X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao101.cox.net ([68.230.241.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3549635 for flyrotary@lancaironline.net; Mon, 16 Mar 2009 20:59:16 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.45; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao101.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090317005839.RSRE27308.fed1rmmtao101.cox.net@fed1rmimpo03.cox.net> for ; Mon, 16 Mar 2009 20:58:39 -0400 Received: from wills ([68.105.85.56]) by fed1rmimpo03.cox.net with bizsmtp id U0yd1b0031CvZmk040yfQS; Mon, 16 Mar 2009 20:58:39 -0400 X-Authority-Analysis: v=1.0 c=1 a=kviXuzpPAAAA:8 a=Ia-xEzejAAAA:8 a=pcLIrrrKAAAA:8 a=7g1VtSJxAAAA:8 a=5MvF0rhXdCl8_j6UZSgA:9 a=Ad09LbssCkCCtkONr5IA:7 a=2uysWbld75YuQs4L-p3Jk_IvxA0A:4 a=uv1ck3d6JtEA:10 a=4vB-4DCPJfMA:10 a=EzXvWhQp4_cA:10 a=ftFGBYpk1mUA:10 a=ImHZSHJnFm5KrQTh:21 a=5pHVfqt5NKsxlzuq:21 a=HZJGGiqLAAAA:8 a=4VHdTuTRDcFqoEuEzogA:9 a=wrmnwo49aZkQIlE0SR4A:7 a=sp-rpdIH5wkcsjOVsr8Og6g807kA:4 a=AfD3MYMu9mQA:10 a=HeoGohOdMD0A:10 X-CM-Score: 0.00 Message-ID: <001f01c9a69b$80a8d620$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: IVO Prop Date: Mon, 16 Mar 2009 17:58:36 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001C_01C9A660.D3FDB2E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_001C_01C9A660.D3FDB2E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jim, So can you describe your specific application? Engine, prop, ratio, = airframe, and some performance data? In my case I have the 2.17 ratio - when I bought it there was no 2.85 = option. This is in an RV-4 with a second gen 13B built by Bruce = Turrentine with high compression NA rotors and turbo rotor housings. I always kind of assumed that with variable pitch, prop selection was = considerably more forgiving. Did not realize there were so many options = for the IVO (actually I dont think there were so many when I was looking = before). Mike Mike ----- Original Message -----=20 From: James Maher=20 To: Rotary motors in aircraft=20 Sent: Sunday, March 15, 2009 12:05 PM Subject: [FlyRotary] Re: IVO Prop I have been reading with much interest the discussion about IVO = props lately and felt that as a, so far, happy owner of one that I should chime in. When determining the success or failure of the IVO prop it is = much the same as determining the success or failure of the rotary = engine. The IVO prop like the rotary engine is not a single entity. There are many different sizes and possible configurations of = both a rotary engine and=20 the IVO prop. When you combine the two then the combinations become = staggering. The "IVO prop" has at least 3 different blade profiles, the = blades can be configured from 2 to 6 blades in a hub determined by the = amount of HP you wish to absorb, the length of the blades and their = pitch adjustment are also factors. Finding the proper combination will ultimately determine the = success or failure of the "system". The correct combination must also be determined based upon the = application. An example of this is in the early years of matching the rotary = to the prop was that the conventional wisdom of the time was to use the 2.17:1 PRSU and a = short prop turning at high revs.=20 Some tried this using the IVO prop and it did not perform as = well as some other props in this situation. I think that it has been discovered over time that a better = combination for the IVO in higher performance aircraft is a longer blade with higher pitch = turning slower gives better efficiency. So it is not so much whether the IVO has succeeded or failed but = more like do you have=20 the correct combination of engine, PSRU, and prop configuration = for the application you=20 are intending it to operate in. Just my opinion of course. YMMV Jim --- On Wed, 3/11/09, Mike Wills wrote: From: Mike Wills Subject: [FlyRotary] Re: IVO Prop To: "Rotary motors in aircraft" Date: Wednesday, March 11, 2009, 10:02 PM John, I looked pretty seriously at the IVO a number of years ago. But was = scared off by a number of things: 1) Watched Dave Atkins repairing a delaminated trailing edge on the = flight line at Copperstate fly-in. 2) A friend with a Kolb Firestar/Rotax 503/ground adjustable IVO had the = prop come apart in flight resulting in a forced landing that totaled the = plane. 3) Tracy's experience re reduced performance at speed. 4) The issues experienced by Lyc powered users. Numbers 1 & 2 were possibly due to something going through the prop with the engine running. Issue 4 seems to be not relevant. This leaves = Tracy's experience with the IVO. I wasnt thinking about the fact that you fly a = pusher when I asked, but presumably a pusher would not have the prop root issue = that Tracy reported. On my RV-4 I use a much larger than stock spinner and = this issue may not be as significant as it was for Tracy. But I'm not sure I want = to buy one to find out. My current prop seems to be pretty close though I = havent flown it enough to really make a judgement. Thanks for the feedback. Mike Wills RV-4 N144MW ----- Original Message ----- From: "John Slade" To: "Rotary motors in aircraft" Sent: Tuesday, March 10, 2009 9:41 PM Subject: [FlyRotary] IVO Prop > >I didn't know anyone had ever had any success with an IVO. Tell me more. > What do you want to know? Its a very well engineered piece of = equipment. The CF blades are hollow and have a steel rod running to the hub. = Activating the motor via brushes twists the steel and thus twists the blades equally. = The twist change is quite visible. There were problems with the individual blades = slipping on the hub. This has been solved by providing a knurled hub, and not = selling to guys with Lycomings. The IVO is available for rotary, subaru, Franklin 6 = and other less "pulsy" engines. After the first 15 hours or so my blades have hardly taken any extra torque. >=20 > My performance is greatly enhanced compared to the fixed pitch = Performance prop. Static with the wood prop was around 4500. With the IVO on full = fine I get closer to 5400 which gives me access to a lot more power on take off. = I've never done a "high speed" run with the IVO, but I've had 180 kts indicated at 2000' a few times without much effort, and without ever = going to the full course setting. Another nice bonus is that throttled back on = full fine for landing, the prop acts like a brake. Its much easier to land = and stop than the fixed pitch that's pushing you along fairly well, even at idle. >=20 > I know a Velocity driver (Mike Watson) who also uses an IVO (Franklin = 6) and is very happy with it after around 5 years of use. >=20 > The factory people are very easy to deal with and very helpful. >=20 > The Cozy Girrrls are installing an IVO. What better recommendation = could you want? :) >=20 > Regards, > John Slade > Turbo Rotary Cozy IV, N96PM > 98.1 Hrs. >=20 > Mike Wills wrote: >>=20 >>=20 >> Mike Wills >> RV-4 N144MW >>=20 >> ----- Original Message ----- From: "John Slade" >> To: "Rotary motors in aircraft" >> Sent: Tuesday, March 10, 2009 10:30 AM >> Subject: [FlyRotary] Re: Ground Testing >>=20 >>=20 >>> The IVO electric in-flight adjustable costs around $2350. I'm very pleased with mine. My "spare" is a $2700 fixed pitch wood prop thats a piece of art, but doesn't work anywhere near as well. >>> John >>>=20 >>> Tracy Crook wrote: >>> A variable pitch prop would be nice to get the best of both worlds but it's an expensive option and $10,000 buys a lot of gas. >>>=20 >>>=20 >>>=20 >>> -- Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html >>>=20 >>=20 >>=20 >>=20 >> -- Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html >>=20 >=20 >=20 > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html >=20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html =20 ------=_NextPart_000_001C_01C9A660.D3FDB2E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Jim,
 
 So can you describe your specific = application? Engine, prop, ratio, airframe, and some performance=20 data?
 
 In my case I have the 2.17 ratio = - when I=20 bought it there was no 2.85 option. This is in an RV-4 with a second gen = 13B=20 built by Bruce Turrentine with high compression NA rotors and turbo = rotor=20 housings.
 
 I always kind of assumed that = with variable=20 pitch, prop selection was considerably more forgiving. Did not realize = there=20 were so many options for the IVO (actually I dont think there were so = many when=20 I was looking before).
 
Mike
 
Mike
----- Original Message -----
From:=20 James = Maher=20
Sent: Sunday, March 15, 2009 = 12:05=20 PM
Subject: [FlyRotary] Re: IVO = Prop

I have been reading with much interest the discussion about = IVO=20 props lately and felt
that as a, so far, happy owner of one that I should chime = in.
When determining the success or failure of the IVO prop it = is much=20 the same as determining the success or failure of the rotary=20 engine.
The IVO prop like the rotary engine is not a single = entity.
There are many different sizes and possible configurations = of both=20 a rotary engine and
the IVO prop.
When you combine the two then the combinations become=20 staggering.
The "IVO prop" has at least 3 different blade profiles, the = blades=20 can be configured from 2 to 6 blades in a hub determined by the = amount=20 of HP you wish to absorb, the length of the blades and their = pitch=20 adjustment are also factors.
Finding the proper combination will ultimately determine = the=20 success or failure of the "system".
The correct combination must also be determined based upon = the=20 application.
An example of this is in the early years of matching the = rotary to=20 the prop was that the
conventional wisdom of the time was to use the 2.17:1 PRSU = and a=20 short prop turning at
high revs.
Some tried this using the IVO prop and it did not perform = as well=20 as some other props in this situation.
I think that it has been discovered over time that a better = combination for the  IVO in
higher performance aircraft is a longer blade = with higher=20 pitch turning slower gives better
efficiency.
So it is not so much whether the IVO has succeeded or = failed but=20 more like do you have
the correct combination of engine, PSRU, and prop = configuration for=20 the application you
are intending it to operate in.
Just my opinion of course. YMMV
 
Jim

--- On Wed, 3/11/09, Mike Wills=20 <rv-4mike@cox.net> wrote:
From:=20 Mike Wills <rv-4mike@cox.net>
Subject:=20 [FlyRotary] Re: IVO Prop
To: "Rotary motors in = aircraft" <flyrotary@lancaironline.net>
Date: = Wednesday,=20 March 11, 2009, 10:02 PM

John,

I looked pretty seriously at the IVO a number of years ago. But was =
scared off
by a number of things:

1) Watched Dave Atkins repairing a delaminated trailing edge on the =
flight line
at Copperstate fly-in.
2) A friend with a Kolb Firestar/Rotax 503/ground adjustable IVO had the =
prop
come apart in flight resulting in a forced landing that totaled the =
plane.
3) Tracy's experience re reduced performance at speed.
4) The issues experienced by Lyc powered users.

Numbers 1 & 2 were possibly due to something going through the prop =
with
the engine running. Issue 4 seems to be not relevant. This leaves =
Tracy's
experience with the IVO. I wasnt thinking about the fact that you fly a =
pusher
when I asked, but presumably a pusher would not have the prop root issue =
that
Tracy reported. On my RV-4 I use a much larger than stock spinner and =
this issue
may not be as significant as it was for Tracy. But I'm not sure I want =
to
buy one to find out. My current prop seems to be pretty close though I =
havent
flown it enough to really make a judgement.

Thanks for the feedback.

Mike Wills
RV-4 N144MW



----- Original Message ----- From: "John Slade"
<sladerj@sbcglobal.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Tuesday, March 10, 2009 9:41 PM
Subject: [FlyRotary] IVO Prop


> >I didn't know anyone had ever had any success with an IVO. Tell =
me
more.
> What do you want to know? Its a very well engineered piece of =
equipment.
The CF blades are hollow and have a steel rod running to the hub. =
Activating the
motor via brushes twists the steel and thus twists the blades equally. =
The twist
change is quite visible. There were problems with the individual blades =
slipping
on the hub. This has been solved by providing a knurled hub, and not =
selling to
guys with Lycomings. The IVO is available for rotary, subaru, Franklin 6 =
and
other less "pulsy" engines. After the first 15 hours or so my blades
have hardly taken any extra torque.
>=20
> My performance is greatly enhanced compared to the fixed pitch =
Performance
prop. Static with the wood prop was around 4500. With the IVO on full =
fine I get
closer to 5400 which gives me access to a lot more power on take off. =
I've
never done a "high speed" run with the IVO, but I've had 180 kts
indicated at 2000' a few times without much effort, and without ever =
going
to the full course setting. Another nice bonus is that throttled back on =
full
fine for landing, the prop acts like a brake. Its much easier to land =
and stop
than the fixed pitch that's pushing you along fairly well, even at idle.
>=20
> I know a Velocity driver (Mike Watson) who also uses an IVO =
(Franklin 6)
and is very happy with it after around 5 years of use.
>=20
> The factory people are very easy to deal with and very helpful.
>=20
> The Cozy Girrrls are installing an IVO. What better recommendation =
could
you want? :)
>=20
> Regards,
> John Slade
> Turbo Rotary Cozy IV, N96PM
> 98.1 Hrs.
>=20
> Mike Wills wrote:
>>=20
>>=20
>> Mike Wills
>> RV-4 N144MW
>>=20
>> ----- Original Message ----- From: "John Slade"
<sladerj@sbcglobal.net>
>> To: "Rotary motors in aircraft"
<flyrotary@lancaironline.net>
>> Sent: Tuesday, March 10, 2009 10:30 AM
>> Subject: [FlyRotary] Re: Ground Testing
>>=20
>>=20
>>> The IVO electric in-flight adjustable costs around $2350. =
I'm
very pleased with mine. My "spare" is a $2700 fixed pitch wood prop
thats a piece of art, but doesn't work anywhere near as well.
>>> John
>>>=20
>>> Tracy Crook wrote:
>>> A variable pitch prop would be nice to get the best of both =
worlds
but it's an expensive option and $10,000 buys a lot of gas.
>>>=20
>>>=20
>>>=20
>>> -- Homepage:  http://www.flyrotary.com/
>>> Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>>=20
>>=20
>>=20
>>=20
>> -- Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>=20
>=20
>=20
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>=20



--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   =
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