Today's Message Index:
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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)
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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
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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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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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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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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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