X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from bay0-omc2-s23.bay0.hotmail.com ([65.54.190.98] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with ESMTP id 4551342 for flyrotary@lancaironline.net; Mon, 01 Nov 2010 21:36:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.190.98; envelope-from=stol83001@live.com Received: from BAY143-W23 ([65.54.190.125]) by bay0-omc2-s23.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Mon, 1 Nov 2010 18:36:15 -0700 Message-ID: Return-Path: stol83001@live.com Content-Type: multipart/alternative; boundary="_0c367574-add7-4c72-95dc-d58f4bd509dc_" X-Originating-IP: [75.174.166.225] From: ben haas To: Subject: RE: [FlyRotary] How fast is it safe to turn a Prop. Opinion Poll Date: Mon, 1 Nov 2010 19:36:14 -0600 Importance: Normal In-Reply-To: References: MIME-Version: 1.0 X-OriginalArrivalTime: 02 Nov 2010 01:36:15.0057 (UTC) FILETIME=[569F8410:01CB7A2E] --_0c367574-add7-4c72-95dc-d58f4bd509dc_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable For a base line....... =20 76" diameter Ivo prop. These are the magnum series=2C=2C not my paddle blad= es. 3076 prop rpm.... Motor turning 4400 rpm 35 degrees f=20 =20 695 mph tip speed. .936 mach. =20 Plane still pulling strong up to 4500 motor rpm. =20 http://www.pponk.com/HTML%20PAGES/propcalc.html =20 Prop is not that noisy either. Motor makes more noise. =20 http://www.youtube.com/watch?v=3DAOF6eT6FRmY =20 Been running this way for 400 hours and blades look good. =20 Ben Haas www.haaspowerair.com =20 To: flyrotary@lancaironline.net Date: Mon=2C 1 Nov 2010 11:49:04 -0700 From: wdleonard@gmail.com Subject: [FlyRotary] How fast is it safe to turn a Prop. Opinion Poll So I am getting a little more bold with my new turbo. On the way home toda= y I decided to open it up a little bit. At 8500' and MAP around 34"=2C I w= as at 6700 RPM and 201 KTAS (about 3060 RPM at the prop with the tips doing= 860fps). Temps still less than 160=2C plenty of throttle left. I just co= uldn't accept turning the prop any faster=2C not knowing what the limit rea= lly is. My prop is a 64" diameter (pretty short) Catto (wood/composite) with a numb= er of nicks in the leading edge and has not been dynamical balanced to date= . =20 I talked to Craig Catto about the issue and what he told me completely make= s sense=2C but is utterly unhelpful in setting my racing redline. He said = that I could turn it as fast as I want=2C but the risk of separating the pr= op. increases as I go faster. I just depends on too many factors. =20 I realize the the final number is going to depend on my risk tolerance and = how much I really want to post some big numbers in a race. But it is hard = for me to balance that without better understand or the factors on the prop= =2C hence=2C the opinion poll=2C on various factors.. =20 I have heard that it is important to keep the prop tips under 900 fps=2C wh= ile others say it is not a factor. Is there some important number for the = max tip speed? Is it a safety issue or an efficiency issue? =20 Most of my nicks in the paint and composite layer are in the outer 1/3 of t= he prop. Are these a big deal for safety? Efficiency? =20 If I were to run the engine at 7000 RPM that would give me 3225 at the prop= =2C tips doing 900 FPS an an aircraft speed of around 209 kts (240mph). Th= is seems pretty reasonable to me as an upper limit=2C but it is scary a lit= tle. =20 But what about 8000RPM at the engine (if I have the power to get there)? W= ith a cleaned up and balanced prop=2C that would be almost 3700 RPM at the = prop=2C tips doing 1020fps=2C aircraft going something less than 240kts (27= 5 mph). Stupid though? Or give it a try and see how close to those numbers= I can get? =20 Any issues with the gear-box going that fast=2C other factors I am not cons= idering? =20 Anyway=2C it feels really cool to have broken 200kts in level flight. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net = --_0c367574-add7-4c72-95dc-d58f4bd509dc_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable For a base line.......
 =3B
76" diameter Ivo prop. These are the magnum series=2C=2C not my paddle blad= es.
3076 prop rpm.... Motor turning 4400 rpm
35 degrees f
 =3B
695 mph tip speed. .936 mach.
 =3B
Plane still =3Bpulling strong up to 4500 motor rpm.
 =3B
http://www.ppon= k.com/HTML%20PAGES/propcalc.html
 =3B
Prop is not that noisy either. Motor makes more noise.
 =3B
http://www.youtube= .com/watch?v=3DAOF6eT6FRmY
 =3B
Been running this way for 400 hours and blades look good.
 =3B


Ben Haas
www.haaspowerair.c= om



 =3B
To: flyrotary@lancaironline.net
Date: Mon=2C 1 Nov 2010 11:49:04 -0700From: wdleonard@gmail.com
Subject: [FlyRotary] How fast is it safe to = turn a Prop. Opinion Poll

So I am getting a little more bold with my new =3Bturbo. =3B O= n the way home today I decided to open it up a little bit. =3B At 8500'= and MAP around 34"=2C I was at 6700 RPM and 201 KTAS (about 3060 RPM at th= e prop with the tips doing 860fps). =3B Temps still less than 160=2C pl= enty of throttle left. =3B I just couldn't accept turning the prop any = faster=2C not knowing what the limit really is.

My prop is a 64" dia= meter (pretty short) Catto (wood/composite) with a number of nicks in the l= eading edge and has not been dynamical balanced to date.
 =3B
I talked to Craig Catto about the issue and =3Bwhat he told me com= pletely makes sense=2C but is utterly unhelpful in setting my racing redlin= e. =3B He said that I could turn it as fast as I want=2C but the risk o= f separating the prop. increases as I go faster. =3B I just depends on = too many factors.
 =3B
I realize the the final number is going to depend on my risk tolerance= and how much I really want to post some big numbers in a race. =3B But= it is hard for me to balance that without better understand or the factors= on the prop=2C hence=2C the opinion poll=2C on various factors..
 =3B
I have heard that it is important to keep the prop tips under 900 fps= =2C while others say it is not a factor. =3B Is there some important nu= mber for the max tip speed? =3B Is it a safety issue or an efficiency i= ssue?
 =3B
Most of my nicks in the paint and composite layer are in the outer 1/3= of the prop. =3B Are these a big deal for safety? =3B Efficiency?<= /DIV>
 =3B
If I were to run the engine at 7000 RPM that would give me 3225 at the= prop=2C tips doing 900 FPS an an aircraft speed of around 209 kts (240mph)= . =3B This seems pretty reasonable to me as an upper limit=2C but it is= scary a little.
 =3B
But what about 8000RPM at the engine (if I have the power to get there= )? =3B With a cleaned up and balanced prop=2C that would be almost 3700= RPM at the prop=2C tips doing 1020fps=2C aircraft going =3Bsomething l= ess than 240kts =3B(275 mph). =3B Stupid though? Or give it a try a= nd see how close to those numbers I can get?
 =3B
Any issues with the gear-box going that fast=2C other factors I am not= considering?
 =3B
Anyway=2C it feels really cool to have broken 200kts in level flight.<= BR clear=3Dall>
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryR= oster.net
http:= //RotaryRoster.net
= --_0c367574-add7-4c72-95dc-d58f4bd509dc_--