X-Virus-Scanned: clean according to Sophos on Logan.com From: "Ed Anderson" Received: from [107.14.166.225] (HELO cdptpa-oedge-vip.email.rr.com) by logan.com (CommuniGate Pro SMTP 6.1.5) with ESMTP id 7998777 for flyrotary@lancaironline.net; Fri, 18 Sep 2015 06:57:07 -0400 Received-SPF: pass receiver=logan.com; client-ip=107.14.166.225; envelope-from=eanderson@carolina.rr.com Return-Path: Received: from [71.75.143.5] ([71.75.143.5:53550] helo=EdPC) by cdptpa-oedge01 (envelope-from ) (ecelerity 3.5.0.35861 r(Momo-dev:tip)) with ESMTP id 79/DC-13021-2EDEBF55; Fri, 18 Sep 2015 10:56:34 +0000 Message-ID: To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: New psru Date: Fri, 18 Sep 2015 06:55:52 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01D0F1DF.0F3CD3B0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 16.4.3528.331 X-MimeOLE: Produced By Microsoft MimeOLE V16.4.3528.331 X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 This is a multi-part message in MIME format. ------=_NextPart_000_0021_01D0F1DF.0F3CD3B0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I agree with your assessment, Bill I started out with a 67x72 prop and 2.14:1 gear box. I later switched = to the 2.85 and a 74x88 prop and the takeoff performance was = tremendously improved =E2=80=93 not that the 2.14 was bad, it = wasn=E2=80=99t. But, the 2.85 made a good thing so much better in my = opinion. I even got a couple of MPH more on the top end. My = experience with the rotary is that rpm =3D power produced, my take off = rpm rose from around 5200-5500 rpm with the old set up to 6000-6100 with = the new prop. I am uncertain about the 3.12 ratio, but the 2.85 was a = definite improvement as far as I was concerned. Ed From: Neil Unger=20 Sent: Friday, September 18, 2015 12:09 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: New psru Bill, The ratio is either 2.85 or 3.12 depending what gear set you = buy. My experience is that the Lyco give good torque which is good low = speed Hp. the rotary however has little comparative torque and must = compensate with RPM. I bought a prop for 250 Hp and put it on my rotary = with the 2.85 reduction and it killed the rotary. Could only get a = little over 6000 RPM. The rotary real;ly only comes into its own above = 7500 RPM, so I am planning on getting something near 8000 rpm for full = HP. It seems that the rotary must be under proped or it will struggle = to get the HP required. I may be wrong, but that is my experience. From: Bill Bradburry=20 Sent: Thursday, September 17, 2015 10:54 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: New psru Neil, =20 This is great news for people wanting to install a rotary! I don=E2=80=99t know what drives the selection of a gear ratio, but a = better ratio would be closer to 2.5 to 1. This would make the use of = more standard props easier. With this high a ratio, you will need to = run the engine at high rpm, or the prop will have to turn at a slow = speed requiring a high pitch on the blades. =20 Is the ratio selectable at all? =20 Bill=20 =20 -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]=20 Sent: Wednesday, September 16, 2015 11:28 PM To: Rotary motors in aircraft Subject: [FlyRotary] New psru =20 Gents, Finally the first PSRU with a reduction of 3.12 to 1. = Pictured is the basic box which is heavily based on Tracy=E2=80=99s PSRU = but with the larger reduction and 2 oil lubricated thrust bearings on = the prop shaft instead of a single sealed roller bearing in = Tracy=E2=80=99s. This psru will mount directly in place of Tracy's 2.85 = reduction PSRU with no modification. Now to put to test to see if the practice matches the theory. = Already found one fault. The =E2=80=9CO=E2=80=9D ring seal that seals = the main body of the PSRU to the base that attaches to the mounting = plate is outside all the attachment bolts, which means that the oil can = wick down the bolts and make a lovely mess of your pride and joy. Now = looking for more faults as this is easily fixed. Unlike Tracy's , this = PSRU is totally sealed with O rings to ease dismantling with no clean up = of whatever gasket sealer you have had to use. Now the terrible part and still undecided as I am yet to cost a = damper on the drive. Sadly it also is not cheap and may yet cost near = $500 for a =E2=80=9Dbit of rubber=E2=80=9D. Then comes a mounting plate = as made by Geoff Doddridge which he sells for around $400 USD. There is = no point in me trying to compete with Geoff as he does a magnificent job = at a cheap price. Freight is always a horrible price so he makes the = plate and there is no freight from Aust to be added. The total cost in Aust dollars (including Geoff=E2=80=99s plate) = will be around the $5000 which equates to $3500 USD. Then freight of = possibly $200. Currently looking at further reduction in price if you = source the gear set locally saving on freight both ways to Aust and = back. I will have to alter the way it is constructed so that all the = mods can be done by you the builder. Still looking! So far the progress. Neil. No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.6140 / Virus Database: 4431/10658 - Release Date: = 09/17/15 ------=_NextPart_000_0021_01D0F1DF.0F3CD3B0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I agree with your assessment, Bill
 
I started out with a 67x72 prop and 2.14:1 gear box.  I later = switched=20 to the 2.85 and a 74x88 prop and the  takeoff performance was=20 tremendously  improved =E2=80=93 not that the 2.14 was bad, it = wasn=E2=80=99t.  But,=20 the 2.85 made a good thing so much better in my opinion.   I = even got=20 a couple of MPH more on the top end.  My experience with the rotary = is that=20 rpm =3D power produced, my take off rpm rose from around 5200-5500 rpm = with the=20 old set up to 6000-6100 with the new prop. I am uncertain about the 3.12 = ratio,=20 but the 2.85 was a definite improvement as far as I was concerned.
 
Ed
 
 
 
From: Neil Unger
Sent: Friday, September 18, 2015 12:09 AM
Subject: [FlyRotary] Re: New psru
 
Bill,   The ratio is either 2.85 or 3.12 = depending what gear set you buy.  My experience is that the Lyco = give good=20 torque which is good low speed Hp.  the rotary however has little=20 comparative torque and must compensate with RPM.  I bought a prop = for 250=20 Hp and put it on my rotary with the 2.85 reduction and it killed the=20 rotary.  Could only get a little over 6000 RPM.  The rotary = real;ly=20 only comes into its own above 7500 RPM, so I am planning on getting = something=20 near 8000 rpm for full HP.  It seems that the rotary must be under=20 proped  or it will struggle to get the HP required.  I may be = wrong,=20 but that is my experience.
 
Sent: Thursday, September 17, 2015 10:54 PM
Subject: [FlyRotary] Re: New psru
 

Neil,

 

This is great = news for=20 people wanting to install a rotary!

I = don=E2=80=99t know what=20 drives the selection of a gear ratio, but a better ratio would be closer = to 2.5=20 to 1.  This would make the use of more standard props easier.  = With=20 this high a ratio, you will need to run the engine at high rpm, or the = prop will=20 have to turn at a slow speed requiring a high pitch on the=20 blades.

 

Is the ratio = selectable=20 at all?

 

Bill=20

 

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net]
Sent: Wednesday, September 16, = 2015 11:28=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] New=20 psru

 

Gents,

           =   =20 Finally the first PSRU with a reduction of 3.12  to 1.  = Pictured is=20 the basic box which is heavily based on Tracy=E2=80=99s=20 PSRU but with the larger reduction and 2 oil lubricated = thrust  =20 bearings on the prop shaft instead of a single sealed roller bearing in=20 Tracy=E2=80=99s. =20 This psru will mount directly in place of Tracy's 2.85 reduction PSRU with no=20 modification.

   =20 Now to put to test to see if the practice matches the theory.  = Already=20 found one fault. The =E2=80=9CO=E2=80=9D ring seal that seals the main = body of the PSRU to the=20 base that attaches to the mounting plate is outside all the attachment = bolts,=20 which means that the oil can wick down the bolts and make a lovely mess = of your=20 pride and joy.  Now looking for more faults as this is easily = fixed. =20 Unlike Tracy's ,=20 this PSRU is totally sealed with O rings to ease dismantling with no = clean up of=20 whatever gasket sealer you have had to = use.

   =20 Now the terrible part and still undecided as I am yet to cost a damper = on the=20 drive.  Sadly it also is not cheap and may yet cost near $500 for a = =E2=80=9Dbit of=20 rubber=E2=80=9D.  Then comes a mounting plate as made by Geoff = Doddridge which he=20 sells for around $400 USD.  There is no point in me trying to = compete with=20 Geoff as he does a magnificent job at a cheap price.  Freight is = always a=20 horrible price so he makes the plate and there is  no freight from = Aust to=20 be added.

   =20 The total cost in Aust dollars (including Geoff=E2=80=99s plate) will be = around the=20 $5000 which equates to $3500 USD.  Then freight of possibly = $200. =20 Currently looking at further reduction in price if you source the gear = set=20 locally saving on freight both ways to Aust and back.  I will have = to alter=20 the way it is constructed so that all the mods can be done by you the=20 builder.  Still looking!

   =20 So far the progress. =20 Neil.

No virus found in this=20 message.
Checked by AVG - www.avg.com
Version: 2015.0.6140 / = Virus=20 Database: 4431/10658 - Release Date:=20 09/17/15

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