X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost03.isp.att.net ([204.127.217.103] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5507877 for flyrotary@lancaironline.net; Thu, 26 Apr 2012 09:39:29 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.217.103; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-98-85-91-126.mco.bellsouth.net[98.85.91.126]) by isp.att.net (frfwmhc03) with SMTP id <20120426133851H0300f4ushe>; Thu, 26 Apr 2012 13:38:51 +0000 X-Originating-IP: [98.85.91.126] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Fixed Pitch props. Date: Thu, 26 Apr 2012 09:38:52 -0400 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0025_01CD2390.646BEDB0" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Ac0jndTDr1G3P8LHQQaI3va9lkuTwAAEd1JQ X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18463 This is a multi-part message in MIME format. ------=_NextPart_000_0025_01CD2390.646BEDB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Tom, What engine/PSRU are you planning to put in your Venture? It seems to = me that you are going to have to do some thinking about this combination if = you plan to use a Mazda engine. =20 If you use Tracy=92s RD1-C, you will be limited to about 2450 rpm prop = speed (7000 engine) on take off and about 2100 rpm prop speed (6000 engine) in cruise. That means a heck of a lot of pitch to get a cruise speed of = 240 knots! I think that would work out to around 138 inches of pitch. On takeoff, you would probably think the prop was feathered! =20 Tracy=92s RD1-A or B has a ratio of 2.17 and turns backward to normal aircraft, but I don=92t know if he has them rated at high HP.=20 =20 You may want to try and buy a Mistral PSRU so you can fit a constant = speed prop of some kind. I don=92t know if that is even possible?? =20 I hope this msg will generate some comments from people with more = knowledge about this than I and maybe they will have some nuggets you can use. =20 Bill B =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Thomas Giddings Sent: Thursday, April 26, 2012 7:14 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Fixed Pitch props. =20 Thanks for your info. I did contact Craig Catto and here is his = response: =20 Hello Tom, That is going to be quite a challenge to fit. We make them for the 540 Berkut, and that is about a 285mph aircraft and have done one for a = E-racer turbo 540 at 350HP doing over 300mph. I do not think I want to challenge the auto conversion, just the power = curve many times seems hard to fit. We know the curve of the Lyc engine very = well and so not such a big deal to fit in these types of applications. = Easiest way for you to fit it is probably with a MT. All the best, Craig =20 I was surprised at his answer as i thought he did Tracy's prop. The = speed of the Venture will not be that much more then what he described. It may be = the high HP I will be using.Any more suggestions would be appreciated. KIND REGARDS Thomas Giddings n360tg@earthlink.net 727 858 1772 =20 =20 =20 On Apr 26, 2012, at 1:28 AM, William Jepson wrote: Another possibility is Senessich (never could spell that), they have a = new ground adjustable prop. Carbon blades aluminum hub, which is supposed to = be designed around RV speed and HP. They are supposed to offer a 2 and 3 = blade option. Bill Jepson On Apr 25, 2012 8:53 PM, "Michael McMahon" wrote: I=92ve been thinking along the same lines. The one person I=92ve heard = of often as a potential builder is Craig Catto, www.cattoprops.com . Last time I looked his props were = around $3,000, I think, but I have no idea if that is current. There is also = a new possibility, which is to have the prop manufactured on a resin = printer and then wrap it in carbon fiber. I=92ve done a little research on that = front and spoke to a manufacturer last year at the CAF=C9 Electric Flight = Symposium (this weekend in Santa Rosa!) who confirmed that it=92s possible and is already being done for military drones. =20 Please post your findings! =20 Thanks, =20 Mike =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Thomas Giddings Sent: Wednesday, April 25, 2012 6:57 PM To: Rotary motors in aircraft Subject: [FlyRotary] Fixed Pitch props. =20 I am curious what you folks might recommend for a fixed pitch prop = builder for my project. I will have a lot of excess power and do not think it = would be as difficult to get an acceptable level of performance with a lot = less money and simplicity. Your thoughts KIND REGARDS Thomas Giddings n360tg@earthlink.net 727 858 1772 =20 =20 =20 =20 =20 ------=_NextPart_000_0025_01CD2390.646BEDB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Tom,

What engine/PSRU are you planning = to put in your Venture?=A0 It seems to me that you are going to have to do some = thinking about this combination if you plan to use a Mazda = engine.

 

If you use Tracy’s RD1-C, you will be = limited to about 2450 rpm prop speed (7000 engine) on take off and about 2100 rpm = prop speed (6000 engine) in cruise.=A0 That means a heck of a lot of pitch to = get a cruise speed of 240 knots!=A0 I think that would work out to around 138 = inches of pitch.=A0 On takeoff, you would probably think the prop was = feathered!

 

Tracy’s RD1-A or B has a ratio of 2.17 and turns backward = to normal aircraft, but I don’t know if he has them rated at high HP. =

 

You may want to try and buy a = Mistral PSRU so you can fit a constant speed prop of some kind.=A0 I don’t know = if that is even possible??

 

I hope this msg will =A0generate = some comments from people with more knowledge about this than I and maybe = they will have some nuggets you can use.

 

Bill B

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Thomas Giddings
Sent: Thursday, April 26, = 2012 7:14 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Fixed Pitch props.

 

Thanks for your info. I did contact Craig Catto and here is his response:

 =

Hello = Tom,

That is = going to be quite a challenge to fit.   We make them for the 540 Berkut, = and that is about a 285mph aircraft and have done one for a E-racer turbo 540 at = 350HP doing over 300mph.

I do not = think I want to challenge the auto conversion, just the power curve many times = seems hard to fit. We know the curve of the Lyc engine very well and so not = such a big deal to fit in these types of applications.  Easiest way for = you to fit it is probably with a MT.

All the = best,

Craig<= /u1:p>

 =

I was surprised at his answer as i thought he did Tracy's prop. The speed of the = Venture will not be that much more then what he described. It may be the high HP I = will be using.Any more suggestions would be = appreciated.



KIND = REGARDS

Thomas = Giddings

727 858 = 1772

 <= /o:p>

 

 

On Apr 26, 2012, at 1:28 AM, William Jepson = wrote:



Another possibility is Senessich (never could spell that), they have a new = ground adjustable prop. Carbon blades aluminum hub, which is supposed to be = designed around RV speed and HP. They are supposed to offer a 2 and 3 blade = option. Bill Jepson

On Apr 25, 2012 8:53 PM, "Michael McMahon" <afm528@gmail.com> = wrote:

I’ve been thinking along the same = lines.  The one person I’ve heard of often as a potential builder is Craig = Catto, www.cattoprops.com .  Last time I looked his props were around $3,000, I think, but I = have no idea if that is current.   There is also a new possibility, = which is to have the prop manufactured on a resin printer and then wrap it in = carbon fiber.  I’ve done a little research on that front and spoke = to a manufacturer last year at the CAF=C9 Electric Flight Symposium (this = weekend in Santa Rosa!) = who confirmed that it’s possible and is already being done for = military drones.

 

Please post your = findings!

 

Thanks,

 

Mike

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Thomas = Giddings
Sent: Wednesday, April = 25, 2012 6:57 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] = Fixed Pitch props.

 

I am = curious what you folks might recommend for a fixed pitch prop builder for my project. = I will have a lot of excess power and do not think it would be as difficult to = get an acceptable level of performance with a lot less money and simplicity. = Your thoughts

KIND REGARDS

Thomas Giddings

 

 

 

 

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