X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-iw0-f180.google.com ([209.85.214.180] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTPS id 5054702 for flyrotary@lancaironline.net; Sun, 17 Jul 2011 15:28:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.180; envelope-from=rwstracy@gmail.com Received: by iwn9 with SMTP id 9so2317034iwn.25 for ; Sun, 17 Jul 2011 12:28:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=DRCFO66G1kx9gvkt1aYfCQZ4iDYTPiQHKosT4+FYBYY=; b=fap8o/JNEw8+IKW8ApuS3g1tE49QPbtXvGMq5bc7LhsG0/MS6rCBdt3dq08E2dfJAS OFxw50U4wQqtNijVjUH+inveVg0a7u1HwqoRCfWzOXudJNPzT3sOdXRUg9g7qSQgID5L svnQgXgjRCx5IERTE/8qwHj7zjmpRAYhBMQO4= Received: by 10.42.21.204 with SMTP id l12mr6156228icb.341.1310930888865; Sun, 17 Jul 2011 12:28:08 -0700 (PDT) Return-Path: Received: from [10.0.1.3] (99-197-145-127.cust.wildblue.net [99.197.145.127]) by mx.google.com with ESMTPS id j8sm3986585icz.16.2011.07.17.12.27.56 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 17 Jul 2011 12:28:07 -0700 (PDT) Subject: Re: [FlyRotary] Re: Flex Plate Failure - Improvements References: From: Tracy Content-Type: multipart/alternative; boundary=Apple-Mail-17--236287174 X-Mailer: iPad Mail (8F191) In-Reply-To: Message-Id: Date: Sun, 17 Jul 2011 15:27:46 -0400 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (iPad Mail 8F191) --Apple-Mail-17--236287174 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 I've worked around this problem in past projects. Just a little die grinder= work to bevel the appropriate edge of the ring gear teeth makes the starter= engage just fine. Copy the bevel that's on the wrong side of the tooth. Tracy Sent from my iPad On Jul 16, 2011, at 9:39 AM, "Bill Bradburry" wro= te: > The RX-8 flywheel/flexplate is designed to have the starter gear enter fro= m the front as related to the engine. The RX-7 has the starter entering fro= m the rear as related to the engine. As a result the RX-8 flywheel will not= work with the RX-7 starter. That is my opinion as I remember the layout. = I am willing to stand corrected by more knowledgeable folks. > =20 > Bill B > =20 > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Be= half Of Tracy > Sent: Friday, July 15, 2011 2:41 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: Flex Plate Failure - Improvements > =20 > I'm still in analysis mode on this myself. >=20 > So far the possibilities are: >=20 > 1. The flex plate may have been warped when installed ( I bought several t= hat were) I think the standard should be close to zero runout or wobble on t= he flexplate in view of this failure. >=20 > 2. The flexplate could have had cracks when installed (I also bought sev= eral that had cracks and they were not visible unless you looked closely) >=20 > 3. The dang things (RX-7 flexplates) are not strong enough for boosted 13= Bs or 20Bs. =20 >=20 > I do NOT think the problem is fore & aft travel of the input shaft. The R= D-1x drives have had thrust bearings from day one. There is no thrust load a= t all on the damper, flexplate or crankshaft imposed by the drive. This wa= s not the case with the Ross drive I used at first. >=20 > I have over 1000 hours on the same flexplate on my NA 13B. I have only 55= hours on the 20B. But I'll be checking both. I did inspect both flexplat= es VERY carefully before installing. =20 >=20 > If I found that a change were necessary, I would consider two possibilitie= s.=20 >=20 > 1. Use a modified aluminum racing flywheel used with an auto counterweigh= t. (Or possibly a lightweight steel one if there is such a thing) >=20 > 2. Use an RX-8 flexplate with an adapter plate made of aluminum or steel s= heet to go between the flexplate and damper. The RX-8 version looks stronge= r than the RX-7. I briefly studied this when good RX-7 flexplates were getti= ng hard to find. I did not develop a formal procedure for doing this but i= t looked like it would be pretty easy. Anybody with spare time out there wa= nt to take a closer look? Hint: The damper bolt pattern would be offset 4= 5 degrees from the RX-8 torque converter bolt pattern. > =20 > Tracy Crook, RWS >=20 > On Fri, Jul 15, 2011 at 1:47 PM, Bobby J. Hughes wrote:= > Bill summed up what I=E2=80=99ve been thinking the last few days. I=E2=80=99= m not changing anything until Tracy makes a recommendation. It could be fore= and aft movement on the shaft, flex plate out of round, worn rubber isolato= rs or a combination of all these items. We may need a scheduled maintenance p= lan to replace items like the rubber isolators or other items that wear and l= oosen tolerances. > =20 > =20 > I will however be inspecting for this problem before most flights. > =20 > Bobby Hughes > (playing with fiberglass again) > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Be= half Of Bill Bradburry > Sent: Friday, July 15, 2011 10:03 AM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: Ok Here are the important flywheel measurements > =20 > =20 > David, > =20 > I can=E2=80=99t help but think that you may be fixing something that is no= t broken. I realize that the flexplate came apart on your plane, but that d= oesn=E2=80=99t mean that the flexplate is the cause of the problem. That fl= explate holds up quite well in the car with a heavy torque converter attache= d to it. Think of the forces when a car under heavy acceleration changes ge= ar! As long as the forces are along the plane of the plate it is very strong= . Not so much in the forward/rearward directions. In fact that would cause= metal fatigue and cause it to break just like yours did. I think that what= ever is causing the endplay is what you should be looking at. I suspect th= at if you check out the transmission on the car you will find that the endpl= ay of the input shaft is controlled by thrust bearings or some such device. = Lynn may know the answer to this?? > =20 > That msg from Al Wick really resonates with me. Tracy had to install a th= rust bearing to prevent the drive shaft from hitting the bottom of the pilot= bearing and causing an eccentric shaft failure on the engine. Maybe you no= w need to add a cage similar to what Al was discussing that will trap the sh= aft end play completely. That, to me, makes more sense than adding a bigger= flywheel. If you strengthen the weak spot, you will then discover where th= e next weakest spot is because that will be the next failure!=20 > =20 > This is a real opportunity for you and the rest of us with the same drive.= Please study this a little more before you begin the fix! > =20 > Bill B > =20 > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Be= half Of David Leonard > Sent: Friday, July 15, 2011 12:42 AM > To: Rotary motors in aircraft > Subject: [FlyRotary] Ok Here are the important flywheel measurements > =20 > I finally got to the hangar and measured out my S5 turbo flywheel and the r= emains of my S5 flexplate. The results are very encouraging, even as good a= s the possibly could be to make the swap, but I only had ten min at the hang= ar before I had to leave to pick up my daughter from daycare, so they are on= e try and slightly sloppy... I make no guarantees. The height measurements o= f the flex plate were particularly suspect because, well, mine is all warped= and broken. >=20 > Ring Gear Diameter - Perfect fit. As we suspected, same size, same tooth s= pacing. >=20 > Ring Gear Fore-Aft Placement - As measured from the underside of the big n= ut. (for all further reference, aft means aft in the CAR). The flex plate p= uts the aft side of the ring gear 1.290 inches from the front of the big nut= . The flywheel puts it 0.913. So the flex plate puts the ring gear (appx) 0= .377 in. further aft. This is actually fortuitous because it just so happen= s that the ring gear thickness is .365 ... So all we have to do to fix th= e discrepancy is weld and extra ring gears onto to the flywheel ring gear an= d there will be teeth that the starter can reach:(bottom of the page.. the c= ost $80) > http://mazdatrix.com/flywheel.htm > It may also be possible to fix the discrepancy by changing the starter... w= ill look into that. >=20 > Damper Plate Placement - On the flywheel, the mounting surface is proud (o= r aft) of the ring gear. On the flex plate, the mounting surface is recesse= d (or forward) from the ring gear. And it all pretty much works out. That p= osition on the flywheel will vary somewhat depending on which flywheel you h= ave and how much wear you have on the clutch slip surface. But on my (I assu= me well-worn) flywheel the placement was 0.965 while the flex plate was 0.95= 0. Pretty damn close and given measurement error it might me meant to be ri= ght on. Or, any difference could be made up by trimming down the spline on t= he damper plate or removing or adding spacers between the two. >=20 > So in my mind, a flywheel is the way to go. Stout, easy to get, pick your= weight, only mods seem to be drilling the mounting holes and welding on a s= econd gear ring. >=20 > --=20 > David Leonard >=20 > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > =20 --Apple-Mail-17--236287174 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
I've worked around this problem in past= projects.  Just a little die grinder work to bevel the appropriate edg= e of the ring gear teeth makes the starter engage just fine.   Copy the= bevel that's on the wrong side of the tooth.

Tracy=

Sent from my iPad

On Jul 16, 2011, at 9:39 AM, "Bill B= radburry" <bbradburry@bellsou= th.net> wrote:

The RX-8 flywheel/flexplate is designed= to have the starter gear enter from the front as related to the engine.  T= he RX-7 has the starter entering from the rear as related to the engine.  As a result the RX-8 flywheel will not work with the RX-7 starter.   Th= at is my opinion as I remember the layout.  I am willing to stand corrected b= y more knowledgeable folks.

 

Bill B

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy
Sent: Friday, July 15, 2011 2= :41 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Flex= Plate Failure - Improvements

 

I'm still in analysis mode on this myself.

So far the possibilities are:

1. The flex plate may have been warped when installed  ( I bought sever= al that were)  I think the standard should be close to zero runout or wobb= le on the flexplate in view of this failure.

2.  The flexplate could have had cracks when installed  (I also bought several that had cracks and they were not visible unless you looked closely)

3.  The dang things (RX-7 flexplates) are not strong enough for boosted= 13Bs or 20Bs. 

I do NOT think the problem is fore & aft travel of the input shaft. = ; The RD-1x drives have had thrust bearings from day one.  There is no thrust load at all on the damper, flexplate or crankshaft imposed by the drive.   This was not the case with the Ross drive I used at first= .

I have over 1000 hours on the same flexplate on my NA 13B.  I have only= 55 hours on the 20B.   But I'll be checking both.  I did inspect= both flexplates VERY carefully before installing. 

If I found that a change were necessary, I would consider two possibilities.=

1.  Use a modified aluminum racing flywheel used with an auto counterweight.  (Or possibly a lightweight steel one if there is such a= thing)

2.  Use an RX-8 flexplate with an adapter plate made of aluminum or ste= el sheet to go between the flexplate and damper.  The RX-8 version looks stronger than the RX-7. I briefly studied this when good RX-7 flexplates wer= e getting hard to find.   I did not develop a formal procedure for doing this but it looked like it would be pretty easy.  Anybody with spare ti= me out there want to take a closer look?  Hint:   The damper bolt pattern would be offset 45 degrees from the RX-8 torque converter bolt patte= rn.
 
Tracy Crook,   RWS

On Fri, Jul 15, 2011 at 1:47 PM, Bobby J. Hughes <bhughes@qnsi.net> wrote:

Bill summed up what I=E2=80=99ve been thinking the last few days= . I=E2=80=99m not changing anything until Tracy makes a recommendation. It could be fore and aft movement on the shaft, flex= plate out of round, worn rubber isolators or a combination of all these item= s. We may need a scheduled maintenance plan to replace items like the rubber isolators or other items that wear and loosen tolerances.=

 

 

 I will however be inspecting for this problem before most flights.

 

Bobby Hughes

 (playing with fiberglass again)

From: Rotary motors in air= craft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Friday, July 15, 2011 1= 0:03 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Ok H= ere are the important flywheel measurements

 

 

David,

 

I can=E2=80=99t help but think that you may be fixing something t= hat is not broken.  I realize that the flexplate came apart on your plane, b= ut that doesn=E2=80=99t mean that the flexplate is the cause of the problem.&nb= sp; That flexplate holds up quite well in the car with a heavy torque converter attached to it.  Think of the forces when a car under heavy acceleratio= n changes gear! As long as the forces are along the plane of the plate it is v= ery strong.  Not so much in the forward/rearward directions.  In fact that would cause metal fatigue and cause it to break just like yours did.&nb= sp; I think that what ever is causing the endplay is what you should be looking at.  I suspect that if you check out the transmission on the car you wi= ll find that the endplay of the input shaft is controlled by thrust bearings or= some such device.  Lynn may know the answer to this??

 

That msg from Al Wick really resonates with me.  Tracy had to instal= l a thrust bearing to prevent the drive shaft from hitting the bottom of the pil= ot bearing and causing an eccentric shaft failure on the engine.  Maybe yo= u now need to add a cage similar to what Al was discussing that will trap the shaft end play completely.  That, to me, makes more sense than adding a= bigger flywheel.  If you strengthen the weak spot, you will then discov= er where the next weakest spot is because that will be the next failure!  <= /span>

 

This is a real opportunity for you and the rest of us with the s= ame drive.  Please study this a little more before you begin the fix!

 

Bill B

 

From: Rotary motors in air= craft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard Sent: Friday, July 15, 2011 1= 2:42 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Ok Here a= re the important flywheel measurements

 

I finally got to the hangar and measured out my S5 turbo flywheel and the remains of my S5 flexplate.  The results are very encouraging, even as good as the possi= bly could be to make the swap, but I only had ten min at the hangar before I had= to leave to pick up my daughter from daycare, so they are one try and slightly sloppy... I make no guarantees.  The height measurements of the flex pl= ate were particularly suspect because, well, mine is all warped and broken.

Ring Gear Diameter - Perfect fit.  As we suspected, same size, same tooth spacing.

Ring Gear Fore-Aft Placement -= As measured from the underside of the big nut. (for all further reference, aft means aft in the CAR).  The flex plate puts the aft side of the ring ge= ar 1.290 inches from the front of the big nut. The flywheel puts it 0.913. = ; So the flex plate puts the ring gear (appx) 0.377 in. further aft.  Thi= s is actually fortuitous because it just so happens that the ring gear thickne= ss is .365 ...    So all we have to do to fix the discrepancy is= weld and extra ring gears onto to the flywheel ring gear and there will be teeth that the starter can reach:(bottom of the page.. the cost $80)
http://mazdatrix.com/flywheel.htm<= br> It may also be possible to fix the discrepancy by changing the starter... wi= ll look into that.

Damper Plate Placement - On t= he flywheel, the mounting surface is proud (or aft) of the ring gear.  On t= he flex plate, the mounting surface is recessed (or forward) from the ring gear= . And it all pretty much works out.  That position on the flywheel will v= ary somewhat depending on which flywheel you have and how much wear you have on t= he clutch slip surface. But on my (I assume well-worn) flywheel the placement w= as 0.965 while the flex plate was 0.950.  Pretty damn close and given measurement error it might me meant to be right on.  Or, any difference= could be made up by trimming down the spline on the damper plate or removing= or adding spacers between the two.

So in my mind, a flywheel is the way to go.  Stout, easy to get, pick y= our weight, only mods seem to be drilling the mounting holes and welding on a second gear ring.

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

 

= --Apple-Mail-17--236287174--