---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Sat 08/30/14: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:02 AM - Re: pitch? (Jack B. Hart) 2. 08:25 AM - Re: Right turn (Richard Pike) 3. 08:57 AM - Re: Right turn (Rick Neilsen) 4. 09:03 AM - Re: Kolb List- Right Turn (william sullivan) 5. 09:04 AM - Re: pitch? (Stuart Harner) 6. 10:53 AM - Re: pitch? (Dennis Rowe) 7. 01:00 PM - Re: pitch? (John Hauck) 8. 02:41 PM - Re: 80 or 100 hp? (alienwes) 9. 02:57 PM - Re: Re: 80 or 100 hp? (John Hauck) 10. 03:00 PM - Re: Re: 80 or 100 hp? (John Hauck) 11. 04:07 PM - Re: pitch? (Richard Girard) 12. 05:43 PM - Re: New Kolb Twinstar Owner (Shadow94) 13. 05:47 PM - Re: pitch? (Stuart Harner) 14. 06:19 PM - Re: pitch? (Richard Girard) ________________________________ Message 1 _____________________________________ Time: 07:02:18 AM PST US From: "Jack B. Hart" Subject: RE: Kolb-List: pitch? > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] Sent: Thursday, August 28, 2014 3:41 PM Hi, My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready to set it up. It is going on my Firefly with a Rotax 447 (single carb), B-Gearbox with 2.58 ratio. ........................ > Stuart, I hope you have considered the following: The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or 3000 kg-cm squared. Ultralight News of Canada found the three blade Warp prop exceeded these numbers. See: http://www.ultralightnews.ca/articles/driveselection.htm Warp Drive should be able to tell you the moment of inertia of your propeller. Or, the above site can direct you to a Rotax Service Bulletin that explains how to determine the moment of inertia of your prop. Jack B. Hart FF004 Winchester, IN ________________________________ Message 2 _____________________________________ Time: 08:25:47 AM PST US Subject: Kolb-List: Re: Right turn From: "Richard Pike" Since the aileron trim changes depending on whether you have a passenger or not, I made my trim tab adjustable. http://www.bcchapel.org/pages/0003/pg6.htm I also made the mod to change aileron leverage. http://www.bcchapel.org/pages/0003/pg7.htm -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kingsport, TN 3TN0 My soul shall be joyful in the LORD; It shall rejoice in His salvation. Psalm 35:9 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=429633#429633 ________________________________ Message 3 _____________________________________ Time: 08:57:11 AM PST US Subject: Re: Kolb-List: Right turn From: Rick Neilsen Frank The Kolb MKIII isn't a firestar or firefly. The ailerons are a bit heavy compared to the lighter Kolbs and the roll rate is more leisurely. The best way to fix roll trim issues is to use the English trim fitting that Kolb offers. That way you get all flying surfaces all going the same direction. Trim tabs and flap adjustments may resolve the issue but add unnecessary drag. The stick forces you describe are not normal and I would not fly it that way. Well... I'm right handed and fly from the left seat is your left arm weak? Go back over what you have done and make sure you haven't introduced a problem. Aileron control force in a MKIIIC is heaver than elevator control force but is never to the point that you would need two hands. Everything set up correctly roll forces should be the same right and left. Homer designed the ailerons to have enough power to handle wind direction changes that can occur flying slow near the ground, moving the hinge point to make it easier also reduces the deflection that you might need someday. Worth what you paid for it, refunds available anytime. Rick Neilsen Redrive VW Powered MKIIIC On Fri, Aug 29, 2014 at 2:26 PM, Frank Goodnight wrote: > Hi Boyd, > Thanks for your reply. > When I bought the plane from Bruce he was flying it from the left seat and > I suppose > had it trimmed to suit him. I switched to the right seat so the throttle > is on my left , been > on the left in every plane I've ever owned. I almost tore the trim lever > out of the MK3 > the first timeI landed it from the left seat trying to get to idle rpm. > When I switched to the right seat > The right wing was extremely heavy. I called kolb and talked to Travis and > to Bryan, Bryan > Suggested two things. He explained that because of the way the flaps are > attached to the > torque tube for the ailerons they can be used as huge aileron trim tabs > and should be adjusted > the same way as if you were adjusting a Alieron trim tab , I did that and > it helped to raise the > right wing. Travis had told me that in order to sell Kolbs in England > there has to be a way to > Adjust the incidence of the wings. In order to comply Kolb sells an extra > wide 1/2 of the u joint > that attaches the trailing edge of the wing to the fuselage. The > adjustment is made by stacking > 4 washers above or below the attach point. Bryan suggested that if I > needed more adjustment > than I could get with the flaps I should try that , I lowered the angle of > attack of the left wing > By 4 washers--don't know many degrees--it worked , the plane flys straight > and level hands > off and the yaw string is right down the middle at cruise. So tail trim > tab is OK. I do have a > 912 ULS 100HP The only problem is the one I mentioned in the earlier > post.I would like to > hear from any and all kolb pilots. > Frank G > Fayetteville ,AR > PS Boyd I changed the hole position on the Firestar , it helped. Will look > into doing it to the > MK3 tomorrow, thanks > > Sent from my iPad > > On Aug 29, 2014, at 8:29 AM, B Young wrote: > > What kind of fooling around with the flaps and incidence did you do? > If you have trimmed the plane by putting the wings and control surfaces > out of proper alignment instead of installing a trim tab that may be adding > to the condition??? > As for the heavy stick,, mine was a bit heavy as well, I drilled holes > about 1 inch in on the control linkage just above the boom tube, this > gives a bit more mechanical advantage > Do you have a912? If so you should need Bit of right rudder,,,a trim there > will reduce the pilot work load > Boyd Young > On Aug 29, 2014 6:58 AM, "Frank Goodnight" > wrote: > >> > >> >> Kolbers >> Just starting to get used to my mk3 classic. I have a question for those >> of you with >> experience in mk3s. I fly from the right seat, after a bit of fooling >> around with the flaps and wing incedence i have got the >> plane so it flys pretty much straight and level, handsoff. I find the >> ailerons to be very heavy >> and slow to react, much more so than my Firestar. If I enter a decending >> left turn at about >> 75 mph ---nothing radical just a normal turn to left base ,close >> pattern---to roll level takes about >> 3 seconds and enough right stick and rudder pressure that I'm almost >> afraid something will >> break I' m tempted to use both hands on the stick. Doesn't seem to matter >> much what power >> setting is used. If the initial turn is to the right there seems not to >> be a problem to roll left >> to level. From level flight the problem is much less pronounced, although >> it is somewhat >> easier to turn left than to turn right.Any thoughts and comments would be >> much appreciated. >> I don't think it's dangerous , but not sure >> Frank Goodnight >> Fayetteville ,AR >> 912 uls >> Sent from my iPad >> >> ========== >> -List" target="_blank">http://www.matronics.com/Navigator?Kolb-List >> ========== >> FORUMS - >> _blank">http://forums.matronics.com >> ========== >> b Site - >> -Matt Dralle, List Admin. >> target="_blank">http://www.matronics.com/contribution >> ========== >> >> >> >> * > > ================================== > ://www.matronics.com/Navigator?Kolb-List > ================================== > cs.com > ================================== > matronics.com/contribution > ================================== > > * > > * > > > * > > ________________________________ Message 4 _____________________________________ Time: 09:03:54 AM PST US From: william sullivan Subject: Kolb-List: Re: Kolb List- Right Turn Frank- I have no experience with this, but after reading all the comments I do have a suggestion. Try flying it from the left seat, just to see if it's a sideways balance issue of some type. Bill Sullivan ________________________________ Message 5 _____________________________________ Time: 09:04:20 AM PST US From: "Stuart Harner" Subject: RE: Kolb-List: pitch? Jack, Some others have raised that issue. I was aware of the MOI limits on gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He assured me it would be OK, but had no hard numbers for me. Now I am beginning to wonder if I was fooled by a salesman. :( I can easily set up and run the MOI tests myself to get the true answer, but I suspect I am not going to like it. Options are buy a new milled aluminum hub, but that is saving all the weight at the center, which won't help the MOI much. I could convert to a two blade hub, but the 60" is probably not able to put enough load on the engine at any kind of a reasonable pitch. I wanted to check out the Power Fin props at OSH, but could not find them on the field nor in the list of vendors. Now what I am going to say next is strictly personal and is NOT meant to start any flame wars over props: I know Travis recommends the IVO, but for me they are not an option due to other's experiences. End of story, no more gas for the flames. I have a good regard for the Warp Drives, related to the above sentence, again, no more gas. I am completely open to any other prop that gets the job done that is reasonably priced. I don't care about looks, but am concerned about vibration, price and noise, but of course they have to take a back seat to proper application. Some things I have read and conversations I have had led me to think that the 3 blade would be a better choice as it would be smoother and quieter than a 2 blade. I also liked the idea of a lower overall folded size (my hanger/trailer situation came into play here). Anybody want to buy a new prop that has not even had the bolts torqued down? Not the first stupid thing I have done, probably not the last either..... Stuart -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart Sent: Saturday, August 30, 2014 9:02 AM Subject: RE: Kolb-List: pitch? --> > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] Sent: Thursday, August 28, 2014 3:41 PM Hi, My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready to set it up. It is going on my Firefly with a Rotax 447 (single carb), B-Gearbox with 2.58 ratio. ........................ > Stuart, I hope you have considered the following: The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or 3000 kg-cm squared. Ultralight News of Canada found the three blade Warp prop exceeded these numbers. See: http://www.ultralightnews.ca/articles/driveselection.htm Warp Drive should be able to tell you the moment of inertia of your propeller. Or, the above site can direct you to a Rotax Service Bulletin that explains how to determine the moment of inertia of your prop. Jack B. Hart FF004 Winchester, IN ________________________________ Message 6 _____________________________________ Time: 10:53:01 AM PST US From: Dennis Rowe Subject: Re: Kolb-List: pitch? I would think that the shorter blades of your 60"prop would drastically reduce it's inertia. Also if it's a tapered tip that would also make it lighter. Most Kolb props are 66-72" dia. Dennis "Skid" Rowe Mk3, Rotax 670, Leechburg, PA > On Aug 30, 2014, at 12:03 PM, "Stuart Harner" wrote: > > > Jack, > > Some others have raised that issue. I was aware of the MOI limits on > gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He > assured me it would be OK, but had no hard numbers for me. > > Now I am beginning to wonder if I was fooled by a salesman. :( > > I can easily set up and run the MOI tests myself to get the true answer, but > I suspect I am not going to like it. > > Options are buy a new milled aluminum hub, but that is saving all the weight > at the center, which won't help the MOI much. I could convert to a two > blade hub, but the 60" is probably not able to put enough load on the engine > at any kind of a reasonable pitch. > > I wanted to check out the Power Fin props at OSH, but could not find them on > the field nor in the list of vendors. > > Now what I am going to say next is strictly personal and is NOT meant to > start any flame wars over props: > > I know Travis recommends the IVO, but for me they are not an option due to > other's experiences. End of story, no more gas for the flames. > I have a good regard for the Warp Drives, related to the above sentence, > again, no more gas. > > I am completely open to any other prop that gets the job done that is > reasonably priced. > > I don't care about looks, but am concerned about vibration, price and noise, > but of course they have to take a back seat to proper application. > > Some things I have read and conversations I have had led me to think that > the 3 blade would be a better choice as it would be smoother and quieter > than a 2 blade. I also liked the idea of a lower overall folded size (my > hanger/trailer situation came into play here). > > Anybody want to buy a new prop that has not even had the bolts torqued down? > > Not the first stupid thing I have done, probably not the last either..... > > Stuart > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart > Sent: Saturday, August 30, 2014 9:02 AM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > --> > > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] > Sent: Thursday, August 28, 2014 3:41 PM > > Hi, > > My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready to > set it up. It is going on my Firefly with a Rotax 447 (single carb), > B-Gearbox with 2.58 ratio. > ........................ > > Stuart, > > I hope you have considered the following: > > The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or > 3000 kg-cm squared. > > Ultralight News of Canada found the three blade Warp prop exceeded these > numbers. > > See: http://www.ultralightnews.ca/articles/driveselection.htm > > Warp Drive should be able to tell you the moment of inertia of your > propeller. > Or, the above site can direct you to a Rotax Service Bulletin that explains > how to determine the moment of inertia of your prop. > > Jack B. Hart FF004 > Winchester, IN > > > > > > > > > > ________________________________ Message 7 _____________________________________ Time: 01:00:38 PM PST US From: "John Hauck" Subject: RE: Kolb-List: pitch? Daryl Heineman, President of Warp Drive, is probably the salesman you are referring to that sold you the prop. Normally, he is the only one selling them. Good man. Knowledgeable when it comes to Warp Drive Props and engine combos. I've flown with Warp, and done business with them, for 21 years. Tested them, unintentionally, to the max. They always come through and get me back home. I don't know what kind of flying you will be doing, but doubt you will ever be able to over stress your gear box with this prop and a FS???? Daryl was not trying to fool you, I am sure. I'd fly that combo. My experience and opinion only. Don't try this at home. john h mkIII Titus, Alabama -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner Sent: Saturday, August 30, 2014 11:04 AM Subject: RE: Kolb-List: pitch? Jack, Some others have raised that issue. I was aware of the MOI limits on gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He assured me it would be OK, but had no hard numbers for me. Now I am beginning to wonder if I was fooled by a salesman. :( I can easily set up and run the MOI tests myself to get the true answer, but I suspect I am not going to like it. Options are buy a new milled aluminum hub, but that is saving all the weight at the center, which won't help the MOI much. I could convert to a two blade hub, but the 60" is probably not able to put enough load on the engine at any kind of a reasonable pitch. I wanted to check out the Power Fin props at OSH, but could not find them on the field nor in the list of vendors. Now what I am going to say next is strictly personal and is NOT meant to start any flame wars over props: I know Travis recommends the IVO, but for me they are not an option due to other's experiences. End of story, no more gas for the flames. I have a good regard for the Warp Drives, related to the above sentence, again, no more gas. I am completely open to any other prop that gets the job done that is reasonably priced. I don't care about looks, but am concerned about vibration, price and noise, but of course they have to take a back seat to proper application. Some things I have read and conversations I have had led me to think that the 3 blade would be a better choice as it would be smoother and quieter than a 2 blade. I also liked the idea of a lower overall folded size (my hanger/trailer situation came into play here). Anybody want to buy a new prop that has not even had the bolts torqued down? Not the first stupid thing I have done, probably not the last either..... Stuart -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart Sent: Saturday, August 30, 2014 9:02 AM Subject: RE: Kolb-List: pitch? --> > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] Sent: Thursday, August 28, 2014 3:41 PM Hi, My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready to set it up. It is going on my Firefly with a Rotax 447 (single carb), B-Gearbox with 2.58 ratio. ........................ > Stuart, I hope you have considered the following: The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or 3000 kg-cm squared. Ultralight News of Canada found the three blade Warp prop exceeded these numbers. See: http://www.ultralightnews.ca/articles/driveselection.htm Warp Drive should be able to tell you the moment of inertia of your propeller. Or, the above site can direct you to a Rotax Service Bulletin that explains how to determine the moment of inertia of your prop. Jack B. Hart FF004 Winchester, IN ________________________________ Message 8 _____________________________________ Time: 02:41:43 PM PST US Subject: Kolb-List: Re: 80 or 100 hp? From: "alienwes" Allan, John, thanks for the replies. I find it interesting that the 100 hp took longer on takeoffs. Too much of a good thing maybe?? Would be interested in hearing the benefits you have for the 80 hp John if you get the time. Seems it is more popular when I see Mark III's for sale. Maybe lower fuel consumption from the 80 hp? -------- Wesley Elliott Sport Pilot-PPC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=429644#429644 ________________________________ Message 9 _____________________________________ Time: 02:57:15 PM PST US From: "John Hauck" Subject: RE: Kolb-List: Re: 80 or 100 hp? First off 80 hp runs on 87 octane unleaded. 100 requires 91 and higher. Recommended spark plug change: 200 hours for the 80 and 100 hours for the 100. 80 runs a lot cooler. Mine burned 4 gph at 5000 cruise. 100 hp burns 5 gph at 5000 cruise. Both have same cruise speed on my mkIII. The 100 definitely climbs better and gives you a lot more boot in the butt than the 80. I could never go back to the 80. I did the 1994 flight, US border and Deadhorse/Prudhoe Bay, Alaska, flight with an 80. Did fine, but the 100 gave me a lot more comfort flying over Atigun Pass through the Brooks Range in Alaska. Both are great engines. Wish I had the money for a 912IS. I always wanted a good fuel injection system to simplify the system, but I think the 912IS also has dual carbs. ;-( john h mkIII Titus, Alabama Allan, John, thanks for the replies. I find it interesting that the 100 hp took longer on takeoffs. Too much of a good thing maybe?? Would be interested in hearing the benefits you have for the 80 hp John if you get the time. Seems it is more popular when I see Mark III's for sale. Maybe lower fuel consumption from the 80 hp? -------- Wesley Elliott Sport Pilot-PPC ________________________________ Message 10 ____________________________________ Time: 03:00:00 PM PST US From: "John Hauck" Subject: RE: Kolb-List: Re: 80 or 100 hp? Where did I get that idea from? Probably the 914 turbo? Looks like the 912IS is a single throttle body. That makes a lot of sense. john Both are great engines. Wish I had the money for a 912IS. I always wanted a good fuel injection system to simplify the system, but I think the 912IS also has dual carbs. ;-( john h mkIII Titus, Alabama ________________________________ Message 11 ____________________________________ Time: 04:07:37 PM PST US Subject: Re: Kolb-List: pitch? From: Richard Girard Stuart, Before you get rid of your WD prop, know this. Most of the MOI problems on "B" gearboxes come from trying to make the engine idle at too low an RPM. Doing this beats up the dogs and wears out the spring washers in the gearbox. Just keep the RPM at idle at 2000 or more and you'll be just fine. You have one more option before you dump the prop. Have the blades tapered. It's going to mean putting another $200 or so dollars into the prop but tapering the blades gets rid of mass on the blade tips where you get some good out of it. My 2 cents, your $200 bucks if you decide to do it. Rick Girard On Sat, Aug 30, 2014 at 2:59 PM, John Hauck wrote: > > Daryl Heineman, President of Warp Drive, is probably the salesman you are > referring to that sold you the prop. Normally, he is the only one selling > them. Good man. Knowledgeable when it comes to Warp Drive Props and > engine > combos. > > I've flown with Warp, and done business with them, for 21 years. Tested > them, unintentionally, to the max. They always come through and get me > back > home. > > I don't know what kind of flying you will be doing, but doubt you will ever > be able to over stress your gear box with this prop and a FS???? > > Daryl was not trying to fool you, I am sure. > > I'd fly that combo. > > My experience and opinion only. Don't try this at home. > > john h > mkIII > Titus, Alabama > > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner > Sent: Saturday, August 30, 2014 11:04 AM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > > Jack, > > Some others have raised that issue. I was aware of the MOI limits on > gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He > assured me it would be OK, but had no hard numbers for me. > > Now I am beginning to wonder if I was fooled by a salesman. :( > > I can easily set up and run the MOI tests myself to get the true answer, > but > I suspect I am not going to like it. > > Options are buy a new milled aluminum hub, but that is saving all the > weight > at the center, which won't help the MOI much. I could convert to a two > blade hub, but the 60" is probably not able to put enough load on the > engine > at any kind of a reasonable pitch. > > I wanted to check out the Power Fin props at OSH, but could not find them > on > the field nor in the list of vendors. > > Now what I am going to say next is strictly personal and is NOT meant to > start any flame wars over props: > > I know Travis recommends the IVO, but for me they are not an option due to > other's experiences. End of story, no more gas for the flames. > I have a good regard for the Warp Drives, related to the above sentence, > again, no more gas. > > I am completely open to any other prop that gets the job done that is > reasonably priced. > > I don't care about looks, but am concerned about vibration, price and > noise, > but of course they have to take a back seat to proper application. > > Some things I have read and conversations I have had led me to think that > the 3 blade would be a better choice as it would be smoother and quieter > than a 2 blade. I also liked the idea of a lower overall folded size (my > hanger/trailer situation came into play here). > > Anybody want to buy a new prop that has not even had the bolts torqued > down? > > Not the first stupid thing I have done, probably not the last either..... > > Stuart > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart > Sent: Saturday, August 30, 2014 9:02 AM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > --> > > > > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] > Sent: Thursday, August 28, 2014 3:41 PM > > Hi, > > My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready > to > set it up. It is going on my Firefly with a Rotax 447 (single carb), > B-Gearbox with 2.58 ratio. > ........................ > > > > Stuart, > > I hope you have considered the following: > > The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or > 3000 kg-cm squared. > > Ultralight News of Canada found the three blade Warp prop exceeded these > numbers. > > See: http://www.ultralightnews.ca/articles/driveselection.htm > > Warp Drive should be able to tell you the moment of inertia of your > propeller. > Or, the above site can direct you to a Rotax Service Bulletin that explains > how to determine the moment of inertia of your prop. > > Jack B. Hart FF004 > Winchester, IN > > -- Zulu Delta Mk IIIC Thanks, Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx ________________________________ Message 12 ____________________________________ Time: 05:43:31 PM PST US Subject: Kolb-List: Re: New Kolb Twinstar Owner From: "Shadow94" I would like to thank Mike and Lee for reaching out to me and being willing to help me with my Twinstar documents. Mike and Lee I really appreciate you help. Looking forward to hearing more from the both of you as I move forward with my rebuild. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=429651#429651 ________________________________ Message 13 ____________________________________ Time: 05:47:35 PM PST US From: "Stuart Harner" Subject: RE: Kolb-List: pitch? John, That was the exact impression I had, and the reason I did not question it any further. Seemed like he knew the plane, the engine and the gearbox. I did not get the "used car salesman" red flag. I really did not give it much extra thought until some replies to my starting pitch angle came back, indicating that this combo would not work. The numbers back this up, Rotax did not put the limits in the book just for the heck of it. However, no one has replied that Yes, they are running this combination and it is fine. The flip side of that is no one has said "I tried that and it tore up my gearbox", only some have warned that it would not work, according to the numbers. So, it would seem that it all comes down to whether I want to try it or not. I have been doing some research on this subject today, some of it I did not understand. I like physics, but am not very good at it. To me, a heavier prop (flywheel) would help smooth out the pulses of combustion, at the expense of quick throttle response. It seems to me that a lighter prop would speed up and slow down "faster" so that it would "hammer" the gears more. More rotational mass (MOI) would be slower to reach a set speed, but would also tend to continue rotating at that speed (minus the drag of producing thrust) therefore carrying the inertia into the next combustion pulse. To me this should dampen the "hammering of the gears effect". Maybe I just don't "get it". Something else I find interesting is that the Rotax manual warns never to run the engine without a prop (load) as it will damage the gearbox. They give a max MOI, but wouldn't there also be a minimum MOI? Maybe I am fretting over nothing. Maybe I should bolt it on and fly! I value EVERYONE's input, and thank you one and all. Stuart P.S. I still haven't heard a suggested starting pitch angle.... -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck Sent: Saturday, August 30, 2014 3:00 PM Subject: RE: Kolb-List: pitch? Daryl Heineman, President of Warp Drive, is probably the salesman you are referring to that sold you the prop. Normally, he is the only one selling them. Good man. Knowledgeable when it comes to Warp Drive Props and engine combos. I've flown with Warp, and done business with them, for 21 years. Tested them, unintentionally, to the max. They always come through and get me back home. I don't know what kind of flying you will be doing, but doubt you will ever be able to over stress your gear box with this prop and a FS???? Daryl was not trying to fool you, I am sure. I'd fly that combo. My experience and opinion only. Don't try this at home. john h mkIII Titus, Alabama -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner Sent: Saturday, August 30, 2014 11:04 AM Subject: RE: Kolb-List: pitch? Jack, Some others have raised that issue. I was aware of the MOI limits on gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He assured me it would be OK, but had no hard numbers for me. Now I am beginning to wonder if I was fooled by a salesman. :( I can easily set up and run the MOI tests myself to get the true answer, but I suspect I am not going to like it. Options are buy a new milled aluminum hub, but that is saving all the weight at the center, which won't help the MOI much. I could convert to a two blade hub, but the 60" is probably not able to put enough load on the engine at any kind of a reasonable pitch. I wanted to check out the Power Fin props at OSH, but could not find them on the field nor in the list of vendors. Now what I am going to say next is strictly personal and is NOT meant to start any flame wars over props: I know Travis recommends the IVO, but for me they are not an option due to other's experiences. End of story, no more gas for the flames. I have a good regard for the Warp Drives, related to the above sentence, again, no more gas. I am completely open to any other prop that gets the job done that is reasonably priced. I don't care about looks, but am concerned about vibration, price and noise, but of course they have to take a back seat to proper application. Some things I have read and conversations I have had led me to think that the 3 blade would be a better choice as it would be smoother and quieter than a 2 blade. I also liked the idea of a lower overall folded size (my hanger/trailer situation came into play here). Anybody want to buy a new prop that has not even had the bolts torqued down? Not the first stupid thing I have done, probably not the last either..... Stuart -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart Sent: Saturday, August 30, 2014 9:02 AM Subject: RE: Kolb-List: pitch? --> > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] Sent: Thursday, August 28, 2014 3:41 PM Hi, My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready to set it up. It is going on my Firefly with a Rotax 447 (single carb), B-Gearbox with 2.58 ratio. ........................ > Stuart, I hope you have considered the following: The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or 3000 kg-cm squared. Ultralight News of Canada found the three blade Warp prop exceeded these numbers. See: http://www.ultralightnews.ca/articles/driveselection.htm Warp Drive should be able to tell you the moment of inertia of your propeller. Or, the above site can direct you to a Rotax Service Bulletin that explains how to determine the moment of inertia of your prop. Jack B. Hart FF004 Winchester, IN ________________________________ Message 14 ____________________________________ Time: 06:19:59 PM PST US Subject: Re: Kolb-List: pitch? From: Richard Girard Stuart, I'm re-posting this response just in case it didn't come through. And I'm going to add something after. Before you get rid of your WD prop, know this. Most of the MOI problems on "B" gearboxes come from trying to make the engine idle at too low an RPM. Doing this beats up the dogs and wears out the spring washers in the gearbox. Just keep the RPM at idle at 2000 or more and you'll be just fine. You have one more option before you dump the prop. Have the blades tapered. It's going to mean putting another $200 or so dollars into the prop but tapering the blades gets rid of mass on the blade tips where you get some good out of it. My 2 cents, your $200 bucks if you decide to do it. Rick Girard In the winter of 2006, hot out of LSARM training I built a rig and did the rotational inertia per Rotax Service Instruction 11 UL 91E published December of 1992 (attached). At the time I had six props for various aircraft in the shop. As I recall only the wood two blade that came with my Firestar passed and being of multi-laminate constuction only did barely. Jimmy Young also did tests on two props, a WD and an IVO if memory serves. Both were three blade props. Anyway, I stand by the recommendations above. I know I'm not alone in recommending WD props for one simple reason. They are great at holding up to the trials and tribulations of the pusher configuration. I put an AN 6 bolt through a Warp and didn't even know it until I landed. I put a cheap pair of bifocals through the Power Fin on my trike and it cost me two new blades. Rick On Sat, Aug 30, 2014 at 7:47 PM, Stuart Harner wrote: > > John, > > That was the exact impression I had, and the reason I did not question it > any further. Seemed like he knew the plane, the engine and the gearbox. I > did not get the "used car salesman" red flag. > > I really did not give it much extra thought until some replies to my > starting pitch angle came back, indicating that this combo would not work. > The numbers back this up, Rotax did not put the limits in the book just for > the heck of it. > > However, no one has replied that Yes, they are running this combination and > it is fine. The flip side of that is no one has said "I tried that and it > tore up my gearbox", only some have warned that it would not work, > according > to the numbers. > > So, it would seem that it all comes down to whether I want to try it or > not. > > I have been doing some research on this subject today, some of it I did not > understand. I like physics, but am not very good at it. > > To me, a heavier prop (flywheel) would help smooth out the pulses of > combustion, at the expense of quick throttle response. It seems to me that > a lighter prop would speed up and slow down "faster" so that it would > "hammer" the gears more. More rotational mass (MOI) would be slower to > reach a set speed, but would also tend to continue rotating at that speed > (minus the drag of producing thrust) therefore carrying the inertia into > the > next combustion pulse. To me this should dampen the "hammering of the > gears > effect". Maybe I just don't "get it". > > Something else I find interesting is that the Rotax manual warns never to > run the engine without a prop (load) as it will damage the gearbox. They > give a max MOI, but wouldn't there also be a minimum MOI? > > Maybe I am fretting over nothing. Maybe I should bolt it on and fly! > > I value EVERYONE's input, and thank you one and all. > > Stuart > P.S. I still haven't heard a suggested starting pitch angle.... > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck > Sent: Saturday, August 30, 2014 3:00 PM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > > Daryl Heineman, President of Warp Drive, is probably the salesman you are > referring to that sold you the prop. Normally, he is the only one selling > them. Good man. Knowledgeable when it comes to Warp Drive Props and > engine > combos. > > I've flown with Warp, and done business with them, for 21 years. Tested > them, unintentionally, to the max. They always come through and get me > back > home. > > I don't know what kind of flying you will be doing, but doubt you will ever > be able to over stress your gear box with this prop and a FS???? > > Daryl was not trying to fool you, I am sure. > > I'd fly that combo. > > My experience and opinion only. Don't try this at home. > > john h > mkIII > Titus, Alabama > > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner > Sent: Saturday, August 30, 2014 11:04 AM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > > Jack, > > Some others have raised that issue. I was aware of the MOI limits on > gearboxes and quizzed Darrell at Warp Drive before I ordered the prop. He > assured me it would be OK, but had no hard numbers for me. > > Now I am beginning to wonder if I was fooled by a salesman. :( > > I can easily set up and run the MOI tests myself to get the true answer, > but > I suspect I am not going to like it. > > Options are buy a new milled aluminum hub, but that is saving all the > weight > at the center, which won't help the MOI much. I could convert to a two > blade hub, but the 60" is probably not able to put enough load on the > engine > at any kind of a reasonable pitch. > > I wanted to check out the Power Fin props at OSH, but could not find them > on > the field nor in the list of vendors. > > Now what I am going to say next is strictly personal and is NOT meant to > start any flame wars over props: > > I know Travis recommends the IVO, but for me they are not an option due to > other's experiences. End of story, no more gas for the flames. > I have a good regard for the Warp Drives, related to the above sentence, > again, no more gas. > > I am completely open to any other prop that gets the job done that is > reasonably priced. > > I don't care about looks, but am concerned about vibration, price and > noise, > but of course they have to take a back seat to proper application. > > Some things I have read and conversations I have had led me to think that > the 3 blade would be a better choice as it would be smoother and quieter > than a 2 blade. I also liked the idea of a lower overall folded size (my > hanger/trailer situation came into play here). > > Anybody want to buy a new prop that has not even had the bolts torqued > down? > > Not the first stupid thing I have done, probably not the last either..... > > Stuart > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Jack B. Hart > Sent: Saturday, August 30, 2014 9:02 AM > To: kolb-list@matronics.com > Subject: RE: Kolb-List: pitch? > > --> > > > > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] > Sent: Thursday, August 28, 2014 3:41 PM > > Hi, > > My Warp Drive prop (3 blade- 60) arrived yesterday and I am getting ready > to > set it up. It is going on my Firefly with a Rotax 447 (single carb), > B-Gearbox with 2.58 ratio. > ........................ > > > > Stuart, > > I hope you have considered the following: > > The B gearbox is rated for a max moment of inertia of 1025 lb-in squared or > 3000 kg-cm squared. > > Ultralight News of Canada found the three blade Warp prop exceeded these > numbers. > > See: http://www.ultralightnews.ca/articles/driveselection.htm > > Warp Drive should be able to tell you the moment of inertia of your > propeller. > Or, the above site can direct you to a Rotax Service Bulletin that explains > how to determine the moment of inertia of your prop. > > Jack B. Hart FF004 > Winchester, IN > > -- Zulu Delta Mk IIIC Thanks, Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx ------------------------------------------------------------------------------------- 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.