---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Sun 05/20/07: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:14 AM - Re: Mark IIIC won't turn right in straight and level (Mike Welch) 2. 10:50 AM - Re: Re: FireFly prop & others (Charlie England) 3. 11:42 AM - Re: Mark IIIC won't turn right in straight and level (Richard Pike) 4. 12:53 PM - Re: Mark IIIC won't turn right in straight and level (JetPilot) 5. 01:28 PM - Re: Re: FireFly prop & others (Ron) 6. 01:47 PM - Re: Re: Mark IIIC won't turn right in straight and level (Richard Girard) 7. 02:15 PM - Re: Re: FireFly prop & others (Richard Girard) 8. 03:39 PM - Re: Re: FireFly prop & others (possums) 9. 03:44 PM - Re: Re: FireFly prop & others (Dennis Souder) 10. 05:56 PM - Re: Re: FireFly prop & others (Jack B. Hart) 11. 06:18 PM - Re: Re: FireFly prop & others (Ron) 12. 08:14 PM - Re: Re: FireFly prop & others (Dana Hague) ________________________________ Message 1 _____________________________________ Time: 06:14:33 AM PST US From: "Mike Welch" Subject: RE: Kolb-List: Mark IIIC won't turn right in straight and level John, There didn't seem to be too many responses to your dilemma, so I thought I would make a suggestion. Verify the following: Take a look at the pivot hinges for the ailerons. Are they bOTH oriented in the same direction? Meaning....the pivoting action of the hinge, are they both UP, or both down?? Just an idea, Mike in SW Utah (who didn't make it to MV, I'm sorry to say!! >From: "John Bickham" >To: kolb-list@matronics.com >Subject: Kolb-List: Mark IIIC won't turn right in straight and level >Date: Thu, 17 May 2007 17:12:53 -0700 > > >Need help with this one. > >A local friend of mine purchased a Kolb Mark IIIC. I think the previous >owner was the former partners of the TNK. I'm terrible with names but I >remember he was a big old boy. I think I remember him flying this plane at >the first TNK homecoming I went to. > >Anyway, this Mark IIIC will not turn right in straight and level cruise. >The stick moves easily to the left but takes two hands to move it a even a >little bit to the right. If you put the plane in a climb or a descent, it >unloads the problem and allows the stick to move to the right. > >I've looked it over and see no obvious problem. I noticed that the center >line of the elevator hinge on the left side is not exactly centered with >the pivot bolt. Off about a 1/8" I suggested getting that aligned and >tightening the cables a bit. > >If anyone has faced this problem or has suggestions, it would be greatly >appreciated. > >-------- >Thanks too much, > >John Bickham >Mark III-C >"Using my Repairman Certificate" >St. Francisville, LA > >Do Not Archive > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=113488#113488 > > _________________________________________________________________ Like the way Microsoft Office Outlook works? Youll love Windows Live Hotmail. ________________________________ Message 2 _____________________________________ Time: 10:50:23 AM PST US From: Charlie England Subject: Re: Kolb-List: Re: FireFly prop & others Actually, they aren't that efficient; they are just better than turbines without the bypass. They would be a lot more efficient if you could put a 2 blade prop on them, but a 2-blade big enough to absorb that much hp would probably have a larger diameter than the plane & weigh more than the plane, too. The entire *system* is efficient, but that's because of extremely low drag, extreme span-loading of the wings, flying at extreme altitude, etc. Charlie Jim Dunn wrote: > > Then why is a high-bipass turbofan so efficient? These are found on > 747-767 and are just a whole bunch of ducted short propeller blades. > > > At 11:01 PM 5/15/2007, Eugene Zimmerman wrote: >> > Similarly, the close together the prop blades are (i.e. 3 > blade vs. 2 blade) the more interference. > -Dana > ________________________________ Message 3 _____________________________________ Time: 11:42:04 AM PST US From: "Richard Pike" Subject: Re: Kolb-List: Mark IIIC won't turn right in straight and level Not a clue. So here's some questions to get things started. Does it fly pretty much straight and level without effort, does it only take minimal pressure to keep it flying straight? If so, what sort of rigging does it have to make it fly straight? What are it's current rigging adjustments? Does it have a tendency to turn left anyway? What is the prop rotation? Does if turn equally well either way power off? Does it turn equally well either way in a full power climb? Does it always break off to one side in a stall? Are the flaps rigged the same, or is there differential in their droop or angle? Not sure what I am looking for, just fishing. Richard Pike MKIII N420P (420ldPoops) do not archive ----- Original Message ----- From: "John Bickham" Sent: Thursday, May 17, 2007 8:12 PM Subject: Kolb-List: Mark IIIC won't turn right in straight and level > > Need help with this one. > > A local friend of mine purchased a Kolb Mark IIIC. I think the previous > owner was the former partners of the TNK. I'm terrible with names but I > remember he was a big old boy. I think I remember him flying this plane > at the first TNK homecoming I went to. > > Anyway, this Mark IIIC will not turn right in straight and level cruise. > The stick moves easily to the left but takes two hands to move it a even a > little bit to the right. If you put the plane in a climb or a descent, it > unloads the problem and allows the stick to move to the right. > > I've looked it over and see no obvious problem. I noticed that the center > line of the elevator hinge on the left side is not exactly centered with > the pivot bolt. Off about a 1/8" I suggested getting that aligned and > tightening the cables a bit. > > If anyone has faced this problem or has suggestions, it would be greatly > appreciated. > > -------- > Thanks too much, > > John Bickham > Mark III-C > "Using my Repairman Certificate" > St. Francisville, LA > > Do Not Archive > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=113488#113488 > > > ________________________________ Message 4 _____________________________________ Time: 12:53:20 PM PST US Subject: Kolb-List: Re: Mark IIIC won't turn right in straight and level From: "JetPilot" What you describe sounds strange, but if description of the proplem is very accurate, this sounds like a control system jamming problem to me. Espeically given that the stick frees up when you climb or descend, it sounds like it may be taking some load off the control system allowing it to move. I would check to make sure that the bushings that the aileron control tube go through are well greased and free. On the ground, have two people put a little up force on BOTH ailerons at the same time, then see if the stick moves left and right freely. Then have them put some down force and see if you feel any binding in the stick. Then check every part of the aileron control system that could possibly jam under load. The elevator problem you describe should not cause a roll jam as you describe, it is most likely un related. Attached is a picture of the area I am talking about, this loads up with a lot of downforce in flight, and needs to be well greased through the holes in the bushing. Good luck and let us know what you find. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=113867#113867 Attachments: http://forums.matronics.com//files/ultralightmikekolbdetail1_671.jpg ________________________________ Message 5 _____________________________________ Time: 01:28:04 PM PST US From: Ron Subject: Re: Kolb-List: Re: FireFly prop & others I think the point he is trying to make and legitimately so is that; if a two blade prop was so efficient you would have a 2 blade fan section. Obviously a multi fan is more efficient considering the space allocated and the parameters in which it operates. Its an important distinction to make. As someone else pointed out in a perfect world many things would be different. In an imperfect world you create perfection through adaptation for the task you need to perform. One of those things is a multi blade prop. I can see where theoretically a two blade is superior however in real life it is almost never the case. In real life almost always a 3 blade prop is superior performance wise to a two blade prop and a 4 blade prop is most times superior to 3 blade prop. Its hard to win against a theoretical argument, the only way to "win" is to do a real world comparison when all the real factors that exist including bugs and paint chipped off the leading edge come into play. I will install a 4 blade prop on my M3X and then I will try a 2 blade prop I will be surprised if I get better performance at *any* flight regime with the 2 blader. Ron ======================= ---- JetPilot wrote: ============ jim wrote: > > > Then why is a high-bipass turbofan so efficient? These are found on > 747-767 and are just a whole bunch of ducted short propeller blades. > > -Dana A high bybpas turbofan is NOT efficient. If you look at a jet compared to a prop plane, there is no comparison in in efficiency, the prop wins every time. Where did you get the idea that a turbofan is so efficient , by comparing it to a turbojet, which is even less efficient [Laughing] It is well known that a 2 blade prop is more efficient than a 3 blade. The problem is that there is not always room for a long 2 blade prop, or noise is more of an issue etc. etc. But the 2 blade is more efficient. If someone outclimbed someone else with a 3 blade prop, making the assumption that it was because of having a 3 bladed prop is just dumb. Ever think it could have been variations in the airplane, pilot technique, or a hundred other possible factors ??? Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=113164#113164 -- kugelair.com ________________________________ Message 6 _____________________________________ Time: 01:47:35 PM PST US From: "Richard Girard" Subject: Re: Kolb-List: Re: Mark IIIC won't turn right in straight and level Since the description of the solution, climbing or descending, didn't mention actually unloading the system, i.e. pulling negative or positive G's, but rather movement of the stick, I'm guessing the problem lies in the mixer mechanism at the bottom of the stick. I agree with Mike, it sounds like a mechanical jamming. If you have access to a stethescope you might try listening to all the areas mentioned to check for any slight clicking or grinding sounds as you move the stick. Rick On 5/20/07, JetPilot wrote: > > > What you describe sounds strange, but if description of the proplem is > very accurate, this sounds like a control system jamming problem to > me. Espeically given that the stick frees up when you climb or descend, it > sounds like it may be taking some load off the control system allowing it to > move. I would check to make sure that the bushings that the aileron control > tube go through are well greased and free. On the ground, have two people > put a little up force on BOTH ailerons at the same time, then see if the > stick moves left and right freely. Then have them put some down force and > see if you feel any binding in the stick. Then check every part of the > aileron control system that could possibly jam under load. > > The elevator problem you describe should not cause a roll jam as you > describe, it is most likely un related. > > Attached is a picture of the area I am talking about, this loads up with a > lot of downforce in flight, and needs to be well greased through the holes > in the bushing. Good luck and let us know what you find. > > Mike > > -------- > "NO FEAR" - If you have no fear you did not go as fast as you could have > !!! > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=113867#113867 > > > Attachments: > > http://forums.matronics.com//files/ultralightmikekolbdetail1_671.jpg > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 7 _____________________________________ Time: 02:15:34 PM PST US From: "Richard Girard" Subject: Re: Kolb-List: Re: FireFly prop & others Consider the original Supermarine Spitfire Mk 1, #5054, had a two blade prop. By the Mk IX it was running a four blade prop and by the Mk XIV, with the RR Griffon engine replacing the Merlin, it was running a five blade. The difference in speed between the Mk I and the Mk XIV was almost 100 MPH. The difference in HP was a bit over 800 between the two and the extra three blades were required to soak it up. Rick On 5/20/07, Ron wrote: > > I think the point he is trying to make and legitimately so is that; if a > two blade prop was so efficient you would have a 2 blade fan section. > Obviously a multi fan is more efficient considering the space allocated and > the parameters in which it operates. Its an important distinction to make. > As someone else pointed out in a perfect world many things would be > different. > > In an imperfect world you create perfection through adaptation for the > task you need to perform. One of those things is a multi blade prop. I can > see where theoretically a two blade is superior however in real life it is > almost never the case. In real life almost always a 3 blade prop is superior > performance wise to a two blade prop and a 4 blade prop is most times > superior to 3 blade prop. Its hard to win against a theoretical argument, > the only way to "win" is to do a real world comparison when all the real > factors that exist including bugs and paint chipped off the leading edge > come into play. > > I will install a 4 blade prop on my M3X and then I will try a 2 blade prop > I will be surprised if I get better performance at *any* flight regime with > the 2 blader. > > Ron > > ======================= > ---- JetPilot wrote: > > ============ > > > jim wrote: > > > > > > Then why is a high-bipass turbofan so efficient? These are found on > > 747-767 and are just a whole bunch of ducted short propeller blades. > > > > -Dana > > > A high bybpas turbofan is NOT efficient. If you look at a jet compared to > a prop plane, there is no comparison in in efficiency, the prop wins every > time. Where did you get the idea that a turbofan is so efficient , by > comparing it to a turbojet, which is even less efficient [Laughing] > > It is well known that a 2 blade prop is more efficient than a 3 blade. The > problem is that there is not always room for a long 2 blade prop, or noise > is more of an issue etc. etc. But the 2 blade is more efficient. > > If someone outclimbed someone else with a 3 blade prop, making the > assumption that it was because of having a 3 bladed prop is just dumb. Ever > think it could have been variations in the airplane, pilot technique, or a > hundred other possible factors ??? > > Mike > > -------- > "NO FEAR" - If you have no fear you did not go as fast as you > could > > * > > > * > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 8 _____________________________________ Time: 03:39:27 PM PST US From: possums Subject: Re: Kolb-List: Re: FireFly prop & others At 04:27 PM 5/20/2007, you wrote: >I think the point he is trying to make and legitimately so is that; >if a two blade prop was so efficient you would have a 2 blade fan >section. Obviously a multi fan is more efficient considering the >space allocated and the parameters in which it operates. Its an >important distinction to make. As someone else pointed out in a >perfect world many things would be different. > >In an imperfect world you create perfection through adaptation for >the task you need to perform. One of those things is a multi blade >prop. I can see where theoretically a two blade is superior however >in real life it is almost never the case. In real life almost always >a 3 blade prop is superior performance wise to a two blade prop and >a 4 blade prop is most times superior to 3 blade prop. Its hard to >win against a theoretical argument, the only way to "win" is to do a >real world comparison when all the real factors that exist including >bugs and paint chipped off the leading edge come into play. > >I will install a 4 blade prop on my M3X and then I will try a 2 >blade prop I will be surprised if I get better performance at *any* >flight regime with the 2 blader. > >Ron We tried a 6 blade - double 3 blade - prop on one of ours that had enough house power to turn it and it didn't do worth a crap. ________________________________ Message 9 _____________________________________ Time: 03:44:35 PM PST US From: "Dennis Souder" Subject: RE: Kolb-List: Re: FireFly prop & others Hi Ron and Kolbers, Over the many years at TOK I experimented with many different 2 and 3 blade propellers on the FF, FS, TS, M2, M3, SS and Laser. It is my recollection that a 2-blade would be faster than a 3-blade every time. The only reason we would run a 3-blade was for their typically smoother operation. I used the same aircraft for speed runs using a stopwatch to measure the speed over our 3,000 ft runway. This was done in zero-to- minimal wind conditions - usually late evenings - and I would average the run in both directions. This gave very repeatable results. This was my experience - I'll let others debate the theory. Dennis _____ From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Ron Sent: Sunday, May 20, 2007 4:28 PM Subject: Re: Kolb-List: Re: FireFly prop & others I think the point he is trying to make and legitimately so is that; if a two blade prop was so efficient you would have a 2 blade fan section. Obviously a multi fan is more efficient considering the space allocated and the parameters in which it operates. Its an important distinction to make. As someone else pointed out in a perfect world many things would be different. In an imperfect world you create perfection through adaptation for the task you need to perform. One of those things is a multi blade prop. I can see where theoretically a two blade is superior however in real life it is almost never the case. In real life almost always a 3 blade prop is superior performance wise to a two blade prop and a 4 blade prop is most times superior to 3 blade prop. Its hard to win against a theoretical argument, the only way to "win" is to do a real world comparison when all the real factors that exist including bugs and paint chipped off the leading edge come into play. I will install a 4 blade prop on my M3X and then I will try a 2 blade prop I will be surprised if I get better performance at *any* flight regime with the 2 blader. Ron ======================= ---- JetPilot wrote: ============ jim wrote: > > > Then why is a high-bipass turbofan so efficient? These are found on > 747-767 and are just a whole bunch of ducted short propeller blades. > > -Dana A high bybpas turbofan is NOT efficient. If you look at a jet compared to a prop plane, there is no comparison in in efficiency, the prop wins every time. Where did you get the idea that a turbofan is so efficient , by comparing it to a turbojet, which is even less efficient [Laughing] It is well known that a 2 blade prop is more efficient than a 3 blade. The problem is that there is not always room for a long 2 blade prop, or noise is more of an issue etc. etc. But the 2 blade is more efficient. If someone outclimbed someone else with a 3 blade prop, making the assumption that it was because of having a 3 bladed prop is just dumb. Ever think it could have been variations in the airplane, pilot technique, or a hundred other possible factors ??? Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could ________________________________ Message 10 ____________________________________ Time: 05:56:16 PM PST US From: "Jack B. Hart" Subject: RE: Kolb-List: Re: FireFly prop & others From: "Dennis Souder" >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Over the many years at TOK I experimented with many different 2 and 3 blade propellers on the FF, FS, TS, M2, M3, SS and Laser. It is my recollection that a 2-blade would be faster than a 3-blade every time. The only reason we would run a 3-blade was for their typically smoother operation. I used the same aircraft for speed runs using a stopwatch to measure the speed over our 3,000 ft runway. This was done in zero-to- minimal wind conditions usually late evenings - and I would average the run in both directions. This gave very repeatable results. This was my experience - Ill let others debate the theory. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Kolbers, If you keep the same propeller diameter and switch from a two to three blades and set the engine to top out at the same rpm, the two blade will cruise faster due to greater pitch. The three blade will climb better. Jack B. Hart FF004 Winchester, IN ________________________________ Message 11 ____________________________________ Time: 06:18:06 PM PST US From: Ron Subject: Re: Kolb-List: Re: FireFly prop & others Yes we will get to a point of diminishing returns, however with more blades you will need to optimize the diameter of the blades (smaller) etc.. The only drag increase that I can off hand think of is parasitic drag etc... However its of minor significance and the multi blade better radial efficiency during flight should more than compensate for it. Ron (Arizona) =========================== ---- possums wrote: ============ At 04:27 PM 5/20/2007, you wrote: >I think the point he is trying to make and legitimately so is that; >if a two blade prop was so efficient you would have a 2 blade fan >section. Obviously a multi fan is more efficient considering the >space allocated and the parameters in which it operates. Its an >important distinction to make. As someone else pointed out in a >perfect world many things would be different. > >In an imperfect world you create perfection through adaptation for >the task you need to perform. One of those things is a multi blade >prop. I can see where theoretically a two blade is superior however >in real life it is almost never the case. In real life almost always >a 3 blade prop is superior performance wise to a two blade prop and >a 4 blade prop is most times superior to 3 blade prop. Its hard to >win against a theoretical argument, the only way to "win" is to do a >real world comparison when all the real factors that exist including >bugs and paint chipped off the leading edge come into play. > >I will install a 4 blade prop on my M3X and then I will try a 2 >blade prop I will be surprised if I get better performance at *any* >flight regime with the 2 blader. > >Ron We tried a 6 blade - double 3 blade - prop on one of ours that had enough house power to turn it and it didn't do worth a crap. -- kugelair.com ________________________________ Message 12 ____________________________________ Time: 08:14:45 PM PST US From: Dana Hague Subject: Re: Kolb-List: Re: FireFly prop & others At 05:15 PM 5/20/2007, Richard Girard wrote: >Consider the original Supermarine Spitfire Mk 1, #5054, had a two blade >prop. By the Mk IX it was running a four blade prop and by the Mk XIV, >with the RR Griffon engine replacing the Merlin, it was running a five >blade. The difference in speed between the Mk I and the Mk XIV was almost >100 MPH. The difference in HP was a bit over 800 between the two and the >extra three blades were required to soak it up. True, but consider the reason... it wasn't practical to make the landing gear long enough to put on a sufficiently large prop of less blades to absorb all the available power. Even the early Spitfires had very limited prop ground clearance, so that pilots had to be very careful not to let the tail get too high while on the ground. -Dana -- -- Okay, who put a "stop payment" on my reality check? ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.