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slyck(at)frontiernet.net
Guest

Posted: Tue Feb 03, 2009 9:20 am Post subject: legs

I currently have aluminum gear legs on my MkIII (and a spare set on  

the shelf)

Now I am considering changing out for the steel ones, not for any  

reason other than

the increased stance on the ground. -not because it "looks cool" but  

because I am

going to experiment with decreased wing incidence and it would be  

nice to have enough

to get off the ground.

Anyone with a spare set lying around? I would be interested.   

Otherwise I will go to TNK



BTW, what is the actual height gain over the original?

BB

mdnanwelch7(at)hotmail.co
Guest

Posted: Tue Feb 03, 2009 9:37 am Post subject: legs

Bob,

 

  Although I built my own steel gear legs, I did build them from the measurements

of someone who does have genuine Kolb steel legs.  Plus, I called TNK and had Donnie

measure the stance height of the cage, directly below the socket.

  The gain in height will be very close to 5 inches.  5" may not sound like much, but it

is a bunch!!  

 

Mike Welch

MkIII



----------------------------------------

 	  Quote: 	
		   To: kolb-list(at)matronics.com

 From: slyck(at)frontiernet.net

 Subject: legs

 Date: Tue, 3 Feb 2009 12:18:24 -0500



 



 I currently have aluminum gear legs on my MkIII (and a spare set on

 the shelf)

 Now I am considering changing out for the steel ones, not for any

 reason other than

 the increased stance on the ground. -not because it "looks cool" but

 because I am

 going to experiment with decreased wing incidence and it would be

 nice to have enough

 to get off the ground.

 Anyone with a spare set lying around? I would be interested.

 Otherwise I will go to TNK



 BTW, what is the actual height gain over the original?

 BB





_________________________________________________________________
	


Windows Live™ Hotmail®:…more than just e-mail. 

http://windowslive.com/explore?ocid=TXT_TAGLM_WL_t2_hm_justgotbetter_explore_012009

ulflyer(at)verizon.net
Guest

Posted: Tue Feb 03, 2009 8:06 pm Post subject: legs

Robert - first I am not challenging you on what your proposing to do, 

that is reduce your wings incidence, just trying to understand why 

and what your trying to accomplish.



I know you have been around a while so for others by changing the 

wing incidence on an aircraft like a Kolb will change it's takeoff 

performance, make it better or make worst.  It can also impact it's 

stall attitude thus the desired stance during landing operation which 

thus impacts the gear configuration and vise-versa.  It will also 

impact the planes cruise attitude which can impact it's cruise speed, 

clean and straight at cruise power setting versus a less than optimum 

flight attitude at cruise resulting in greater induced drag thus lower speed.

jerb



At 11

:18 AM 2/3/2009, you wrote:

 	  Quote: 	
		  



I currently have aluminum gear legs on my MkIII (and a spare set on

the shelf)

Now I am considering changing out for the steel ones, not for any

reason other than

the increased stance on the ground. -not because it "looks cool" but

because I am

going to experiment with decreased wing incidence and it would be

nice to have enough

to get off the ground.

Anyone with a spare set lying around? I would be interested.

Otherwise I will go to TNK



BTW, what is the actual height gain over the original?

BB

slyck(at)frontiernet.net
Guest

Posted: Wed Feb 04, 2009 5:26 am Post subject: legs

You are quite right,  and I hope to be around for a while longer 



Just experimenting.  I can always revert back to stock.

It is an easy process with my bird as I don't have as much to fiddle  

with the center section.

A couple of new holes in the spar ears and shims for the tin.

Check for control rod adjustment.

I won't initially change horizontal stab incidence because of a  

factor I shall not divulge yet.

-only if it works

BB



On 3, Feb 2009, at 11:05 PM, jerb wrote:



 	  Quote: 	
		   



 Robert - first I am not challenging you on what your proposing to  

 do, that is reduce your wings incidence, just trying to understand  

 why and what your trying to accomplish.



 I know you have been around a while so for others by changing the  

 wing incidence on an aircraft like a Kolb will change it's takeoff  

 performance, make it better or make worst.  It can also impact it's  

 stall attitude thus the desired stance during landing operation  

 which thus impacts the gear configuration and vise-versa.  It will  

 also impact the planes cruise attitude which can impact it's cruise  

 speed, clean and straight at cruise power setting versus a less  

 than optimum flight attitude at cruise resulting in greater induced  

 drag thus lower speed.

 jerb



 At 11

 :18 AM 2/3/2009, you wrote:

> 

>

> I currently have aluminum gear legs on my MkIII (and a spare set on

> the shelf)

> Now I am considering changing out for the steel ones, not for any

> reason other than

> the increased stance on the ground. -not because it "looks cool" but

> because I am

> going to experiment with decreased wing incidence and it would be

> nice to have enough

> to get off the ground.

> Anyone with a spare set lying around? I would be interested.

> Otherwise I will go to TNK

>

> BTW, what is the actual height gain over the original?

> BB

>

>

ulflyer(at)verizon.net
Guest

Posted: Wed Feb 04, 2009 8:17 am Post subject: legs

Liked your reply Robert, sounds like some past experience and lessons 

learned.



Knowledge can be taught or in some cases learned and confirmed from 

practice, (some past experience comes to mind of my mother telling me 

not to touch the stove because it was hot and I would get burned - 

yep confirmed she was right, she had knowledge).



In reference to incidence and stance I got mine from practice with 

another aircraft.  Lesson 1 - If you have the wrong stance an 

airplane will resist becoming airborne at lower normally flyable 

takeoff roll speeds.  Lesson 2- if it has the correct stance but the 

wing has the wrong incidence, it will increase take off roll and lift 

off speed.  Think about what would contribute to this.



Robert, now we need for you to pass on your knowledge to us younger 

generations of lessons learned pertaining to the horizontal stabilizer.

jerb



At 07:25 AM 2/4/2009, you wrote:

 	  Quote: 	
		  



You are quite right,  and I hope to be around for a while longer 



Just experimenting.  I can always revert back to stock.

It is an easy process with my bird as I don't have as much to fiddle

with the center section.

A couple of new holes in the spar ears and shims for the tin.

Check for control rod adjustment.

I won't initially change horizontal stab incidence because of a

factor I shall not divulge yet.

-only if it works

BB



On 3, Feb 2009, at 11:05 PM, jerb wrote:



>

>

>Robert - first I am not challenging you on what your proposing to

>do, that is reduce your wings incidence, just trying to understand

>why and what your trying to accomplish.

>

>I know you have been around a while so for others by changing the

>wing incidence on an aircraft like a Kolb will change it's takeoff

>performance, make it better or make worst.  It can also impact it's

>stall attitude thus the desired stance during landing operation

>which thus impacts the gear configuration and vise-versa.  It will

>also impact the planes cruise attitude which can impact it's cruise

>speed, clean and straight at cruise power setting versus a less

>than optimum flight attitude at cruise resulting in greater induced

>drag thus lower speed.

>jerb

>

>At 11

>:18 AM 2/3/2009, you wrote:

>>

>>

>>I currently have aluminum gear legs on my MkIII (and a spare set on

>>the shelf)

>>Now I am considering changing out for the steel ones, not for any

>>reason other than

>>the increased stance on the ground. -not because it "looks cool" but

>>because I am

>>going to experiment with decreased wing incidence and it would be

>>nice to have enough

>>to get off the ground.

>>Anyone with a spare set lying around? I would be interested.

>>Otherwise I will go to TNK

>>

>>BTW, what is the actual height gain over the original?

>>BB

>>

>>

>>

>

>

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Feb 04, 2009 8:59 am Post subject: legs

Homer Kolb was, and still is, more interested in slow flight, than faster 

flight.  He is still designing and building slow, high lift airplanes.



Designing increased wing incidence into his airplanes, Homer was able to 

satisfy several of his requirements:



-Design the airplane to sit in a near level attitude on the ground, and be 

able to take off and land in a near level attitude.  His idea was to prevent 

low time pilots from getting into take off and landing stalls.



-Fly very slow without the tail sagging excessively.



In accomplishing the above, it created some problems for my kind of flying:



-Cruise speed is reduced because the tail flies high, dragging the top of 

the tail boom through the air, increasing drag.



-Discourages three point landings, increasing landing and take off 

distances.



I would have already removed a lot of the incidence in my wings if it 

weren't for refitting the windshield and center section.  If I did it would 

be very easy to increase nose height on the ground by increasing gear leg 

length.  I'm running 24" gear legs on my "Hauck" main gear.  This puts my 

MKIII about 4 or 5" higher than a stock MKIII.  Would be pretty easy to 

increase them as much as required to get the job done.  Using standard MKIII 

gear leg sockets with their low angle, turned down gear legs are required to 

get the nose up without getting excessive track (width between main gear).



The primary reason the Sling Shot sits in a nose high attitude on the ground 

is because of reduced wing incidence.  The tail boom flies level, reducing 

drag.



The Kolbra has less wing incidence, flies in a similar attitude as the Sling 

Shot, and cruises 10 to 15 mph faster than my mkIII when both aircraft are 

powered with the 912ULS.



Too late in the game for me to start making major changes to my MKIII. 

Although another 10 to 15 mph cruise would be nice on a long cross country, 

it ain't worth all the effort to make the changes.



john h

mkIII - From 18F to 31F by 1100 hours.  Too cold to play outside today.

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

The BaronVonEvil

Joined: 23 Jun 2006
Posts: 76
Location: Walla Walla, WA.

Posted: Wed Feb 04, 2009 9:22 am Post subject: Re: legs

Hi All,



Perhaps another way to tweak the incidence on your Kolbs is to pickup a set of the England U-Joints.  They will allow you to make minor changes in the wing incidence to see if it is something that would improve your Kolb with out cutting or welding.  



If you see some improvement you like then you can make permanent changes  to your wings or tail feathers.



Best Regards 



Carlos G

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by0ung(at)brigham.net
Guest

Posted: Wed Feb 04, 2009 9:50 am Post subject: legs

Just experimenting.  I can always revert back to stock.

It is an easy process with my bird as I don't have as much to fiddle  

with the center section.

A couple of new holes in the spar ears and shims for the tin.

Check for control rod adjustment.

I won't initially change horizontal stab incidence because of a  

factor I shall not divulge yet.

-only if it works

 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


	


Just my two cents worth......



Lets just say as an example:

If the plane is flying in a straight and level configuration at say 60 MPH.



Lets say that the bottom of the fuselage is parallel to the air flow and

the wing is at 9 deg  to the relative air flow.  It will be producing lift

equal to the weight of the aircraft and occupants.



Now lets say we change the rigging of the aircraft and decrease the wing

incidence in relation to the main fuselage by 5 deg.



Lets put it back in the same flight configuration of straight and level and

60 mph.

In order for the wing to create the same lift as before it will still have

to be flying at 9 deg to the relative air flow...  

The change will be in the incidence of fuselage,  it will have to be at a

positive 5 Deg to the airflow...   this will put the horizontal stabilizer

at a 5 deg up pitch as well....  and will require massive amounts of up trim

to fly at that attitude,,,   or the leading edge will have to be dropped 5

deg  to keep in the same relative air flow with the wing. 



If I have calculated things correctly,,,   with the fuselage in a 5 deg

pitch up attitude in flight,,,   the tail wheel will be about 16 inches

lower, relative to the nose of the aircraft while in flight...  this would

make it east to hit the tail wheel first during landing,,  but the mains

will come down hard.....   OR  the landing speeds would have to go up by a

large margin.  Also the takeoff roll would have to much faster in order to

create sufficient lift at the decreased incidence.   Or with longer gear

legs, the amount of change will be less.



If the reason for the changes is to make the plane fly faster,,,,  that

would only be realized if the drag of the fuselage was greatly reduced at

the changed attitude.  If you have other reasons for the change...  there

may be some justification....   if you want to change the speed, you will

need to change the airfoil.



Boyd young..    do not archive.

slyck(at)frontiernet.net
Guest

Posted: Wed Feb 04, 2009 10:47 am Post subject: legs

I agree once more and that approach would be simpler but lowering the  

front will accomplish another

feat that I, personally, wish to do. -the change in geometry will  

also increase dihedral.  Counterproductive?

Yes, in that it will reduce the lift efficiency of the wing a trifle  

by increasing tip loss (and vortex)

But that's what old knothead here is curious about.

BB

I like the behavior of more dihedral because it allows you to cruise  

more with your feet.



On 4, Feb 2009, at 12:22 PM, The BaronVonEvil wrote:



 	  Quote: 	
		   



 Hi All,



 Perhaps another way to tweak the incidence on your Kolbs is to  

 pickup a set of the England U-Joints.  They will allow you to make  

 minor changes in the wing incidence to see if it is something that  

 would improve your Kolb with out cutting or welding.



 If you see some improvement you like then you can make permanent  

 changes  to your wings or tail feathers.



 Best Regards



 Carlos G





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 http://forums.matronics.com/viewtopic.php?p 28462#228462





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by0ung(at)brigham.net
Guest

Posted: Wed Feb 04, 2009 12:17 pm Post subject: legs

When I rebuilt my mkIII after a hard landing...  I bought new lift strut

fittings  and I put in twice the dihedral recommended...   from memory here

I went from 1 1/2 to 3 inches at the end rib.   

I went from a bit of negative roll stability to neutral roll stability..

still not going to drive with your feet..  but it was an improvement for me.



Boyd young



 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>>

I agree once more and that approach would be simpler but lowering the  
	


front will accomplish another

feat that I, personally, wish to do. -the change in geometry will  

also increase dihedral.  Counterproductive?

Yes, in that it will reduce the lift efficiency of the wing a trifle  

by increasing tip loss (and vortex)

But that's what old knothead here is curious about.

BB

I like the behavior of more dihedral because it allows you to cruise  

more with your feet.

slyck(at)frontiernet.net
Guest

Posted: Wed Feb 04, 2009 5:13 pm Post subject: legs

Boyd, thanx for your input and I will render more thought into my  

future changes.

The main concern would be to have a struggle with the first test  

flight after such "improvements"

BB



On 4, Feb 2009, at 3:16 PM, boyd wrote:



 	  Quote: 	
		   



 When I rebuilt my mkIII after a hard landing...  I bought new lift  

 strut

 fittings  and I put in twice the dihedral recommended...   from  

 memory here

 I went from 1 1/2 to 3 inches at the end rib.

 I went from a bit of negative roll stability to neutral roll  

 stability..

 still not going to drive with your feet..  but it was an  

 improvement for me.



 Boyd young



>>>>>>>>>>>>>>>>>>>>>>>

 I agree once more and that approach would be simpler but lowering the

 front will accomplish another

 feat that I, personally, wish to do. -the change in geometry will

 also increase dihedral.  Counterproductive?

 Yes, in that it will reduce the lift efficiency of the wing a trifle

 by increasing tip loss (and vortex)

 But that's what old knothead here is curious about.

 BB

 I like the behavior of more dihedral because it allows you to cruise

 more with your feet.

etzimm(at)gmail.com
Guest

Posted: Wed Feb 04, 2009 5:44 pm Post subject: legs

Bob.



Think about this.

Anything you do on a Kolb to gain roll ability with your feet will be at the expense of your cross wind capability.

Gene



On Feb 4, 2009, at 1:44 PM, robert bean wrote:

[quote] [quote][b]

slyck(at)frontiernet.net
Guest

Posted: Wed Feb 04, 2009 5:59 pm Post subject: legs

Thought accepted for consideration.



Legs ordered today.  I woke Travis up.

Now thinking about wasting some more moola on another prop.  My office gets more artifacts hanging on the wall.

I have a beautiful 3 blade powerfin hanging behind my head now.  Hope the nail doesn't pull out of the wall.

Soon to be joined by a 70" warp.  Both near virgin.

BB



On 4, Feb 2009, at 8:43 PM, Eugene Zimmerman wrote:

[quote]Bob.



Think about this.

Anything you do on a Kolb to gain roll ability with your feet will be at the expense of your cross wind capability.

Gene



On Feb 4, 2009, at 1:44 PM, robert bean wrote:

 	  Quote: 	
		   href="http://www.matronics.com/Navigator?Kolb-List">http://www.matronics.com/Navigator?Kolb-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/contribution  [/b] 	
[b]

beauford

Joined: 25 Apr 2007
Posts: 127
Location: Brandon, FL

Posted: Wed Feb 04, 2009 6:26 pm Post subject: Re: legs

On Dihedral...

Cranked about 3 degrees into the Fly when building to induce positive (or at least neutral) roll stability.  No regrets.  It works.  Crosswinds no problem.



Worth what ye paid fer it...



Beauford

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JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Thu Feb 05, 2009 11:16 am Post subject: Re: legs

I don't think you will gain any appreciable speed by lowering the incidence of the wings.  In the end, at cruise, you will still have to fly with the wings at the same angle of attack for a given speed.  Your nose will be sticking up more in cruise, and you will feel like you are climbing when you are level.



I think the much faster speeds in the Kolbra and Slingshot are due to the reduced drag of a narrow tandem fuselage, and very little to do with the reduced wing incidence.  If a lot of cruise speed could be gained as easily as just reducing the wing incidence and putting taller gear in, I think Kolb and a lot of others would have already done this.



Mike

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

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