast.com/antivirus
>>>>>
>>>>= ;>
>>>>> --
>>>>> Homepage:  <= a href=3D"http://www.flyrotary.com/" target=3D"_blank">http://www.flyrotary= .com/
>>>>> Archive and UnSub:  ht= tp://mail.lancaironline.net:81/lists/flyrotary/List.html
>>>= ;>
>>>>
>>>> --
>>>> Home= page:  http://= www.flyrotary.com/
>>>> Archive and UnSub:  http://mail.lancaironline.net:81/lists/flyrotary/List.html
&g= t;>>
>>>
>>> --
>>> Homepage:&n= bsp; http://www.fly= rotary.com/
>>> Archive and UnSub:  http= ://mail.lancaironline.net:81/lists/flyrotary/List.html
>>
= >>
>> --
>> Homepage:  http://www.flyrotary.com/
>>= Archive and UnSub:  http://mail.lancaironline.net:81/l= ists/flyrotary/List.html
>
>
> --
> Homepage:=   http://www.f= lyrotary.com/
> Archive and UnSub:  http://ma= il.lancaironline.net:81/lists/flyrotary/List.html--
Homepage:  = http://www.flyrotar= y.com/
Archive and UnSub:  http://mail.lancairon= line.net:81/lists/flyrotary/List.html
------=_Part_4478316_378153556.1607350805094--