X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from outbound-mail.dca.untd.com ([64.136.47.15] verified) by logan.com (CommuniGate Pro SMTP 5.2.15) with SMTP id 3791442 for flyrotary@lancaironline.net; Sat, 01 Aug 2009 11:13:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.47.15; envelope-from=alwick@juno.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=juno.com; s=alpha; t=1249139597; bh=47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=; l=0; h=Message-ID:From:To:Subject:Date:Content-Type:X-UNTD-OriginStamp; b=OT6jxeiy6RAFpZuupshs5VN9s2N51P4dgeRd/cDB4C1DAaB8AAmEMj9cCHZ04qmrS 8iGaPsAna233J1Sabz6VH5C1jO3fZZWCM5wiBqqdTQE4Uh/tb6/39USe2JINQV+mw0 +VJT+w/kYr10wJIQ6SuFESZl5FHUxLRBOEoIq7Mg= Received: from Penny (c-98-246-117-71.hsd1.or.comcast.net [98.246.117.71]) by smtpout02.dca.untd.com with SMTP id AABFHJY6BACYKNJJ for (sender ); Sat, 1 Aug 2009 08:13:05 -0700 (PDT) Message-ID: From: "Al Wick" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: EC2 and Ed's EFISM - a great combination Date: Sat, 1 Aug 2009 08:13:05 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_014A_01CA127F.E554B1C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18005 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18005 X-ContentStamp: 42:21:3590490186 X-MAIL-INFO: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 be3f0707f35a13be17d35edfd3df2abe071363fa8a8a1acedac34ac73f83ab17c71e47cac7cb0b02b71ec7d7aa2a738bf30f171e7ae7ebebf7a39e7b1bb3d77b6e7702037ee70302bac76bb3230e5a2ea7832f8333eae38f9b431fba77efef373fbb5af39fcfd3 X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkJF+SWaEEOLR9A5GWCXoKI58QYoV70mOlg== X-UNTD-Peer-Info: 10.171.42.32|smtpout02.dca.untd.com|smtpout02.dca.untd.com|alwick@juno.com This is a multi-part message in MIME format. ------=_NextPart_000_014A_01CA127F.E554B1C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I flew 5 years with a Ross. I've disassembled and inspected 5 or so, = just to help out other builders. Just want to offer a different = viewpoint based on my findings:=20 First, all of the Ross's have large bearing that absorbs the prop thrust = forces. I'm quite puzzled your statement that they don't. A very = important part of the installation is to verify you have clearance to = flywheel. I'm wondering if you are just confusing the pilot bearing = damage issue with prop thrust? Ross redrive had one significant design = oversight. This oversight caused around 80% of their field failures. = Basically Ross picked a poor method of controlling input shaft = clearance. Input shaft is the short shaft that goes between flywheel and = gears. Low rpm torsionals caused that shaft to slam back and forth = between flywheel and gears. This caused pilot bearing damage, fatigue = failures on the drive plate. I changed the design by controlling thrust = at the sun gear. All of those failures then disappear.=20 Second, Ross decision to restrict oil flow to redrive is very sound = design. It limits flow because excess oil flow to redrive has = significant effect on hp loss. A friend actually measured hp loss = related to oil volume. I verified flow on my redrive gears & bearings, = absolutely no issues. I do believe there were lube issues on some Ross = applications, but definitely not true on mine. I don't understand why = the difference.=20 There is a method of proving design changes that Tracy doesn't use often = enough. Basically you measure how close the design is to failure. You = don't rely on theory. For example, I verified oil flow just by placing = aluminum slivers at key oil locations. Operate drive for a minute, = disassemble. Slivers were washed away by oil flow. Likewise, you operate = it, then quickly disassemble and measure temperature of various = components. A friend slapped a plastic cover on his redrive, then = watched the oil flow. These methods let you predict future failures. Too = much design theory, not enough actual measurements. If you can force = yourself to test your theories, you'll find tons of things you believe = in, that just aren't significant.=20 I am in agreement that Tracy version of the Ross design is looking = pretty good. When asked by builders which redrive to consider, his gets = high marks. I don't have rose colored glasses. There have been a couple = design oversights that resulted in failures. I like the solutions.=20 -al wick ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, July 31, 2009 3:46 PM Subject: [FlyRotary] Re: EC2 and Ed's EFISM - a great combination Actually, George, The RWS drive was not just a redevelopment of the = Ross drive. =20 =20 Tracy basically started from scratch and engineered a redrive that was = designed to meet certain objectives while achieving a reasonable cost. = There is no other redrive I am familiar with that has anywhere near the = number of flying hours that the RWS redrive has with none of the = problems associated with the Ross. =20 While there is a superficial similarly to the Ross (Prop on one end = and rotary on the other, planetary gears in the middle {:>)) in = appearance, the internals are considerably ahead of anything Ross had. = Pressure lubrication of the prop shaft for one thing, an integral thrust = bearing for another, a removable propeller shaft for yet another, full = oil pressure lubrication. The Ross drive required a restrictor in the = oil line to (can you believe this) reduce oil pressure - otherwise the = thing leaked like crazy - even with the restrictor, the rear seal = frequently was a leaky mess. But, reducing the oil pressure was one = reason the Ross had marginal lubrication in my opinion. Even then, the = oil distribution inside the Ross was also not well designed.=20 =20 Don't get me wrong, I was glad to get a Ross - because it was the only = thing around at the time. Had old man, Lou Ross, lived longer he may = have eventually fixed a lot of these issues, but unfortunately he did = not and I won't go into the situation with his son, Chris. But, we are = fortunate that Tracy took on this challenge and did it right. =20 =20 One thing I really appreciate about the RWS design is that it has a = considerably different internal set up with easily replaceable parts - = which was not the case with the Ross. If you wanted to completely = disassembly a Ross unit you most likely had to take it to a machine = shop. =20 Just wanted to make it clear that in my opinion the RWS should not be = associated with the Ross unit which many have found shortcomings in. =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of George Lendich Sent: Friday, July 31, 2009 5:20 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: EC2 and Ed's EFISM - a great combination =20 =20 Steve, The Ross drive was redeveloped by Tracy Crook of Real World = Solutions (RWS). Tracy now uses the 6 planet planetary (Ford Unit) and = is about the best you will get weight wise and value for money. =20 There are other similar units - all have slightly different = construction, however Tracy's is well proven. I will probably make my = own, but only because of the tyranny of distance and associated costs. George (down under). =20 Steve, I went with the RD-1B PSRU from RWS. =20 T Mann __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ------=_NextPart_000_014A_01CA127F.E554B1C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I flew 5 years with a Ross. I've = disassembled and=20 inspected 5 or so, just to help out other builders. Just want to offer a = different viewpoint based on my findings:
 
First, all of the Ross's have large = bearing that=20 absorbs the prop thrust forces. I'm quite puzzled your statement that = they=20 don't. A very important part of the installation is to verify you have = clearance=20 to flywheel. I'm wondering if you are just confusing the pilot bearing = damage=20 issue with prop thrust? Ross redrive had one significant design = oversight. This=20 oversight caused around 80% of their field failures. Basically Ross = picked a=20 poor method of controlling input shaft clearance. Input shaft is the = short shaft=20 that goes between flywheel and gears. Low rpm torsionals caused that = shaft to=20 slam back and forth between flywheel and gears. This caused pilot = bearing=20 damage, fatigue failures on the drive plate. I changed the design by = controlling=20 thrust at the sun gear. All of those failures then disappear. =
 
Second, Ross decision to restrict oil = flow to=20 redrive is very sound design. It limits flow because excess oil flow to = redrive=20 has significant effect on hp loss. A friend actually measured hp loss = related to=20 oil volume. I verified flow on my redrive gears & bearings, = absolutely=20 no issues. I do believe there were lube issues on some Ross = applications, but=20 definitely not true on mine. I don't understand why the difference.=20
 
 
There is a method of proving design = changes that=20 Tracy doesn't use often enough. Basically you measure how close the = design is to=20 failure. You don't rely on theory. For example, I verified oil flow just = by=20 placing aluminum slivers at key oil locations. Operate drive for a = minute,=20 disassemble. Slivers were washed away by oil flow. Likewise, you operate = it,=20 then quickly disassemble and measure temperature of various components. = A friend=20 slapped a plastic cover on his redrive, then watched the oil flow. These = methods let you predict future failures. Too much design = theory, not=20 enough actual measurements. If you can force yourself to test your = theories,=20 you'll find tons of things you believe in, that just aren't significant. =
 
I am in agreement that Tracy version of = the Ross=20 design is looking pretty good. When asked by builders which redrive to = consider,=20 his gets high marks. I don't have rose colored glasses. There have been = a couple=20 design oversights that resulted in failures. I like the solutions. =
 
-al  wick
 
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Friday, July 31, 2009 = 3:46 PM
Subject: [FlyRotary] Re: EC2 = and Ed's=20 EFISM - a great combination

Actually, = George, The=20 RWS drive was not just a redevelopment of the Ross drive.=20  

 

Tracy basically = started=20 from scratch and engineered a redrive that was designed to meet = certain=20 objectives while achieving a reasonable cost.   There is no = other=20 redrive I am familiar with that has anywhere near the number of flying = hours=20 that the RWS redrive has with none of the problems associated with the = Ross.

 

While there = is a=20 superficial similarly to the Ross (Prop on one end and rotary on the = other,=20 planetary gears in the middle {:>)) in appearance, the internals = are=20 considerably ahead of anything Ross had.  Pressure lubrication of = the=20 prop shaft for one thing, an integral thrust bearing for another, a = removable=20 propeller shaft for yet another, full oil pressure lubrication.  = The Ross=20 drive required a restrictor in the oil line to (can you believe this) = reduce=20 oil pressure =96 otherwise the thing leaked like crazy =96 even with = the=20 restrictor, the rear seal frequently was a leaky mess.  But, = reducing the=20 oil pressure was one reason the Ross had marginal lubrication in my = opinion.=20 Even then, the oil distribution inside the Ross was also not well = designed.=20

 

Don=92t get = me wrong, I=20 was glad to get a Ross =96 because it was the only thing around at the = time.  Had old man, Lou Ross, lived longer he may have eventually = fixed a=20 lot of these issues, but unfortunately he did not and I won=92t go = into the=20 situation with his son, Chris.  But, we are fortunate that = Tracy took = on this=20 challenge and did it right.  

 

One thing I = really=20 appreciate about the RWS design is that it has a considerably = different=20 internal set up with easily replaceable parts =96 which was not the = case with=20 the Ross.  If you wanted to completely disassembly a Ross unit = you most=20 likely had to take it to a machine shop.

 

Just wanted = to make=20 it clear that in my opinion the RWS should not be associated with the = Ross=20 unit which many have found shortcomings = in.

 

Ed=20 Anderson

Rv-6A N494BW=20 Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of George Lendich
Sent: Friday, July 31, 2009 = 5:20=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: EC2 = and Ed's=20 EFISM - a great combination

 

 

Steve,

The Ross drive was = redeveloped=20 by Tracy Crook of Real World Solutions (RWS). Tracy now uses the 6 planet = planetary (Ford=20 Unit) and is about the best you will get  weight wise and value = for=20 money.

 

There are other = similar units=20 - all have slightly different construction, however Tracy's is = well=20 proven. I will probably make my own, but only because of the tyranny = of=20 distance and associated costs.

George (down=20 under).

 

Steve,

I = went with=20 the RD-1B PSRU from RWS.

 

T=20 Mann



__________ Information from ESET = NOD32=20 Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 = Antivirus.

http://www.eset.com

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