KR> forward sweep

[Tim]

To match the lift distribution over the wing with weight distribution over 
the wing. Most aircraft have all their weight in the centre (eg. fuselage). 
The ideal match is actually an eliptical shaped wing planform but tapering 
is easier to build and is a good compromise.

If a plank flying wing aircraft had its weight evenly distributed over it's 
entire span then a constant cord would be best.

Tapered wing planforms are most often employed to approximate the ideal 
elliptical planform. Theoretically a perfectly elliptical planform enables 
every part of the wing to reach the maximum CL at the same time, which will 
result in a wing with the lowest posible drag for a given lift.

Since it is difficult to build a wing with a curved elliptical planform a 
tapered shape is often used as an approximation.

KR> forward sweep

[Larry H.]

Mooneys don't have forward swept wings, they have forward swept trailing edges 
on the main wing and the horizontal tail and both have straight leading edges , 
except the Mooneys inboard first 3 feet are tapered rearward, then outboard of 
that they are straight perpendicular to the fuselage centerline.
Mooneys are very stable.
Larry Howell







Then I guess every Mooney out there must be terribly unstable

Bill Zorc
Vero Beach, FL
RV-8 N2046F

KR> FORWARD SWEEP OR CONSTANT CHORD WING

[Larry H.]

I talked to a hot shot NASA Aeronautical Engineer some years back who had been 
involved heavily in studying and testing different wing shapes on real 
airplanes. He said if your airplane design would not exceed 250 miles per hour 
that tapering a wing might look cool but it gained you absolutely nothing. He 
said you may as well make it easy on yourself and build a CONSTANT CHORD WING 
AIRPLANE. While we can dream and wish, guys like him actually had our tax 
dollars and lots of people on their teams to actually go and do this testing.
I know why all the early models if not all Vans aircraft models have a 
rectangular constant chord wing, easy to make parts!

He also talked about drag in the engine compartment. I do not remember the 
percentage now but the largest drag on a piston powered airplane, probably all 
others as well is in the engine compartment. Figure out a way to move the 
engine 
cooling air through the engine compartment less draggy and more efficiently and 
you will use less fuel for same speed or go faster.

Larry Howell

KR> forward sweep

[Joe Coggiano]

Hope nobody minds my 2 cents. Military speaking swept wing aircraft normally 
will not change wing position until higher speeds are attained. This is
where maximum advantage is attained. The advantage at lower speeds is 
negligible 
for the expense.

However I am not familiar with low speed homebuilds along these lines. It has 
been many years so my observations may be all  wet.
Joe





From: J L 
To: KRnet 
Sent: Mon, July 12, 2010 11:47:44 AM
Subject: Re: KR> forward sweep

I have a model airplane that has about 10 degrees of forward sweep.
Flies normally. However the wing is extremely stiff and will still
flutter at high speed (150mph) if the ailerons have any slop in them.

On 7/12/10, zorc...@aol.com  wrote:
> Then I guess every Mooney out there must be terribly unstable
>
> Bill Zorc
> Vero Beach, FL
> RV-8 N2046F
>
>
>
>
> In a message dated 7/12/2010 12:45:27 P.M. Eastern Daylight Time,
> aerona...@sbcglobal.net writes:
>
> On a  more basic note, I will add two things about forward sweep.
> 1. Your wings  must be much stronger to handle the forces caused by the
> negative  stability.
> 2. It generally requires a computer controlled flight system to  handle the
> bending moments.
> Not recommended.
> Hal  Dantone
>
> --- On Mon, 7/12/10, Mark Langford   wrote:
>
> From: Mark Langford 
> Subject: Re:  KR> forward sweep
> To: "KRnet" 
> Date: Monday,  July 12, 2010, 2:38 PM
>
> I don't remember the exact reason, but I read in  a Raymer aircraft design
> book that any kind of forward sweep was a bad  idea on general aviation
> aircraft, for various reasons including stability  and stall
> characteristics.
> We're talking forward sweep though, not just  "no" sweep.
>
> Below is something I snagged off the  web:
>
> Advantages
>
> a.. Better off-design span loading (but  with less taper: Cl advantage,
> weight penalty)
>
> b..  Aeroelastically enhanced maneuverability
>
> c.. Smaller basic lift  distribution
>
> d.. Reduced leading edge sweep for given structural  sweep
>
> e.. Increased trailing edge sweep for given structural  sweep - lower CDc
>
> f.. Unobstructed cabin
>
> g.. Easy  gear placement
>
> h.. Good for turboprop placement
>
> i.. Laminar flow advantages?
>
>
> Disadvantages
>
> a..  Aeroelastic divergence or penalty to avoid it
>
> b.. Lower |Cl?|  (effective dihedral)
>
> c.. Lower Cn? (yaw stability)
>
> d.. Bad for winglets
>
> e.. Stall location (more  difficult)
>
> f.. Large Cm0 with flaps
>
> g.. Reduced  pitch stability due to additional lift and fuse interference
>
> h..  Smaller tail length???
>
> Mark Langford
> n5...@hiwaay.net
> website  www.n56ml.com
>
>
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KR> New air foil conversion from completed RAF airfoil spars

[Mark]

Forgot to mention... the H/S is complete (glassed) and 6" wider than
plans... can I use this with the new airfoil, or do I need to think about
modifying this too?

Thanks again.

Mark W.

-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Mark
Sent: Monday, July 12, 2010 8:20 PM
To: 'KRnet'
Subject: KR> New air foil conversion from completed RAF airfoil spars

I acquired a project (KR2S) that is about 40 - 50% complete; boat, spars,
tail feathers etc. that was originally built to the plan's wing
configuration. I would like to use the "new" airfoil and know that the spars
need to be "taller". 

What do you think is the best approach to doing this? The spars I have are
extraordinarily well built... they are complete, including the "weep" holes
for vacuum relief in the mahogany. Should I "cap" them fully, in other words
over the mahogany facings on the spars, or should I just cap the main spruce
spar material?

Any input from anyone who has done this, or has built the new spars from
scratch would be appreciated.

Thanks

Mark W.
N952MW (res)


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KR> New air foil conversion from completed RAF airfoil spars

[Mark]

I acquired a project (KR2S) that is about 40 - 50% complete; boat, spars,
tail feathers etc. that was originally built to the plan's wing
configuration. I would like to use the "new" airfoil and know that the spars
need to be "taller". 

What do you think is the best approach to doing this? The spars I have are
extraordinarily well built... they are complete, including the "weep" holes
for vacuum relief in the mahogany. Should I "cap" them fully, in other words
over the mahogany facings on the spars, or should I just cap the main spruce
spar material?

Any input from anyone who has done this, or has built the new spars from
scratch would be appreciated.

Thanks

Mark W.
N952MW (res)

KR> Wing sweep question.

[John Martindale]

Hi Larry

I think Pete is saying the 25% chord line is swept forward slightly as it
progresses outwards NOT the leading edge of the wing. The former being
determined by the ratio of the leading edge angle to the trailing edge angle
where the latter is proportionately greater. Nonetheless it is an
interesting characteristic that we haven't known about or commented on
before to my knowledge.

I think the KR sensitivity that some allude to stems mainly from the short
fuselage and tail (maybe less so in the S series). My bird is stable as
anything at the moment stuck in the hangar waiting for me to re do the cowl
to suit the prop gearbox.


John Martindale
29 Jane Circuit
Toormina NSW 2452
AUSTRALIA

ph: 61 2 6658 4767
mobile: 0403 432179
email: john_martind...@bigpond.com

KR> Wing sweep question.

[Larry Flesner]

At 05:34 AM 7/12/2010, you wrote:
>I was working with the CAD drawings I've done in Rhino for the KR2S and
>I noticed that the outer wing according to plans has a minute amount of
>forward sweep.
>Pete.
+++

Pete & all,

I just got back from the airport where I installed a new EGT probe in 
the KR.  While there I did a bit of bug removal as well.  I checked 
the "wing sweep" on my KR, which is plans built, and I have a slight 
aft sweep from the attach point to the tip, just a I suspected.  When 
I got home I pulled out the full scale drawings for the "new airfoil" 
and measured the ribs.  The 48" rib extends 10 inches forward of the 
spar and the 33 inch tip rib extends 7 inches forward of the 
spar.  Assuming the spar is straight from tip to tip as the plans 
call for, there would be a 3 inch aft sweep from the attach point to 
the tip, not a forward sweep.  Based on my observations, I'd say 
anyone that has a KR with a forward sweep in the wing has a severe 
structural problem that should be addressed immediately. :-)

Larry Flesner

KR> forward sweep

[J L]

I have a model airplane that has about 10 degrees of forward sweep.
Flies normally. However the wing is extremely stiff and will still
flutter at high speed (150mph) if the ailerons have any slop in them.

On 7/12/10, zorc...@aol.com  wrote:
> Then I guess every Mooney out there must be terribly unstable
>
> Bill Zorc
> Vero Beach, FL
> RV-8 N2046F
>
>
>
>
> In a message dated 7/12/2010 12:45:27 P.M. Eastern Daylight Time,
> aerona...@sbcglobal.net writes:
>
> On a  more basic note, I will add two things about forward sweep.
> 1. Your wings  must be much stronger to handle the forces caused by the
> negative  stability.
> 2. It generally requires a computer controlled flight system to  handle the
> bending moments.
> Not recommended.
> Hal  Dantone
>
> --- On Mon, 7/12/10, Mark Langford   wrote:
>
> From: Mark Langford 
> Subject: Re:  KR> forward sweep
> To: "KRnet" 
> Date: Monday,  July 12, 2010, 2:38 PM
>
> I don't remember the exact reason, but I read in  a Raymer aircraft design
> book that any kind of forward sweep was a bad  idea on general aviation
> aircraft, for various reasons including stability  and stall
> characteristics.
> We're talking forward sweep though, not just  "no" sweep.
>
> Below is something I snagged off the  web:
>
> Advantages
>
> a.. Better off-design span loading (but  with less taper: Cl advantage,
> weight penalty)
>
> b..  Aeroelastically enhanced maneuverability
>
> c.. Smaller basic lift  distribution
>
> d.. Reduced leading edge sweep for given structural  sweep
>
> e.. Increased trailing edge sweep for given structural  sweep - lower CDc
>
> f.. Unobstructed cabin
>
> g.. Easy  gear placement
>
> h.. Good for turboprop placement
>
> i.. Laminar flow advantages?
>
>
> Disadvantages
>
> a..  Aeroelastic divergence or penalty to avoid it
>
> b.. Lower |Cl?|  (effective dihedral)
>
> c.. Lower Cn? (yaw stability)
>
> d.. Bad for winglets
>
> e.. Stall location (more  difficult)
>
> f.. Large Cm0 with flaps
>
> g.. Reduced  pitch stability due to additional lift and fuse interference
>
> h..  Smaller tail length???
>
> Mark Langford
> n5...@hiwaay.net
> website  www.n56ml.com
>
>
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>

KR> Airventure Cup Update

[J L]

Guys,

3 days left to sign up!

Here is a quick note from Eric Whyte the race organizer. Sounds like
its going to be a great time.

Hello everyone,

I wanted to take a moment and bring you all up to date on plans for the 2010
AirVenure Cup Race. We have an excellent field this year, approximately 60
airplanes registered. We have expanded the classes to include Light Sport
Aircraft for the first time. We only have one entry, a Kitfox but it
is a start.
We also have 3 airplanes running in the turbine class for the first time ever.
In the past we have never had more than 1 in any given year. We are also
expanding the Formula classes to include a Gold Division for 390 cubic inch
engines and high compression 360s.

The city of Mitchell and the Wright Brothers FBO have been extremely supportive
and helpful in planning this year's event and we have a bunch of fun things
planned this year that I am really looking forward to.

On Friday night we will be doing the media event once again, the Mitchell
Convention and Visitors Bureau is helping to set up the media side of
things. In
2008 when we were out in Mitchell, we did a Friday night social gathering at
Blarney's Pub which was a lot of fun and we are planning on doing it again. We
have the outdoor patio reserved for the group again so we should have a great
time. Blarney's as you might remember is a sports themed place so
anyone wanting
to donated an autographed picture of you with your airplane for their
wall would
be appreciated.  Bring it with you to South Dakota.

On Saturday we are doing the airport open-house for the public. The race pit
area is going to be opened up and the airplanes on display. This was very
popular in 2008 and will be expanded this year. We have invited the State of
South Dakota to bring in a National Guard Blackhawk for static display. EAA
chapter 289 is going to be hosting a fly-in pancake breakfast on Saturday
Morning. This will be followed buy the burger and brat lunch also at the
airport. In addition Chapter 289 is going to be hosting a Young Eagles Rally on
Saturday. In 2008 we had a big crowd show up so they are hoping to fly as many
kids as possible. If you would like to participate you are welcome to do so.

Saturday night we have the traditional pre-race dinner and briefing. The
pre-race dinner will be help this year at The Brig Steakhouse which is on the
lake close to the airport. After dinner we will be heading to the Pepsi Center
for the Performing Arts for a special screening of the new Documentary Film
"Breaking Through the Clouds" about the 1929 Women's Transcontinental
Air Race.
The film will be introduced by the producer that made it, Heather Taylor.
http://www.breakingthroughtheclouds.com/

On Sunday morning we will be enjoying excellent weather (power of positive
thinking) as we do a secondary briefing prior to the race launch.

The race course is slightly shorter this year, 377 nautical miles. The finish
line has been moved to the Snow Crest Ranch Airport, located in Montello, WI  -
http://www.airport-data.com/airport/0WI4/maps.html There is no fuel available
there so plan accordingly. After crossing the finish line we will be recovering
at Fond du Lac as usual. The airport Identifier is 0WI4, and the lat/longs are
on the website so you can do your pre-flight planning.

If you have raced in the past two years I have assigned you the same race
number. If you are new or haven't raced in a while and haven't heard from me
about race numbers, please contact me ASAP as Sarah and I are working like mad
to get the race program finished up and ready to publish.

We have two hotels lined up for the race this year. They are actually attached
to each other so it is your choice which one you stay in. The Hampton Inn -
(605) 995-1575  Or the Comfort Suites - (605) 990-2400. Be sure to
tell them you
are with the AirVenture Cup race as we have a group rate and a block of rooms
reserved.

Dick Keyt reports that the insurance processing is going fairly well, I thank
all of you for helping him out and getting your insurance in early this year.
That has taken a strain off EAA staff and improved things for everyone.

Let me know if you have any questions.

Eric Whyte
Chairman, 2010 EAA AirVenture Cup Race

KR> Flight Instruction---Off subject

[Charles Burkholder]

Hey guys,

How many of you are current flight instructers? I'm 'shopping' for instructers 
and their pricing.   Email me off list

Thanx
Cheers,

Charles Burkholder

KR> forward sweep

[zorc...@aol.com]

Then I guess every Mooney out there must be terribly unstable

Bill Zorc
Vero Beach, FL
RV-8 N2046F




In a message dated 7/12/2010 12:45:27 P.M. Eastern Daylight Time,  
aerona...@sbcglobal.net writes:

On a  more basic note, I will add two things about forward sweep.
1. Your wings  must be much stronger to handle the forces caused by the 
negative  stability.
2. It generally requires a computer controlled flight system to  handle the 
bending moments.  
Not recommended.  
Hal  Dantone

--- On Mon, 7/12/10, Mark Langford   wrote:

From: Mark Langford 
Subject: Re:  KR> forward sweep
To: "KRnet" 
List-Post: krnet@list.krnet.org
Date: Monday,  July 12, 2010, 2:38 PM

I don't remember the exact reason, but I read in  a Raymer aircraft design 
book that any kind of forward sweep was a bad  idea on general aviation 
aircraft, for various reasons including stability  and stall 
characteristics. 
We're talking forward sweep though, not just  "no" sweep.

Below is something I snagged off the  web:

Advantages

a.. Better off-design span loading (but  with less taper: Cl advantage, 
weight penalty)

b..  Aeroelastically enhanced maneuverability

c.. Smaller basic lift  distribution

d.. Reduced leading edge sweep for given structural  sweep

e.. Increased trailing edge sweep for given structural  sweep - lower CDc

f.. Unobstructed cabin

g.. Easy  gear placement

h.. Good for turboprop placement

i.. Laminar flow advantages?


Disadvantages

a..  Aeroelastic divergence or penalty to avoid it

b.. Lower |Cl?|  (effective dihedral)

c.. Lower Cn? (yaw stability)

d.. Bad for winglets

e.. Stall location (more  difficult)

f.. Large Cm0 with flaps

g.. Reduced  pitch stability due to additional lift and fuse interference

h..  Smaller tail length???

Mark Langford
n5...@hiwaay.net
website  www.n56ml.com


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KR> forward sweep

[Fred Johnson]

I'll put my two cents on this;

Perhaps if we were talking 15 or 20 degrees of forward sweep you guys would
be correct, but I would like to point out that there have been several
sailplanes with forward sweep, the "Genesis" is one and Jim Marske has
designed several too. they have less than 5 degrees of forward sweep and are
TAILLESS... (the "Genesis" has a very small tail for pitch control)

For a KR "type" of airplane with say 3 degrees of "Leading Edge" forward
sweep wouldn't be hard and it wouldn't be UNSTABLE as it is all about
balancing forces. It's not like it's an X-29 or a Cornelius Mallard. And
might I add that the Bugatti model 100 had a small amount of forward
sweep...check it out at OSH this year, it's in there museum.

I do AGREE with Mark L though, it's not a KR anymore...

Fred Johnson
Reno, NV



Hal wrote:

On a more basic note, I will add two things about forward sweep.
1. Your wings must be much stronger to handle the forces caused by the
negative stability.
2. It generally requires a computer controlled flight system to handle the
bending moments.  
Not recommended.  
Hal Dantone

KR> forward sweep

[Hal Dantone]

On a more basic note, I will add two things about forward sweep.
1. Your wings must be much stronger to handle the forces caused by the negative 
stability.
2. It generally requires a computer controlled flight system to handle the 
bending moments.  
Not recommended.  
Hal Dantone

--- On Mon, 7/12/10, Mark Langford  wrote:

From: Mark Langford 
Subject: Re: KR> forward sweep
To: "KRnet" 
List-Post: krnet@list.krnet.org
Date: Monday, July 12, 2010, 2:38 PM

I don't remember the exact reason, but I read in a Raymer aircraft design 
book that any kind of forward sweep was a bad idea on general aviation 
aircraft, for various reasons including stability and stall characteristics. 
We're talking forward sweep though, not just "no" sweep.

Below is something I snagged off the web:

Advantages

  a.. Better off-design span loading (but with less taper: Cl advantage, 
weight penalty)

  b.. Aeroelastically enhanced maneuverability

  c.. Smaller basic lift distribution

  d.. Reduced leading edge sweep for given structural sweep

  e.. Increased trailing edge sweep for given structural sweep - lower CDc

  f.. Unobstructed cabin

  g.. Easy gear placement

  h.. Good for turboprop placement

  i.. Laminar flow advantages?


Disadvantages

  a.. Aeroelastic divergence or penalty to avoid it

  b.. Lower |Cl?| (effective dihedral)

  c.. Lower Cn? (yaw stability)

  d.. Bad for winglets

  e.. Stall location (more difficult)

  f.. Large Cm0 with flaps

  g.. Reduced pitch stability due to additional lift and fuse interference

  h.. Smaller tail length???

Mark Langford
n5...@hiwaay.net
website www.n56ml.com


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KR> HELP!!!

[Larry Knox]

We can help here with a C120, pilot layover W/ bath and a number of Courtesy
car option but you have to make a fun trip to beautiful Lebanon OR.
la...@lebanair.com 

-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of R. Lee Jarvis
Sent: Friday, July 09, 2010 8:54 PM
To: KRnet
Subject: Re: KR> HELP!!!

I can help you Glenn, but I'm in Lakeland, FL.

- Original Message - 
From: "Glenn Martin" 
To: "KRnet" 
Sent: Friday, July 09, 2010 9:56 PM
Subject: KR> HELP!!!


> Alright Guys. I have my PPL, but now I need to complete my tailwheel 
> endorsement. I have 7 hours in a Cessna 140, but couldnt get the 
> endorsment because I didnt have the PPL yet (at the time). The 
> Instructor can no longer complete the training due to medical reasons. I 
> am down here in Biloxi MS. Can anyone help me? I need instruction and 
> plane rental for it. Thanks in advance.
> 
> Glenn Martin
> KR2 N1333A ( in progress)
> Biloxi, MS
> rep...@martekmisasissippi.com
> 
> 
> 
> ___
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KR> forward sweep

[Mark Langford]

I don't remember the exact reason, but I read in a Raymer aircraft design 
book that any kind of forward sweep was a bad idea on general aviation 
aircraft, for various reasons including stability and stall characteristics. 
We're talking forward sweep though, not just "no" sweep.

Below is something I snagged off the web:

Advantages

  a.. Better off-design span loading (but with less taper: Cl advantage, 
weight penalty)

  b.. Aeroelastically enhanced maneuverability

  c.. Smaller basic lift distribution

  d.. Reduced leading edge sweep for given structural sweep

  e.. Increased trailing edge sweep for given structural sweep - lower CDc

  f.. Unobstructed cabin

  g.. Easy gear placement

  h.. Good for turboprop placement

  i.. Laminar flow advantages?


Disadvantages

  a.. Aeroelastic divergence or penalty to avoid it

  b.. Lower |Cl?| (effective dihedral)

  c.. Lower Cn? (yaw stability)

  d.. Bad for winglets

  e.. Stall location (more difficult)

  f.. Large Cm0 with flaps

  g.. Reduced pitch stability due to additional lift and fuse interference

  h.. Smaller tail length???

Mark Langford
n5...@hiwaay.net
website www.n56ml.com

KR> KR2S Wing sweep question.

[Gunnar Olsen]

Sorry, I forgot the straight piece (planing on a wing with straight 
taper ...)

The correct data is quite similar:

The KR2S theoretical wing:
wing area of 84 Sq. Ft.
WingSpan 23.00 FT.
Aspect Ratio 6.3
Taper ratio 0.75
QC Sweep 0.00 Deg.
Mean Chord 3.68 Ft.
MC Span Location 5.48 Ft.

Gunnar


On 12.07.2010 15:53, Gunnar Olsen wrote:
> For a straight wing tapering from 48 to 36 inches; when quarter chord
> sweep is straight, the leading edge of the tip spar is 3 inches behind
> the leading edge of the root spar.
>
> It does not matter where the actual wing spar is located and what angle
> it has. ( but I believe on the KR it should be straight as well)
>
> The KR2S theoretical wing:
>
> wing area of 80.5 Sq. Ft.
> WingSpan 23.00 FT.
> Aspect Ratio 6.75
> Taper ratio 0.75
> QC Sweep 0.00 Deg.
> Mean Chord 3.51 Ft.
> MC Span Location 5.48 Ft.
>
>
> Gunnar
>
> On 12.07.2010 14:46, Larry Flesner wrote:
>
>> At 05:34 AM 7/12/2010, you wrote:
>>
>>  
>>> I was working with the CAD drawings I've done in Rhino for the KR2S and
>>> I noticed that the outer wing according to plans has a minute amount of
>>> forward sweep.
>>> Pete.
>>> Ballina, Aus.
>>>
>>>
>> +
>>
>> I think I'd check the software if I were you.  The forward spar is
>> perfectly straight from tip to tip.  The wing tappers from the 48
>> inch rib to the 36 inch rib at the tip.  I'd have to look at the
>> airplane to be sure but I think my plans built wings tapper slightly
>> aft from the attach point to the tip or at most, straight.
>>
>> Larry Flesner
>>
>>
>>
>>
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KR> KR2S Wing sweep question.

[Gunnar Olsen]

For a straight wing tapering from 48 to 36 inches; when quarter chord 
sweep is straight, the leading edge of the tip spar is 3 inches behind 
the leading edge of the root spar.

It does not matter where the actual wing spar is located and what angle 
it has. ( but I believe on the KR it should be straight as well)

The KR2S theoretical wing:

wing area of 80.5 Sq. Ft.
WingSpan 23.00 FT.
Aspect Ratio 6.75
Taper ratio 0.75
QC Sweep 0.00 Deg.
Mean Chord 3.51 Ft.
MC Span Location 5.48 Ft.


Gunnar

On 12.07.2010 14:46, Larry Flesner wrote:
> At 05:34 AM 7/12/2010, you wrote:
>
>> I was working with the CAD drawings I've done in Rhino for the KR2S and
>> I noticed that the outer wing according to plans has a minute amount of
>> forward sweep.
>> Pete.
>> Ballina, Aus.
>>  
> +
>
> I think I'd check the software if I were you.  The forward spar is
> perfectly straight from tip to tip.  The wing tappers from the 48
> inch rib to the 36 inch rib at the tip.  I'd have to look at the
> airplane to be sure but I think my plans built wings tapper slightly
> aft from the attach point to the tip or at most, straight.
>
> Larry Flesner
>
>
>
>
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
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>
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KR> KR2S Wing sweep question.

[Pete]

I was surprised when I saw it, as I'd always assumed that there was no 
sweep at all. As it turns out it's next to nothing but the spar is 
indeed straight, but the sweep at 25% chord is just a tad under 1° 
forward. When you look at the wing, the trailing edge tapers forward 
more than the leading edge tapers back. The aspect ratio for the outer 
wings is 6.4 and the wing taper ratio is 5.3. The main spar while 
straight does not travel equidistant along the chord line.
Check out this link. 
http://s12.photobucket.com/albums/a217/sarahjeanb/Peters/?action=view=MAC1.jpg
The spar is in green, the 25% chord line used to measure sweep in 
highlighted in yellow. The red line just to the front of the yellow line 
near the centreline of the aircraft denoted the station of the MAC from 
the firewall.
Cheers.
Pete.

Larry Flesner wrote:
>
> 
>
> I think I'd check the software if I were you.  The forward spar is 
> perfectly straight from tip to tip.  The wing tappers from the 48 
> inch rib to the 36 inch rib at the tip.  I'd have to look at the 
> airplane to be sure but I think my plans built wings tapper slightly 
> aft from the attach point to the tip or at most, straight.
>
> Larry Flesner

KR> KR2S Wing sweep question.

[Larry Flesner]

At 05:34 AM 7/12/2010, you wrote:
>I was working with the CAD drawings I've done in Rhino for the KR2S and
>I noticed that the outer wing according to plans has a minute amount of
>forward sweep.
>Pete.
>Ballina, Aus.
+

I think I'd check the software if I were you.  The forward spar is 
perfectly straight from tip to tip.  The wing tappers from the 48 
inch rib to the 36 inch rib at the tip.  I'd have to look at the 
airplane to be sure but I think my plans built wings tapper slightly 
aft from the attach point to the tip or at most, straight.

Larry Flesner

KR> Mains possition

[John Martindale]

Hi Barry

I'm no aeronautical engineer but it seems to me you need to get more weight
forward of the CoG and this is not achieved by moving the wheels. Once the
wheels have left the ground their position becomes irrelevant and if you
can't get the tail up with forward stick at that point then it is because
the CoG is too far back or your elevator is rigged wrongly or too small to
be effective.

Wheel location is more to do with tendency to ground loop I think because if
the CoG is too far behind the axles then it can more easily overtake the
wheels in a loop.

I just feel a bit uneasy about your solution and suggest some expert advice
might be timely.

Regards John 

John Martindale
29 Jane Circuit
Toormina NSW 2452
AUSTRALIA

ph: 61 2 6658 4767
mobile: 0403 432179
email: john_martind...@bigpond.com
-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of Barry Kruyssen
Sent: Monday, 12 July 2010 8:07 AM
To: 'KRnet'
Subject: KR> Mains possition

Hi

When I crashed my KR2 4 years ago, during the rebuild I move the mains
forward to give more weight on the tail wheel when empty.  This worked fine
solo.

2 up there is too much weight behind the CofG and the main wing started to
fly before the tail plane.  Full forward stick and the tail was still on the
ground and with the angle of attack and ground affect the aircraft lifted
off the ground in a very nose high attitude and mushed there, tail still on
the ground. I pulled the power and it flopped back on the ground.  No one
hurt, no damage to the KR2.

I need to move the mains back, but how far? 

The question to you tail dragger builders with non stock KR2 undercarriage,
is how far in front of the CENTER of the CofG is the center of the axle with
the plane in the flying attitude?

Thanks
Barry Kruyssen
k...@bigpond.com



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04:36:00

KR> KR2S Wing sweep question.

[Pete]

I was working with the CAD drawings I've done in Rhino for the KR2S and 
I noticed that the outer wing according to plans has a minute amount of 
forward sweep. I wonder if this has anything to do with the very 
sensitive aft CG issues the plane experiences?
Can anyone else confirm or debunk this discovery?
Cheers.
Pete.
Ballina, Aus.

KR> 0200A starter Motor

[Paul & Karen Smith]

Had a thought, would a boot opener or other automotive solenoid be modified
to pull the manual starter rod?

Paul Smith
Brisbane, AUSTRALIA
pk.sm...@bigpond.net.au
http://kr2spacemodulator.blogspot.com/


-Original Message-
From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf
Of phillip matheson
Sent: Monday, 12 July 2010 7:45 AM
To: KRnet
Subject: KR> 0200A starter Motor

I picked up an Continental 0200a Rolls Royce engine and it has the older
style cable pull starter motor.

Anyone have or know some one who may have a later starter solenoid motor.

Phil Matheson
SAAA Ch 37
http://www.philskr2.50megs.com/ 



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