Kolb-List Digest Archive

Mon 06/06/11


Total Messages Posted: 5



Today's Message Index:
----------------------
 
     1. 06:44 AM - MkIII Xtra (Mike Welch)
     2. 12:13 PM - Re: MkIII Xtra (Richard Girard)
     3. 02:18 PM - Re: MkIII Xtra (Mike Welch)
     4. 04:00 PM - Re: MkIII Xtra (Richard Girard)
     5. 07:13 PM - Re: MkIII Xtra (Mike Welch)
 
 
 


Message 1


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    Time: 06:44:29 AM PST US
    From: Mike Welch <mdnanwelch7@hotmail.com>
    Subject: MkIII Xtra
    Rick G=2C Recently you mentioned you were test flying Ken's Xtra that you just finished working on. Evidently it had "lawn dart syndrome". Did you ever get it figured out=2C and if so=2C what was the final horizontal stabi lizer's position that you settled on? Mike Welch MkIII N212MN


    Message 2


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    Time: 12:13:32 PM PST US
    Subject: Re: MkIII Xtra
    From: Richard Girard <aslsa.rng@gmail.com>
    As of the last flight when I had the horizontal stabilizer lowered to lowest position that the bracked would allow and I was slowly adjusting the flaps and ailerons to make sure they were neutral to slightly reflexed. There was some improvement, but if I let go of the stick the nose would still begin to drop. I was out of adjustment on the flap pushrods, so I put the plane away for the night and began taking measurements. Wings s/b 2.8 to 3.4 degrees, are 3.45 and 3.75 degrees, horizontal stabilizer s/b -6.1 degrees, is -6.9 degrees. This is all referenced to the engine mount set at 0. Out of curiosity I measured the bottom of the cockpit at the nose cone and at two points aft of it. Those angles were 2.9 degrees at the nose cone, 1.1 degrees just aft of the nose cone, and -1.75 degrees on the center longeron approximately even with the pilots seat. The next morning I called Spruce to get some tubing for new flap push rods and then to Bryan Melbourne for his take on the situation. Bryan convinced me that the wing incidence had to be lowered to the least limit and I spent a couple of days trying to find a welder with a portable TIG. When that didn't happen I came up with a way to fill the holes and attach a plate to either side of the wing bracket. The amount of lowering needed amounted to .375" on the right wing and .500" on the left. I machined a plate for the forward side of the plate from 3/8" 4130 so that it was .11" thick with a 3/8" boss sticking up .25". The boss would go through the old mount hole. The plate on the aft side is 3/16" 4130 and has counter sinks at the bolt holes for the boss on the fore plate and the bushing I put through the original IIIC mount hole. The plates are attached with J B Weld and two NAS flat head bolts on each wing. On the spar carry through on the fuselage, I drilled the holes out to 7/16" and made flanged bushings that are a press fit. To seal the area under the head I used J B Weld again. So, at this point, the wings are back on and the new flap push rods are made and installed. The old gap seal, which only fit in a token manner before, now doesn't fit at all. I was hoping to fly this morning before the wind picked up and the thermals began popping off, but I decided to rework the gap seal and hope for light winds tomorrow morning at dawn. To Mark IIIX builders, you may notice from the pictures how high up the wing mount holes are on the spar carry through tabs and the wing tabs. The IIIX requires the wings to be mounted at such low incidence that you can run out of tab if you are not careful. If the holes had been located in the center of the spar carry through tabs more edge margin would have been available on the wing tabs. When you mount the wings, try to make the holes in the spar carry through in the center of the tabs or slightly lower than center. Rick Girard On Mon, Jun 6, 2011 at 8:41 AM, Mike Welch <mdnanwelch7@hotmail.com> wrote: > Rick G, > > Recently you mentioned you were test flying Ken's Xtra that you just > finished working on. Evidently it had "lawn dart syndrome". Did you > ever get it figured out, and if so, what was the final horizontal > stabilizer's > position that you settled on? > > Mike Welch > MkIII N212MN > > * > > * > > -- 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 3


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    Time: 02:18:34 PM PST US
    From: Mike Welch <mdnanwelch7@hotmail.com>
    Subject: MkIII Xtra
    Rick=2C Nice job of relocating the wing's tab holes & tabs. IIRC=2C and I do=2C your reference to the hor. stabs angle of -6.1 is wro ng. That is the boomtube's angle. The hor. stabs are supposed to be -4.6. Of course=2C we're ALWAYS referencing that starting point of "0" degrees for the motor mount. I have a chart I put together a couple of years ago that has all kinds of various angles for the Xtra. But=2C I put this chart together before I knew that the motor mount had to be leveled=2C so for lack of any better idea=2C I asked the guys to set their main wings at "9" degrees. After I built the chart=2C I found out later that Xtra's are advised to u se a precise angle setting procedure. My chart doesn't have much value anymore=2C since Kolb Co. has a specific plan to address angles and incidences. (yay!) Regarding your hor stabs ACTUALLY being -6.9....something's screwed!! No bleeping way!! Not unless Kolb Co. is handing out new angle numbers!! When I talked to Bryan Melbourne about how to go about setting up the pla ne (as an Xtra)=2C he said=3B 1) set motor mount to pure level (left & right=2C & for and aft) 2) boom tube SHOULD come in at -6.1 (mine was spot on!) 3) main wing are to be set at +3.4 degrees. (I have later found out that +2.8 was also 'suggested'. So +2.8 to +3.4 is the acceptable range. (Mine are 3.4.......exact!) 4)horizontal stabs are to be set at -4.6 degrees. (I have adjustable mounts that will let them vary from about -4.0 to -5.5 degrees.) 5) dihedral "should be" around +1.6 degrees (Since my wings were already mounted years ago=2C I decided NOT to change the struts lengths=2C so this had th e effect of creating more dihedral than the stock Xtra's OEM recommended angle. I ended up with +2.7 degrees dihedral) You ought to call Bryan and verify that horizontal stabilizer number! It looks like you're well on your way to getting this thing ironed out. Good job. Mike Welch Subject: Re: Kolb-List: MkIII Xtra From: aslsa.rng@gmail.com As of the last flight when I had the horizontal stabilizer lowered to lowes t position that the bracked would allow and I was slowly adjusting the flap s and ailerons to make sure they were neutral to slightly reflexed. There w as some improvement=2C but if I let go of the stick the nose would still be gin to drop. I was out of adjustment on the flap pushrods=2C so I put the p lane away for the night and began taking measurements. Wings s/b 2.8 to 3.4 degrees=2C are 3.45 and 3.75 degrees=2C horizontal sta bilizer s/b -6.1 degrees=2C is -6.9 degrees. This is all referenced to the engine mount set at 0. Out of curiosity I measured the bottom of the cockpit at the nose cone and at two points aft of it. Those angles were 2.9 degrees at the nose cone=2C 1.1 degrees just aft of the nose cone=2C and -1.75 degrees on the center lo ngeron approximately even with the pilots seat. The next morning I called Spruce to get some tubing for new flap push rods and then to Bryan Melbourne for his take on the situation. Bryan convinced me that the wing incidence had to be lowered to the least limit and I spent a couple of days trying to find a welder with a portable TIG. When that di dn't happen I came up with a way to fill the holes and attach a plate to ei ther side of the wing bracket. The amount of lowering needed amounted to .375" on the right wing and .500" on the left. I machined a plate for the forward side of the plate from 3/8 " 4130 so that it was .11" thick with a 3/8" boss sticking up .25". The bos s would go through the old mount hole. The plate on the aft side is 3/16" 4 130 and has counter sinks at the bolt holes for the boss on the fore plate and the bushing I put through the original IIIC mount hole. The plates are attached with J B Weld and two NAS flat head bolts on each wing. On the spar carry through on the fuselage=2C I drilled the holes out to 7/1 6" and made flanged bushings that are a press fit. To seal the area under t he head I used J B Weld again. So=2C at this point=2C the wings are back on and the new flap push rods are made and installed. The old gap seal=2C which only fit in a token manner b efore=2C now doesn't fit at all. I was hoping to fly this morning before th e wind picked up and the thermals began popping off=2C but I decided to rew ork the gap seal and hope for light winds tomorrow morning at dawn. To Mark IIIX builders=2C you may notice from the pictures how high up the w ing mount holes are on the spar carry through tabs and the wing tabs. The I IIX requires the wings to be mounted at such low incidence that you can run out of tab if you are not careful. If the holes had been located in the ce nter of the spar carry through tabs more edge margin would have been availa ble on the wing tabs. When you mount the wings=2C try to make the holes in the spar carry through in the center of the tabs or slightly lower than cen ter. Rick Girard On Mon=2C Jun 6=2C 2011 at 8:41 AM=2C Mike Welch <mdnanwelch7@hotmail.com> wrote: Rick G=2C Recently you mentioned you were test flying Ken's Xtra that you just finished working on. Evidently it had "lawn dart syndrome". Did you ever get it figured out=2C and if so=2C what was the final horizontal stabi lizer's position that you settled on? Mike Welch MkIII N212MN get="_blank">http://www.matronics.com/Navigator?Kolb-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Zulu Delta Mk IIIC Thanks=2C Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx


    Message 4


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    Time: 04:00:21 PM PST US
    Subject: Re: MkIII Xtra
    From: Richard Girard <aslsa.rng@gmail.com>
    Mike, All I can tell you is that the horizontal stabs are now set right down the center of the boom. I started out with them in the upper most hole of the bracket and moved them down in steps to try and relieve the nose heaviness. Lower was better in each step to the lowest position. It was Bryan that suggested I lower the wings to the lowest setting. I was concerned about being able to get the aircraft to rotate. He assured me that he had welded up holes before that were drilled so as to set the wing incidence too high and it had fixed the problem. Since I have the CG at the almost the farthest aft position, 34.28% (I use 35% as most aft), and I'm running the trim in the most up position, I don't think less horizontal stabilizer incidence is the way to go. The nice thing about having a flying aircraft is that theory can be tested against reality PDQ. With any luck, I'll know in the morning. Rick On Mon, Jun 6, 2011 at 4:15 PM, Mike Welch <mdnanwelch7@hotmail.com> wrote: > Rick, > > Nice job of relocating the wing's tab holes & tabs. > > IIRC, and I do, your reference to the hor. stabs angle of -6.1 is wrong. > That is the boomtube's > angle. The hor. stabs are supposed to be -4.6. Of course, we're ALWAYS > referencing that > starting point of "0" degrees for the motor mount. > > I have a chart I put together a couple of years ago that has all kinds of > various angles for the > Xtra. But, I put this chart together before I knew that the motor mount > had to be leveled, so for > lack of any better idea, I asked the guys to set their main wings at "9" > degrees. > After I built the chart, I found out later that Xtra's are advised to use > a precise angle setting > procedure. My chart doesn't have much value anymore, since Kolb Co. has a > specific plan > to address angles and incidences. (yay!) > > Regarding your hor stabs ACTUALLY being -6.9....something's screwed!! No > bleeping way!! > Not unless Kolb Co. is handing out new angle numbers!! > > When I talked to Bryan Melbourne about how to go about setting up the > plane (as an Xtra), he > said; > 1) set motor mount to pure level (left & right, & for and aft) > 2) boom tube *SHOULD* come in at -6.1 (mine was spot on!) > 3) main wing are to be set at +3.4 degrees. > (I have later found out that +2.8 was also 'suggested'. > So +2.8 to +3.4 is the acceptable range. > (Mine are 3.4.......exact!) > 4)horizontal stabs are to be set at -4.6 degrees. > (I have adjustable mounts that will let them vary > from about -4.0 to -5.5 degrees.) > 5) dihedral "should be" around +1.6 degrees > (Since my wings were already mounted years ago, > I decided NOT to change the struts lengths, so this had the > effect of creating more dihedral than the stock Xtra's > OEM recommended angle. I ended up with +2.7 degrees > dihedral) > > You ought to call Bryan and verify that horizontal stabilizer number! > > It looks like you're well on your way to getting this thing ironed out. > Good job. > > Mike Welch > > > ------------------------------ > Date: Mon, 6 Jun 2011 14:10:28 -0500 > Subject: Re: Kolb-List: MkIII Xtra > From: aslsa.rng@gmail.com > To: kolb-list@matronics.com > > > As of the last flight when I had the horizontal stabilizer lowered to > lowest position that the bracked would allow and I was slowly adjusting the > flaps and ailerons to make sure they were neutral to slightly reflexed. > There was some improvement, but if I let go of the stick the nose would > still begin to drop. I was out of adjustment on the flap pushrods, so I put > the plane away for the night and began taking measurements. > Wings s/b 2.8 to 3.4 degrees, are 3.45 and 3.75 degrees, horizontal > stabilizer s/b -6.1 degrees, is -6.9 degrees. This is all referenced to the > engine mount set at 0. > Out of curiosity I measured the bottom of the cockpit at the nose cone and > at two points aft of it. Those angles were 2.9 degrees at the nose cone, 1.1 > degrees just aft of the nose cone, and -1.75 degrees on the center longeron > approximately even with the pilots seat. > The next morning I called Spruce to get some tubing for new flap push rods > and then to Bryan Melbourne for his take on the situation. Bryan convinced > me that the wing incidence had to be lowered to the least limit and I spent > a couple of days trying to find a welder with a portable TIG. When that > didn't happen I came up with a way to fill the holes and attach a plate to > either side of the wing bracket. > The amount of lowering needed amounted to .375" on the right wing and .500" > on the left. I machined a plate for the forward side of the plate from 3/8" > 4130 so that it was .11" thick with a 3/8" boss sticking up .25". The boss > would go through the old mount hole. The plate on the aft side is 3/16" 4130 > and has counter sinks at the bolt holes for the boss on the fore plate and > the bushing I put through the original IIIC mount hole. The plates are > attached with J B Weld and two NAS flat head bolts on each wing. > On the spar carry through on the fuselage, I drilled the holes out to 7/16" > and made flanged bushings that are a press fit. To seal the area under the > head I used J B Weld again. > So, at this point, the wings are back on and the new flap push rods are > made and installed. The old gap seal, which only fit in a token manner > before, now doesn't fit at all. I was hoping to fly this morning before the > wind picked up and the thermals began popping off, but I decided to rework > the gap seal and hope for light winds tomorrow morning at dawn. > To Mark IIIX builders, you may notice from the pictures how high up the > wing mount holes are on the spar carry through tabs and the wing tabs. The > IIIX requires the wings to be mounted at such low incidence that you can run > out of tab if you are not careful. If the holes had been located in the > center of the spar carry through tabs more edge margin would have been > available on the wing tabs. When you mount the wings, try to make the holes > in the spar carry through in the center of the tabs or slightly lower than > center. > > Rick Girard > > On Mon, Jun 6, 2011 at 8:41 AM, Mike Welch <mdnanwelch7@hotmail.com>wrote: > > Rick G, > > Recently you mentioned you were test flying Ken's Xtra that you just > finished working on. Evidently it had "lawn dart syndrome". Did you > ever get it figured out, and if so, what was the final horizontal > stabilizer's > position that you settled on? > > Mike Welch > MkIII N212MN > > * > > get="_blank">http://www.matronics.com/Navigator?Kolb-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > * > > > -- > Zulu Delta > Mk IIIC > Thanks, Homer GBYM > > It isn't necessary to have relatives in Kansas City in order to be unhappy. > - Groucho Marx > > > * > > * > > -- 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 5


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    Time: 07:13:04 PM PST US
    From: Mike Welch <mdnanwelch7@hotmail.com>
    Subject: MkIII Xtra
    Rick=2C I was only relaying the factory recommended numbers that Bryan says=2C no t suggesting a particular solution in your case. You are infinitely more qualified to k now how to handle what your situation requires than me. I'm just an interested observer who' s trying to find some very valuable information. I got lost in your explanation "He assured me that he had welded up holes before that were drilled so as to set the wing incidence too high and it had fixed the problem." I did not understand what you were getting at. ??? If you have the horizontal stabs set right down the middle of the boom tu be=2C then that means they are essentially -6.1 degrees (or real close) Since there is no adjus tment of the boom tube angle of -6.1 degrees....compared to the motor mount=2C obviously some thing parallel to it would be the same. Now=2C maybe this helps make the plane fly better=2C b ut it sure does NOT sound like the angles I've been led to believe are correct for an Xtra. Br yan told me those numbers I posted. If they don't work very well on Ken's plane=2C I think I 'd be doing some serious investigating. I still say......"sumptin's up!!" Maybe we could get an Xtra owner/flyer to share what his angles and W&B i nformation is. There's nothing like having someone tell us all what works GREAT for him. Plus=2C it might give a good indication why that stab has to be so low=2C compared to the OE M setting. How about it=2C Xtra owners=2C anybody have the digital incidences and an gles=2C and the W&B on a decent flying plane?? BTW=2C it would seem to me that lowering the main wings' incidence down t o their proper angle=2C would make the plane even more nose heavy. At least=2C that's how I would think it would act. I look forward to a successful pirep!! Mike Welch Subject: Re: Kolb-List: MkIII Xtra From: aslsa.rng@gmail.com Mike=2C All I can tell you is that the horizontal stabs are now set right d own the center of the boom. I started out with them in the upper most hole of the bracket and moved them down in steps to try and relieve the nose hea viness. Lower was better in each step to the lowest position. It was Bryan that suggested I lower the wings to the lowest setting. I was concerned about being able to get the aircraft to rotate. He assured me tha t he had welded up holes before that were drilled so as to set the wing inc idence too high and it had fixed the problem. Since I have the CG at the almost the farthest aft position=2C 34.28% (I us e 35% as most aft)=2C and I'm running the trim in the most up position=2C I don't think less horizontal stabilizer incidence is the way to go. The nice thing about having a flying aircraft is that theory can be tested against reality PDQ. With any luck=2C I'll know in the morning. Rick




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