---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Tue 12/09/03: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:36 AM - Re: 2 blade (Jim Stone) 2. 07:02 AM - Cleveland vs. Grove brakes (Frazier, Vincent A) 3. 07:50 AM - Hartzell two blade Service Bulletin (Jim Stone) 4. 08:42 AM - Re: Hartzell two blade Service Bulletin (Boyd Braem) 5. 09:03 AM - Re: Hartzell two blade Service Bulletin (LesDrag@aol.com) 6. 09:28 AM - Re: Hartzell two blade Service Bulletin (Bob & Toodie Marshall) 7. 06:54 PM - Re: 2 blade (Jim Stone) ________________________________ Message 1 _____________________________________ Time: 06:36:00 AM PST US From: "Jim Stone" Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "Jim Stone" Good point and one I haven't considered. The "cool" factor wouldn't be near that of the 3 blade but if performance was equal and the price significantly cheaper, it might be a valid option. But, how do we get some performance comparison data? Jim Stone -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of David.vonLinsowe Subject: Rocket-List: 2 blade --> Rocket-List message posted by: "David.vonLinsowe" Jim, You may want to consider a MT 2 blade. I found the vibration level very close to their 3 blade. I just test flew my 6 with the Hartzell "Blended Airfoil" blades today. Big difference in vibration between it and the 2 or 3 blade MT. I ran into the vibration at 950 and 2700 rpm, other than that it was smooth. I also have to say that the Hartzell hasn't been dynamically balanced yet, but the MTs weren't either. Dave From: "Jim Stone" Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "Jim Stone" Greg and all, Well, we just had a major shift back in favor of the MT because of your post. You seem to agree with Mark F. on the issue. Thanks so much for taking the time for a detailed response. Your experience will undoubtedly help many Rocket builders in the future. I am going to give a little more time to this thread (the weekend) hoping to hear from a few more MT guys before making the "final decision". Jim Stone Back on the fence PS. Some guys are contacting me personally and I appreciate that very much. Sometimes a call is easier than writing a book. Call me and I'll call you back on my nickel, 502 254-3214. ************************************************************************ **************** Note: The information contained in this message may be privileged and confidential and thus protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. ************************************************************************ **************** = == == == == ________________________________ Message 2 _____________________________________ Time: 07:02:19 AM PST US Subject: Rocket-List: Cleveland vs. Grove brakes From: "Frazier, Vincent A" --> Rocket-List message posted by: "Frazier, Vincent A" SNIP Can anyone share their experience with Cleveland vs. Grove brakes and wheel parts ? Has anyone experienced any differences in: performance ? weight ? quality ? fit ? Thanks in advance for your input :-) Larry E. James SNIP Aren't the Grove brake calipers a little thinner than the Clevelands? If so, that should make it much easier to put your wheel pant/gear leg intersection fairings on. I have Clevelands and my intersection fairings are gonna have a big bump in them. Vince ________________________________ Message 3 _____________________________________ Time: 07:50:49 AM PST US From: "Jim Stone" Subject: Rocket-List: Hartzell two blade Service Bulletin --> Rocket-List message posted by: "Jim Stone" I've been doing some more research on the various props and this morning talked with Hartzell and found out some very interesting information. There is a service bulletin out where the owner needs to do a 150 hr eddy current inspection if aerobatics are being performed. Yes, a wingover is considered by Hartzell to be aerobatic. This reoccurring inspection was news to me and is the reason for my including the link below. There is a history of the hubs cracking, leaking grease and even separating from the aircraft. I highly recommend you guys read this one. Jim Stone http://www.hartzellprop.com/pdfs/sb227r2.pdf ________________________________ Message 4 _____________________________________ Time: 08:42:03 AM PST US Subject: Re: Rocket-List: Hartzell two blade Service Bulletin From: Boyd Braem --> Rocket-List message posted by: Boyd Braem Hartzell's SB and the AD on certain hubs states (stated?) that in lieu of replacing the hub with a newer version you are supposed to do the recurrent inspection (there is a list of serial numbers of affected hubs, or you can just call Hartzell and ask). For a time, Hartzell would sell you a replacemnt hub for half-priice. As far as I can remember (1 1/2 yrs ago), with the "new, improved" hubs there was no aerobatic limit (except the 4 g limit on the prop extension). On Tuesday, December 9, 2003, at 10:50 AM, Jim Stone wrote: > --> Rocket-List message posted by: "Jim Stone" > > I've been doing some more research on the various props and this > morning > talked with Hartzell and found out some very interesting information. > > There is a service bulletin out where the owner needs to do a 150 hr > eddy current inspection if aerobatics are being performed. Yes, a > wingover is considered by Hartzell to be aerobatic. This reoccurring > inspection was news to me and is the reason for my including the link > below. There is a history of the hubs cracking, leaking grease and > even > separating from the aircraft. I highly recommend you guys read this > one. > > Jim Stone > > http://www.hartzellprop.com/pdfs/sb227r2.pdf Boyd. RV-Super 6 Venice, FL ________________________________ Message 5 _____________________________________ Time: 09:03:02 AM PST US From: LesDrag@aol.com Subject: Re: Rocket-List: Hartzell two blade Service Bulletin --> Rocket-List message posted by: LesDrag@aol.com The Service bulletin states that the Rev. B hub is not affected. 1997 and later manufacture. Jim Ayers ________________________________ Message 6 _____________________________________ Time: 09:28:33 AM PST US From: "Bob & Toodie Marshall" Subject: Re: Rocket-List: Hartzell two blade Service Bulletin --> Rocket-List message posted by: "Bob & Toodie Marshall" Hello Rocketeers, Do not panic, Read the Hartzell AD very carefully, The very first thing it says , applicable only to props built before 04-97 which do not have the suffix letter B at the END of the HUB and PROP serial numbers, So if you do have an older prop you may have a compliance issue, pull your spinner and look for the Number, And then continue reading very carefully, those of you on the fence may opt for a new hub/ prop design, personally my Hartzell is very smooth in most ranges and my wallet has quit running out of the hangar when I throw it in before I go fly. I have no AD issues on mine, Happy flying and keep the dirty side down most of the time! Bob,N999RM----- Original Message ----- From: "Jim Stone" Subject: Rocket-List: Hartzell two blade Service Bulletin > --> Rocket-List message posted by: "Jim Stone" > > I've been doing some more research on the various props and this morning > talked with Hartzell and found out some very interesting information. > > There is a service bulletin out where the owner needs to do a 150 hr > eddy current inspection if aerobatics are being performed. Yes, a > wingover is considered by Hartzell to be aerobatic. This reoccurring > inspection was news to me and is the reason for my including the link > below. There is a history of the hubs cracking, leaking grease and even > separating from the aircraft. I highly recommend you guys read this > one. > > Jim Stone > > http://www.hartzellprop.com/pdfs/sb227r2.pdf > > ________________________________ Message 7 _____________________________________ Time: 06:54:26 PM PST US From: "Jim Stone" Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "Jim Stone" Thanks for the personal comparison Greg, I hesitate to admit this, but I am now considering the Aero-composite 2 blade prop with my second choice going to the Hartzell 2 blade. I think this prop could very well be the best on the market today. No ADs or service bulletins, almost no wear in any of the hubs they have torn down to inspect (including one with over 900 hours). This prop is truly made to last the life of the airframe. It takes rocks and rain far better than the MT composite and Hartzell aluminum blades. Nothing erodes, corrodes or pits the leading edges which by the way has a 20 year life expectancy (Nickel cobalt alloy). TBO is 5yr or 2000 hours. The TBO is described as a disassemble inspect and then reassemble, very likely with the same parts. All performance comparisons indicate in favor of ACI. They have a custom spinner assembly too. They are becoming so popular that there is a 3 month lead time. 2 blade price is 9,500, 3 blade price is 12,500. As compared to MT or Hartzell, they recommend 2" less length (78"for 2 blades) to get the same thrust, this is good of course for tail draggers as it affords another inch of ground clearance. Weight is only 38 lbs for 2 blades and about 50 for 3 blades. Not to spread any rumors but Sam James knocked the tips off his MT the other day after hitting the brakes too hard trying to avoid another aircraft (this is second hand info, feel free to correct the story). He had a child in the back seat and had become accustom to having his heavier bride back there. I guess the tail just lifted off the ground and onto that expensive prop. He ordered an Aero-composite prop apparently to replace the MT. Hope the info I learned today and passing along helps some of you guys about to make the same decision. Jim Stone (Wasting precious building time researching props) -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Jim Stone Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "Jim Stone" Greg and all, Well, we just had a major shift back in favor of the MT because of your post. You seem to agree with Mark F. on the issue. Thanks so much for taking the time for a detailed response. Your experience will undoubtedly help many Rocket builders in the future. I am going to give a little more time to this thread (the weekend) hoping to hear from a few more MT guys before making the "final decision". Jim Stone Back on the fence PS. Some guys are contacting me personally and I appreciate that very much. Sometimes a call is easier than writing a book. Call me and I'll call you back on my nickel, 502 254-3214. -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of u2nelson Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "u2nelson" OK Jim, here is a positive post for the MT. I had a Hartzell two blade on my Rocket, now I have a 3 blade MT. The 3 blade MT is a few LBs lighter than the 2 blade Hartzell, but those LBs are where you need to reduce the most, way out front of the engine. Here is a performance comparison, and this is with some careful flight testing using GPS algorithms to eliminate any wind variables, and all points were repeated multiple times to gain confidence. 10,000 MSL cruise speeds, 2100 RPM and full manifold pressure, about 21.5 inches; Hartzell 203 knots, MT 201 knots. MT may be a tad slower, but not by much, you can easily gain and loose 3-8 knots just on hot day, cold day. Run the RPM up to 2120 and I'm back at 203 so really its a wash. Acceleration on Take off, maybe slightly better with the 2 blade, but again on timed climbs to 10K, the time was with in seconds of each other and any difference is in how fat is your pencil. Deceleration, surprisingly better with the MT, I can now fly a much steeper final and landing rolls are shorter with the MT. Must be because the MT goes flatter. So why would I part with more bucks and go with the MT. ITS VERY SMOOTH. Like an electric motor up there. That two blade would shake you like crazy at any RPM between 2150 and 2300 and I used to run around at 2400 RPM to stay out of it. I could for high altitude cruise, set 2100 as the power is low enough to keep the vibration away, but it was still there a bit. Those are very usable RPM ranges, power setting wise, but unusable from a vibration standpoint. It was not a balance issue, it is a power issue, as I could take the power off, leave the RPM alone and the vibrations go away. What I believe is happening is the fuselage has a natural frequency that is coincident with the 2 blade power pulses at 2200 ish RPM. With the 3 blade you get 1/3 more power pulses, that are 1/3 less strong, so the effect is no fuselage interaction with the prop. 201 vs. 203 knots?, do the math, I now arrive about 1 minute later after flying 1 hour, but I arrive refreshed, not beat up and my airplane is also in better shape long term maintenance wise. Ultimately, both props do the job quite well, but I would have to recommend the 3 Blade MT if you have the money. BTW full grunt top speed also went down a couple with the MT, but those numbers are classified :) Greg Nelson N144X -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com]On Behalf Of Jim Stone Subject: RE: Rocket-List: 2 blade --> Rocket-List message posted by: "Jim Stone" Thanks Larry, Sure would like to hear why. Jim Stone Do not archive -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of Larry Schneider Subject: Re: Rocket-List: 2 blade --> Rocket-List message posted by: "Larry Schneider" I am an RV6 guy, But a friend of mine has a HRII. he had a Hartzell 2 blade and now an MT 3 blade, He loves the MT! Larry ----- Original Message ----- From: "Jim Stone" Subject: RE: Rocket-List: 2 blade > --> Rocket-List message posted by: "Jim Stone" > > Well guys, thanks for all the feed back on the 2 blade vs. the 3 blade, > both on the list and privately. The consensus is, to be brief, for the > best bang, best price, minimum maintenance and repair cost, the Hartzel > 2 blade stands well above the competition. I would also like to > mention, not one response to my post encouraged me to go with the 3 > blade MT. > Anyone know of a good source for a two blade Hartzel and spinner? > Jim Stone > > -----Original Message----- > From: owner-rocket-list-server@matronics.com > [mailto:owner-rocket-list-server@matronics.com] On Behalf Of > f1rocket@telus.net > To: rocket-list@matronics.com > Subject: Re: Rocket-List: 2 blade > > --> Rocket-List message posted by: f1rocket@telus.net > > I have asked the same question of; Bart (Aero Sport Power), Ken Fowler > (you > know the aerobatics guy) and Eric Hansen (who is considering changing > his three > blade Hartzell for a two blade for more speed). They all say go > lighter, the > engine is smooth anyway (I guess compared to others?). > So I'm going to save some money and weight spend the extra (both) on > avionics. > Like everything, probably no right answer just lots of opinions. > Jeff > > Quoting "Frazier, Vincent A" : > > > --> Rocket-List message posted by: "Frazier, Vincent A" > > > > > Jim, > > > > three-blade, smee-blade. > > > > Everyone I've heard has said that the 3 blade is slower but smoother. > > Personally, I quit listening after they said slower. I want fast! > > > > I've had the good fortune to ride in three different Rockets, all with > 2 > > blade Hartzells. If the only difference were smoothness... who cares? > All > > three of the Rockets gave me a great ride and I never once thought > "Wow, if > > only it were smoother." Nope, not a factor in my opinion. > > > > The 3 blade Hartzell just plain seems too heavy, even though a bit > cheaper > > than the MT. And the MT seems WAY out of line for cost , but really, > all of > > them are too expensive to think about. I was more concerned about > > maintenance costs with the MT. I have heard one third hand horror > account of > > an MT maintenance problem draining a wallet for as much as I paid for > my new > > Hartzell. > > > > One thought about the MT though... the lighter weight is nice and I > suppose > > that it would put less strain on the crank while you're doing inverted > flat > > spins without .... nah, I'll save those comments for the next post. > > > > YMMV, I could be wrong. > > > > Vince Frazier > > 1946 Stinson, NC97535, FOR SALE > > F-1H Rocket, N540VF, Crazy Horse > > > > > > SNIP I'm about to take the MT propeller plunge ( 3 blade with > > counterbalance). Can anyone tell why I shouldn't. Please save me > some > > money. > > > > I keep hearing about guys not being satisfied with the two blade > > Hartzels and end up trading up (at great cost), but great > satisfaction. > > > > Thanks, > > > > Jim Stone > > > > > > > > > > > > > > > > > > == > == > == > == > > = == == == == = == == == == = == == == ==