---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Tue 10/18/05: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:50 AM - Re: 2 blade to 3 blade (blairclan) 2. 01:33 AM - Re: 2 blade to 3 blade (JOHN STARN) 3. 08:18 AM - Re: 2 blade to 3 blade (LesDrag@aol.com) ________________________________ Message 1 _____________________________________ Time: 12:50:49 AM PST US From: "blairclan" Subject: RE: Rocket-List: 2 blade to 3 blade --> Rocket-List message posted by: "blairclan" Was wondering what RPM you guys don't like the vibration at. I find on mine that from 2300 and above its smooth with the 2 blader. So I generally use that RPM. Comments? Cheers Tony -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Milt Subject: Re: Rocket-List: 2 blade to 3 blade --> Rocket-List message posted by: "Milt" You don't get somethin for nothin. Had the 2 blade hartzell and the vibration/propwash was shaking parts off the plane. Hated it so bad I was tempted to sell it. Put the 3 blade MT on and smooth as silk. Lost 3-5kts in cruise. Lost a little in climb and TO performance, still bvlow the doors off anything else around although now I will occassionally see TASs of 198-199 (250HP) The 3 blade MT weighs exactly what the 2 blade Hartzell weighs. Make the change cause you ain't gonna make the shakes go away with balancing. ----- Original Message ----- From: "Stewart, Michael (ISS Atlanta)" Subject: RE: Rocket-List: 2 blade to 3 blade > --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" > > > If I were convinced that the 3 blade would keep me cruising at 200ktas > AND be smooth like an electric motor I'd do it. > > I would loose my big smile during cruise if my TAS indicator did not > start with a 2. > > Thanks for the data. > Mike > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of > LesDrag@aol.com > To: rocket-list@matronics.com > Subject: Re: Rocket-List: 2 blade to 3 blade > > --> Rocket-List message posted by: LesDrag@aol.com > > > Hi Michael, > > I did some performance tests on Ted Rutherford's HR2 using his 2 blade > Hartzell (D blade) propeller, my 2 blade Hartzell (J blade) propeller > and my 3 > blade MTV-9-B/198-52 MT Propeller. > > We ran Ted's "D" blade Hartzell first, then the 3 blade MT propeller, > then > the "J" blade Hartzell. > > The 3 blade propeller had the Lycoming engine running like it was an > electric motor. Both 2 blade propellers had the typical vibration > incorrectly > associated to the Lycoming engine. (The 3 blade propeller doesn't have > a second > order harmonic that is present with the 2 blade propeller. This is a > very > noticeable difference.) > > There was no significant difference in cruise performance. > > The Hartzell 2 blade propeller and spinner assembly weighs about 66 > pounds. > The MTV-9-B/198-52 propeller and spinner assembly weighs about 54 > pounds. > Not the 18 pounds you wanted, but 12 pounds lighter isn't bad. > > You could replace the aft battery with a portable oxygen bottle in the > baggage compartment. The 3 blade propeller should make a noticeable > difference in > cruise speed above 10,000'. What better use for the HR2 climb rate > than to > get to 15,000' to 17,500', and then cruise fast with good fuel economy. > > Best Regards, > Jim Ayers > _www.lessdrag.com_ (http://www.lessdrag.com) > (805) 795-5377 > > In a message dated 10/17/2005 7:19:57 AM Pacific Daylight Time, > mstewart@iss.net writes: > > --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" > > > Looking for real world results on folks who have gone from the fat 2 > blade Hartzel to the 3 blade blended or MT. > > My speed is good but my comfort is not. Got a pretty good vibration > which I suspect is the fat 2 blade hartzell beating my airframe. I have > had 2 independent prop balances. > > I am tempted of spend the $$$ on a smoother operation but my speed is > GREAT and I don't want to loose any. You know the drill. Real world > results please. > > All things being equal, which they never are, would not mind loosing > some nose weight. If I could pull 20lbs off the nose I could pull a > 18lb > battery out of my tail which is not doing anything for me except > ballast. > > That would net me 38lbs off the airframe which I would love to > jettison. > > I want smooth and speed. Please help. > > Thanks > Mike > S8 > Do not archive. > > ________________________________ Message 2 _____________________________________ Time: 01:33:15 AM PST US From: "JOHN STARN" Subject: Re: Rocket-List: 2 blade to 3 blade --> Rocket-List message posted by: "JOHN STARN" "Was wondering what RPM you guys don't like the vibration at." All of them, from start up to shut down. Comes from sitting behind an MT three or four blade........ When compared with the Hartzel 2 blade. "Smoother" above 2300 I would believe. Smoooooooth, ya'll need to come take a ride with us. "It aint bragging iffen ya can do it". One ride will do that. Maybe just the trip up the taxiway. Slower ? ? yea a bit but everything in life is a trade off of some kind. N561FS HRII IO540 J5A4 MT four blade (old style). KABONG Do Not Archive ----- Original Message ----- From: "blairclan" Subject: RE: Rocket-List: 2 blade to 3 blade > --> Rocket-List message posted by: "blairclan" > > Was wondering what RPM you guys don't like the vibration at. > > I find on mine that from 2300 and above its smooth with the 2 blader. > So I generally use that RPM. > > Comments? > > Cheers > Tony ________________________________ Message 3 _____________________________________ Time: 08:18:18 AM PST US From: LesDrag@aol.com Subject: Re: Rocket-List: 2 blade to 3 blade --> Rocket-List message posted by: LesDrag@aol.com Just a side comment. The four blade MT propeller on HR2 N561FS was designed for a 380 hp parallel valve IO-540 engine. And 380 hp is not a typo. Their 4 blade propeller is a different 4 blade propeller design than the one I advertise on my website for a Rocket with the Lyc. IO-360 260 hp engine. Best Regards, Jim Ayers _www.lessdrag.com_ (http://www.lessdrag.com) In a message dated 10/18/2005 1:36:25 AM Pacific Daylight Time, jhstarn@verizon.net writes: --> Rocket-List message posted by: "JOHN STARN" "Was wondering what RPM you guys don't like the vibration at." All of them, from start up to shut down. Comes from sitting behind an MT three or four blade........ When compared with the Hartzel 2 blade. "Smoother" above 2300 I would believe. Smoooooooth, ya'll need to come take a ride with us. "It aint bragging iffen ya can do it". One ride will do that. Maybe just the trip up the taxiway. Slower ? ? yea a bit but everything in life is a trade off of some kind. N561FS HRII IO540 J5A4 MT four blade (old style). KABONG Do Not Archive