---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Mon 10/24/05: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:03 AM - Lord J-3804-20 isolators (Stewart, Michael (ISS Atlanta)) 2. 06:45 AM - Re: Props and vibration (Milt) 3. 07:17 AM - Re: Props and vibration (Stewart, Michael (ISS Atlanta)) 4. 08:24 AM - Re: Lord J-3804-20 isolators (Kevin Shannon) 5. 08:36 AM - Re: Lord J-3804-20 isolators (Richard Riley) 6. 11:08 AM - Re: Lord J-3804-20 isolators (Russ) 7. 12:13 PM - Re: Lord J-3804-20 isolators (Hr2pilot@aol.com) 8. 09:48 PM - Re: Re: Lord J-3804-20 isolators (Mark Neufeld - HR-2) ________________________________ Message 1 _____________________________________ Time: 06:03:38 AM PST US Subject: Rocket-List: Lord J-3804-20 isolators From: "Stewart, Michael (ISS Atlanta)" --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" Bad news gentleman, The Lord J-3804-20 isolators, used by Vans on the RV-10 IO-540, are not even close to the same as the original set I had from Vans. I pulled a set off and roughly an inch of uncompressed difference. Also the center shafts were ~5/8" difference. Fine if your building, but on a flying airplane this would completely destroy the cowl fit. So I am now back to square one unless I can get some help from lord directly on what my options are for changing out the mounts, have hope of gaining on the vibration issue, AND have an engine that hangs in the same place. Les I hope to hear from you on plan B Best, Mike ________________________________ Message 2 _____________________________________ Time: 06:45:24 AM PST US From: "Milt" Subject: Re: Rocket-List: Props and vibration RPD=4.00.0003; RPDID=303030312E30413039303230322E34333543453338442E303034352D412D; ENG=IBF; TS=20051024134458; CAT=NONE; CON=NONE; --> Rocket-List message posted by: "Milt" I talked to a guy in Indianopolis who built an RV 8 with an IO 540. He tells me all of the "Super 8" builders apparently are chopping off 2" from the end of each blade and this apparently eliminates the vibration/beat or whatever you want to call it. I like my MT 3 blade but miss the performance and handling characteristics I had with the 2 blade. Milt ----- Original Message ----- From: "blairclan" Subject: RE: Rocket-List: Props and vibration > --> Rocket-List message posted by: "blairclan" > > Tom, > > Is there any difference in vibration between a Hartzell and an MT 3 > blader? > > Thanks > Tony Blair > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Tom Martin > To: rocket-list@matronics.com > Subject: RE: Rocket-List: Props and vibration > > --> Rocket-List message posted by: "Tom Martin" > > I have 800 hours in five different rockets, all using van's standard > isolators. The thumping went away with a metal three blade Hartzell and > a > three blade MT. Also I have NEVER had any engine sag that other > builders > report. These were the mounts that John Harmon recommended on my first > HRII > and they work for me. > > Tom Martin > EVO ONE on the way > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Stewart, > Michael (ISS Atlanta) > To: rocket-list@matronics.com > Subject: Rocket-List: Props and vibration > > --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" > > > Thought I would follow up that thanks to Japundza(sp) that hooked me up > with a Hartzell prop guy who has figured out that I may(read do) have > the wrong isolators on my engine. I ordered from Vans their std engine > mount isolators thinking they were all created equal. Turns out they are > not. Duh. And the el cheapos that I got from Vans were originally > designed for 0-320, then used for the 360's but were never designed for > the hanging moment of a 540. > So in an effort of Hartzell trying to keep me from buying an MT, and me > from spending 10k, I have ordered the proper iso mounts for a 540. Lord > J-3804-20 is the proper ones and I have a set enroute. I will report the > results from my unscientific testing of how it feels. I am not convinced > that these iso mounts are all that different but I am not schooled in > such things. > > Best > Mike > > ________________________________ Message 3 _____________________________________ Time: 07:17:03 AM PST US Subject: RE: Rocket-List: Props and vibration From: "Stewart, Michael (ISS Atlanta)" --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" I have that same prop chopped off 2" All of those props were built by U.S. Propellers in Gibsonville, NC A google search of them will tell you a bit of history. Mike Do not archive -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Milt Subject: Re: Rocket-List: Props and vibration --> Rocket-List message posted by: "Milt" I talked to a guy in Indianopolis who built an RV 8 with an IO 540. He tells me all of the "Super 8" builders apparently are chopping off 2" from the end of each blade and this apparently eliminates the vibration/beat or whatever you want to call it. I like my MT 3 blade but miss the performance and handling characteristics I had with the 2 blade. Milt ----- Original Message ----- From: "blairclan" Subject: RE: Rocket-List: Props and vibration > --> Rocket-List message posted by: "blairclan" > > Tom, > > Is there any difference in vibration between a Hartzell and an MT 3 > blader? > > Thanks > Tony Blair > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Tom Martin > To: rocket-list@matronics.com > Subject: RE: Rocket-List: Props and vibration > > --> Rocket-List message posted by: "Tom Martin" > > I have 800 hours in five different rockets, all using van's standard > isolators. The thumping went away with a metal three blade Hartzell and > a > three blade MT. Also I have NEVER had any engine sag that other > builders > report. These were the mounts that John Harmon recommended on my first > HRII > and they work for me. > > Tom Martin > EVO ONE on the way > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Stewart, > Michael (ISS Atlanta) > To: rocket-list@matronics.com > Subject: Rocket-List: Props and vibration > > --> Rocket-List message posted by: "Stewart, Michael (ISS Atlanta)" > > > Thought I would follow up that thanks to Japundza(sp) that hooked me up > with a Hartzell prop guy who has figured out that I may(read do) have > the wrong isolators on my engine. I ordered from Vans their std engine > mount isolators thinking they were all created equal. Turns out they are > not. Duh. And the el cheapos that I got from Vans were originally > designed for 0-320, then used for the 360's but were never designed for > the hanging moment of a 540. > So in an effort of Hartzell trying to keep me from buying an MT, and me > from spending 10k, I have ordered the proper iso mounts for a 540. Lord > J-3804-20 is the proper ones and I have a set enroute. I will report the > results from my unscientific testing of how it feels. I am not convinced > that these iso mounts are all that different but I am not schooled in > such things. > > Best > Mike > > ________________________________ Message 4 _____________________________________ Time: 08:24:02 AM PST US From: "Kevin Shannon" Subject: RE: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: "Kevin Shannon" From what I have been reading the last two weeks, the fat two blade prop causes a more turbulent propwash than the three bladers do, which is transmitted through the airframe and perceived as a vibration. So, if this is the case and it is not a balancing issue, I don't see how different the isolation mounts can change this. It will be interesting to see what your results are Mike. Kevin Bad news gentleman, The Lord J-3804-20 isolators, used by Vans on the RV-10 IO-540, are not even close to the same as the original set I had from Vans. I pulled a set off and roughly an inch of uncompressed difference. Also the center shafts were ~5/8" difference. Fine if your building, but on a flying airplane this would completely destroy the cowl fit. So I am now back to square one unless I can get some help from lord directly on what my options are for changing out the mounts, have hope of gaining on the vibration issue, AND have an engine that hangs in the same place. Les I hope to hear from you on plan B Best, Mike ________________________________ Message 5 _____________________________________ Time: 08:36:02 AM PST US From: Richard Riley Subject: RE: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: Richard Riley If you can't get help directly from Lord, talk to Barry. Tell them what you have in a Lord mount, and what you want different. Barry Controls California 4510 Vanowen St Burbank, CA 91505 Tel: 1-818-8431000 Fax: 1-818-8456978 At 08:23 AM 10/24/05, you wrote: >--> Rocket-List message posted by: "Kevin Shannon" > > >From what I have been reading the last two weeks, the fat two blade prop >causes a more turbulent propwash than the three bladers do, which is >transmitted through the airframe and perceived as a vibration. >So, if this is the case and it is not a balancing issue, I don't see how >different the isolation mounts can change this. It will be interesting >to see what your results are Mike. >Kevin > > >Bad news gentleman, > >The Lord J-3804-20 isolators, used by Vans on the RV-10 IO-540, are not >even close to the same as the original set I had from Vans. > >I pulled a set off and roughly an inch of uncompressed difference. Also >the center shafts were ~5/8" difference. > >Fine if your building, but on a flying airplane this would completely >destroy the cowl fit. So I am now back to square one unless I can get >some help from lord directly on what my options are for changing out the >mounts, have hope of gaining on the vibration issue, AND have an engine >that hangs in the same place. > > >Les I hope to hear from you on plan B > > >Best, > >Mike > > >-- -- ________________________________ Message 6 _____________________________________ Time: 11:08:42 AM PST US From: Russ Subject: RE: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: Russ The RV10 engine has completely different mount ears on the engine. ________________________________ Message 7 _____________________________________ Time: 12:13:47 PM PST US From: Hr2pilot@aol.com Subject: Re: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: Hr2pilot@aol.com I have flown over 35 different Harmon Rocket II's and only 3 have had the bad shake that all the talk is about. I also have tested a number of other props, MT 3 blade and 4 blade even a McCauley.The 3& 4 blade well alwase be smoother, is it worth 2 -3 grand more ? not to me John ________________________________ Message 8 _____________________________________ Time: 09:48:05 PM PST US From: Mark Neufeld - HR-2 Subject: Re: Re: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: Mark Neufeld - HR-2 Thanks John, All this prop biz was getting silly and was a waste of space on my compooter. Mark Neufeld From: Hr2pilot@aol.com Subject: Re: Rocket-List: Lord J-3804-20 isolators --> Rocket-List message posted by: Hr2pilot@aol.com I have flown over 35 different Harmon Rocket II's and only 3 have had the bad shake that all the talk is about. I also have tested a number of other props, MT 3 blade and 4 blade even a McCauley.The 3& 4 blade well alwase be smoother, is it worth 2 -3 grand more ? not to me John