X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 1002891 for flyrotary@lancaironline.net; Wed, 15 Jun 2005 11:12:27 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.131.117; envelope-from=keltro@att.net Received: from 204.127.135.75 ([204.127.135.75]) by worldnet.att.net (mtiwmhc13) with SMTP id <2005061515114111300pckbbe>; Wed, 15 Jun 2005 15:11:41 +0000 Received: from [209.247.222.104] by 204.127.135.75; Wed, 15 Jun 2005 15:11:40 +0000 From: keltro@att.net (Kelly Troyer) To: "Rotary motors in aircraft" Subject: Re: planetary gear ratios Date: Wed, 15 Jun 2005 15:11:40 +0000 Message-Id: <061520051511.17941.42B0452C00036D1F000046152160466648019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Feb 14 2005) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_17941_1118848300_0" --NextPart_Webmail_9m3u9jl4l_17941_1118848300_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Ernest, Ross redrives for the early 12A/13b were 3.17-1........Lou Ross had this ratio in a Mooney (not sure if it was 12Aor 13B) which spent at least a few hours in the air in the late 1970's early 1980's........My question is this, is this a three pinion planetary and have you determined it is a Ford C6 part ?? I personally would not put a three pinion planetary on a modern 13B and fly with it !! If there is a direct fit replacement I would choose a six pinion first or a four pinion second choice replacement planetary.........FWIW.......I do not know tooth count for 3.17 ratio as I have never seen one ! -- Kelly Troyer Dyke Delta/13B/RD1C/EC2 -------------- Original message from Ernest Christley : -------------- > George Lendich wrote: > > >Ernest, > >If it turns counter clockwise it's the 2.17 ( you don't add the one in the > >calculations). > >If it turns clockwise it's 3.17. > >The 2.17 turns counter clockwise. > >The 2.85 turns clockwise ( looking at it from the pilots seat) > >George ( down under) > > > > > > George, if you meant to confuse me then you have done a spectacular job 8*) > > Let's back up just a second. The ring gear is locked. The output is > taken from a splined shaft that is driven by the planet gear carrier. > When I turn the sun gear clockwise, the output shaft turns clockwise. > It takes *about* 3 turns of the sun gear to get one turn on the output > shaft. You've said (or at least I read it that way) that this is both a > 2.85 and 3.17. Was there a typo in there somewhere? > > Kelly, I was thinking more along the lines of 8000RPM redline, with a > 7000 cruise. That would put the prop revs at 2208, which I *think* is a > good number. The problem I'm having is trusting the 3-pinion planet set > I have. I took the gearbox to a transmission shop. The technician said > I was wasting money to replace it. They use that same gearset to drive > busses. But I can't help but to be swayed by advertisements like item > number #9X on this site: > > http://www.transmissioncenter.net/C4_C6.htm > > That's a lot of reassurance for $218 that follows all the laws of > physics I know. I would have switched it out already, I'm just not > positive about which gearset I have exactly. Does anyone know for > certain the teeth count on the different gearsets? --NextPart_Webmail_9m3u9jl4l_17941_1118848300_0 Content-Type: text/html Content-Transfer-Encoding: 8bit
Ernest,
    Ross redrives for the early 12A/13b were 3.17-1........Lou Ross had this ratio in
a Mooney (not sure if it was 12Aor 13B) which spent at least a few hours in the
air in the late 1970's early 1980's........My question is this, is this a three pinion
planetary and have you determined it is a Ford C6 part ?? I personally would not
put a three pinion planetary on a modern 13B and fly with it !! If  there is a direct
fit replacement I would choose a six pinion first or a four pinion second choice
replacement planetary.........FWIW.......I do not know tooth count for 3.17 ratio as
I have never seen one !
--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2




-------------- Original message from Ernest Christley <echristley@nc.rr.com>: --------------


> George Lendich wrote:
>
> >Ernest,
> >If it turns counter clockwise it's the 2.17 ( you don't add the one in the
> >calculations).
> >If it turns clockwise it's 3.17.
> >The 2.17 turns counter clockwise.
> >The 2.85 turns clockwise ( looking at it from the pilots seat)
> >George ( down under)
> >
> >
>
> George, if you meant to confuse me then you have done a spectacular job 8*)
>
> Let's back up just a second. The ring gear is locked. The output is
> taken from a splined shaft that is driven by the planet gear carrier.
> When I turn the sun gear clockwise, the output shaft turns clockwise.
> It takes *about* 3 turns of the sun gear to get one turn on the output
> shaft. You've said (or at least I read it that way) that this is both a
> 2.85 and 3.17. Was there a typo in there somewhere?
>
> Kelly, I was thinking more along the lines of 8000RPM redline, with a
> 7000 cruise. That would put the prop revs at 2208, which I *think* is a
> good number. The problem I'm having is trusting the 3-pinion planet set
> I have. I took the gearbox to a transmission shop. The technician said
> I was wasting money to replace it. They use that same gearset to drive
> busses. But I can't help but to be swayed by advertisements like item
> number #9X on this site:
>
> http://www.transmissioncenter.net/C4_C6.htm
>
> That's a lot of reassurance for $218 that follows all the laws of
> physics I know. I would have switched it out already, I'm just not
> positive about which gearset I have exactly. Does anyone know for
> certain the teeth count on the different gearsets?
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