X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.2.1) with ESMTP id 2836433 for flyrotary@lancaironline.net; Mon, 07 Apr 2008 19:29:20 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([75.191.186.236]) by cdptpa-omta05.mail.rr.com with SMTP id <20080407232842.IPDB2167.cdptpa-omta05.mail.rr.com@edward2> for ; Mon, 7 Apr 2008 23:28:42 +0000 Message-ID: <001101c89906$db988b00$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Prop selection Date: Mon, 7 Apr 2008 19:26:50 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01C898E5.5429FDF0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_000E_01C898E5.5429FDF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Greg, its always hard to compare props from different makers, but just = for reference, I fly a 13B (est 180 HP) with a 74x88 two blade = Performance Prop off an RD1C. Even with this size prop I can easily get = 6000 -6100 static rpm. Since the Renesis should produce at least 20 HP = more, I would sure have to wonder whether a 68x80 would be enough prop. = But, then it also depends on what you want out of the prop. I am not = interested in high end top speed as I seldom fly faster that 180 MPH = TAS. However, I do like to get in and out of small grass fields over = tree lines smartly. A larger diameter prop disc ends up accelerating = more air mass (and by reaction - the aircraft) faster than a shorter = diameter prop. Now, on the top end a smaller dia prop would let you = wind the engine rpm higher thereby producing more engine power thereby = producing more speed. Just though I would pass this along for you consideration. Best Regards Ed (Still waiting to launch - day 5 waiting for clouds to lift so I can = make Sun & Fun) ----- Original Message -----=20 From: Greg=20 To: Rotary motors in aircraft=20 Sent: Monday, April 07, 2008 6:37 PM Subject: [FlyRotary] Prop selection Anyone had any experience with Prince props. = http://www.princeaircraft.com/ They recommend a 68x80" (2 blade) prop = for my RV8. The web site claims better efficiency so a shorter prop can = be used, which suites me. I was quoted $1646 for wood and $2185 for = carbon fibre I think that includes crusher plate and bolts. They're = quoting 15 week delivery which is better than some I've heard of. Greg =20 RV8 Renesis RD1C ------=_NextPart_000_000E_01C898E5.5429FDF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Greg, its always hard to compare props = from=20 different makers, but just for reference, I fly a 13B (est 180 HP) with = a 74x88=20 two blade Performance Prop off an RD1C.  Even with this size prop I = can=20 easily get 6000 -6100 static rpm.  Since the Renesis should produce = at=20 least 20 HP more, I would sure have to wonder whether a 68x80 would be = enough=20 prop. 
 
But, then it also depends on what you = want out of=20 the prop.  I am not interested in high end top speed as I seldom = fly faster=20 that 180 MPH TAS.  However, I do like to get in and out of small = grass=20 fields over tree lines smartly.  A larger diameter prop disc ends = up=20 accelerating more air mass (and by reaction - the aircraft) faster = than a=20 shorter diameter prop.  Now, on the top end a smaller dia prop = would let=20 you wind the engine rpm higher thereby producing more engine power = thereby=20 producing more speed.
 
Just though I would pass this along for = you=20 consideration.
 
Best Regards
 
Ed (Still waiting to launch - day = 5 waiting=20 for clouds to lift so I can make Sun & Fun)
 
 
----- Original Message -----
From:=20 Greg =
Sent: Monday, April 07, 2008 = 6:37=20 PM
Subject: [FlyRotary] Prop = selection

Anyone had any experience with Prince = props. http://www.princeaircraft.com/ =20 They recommend a 68x80" (2 blade) prop for my RV8. The web site claims = better=20 efficiency so a shorter prop can be used, which suites me.  I was = quoted=20 $1646 for wood and $2185 for carbon fibre I think that includes = crusher plate=20 and bolts.  They're quoting 15 week delivery which is better than = some=20 I've heard of.
 
Greg 
RV8 Renesis=20 RD1C
------=_NextPart_000_000E_01C898E5.5429FDF0--