X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [65.54.250.75] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 913809 for flyrotary@lancaironline.net; Thu, 05 Jan 2006 09:38:30 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.250.75; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Thu, 5 Jan 2006 06:37:44 -0800 Message-ID: Received: from 4.171.150.59 by BAY115-DAV3.phx.gbl with DAV; Thu, 05 Jan 2006 14:37:44 +0000 X-Originating-IP: [4.171.150.59] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: [FlyRotary]Soapbox Warning! PSRU Ratios Date: Thu, 5 Jan 2006 09:37:38 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0033_01C611DB.AA955060" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Thu, 5 Jan 2006 09:37:38 -0500 X-OriginalArrivalTime: 05 Jan 2006 14:37:44.0469 (UTC) FILETIME=[97087C50:01C61205] This is a multi-part message in MIME format. ------=_NextPart_000_0033_01C611DB.AA955060 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: [FlyRotary]Soapbox Warning! PSRU RatiosYep, the custom = pilot shaft will solve that problem Ken.=20 We must be talking about different transmissions with regard to the ring = gear diameter. I've built over 180 gear drives based on the C6 and E4OD = (modernized C6 with electronic controls) and the ring gear always = measures 5 inches on the 2.176 ratio drives. My calipers just can't be = that far off. Tracy (learning hazards of soapboxes)=20 ----- Original Message -----=20 From: Ken Welter=20 To: Rotary motors in aircraft=20 Sent: Thursday, January 05, 2006 12:27 AM Subject: [FlyRotary] Re: [FlyRotary]Soapbox Warning! PSRU Ratios I will have a pilot shaft that will have a flange on it that the = spline will bolt to and the pilot shaft will go through the seal and to = the damper. As for the the 4.4 inch ring gear the C-6 units that give the 2.17 = ratio are 4.4 inch diameter but the ring gear is not the problem with = the C-6 its the sun gear that likes to chip, also a problem is the = planet bearings are a problem any time they are used where the planet is = spinning like the 2.85 or 3.17 rather than being held solid to to case = like the 2.17 ratio, this is also a concern with the 3.21 Dodge as the = planet is going to be spinning and solution to just trash can the planet = set every couple hundred hrs as they are so cheep and in fact I will = probably replace the sun gear also, hell the whole gear set only cost = 150 bucks so that's cheap insurance as that costs a hell of a lot less = than a tank of gas in my plane. By the way the thing that finally killed my Ross gearbox was the = planet bearings went out. All and all the C-6 seams to be fine for the little rotary but they = have a vary bad track record Compared to the GM or Dodge in the big rig = trucks. Ken Welter I thought maybe that's what you were driving at George, I just took = the opportunity to vent my frustration with the almost daily phone calls = I get asking "Why don't you do it this way ........." : ) No offense = meant to you at all. You and most everyone on this list have done = enough fabricating on your own to know how much goes into the design of = a flying widget. That sun gear spline does sound nice but notice that if the flange = is bolted to the damper and the oil seal runs on the smooth part of the = female spline, it looks like the oil is still going to leak out through = the spline interface. This can be worked out too but the problems = never end : ) Tracy ----- Original Message ----- From: george lendich To: Rotary motors in aircraft Sent: Wednesday, January 04, 2006 4:56 PM Subject: [FlyRotary] Re: [FlyRotary]Soapbox Warning! PSRU Ratios Thanks Tracy, I wasn't advocating that you change your current manufacturing and = models. I was more or less looking for problems associated with MY use = of a 3.21 Ratio. I guess, deep down, I would prefer a 2.5 ratio myself but haven't = found one that has all the attributes on the 'wish list'. The straight = cut gears and the splined sun gear were way up there on the "wish list', = BTW the female splined flange has a neck sufficiently long for a bearing = and a seal. It all looked too good to be true - BUGGER! Good luck to Ken if he can use it, but like you said it's probably = going in the wrong direction for most. I have also that similar advice = from another valued source. I do appreciate you going to the trouble, but from my perspective = it doesn't hurt to keep looking at, and evaluating different = configurations. Thanks again! George ( down under) Hi George, glad you asked, gives me an opportunity to answer it = once for everybody. If you mean 'what problem would it be for me' the answer is "No = problem at all". Except for scrapping every part of the current design, = scrapping all the tooling developed for it, scrapping all the = production procedures (this is no small thing) and replacing all this = with new stuff. Obviously, there has to be a good reason to do this to make it = worth while. It has to solve an existing problem (are there any?), = significantly improve performance (would it?) or reduce cost enough to = justify all the work and expense of changing (does it?). I'm sure that Dodge gear set is a fine piece of hardware but = what does it give us? It has a smaller diameter ring gear (4.4" vs = 5.0") narrower gears (about 3/4" vs 7/8") and one less planet. On = paper, this looks like a minus, not a plus. The availability of = straight cut gears is a possible bonus but on the other hand, I have not = had any problem dealing with the helical gear thrust so far. The splined sun gear might be nice but so far we are paying a = pretty high price for it. A lot of other factors need to be considered. = For instance, How do you isolate the oil in the gear box when using = that mating splined part? Is there a place to put an oil seal? There = are literally hundreds of questions like this that must be answered = during the course of designing a gear reduction drive. As far as the ratio goes, 2.85 : 1 is actually a bit higher than = optimum for most applications. Going even higher is the wrong = direction. Note that I said "most applications". There will of course = be some that would favor a higher one. A detailed discussion of this = would be interesting but is way more involved than I can detail in an = email message. But, to summarize, I believe fuel economy, engine life, = and proper matching with a suitable prop would suffer with a higher = ratio. Anecdotal data from people in the auto transmission industry has = been contradictory at best. It's the Chevy vs Ford vs Mopar thing all = over again. I give the Ford guys as much credit as the Dodge boys - = Zero. I know Paul L. pushes for more power at every turn (higher rpm = (requiring higher ratios), P porting, etc) but I think this focus is = counterproductive in too many other areas. I'm more in tune with = Richard Vangrunsvan's goal - Total Performance. You also asked why I was previously opposed to changing from = 2.17 to 2.85. Note that I did not change. The 2.85 is in addition to = the 2.17 which is still in production. There are plenty of applications = where the 2.17 is clearly a better choice than the 2.85. There are = still times when I would prefer the 2.17 on my own plane. Some of the = reasons are subtle and not quantifiable. I like the BMW better than the = Chevy I drove but I couldn't give you any hard reasons for it. Tracy (now stepping off soap box) ----- Original Message ----- From: george lendich To: Rotary motors in = aircraft Sent: Tuesday, January 03, 2006 5:56 PM Subject: [FlyRotary] PSRU Ratios A question for Tracy. What problems would you envisage using a 3.21 ratio instead of = the 2.85. One of the Lads on the other site has found this 'U-beaut' = Planetary out of a Cummings Diesel ( overdrive). There are two 5 planet arrangements, one with angle cut ( = opposite to the Ford unit) whereby the thrust is between the sun gear = and planet ( internal thrust gear arrangement). The other is a straight cut 5 planet arrangement ( no thrust). The beauty of this planetary is that the sun gear has a spline = at the aft end with a matching female splined flange ( for bolting to = the damper plate). The ring gear is externally notched as in the Ford 2.17. The planet housing is similar in design and size to the Ford = 2.85. Advice from people in the industry are that the Dodge units = are superior to the Ford units, however that would have to be confirmed. Originally you were opposed to going from the 2.17 to 2.85 for = a number of reasons - can quite remember why? Was it because of higher = RPM ( engine workload)? overspeeding the water pump and alternator? = Anything else ? What problems do you envisage with a 3.21:1 ratio? George ( down under) ------=_NextPart_000_0033_01C611DB.AA955060 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: [FlyRotary]Soapbox Warning! PSRU = Ratios
Yep, the custom pilot shaft will solve that problem Ken.
 
We must be talking about different transmissions with regard to the = ring=20 gear diameter.  I've built over 180 gear drives based on the C6 and = E4OD=20 (modernized C6 with electronic controls) and the ring gear always = measures=20 5 inches on the 2.176 ratio drives.  My calipers just can't be that = far=20 off.
 
Tracy (learning hazards of soapboxes) 
----- Original Message -----
From: Ken=20 Welter
To: Rotary motors in = aircraft
Sent: Thursday, January 05, = 2006 12:27=20 AM
Subject: [FlyRotary] Re:=20 [FlyRotary]Soapbox Warning! PSRU Ratios

   I will have a pilot shaft that = will have=20 a flange on it that the spline will bolt to and the pilot shaft will = go=20 through the seal and to the damper.
  As for the the 4.4 inch ring gear = the C-6=20 units that give the 2.17 ratio are 4.4 inch diameter but the ring gear = is not=20 the problem with the C-6 its the sun gear that likes to chip, also a = problem=20 is the planet bearings are a problem any time they are used where the = planet=20 is spinning like the 2.85 or 3.17 rather than being held solid to to = case like=20 the 2.17 ratio, this is also a concern with the 3.21 Dodge as the = planet is=20 going to be spinning and solution to just trash can the planet set = every=20 couple hundred hrs as they are so cheep and in fact I will probably = replace=20 the sun gear also, hell the whole gear set only cost 150 bucks so = that's cheap=20 insurance as that costs a hell of a lot less than a tank of gas in my=20 plane.
  By the way the thing that finally = killed my=20 Ross gearbox was the planet bearings went out.
  All and all the C-6 seams to be fine = for the=20 little rotary but they have a vary bad track record Compared to the GM = or=20 Dodge in the big rig trucks.
  Ken Welter




I thought maybe that's what you = were driving=20 at George, I just took the opportunity to vent my frustration with = the=20 almost daily phone calls I get asking "Why don't you do it = this way=20 ........." : ) No offense meant to you at all.  You and most = everyone=20 on this list have done enough fabricating on your own to = know how much=20 goes into the design of a flying widget.
 
That sun gear spline does = sound nice=20 but notice that if the flange is bolted to the damper and the oil = seal runs=20 on the smooth part of the female spline, it looks like the oil is = still=20 going to leak out through the spline = interface.   This=20 can be worked out too but the problems never end : )
 
Tracy
----- Original Message -----
From: george = lendich
To: Rotary motors in=20 aircraft
Sent: Wednesday, January 04, 2006 4:56 = PM
Subject: [FlyRotary] Re: [FlyRotary]Soapbox = Warning!=20 PSRU Ratios

 
Thanks Tracy,
I wasn't advocating that you change = your=20 current manufacturing and models. I was more or less looking for = problems=20 associated with MY use of a 3.21 Ratio.
 
I guess, deep down, I would prefer a = 2.5=20 ratio myself but haven't found one that has all the attributes on = the=20 'wish list'. The straight cut gears and the splined sun gear were = way up=20 there on the "wish list', BTW the female splined flange has a neck = sufficiently long for a bearing and a seal. It all looked too good = to be=20 true - BUGGER!
 
Good luck to Ken if he can use it, = but like=20 you said it's probably going in the wrong direction for most. = I have=20 also that similar advice from another valued=20 source.
 
I do appreciate you going to the = trouble, but=20 from my perspective it doesn't hurt to keep looking at, and=20 evaluating different configurations.
Thanks again!
George ( down = under)
 
Hi George, glad you asked, gives me an opportunity to = answer=20 it once for everybody.
 
 If you mean 'what problem would it be for me' = the=20 answer is "No problem at all".  Except for = scrapping every=20 part of the current design, scrapping all the tooling developed = for=20 it,  scrapping all the production procedures (this = is no small=20 thing) and replacing all this with new stuff.
 
Obviously, there has to be a good reason to do this to = make=20 it worth while.  It has to solve an existing problem  = (are=20 there any?), significantly improve performance (would it?) = or=20 reduce cost enough to justify all the work and expense of=20 changing (does it?).
 
I'm sure that Dodge gear set is a fine piece of = hardware but=20 what does it give us?  It has a smaller diameter ring gear = (4.4" vs=20 5.0") narrower gears (about 3/4" vs 7/8") and one less=20 planet.  On paper, this looks like a minus, not a = plus.  The=20 availability of straight cut gears is a possible bonus but on = the other=20 hand, I have not had any problem dealing with the helical = gear=20 thrust so far.
 
The splined sun gear might be nice but so far we are = paying=20 a pretty high price for it.  A lot of other factors need to = be=20 considered.  For instance, How do you isolate the oil in = the gear=20 box when using that mating splined part?  Is there a place = to put=20 an oil seal?  There are literally hundreds of questions = like this=20 that must be answered during the course of designing a = gear=20 reduction drive.
 
As far as the ratio goes, 2.85 : 1 is actually a bit = higher=20 than optimum for most applications.  Going even higher is = the wrong=20 direction.  Note that I said "most applications".  = There will=20 of course be some that would favor a higher one.  A = detailed=20 discussion of this would be interesting but is way more involved = than I=20 can detail in an email message.  But, to = summarize, I=20 believe fuel economy, engine life, and proper matching with a = suitable=20 prop would suffer with a higher ratio.
 
Anecdotal data from people in the auto transmission = industry=20 has been contradictory at best.  It's the Chevy vs = Ford vs=20 Mopar thing all over again.  I give the Ford guys = as much=20 credit as the Dodge boys -  Zero.
 
I know Paul L. pushes for more power at every turn = (higher=20 rpm (requiring higher ratios), P porting, etc) but I think this=20 focus is counterproductive in too many other areas.  = I'm more=20 in tune with Richard Vangrunsvan's goal  -  Total=20 Performance.
 
You also asked why I was previously opposed to = changing from=20 2.17 to 2.85.  Note that I did not change.  The 2.85 = is in=20 addition to the 2.17 which is still in production.  There = are=20 plenty of applications where the 2.17 is clearly a better choice = than=20 the 2.85.  There are still times when I would prefer the = 2.17 on my=20 own plane.  Some of the reasons are subtle and not=20 quantifiable.  I like the BMW better than the Chevy I drove = but I=20 couldn't give you any hard reasons for it.
 
Tracy (now stepping off soap box)
----- Original Message -----
From: george = lendich
To: Rotary motors in=20 aircraft
Sent: Tuesday, January 03, 2006 5:56 = PM
Subject: [FlyRotary] PSRU Ratios

A question for=20 Tracy.
What problems would you = envisage=20 using a 3.21 ratio instead of the 2.85.
 
One of the Lads on the = other site=20 has found this 'U-beaut' Planetary out of a Cummings Diesel (=20 overdrive).
There are two 5 planet=20 arrangements, one with angle cut ( opposite to the Ford unit) = whereby=20 the thrust is between the sun gear and planet ( internal = thrust=20 gear arrangement).
The other is a straight = cut 5 planet arrangement ( no = thrust).
 
The beauty of this = planetary is=20 that the sun gear has a spline at the aft end with a matching = female=20 splined flange ( for bolting to the damper = plate).
 
The ring gear is = externally=20 notched as in the Ford  2.17.
The planet housing is = similar in=20 design and size to the Ford 2.85.
 
Advice from people in = the=20 industry are that the Dodge units are superior to the Ford = units,=20 however that would have to be = confirmed.
 
Originally you were = opposed to=20 going from the 2.17 to 2.85 for a number of reasons - can = quite=20 remember why? Was it because of higher RPM ( engine workload)? = overspeeding the water pump and alternator? Anything else=20 ?
 
What problems do you = envisage=20 with a 3.21:1 ratio?
George ( down=20 = under)

------=_NextPart_000_0033_01C611DB.AA955060--