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Adam Canterbury

Joined: 15 Apr 2014
Posts: 7

Posted: Sun Apr 27, 2014 7:39 am Post subject: Uncoordinated flight help!

I have a Kolb Kolbra and I am needing some advice on how to change the rigging of the flight controls. I am having to hold a good deal of right rudder in straight and level flight to get the ball centered. I do have a substantial trim tab on the rudder. What can be done to correct this problem? I would like for the plane to fly straight hands off. Is that too much to ask?

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byoungplumbing(at)gmail.c
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Posted: Sun Apr 27, 2014 8:01 am Post subject: Uncoordinated flight help!

it might not be too much to ask...  but your results may vary.......  when I 

looked at your photo...   I saw your trim tab on the side of the rudder..... 

I am not an aerospace engineer,,,  but in my humble opinion the trim tab  as 

installed is working more as a spoiler,  creating quite a bit of drag behind 

the tab and not deflecting the rudder as you would want........    in my 

humble opinion,,   the trim tab would be more effective if it were installed 

so the bend was just behind the trailing edge.  this way it could become 

part of the airfoil...



boyd young



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


	




I have a Kolb Kolbra and I am needing some advice on how to change the 

rigging of the flight controls. I am having to hold a good deal of right 

rudder in straight and level flight to get the ball centered. I do have a 

substantial trim tab on the rudder. What can be done to correct this 

problem? I would like for the plane to fly straight hands off. Is that too 

much to ask?

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Adam Canterbury

Joined: 15 Apr 2014
Posts: 7

Posted: Sun Apr 27, 2014 8:07 am Post subject: Re: Uncoordinated flight help!

That does make sense. I am just trying to work out all the bugs on this airplane that the previous owner neglected. Thanks for the reply.

frank goodnight

Joined: 27 Dec 2011
Posts: 126

Posted: Sun Apr 27, 2014 8:23 am Post subject: Uncoordinated flight help!

Hi ,

I do believe that Boyd is right. However if that doesn't compleatly

Solve the problem. You might want to try welding up the hole in one or

both of the mounting tabs for the wing and redrilling the holes in a

Slightly differently position. Quite a bit of work but it worked for my Firestar.

Good luck

Frank. 



Sent from my iPad



On Apr 27, 2014, at 11:07 AM, "Adam Canterbury" <canterbury.adam(at)gmail.com> wrote:



 	  Quote: 	
		   

 

 That does make sense. I am just trying to work out all the bugs on this airplane that the previous owner neglected. Thanks for the reply.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422453#422453

pj.ladd(at)btinternet.com
Guest

Posted: Sun Apr 27, 2014 8:50 am Post subject: Uncoordinated flight help!

Hi,

Is the problem that she wants to roll or to yaw?



If its roll. (assuming the Kolbra is rigged like the Xtra) adjust the height 

of the trailing edges.  Yaw. just check that everything is built square, 

engine properly aligned. Probably take the trim tab off and start from 

scratch. When you start making adjustments  do ONE thing at a time.



As one of our main gurus says



Worth what you paid for it.



Pat



--

neilsenrm(at)gmail.com
Guest

Posted: Sun Apr 27, 2014 9:30 am Post subject: Uncoordinated flight help!

Adam

Frank has introduce another component of trim. It your plane rolls right or left it is a rigging issue that can be resolved by as Frank suggests, buying the Kolb universal bracket that allows the owner to do small adjustments to the angle of attack of one wing and/or aileron trim tabs. These will fix roll tendencies that are countered by lateral pressure on the stick.

The trim tab on the rudder counters P factor from the prop under power. You can can get a roll trim issue if you are slipping sideways so you need to know where the issue is.

 You may know this but the trim tab on the rudder doesn't trim the airplane it only moves the rudder in the direction where it will trim the airplane. When installed properly it looks backward. The photo shows the trim tab in less than ideal location. It should be a attached as far aft on the rudder as possible. I would recommend moving it aft as far as possible positioned on the angle of the trailing edge of the rudder and down a bit (may be one rib) from the current location. You may want to round the sharp edges a bit also.

As always worth what you paid for it.

Rick Neilsen

Redrive VW Powered MKIIIC

 On Sun, Apr 27, 2014 at 12:23 PM, Frank Goodnight <frank.goodnight(at)att.net (frank.goodnight(at)att.net)> wrote:

 [quote]--> Kolb-List message posted by: Frank Goodnight <frank.goodnight(at)att.net (frank.goodnight(at)att.net)>

 Hi ,

 I do believe that Boyd is right. However if that doesn't compleatly

 Solve the problem. You might want to try welding up the hole in one or

 both of the mounting tabs for the wing and redrilling the holes in a

 Slightly differently position. Quite a bit of work but it worked for my Firestar.

 Good luck

 Frank.

 Sent from my iPad

 On Apr 27, 2014, at 11:07 AM, "Adam Canterbury" <canterbury.adam(at)gmail.com (canterbury.adam(at)gmail.com)> wrote:

 > --> Kolb-List message posted by: "Adam Canterbury" <canterbury.adam(at)gmail.com (canterbury.adam(at)gmail.com)>

 >

 > That does make sense. I am just trying to work out all the bugs on this airplane that the previous owner neglected. Thanks for the reply.

 >

 >

 >

 >

 > Read this topic online here:

 >

 > http://forums.matronics.com/viewtopic.php?p=422453#422453

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

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[b]

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Sun Apr 27, 2014 9:50 am Post subject: Uncoordinated flight help!

On Sun, Apr 27, 2014 at 11:30 AM, Rick Neilsen <neilsenrm(at)gmail.com (neilsenrm(at)gmail.com)> wrote:

  	  Quote: 	
		  Adam



Frank has introduce another component of trim. It your plane rolls right or left it is a rigging issue that can be resolved by as Frank suggests, buying the Kolb universal bracket that allows the owner to do small adjustments to the angle of attack of one wing and/or aileron trim tabs. These will fix roll tendencies that are countered by lateral pressure on the stick.

  



The trim tab on the rudder counters P factor from the prop under power. You can can get a roll trim issue if you are slipping sideways so you need to know where the issue is.



  You may know this but the trim tab on the rudder doesn't trim the airplane it only moves the rudder in the direction where it will trim the airplane. When installed properly it looks backward. The photo shows the trim tab in less than ideal location. It should be a attached as far aft on the rudder as possible. I would recommend moving it aft as far as possible positioned on the angle of the trailing edge of the rudder and down a bit (may be one rib) from the current location. You may want to round the sharp edges a bit also.

  



As always worth what you paid for it.

Rick Neilsen

Redrive VW Powered MKIIIC

  	  Quote: 	
		  



	




	
All of the previous comments apply, and they better explain your possible fix. My purpose is to show you what I have to counter trim issues with mine, perhaps there will be something there that will help you with your problem. 

 



If you use lexan for your trim tab, it helps with the visibility problem that yours has. I put a much bigger one than I needed and trimmed it down, 1/4 inch at a time with tin snips, until it did no more than was needed to keep the plane flying straight. Lexan can be bent cold with no problem. I used a 2x4 and cut a kerf in it deep enough to get the bend that I needed. Wood does not scratch it. If you have access to a "brake" then protect it with cardboard and you will have something that will better blend in with your paint color.

 Larry





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Adam Canterbury

Joined: 15 Apr 2014
Posts: 7

Posted: Sun Apr 27, 2014 10:17 am Post subject: Re: Uncoordinated flight help!

A lot of great information here. I think that I will take the trim tab off and start from scratch. My problem is not a roll problem. Just yaw.

John Hauck

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

Posted: Sun Apr 27, 2014 2:33 pm Post subject: Uncoordinated flight help!

--> <canterbury.adam(at)gmail.com>



A lot of great information here. I think that I will take the trim tab off

and start from scratch. My problem is not a roll problem. Just yaw.





Adam C/Kolbers:



Looks like the trim tab is on the left side of your rudder.  I am assuming

the prop turns counterclockwise as seen from the rear facing forward.  This

would be the same rotation as a 912.  I don't know what engine you have.

Don't think that is important, but direction of rotation is.



There is a photo attached that shows my trim tab on my MKIII.  The size and

angle centers the ball on my slip/skid indicator, feet off the pedals, at

cruise (80 mph) and most other airspeeds.



The other two photos are of an experimental trim tab that I tested and did

not use.  However, the dimensions are what I have installed.  The squiggly

lines indicate the bottom 1/3 I removed after discovering I had too much

trim tab initially.



The part that rivets to the rudder ribs is 1 7/8" wide.  I used 1/8"

aluminum fabric rivets to attach the trim tab.



The angle is about 30 degrees and the trailing edge is 3 1/8" wide.



Total length is 14".



I have done a lot of experimenting with my MKIII over the past 22 years.

Rudder trim tabs is one of them.  Finally, found the cure for my airplane,

and this is it.



Adverse yaw during cruise flight is caused, primarily, by the way the prop

wash strikes the vertical stabilizer, upper and lower, the rudder, and the

horizontal stabilizer.



It is not necessary to tuft the tail surfaces to find out what is happening

back there during flight.  If you over fill the oil tank or fly in rough

air, there'll be enough oil mist hit the tail section to know right where

the prop wash is going.   Prop wash does not come straight back from the

prop, but has tremendous twist, much like a tornado.  This is what is

constantly hitting the tail surfaces, primarily the left side of the

vertical stab and the top of the left horizontal stab.



When mounting the rudder trim tab, insure the bend is in line with the

trailing edge of the rudder.  Also insure the bottom of the trim tab is

clear of the inboard end of the elevator when the stick is full aft.



The above did not happen overnight.  It took a lot of flying over the years

to nail down what the best fix would be.



This is how I did it.  Not recommending anyone else do it my way.



john h

mkIII

Titus, Alabama

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

Adam Canterbury

Joined: 15 Apr 2014
Posts: 7

Posted: Sun Apr 27, 2014 5:08 pm Post subject: Re: Uncoordinated flight help!

I think I would be well suited to model a new trim tab like yours and go from there. Thanks so much!

Herb Graff

Joined: 21 Sep 2009
Posts: 12

Posted: Sun Apr 27, 2014 7:05 pm Post subject: Uncoordinated flight help!

When you intentionally do a Slip , the ball is all whacked out, because you  are cross-controlled with both ailerons and rudder.

  

 With that in mind, you probably also need aileron trim. Tell. what happens  when you try 

 to fly hands & feet off. The first action of the aircraft  indicates a lot where to start. It takes a careful balancing of both trims to  get it flying straight with the ball in the center. Don't dispair it is a  repetitious process to zero in.

  

 Herb Graff

  

 Mark III N246KT

  

  In a message dated 4/27/2014 11:39:50 A.M. Eastern Daylight Time,  canterbury.adam(at)gmail.com writes:

  	  Quote: 	
		  I have a    Kolb Kolbra and I am needing some advice on how to change the rigging of the    flight controls. I am having to hold a good deal of right rudder in straight    and level flight to get the ball centered. I do have a substantial trim tab on    the rudder. What can be done to correct this problem? I would like for the    plane to fly straight hands off. Is that too much to  ask?

	


 [quote][b]

racerjerry

Joined: 15 Dec 2009
Posts: 202
Location: Deer Park, NY

Posted: Mon Apr 28, 2014 3:01 am Post subject: Re: Uncoordinated flight help!

You might want to identify the source of your problem before applying band-aids.  See if you can borrow a digital protractor to check the wings for mounting at different angles, but also for wing twist along the span.  Tape the protractor to a straight furring strip (1 x 2) that will span the leading and trailing edges of the wing and run it along the underside of the wing to see how much variation you have.  Digital protractors are accurate to one tenth of a degree and also you can zero them at any point to make readings / comparison extremely easy.  Nothing is perfect, but corrections are much better made after you identify the source of the problem.



I hate to say this, but if you purchase a digital protractor from a home store that has a liberal return policy…

Well, the darned things work so well that you will probably want to keep it anyway.

_________________
Jerry King

John Hauck

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

Posted: Mon Apr 28, 2014 3:57 am Post subject: Uncoordinated flight help!

--> <canterbury.adam(at)gmail.com>



I think I would be well suited to model a new trim tab like yours and go

from there. Thanks so much!

 



Adam C/Kolbers:



The latest edition of the Kolb Extra wanted to fly right wing low during

initial flight testing.  Was the weirdest feeling I have ever had in an

airplane.  It did not want to continue to roll right once it got into its

right wing low position.  Could not wait to land and try to figure out what

was going on.  Taped a trim tab on the rudder and she flew straight and

level the next flight.  Which brings up a point.  Duct tape works great

during the initial testing of trim tabs on aileron, elevator, and rudder,

until it is determined what size and where you place them permanently, if at

all.



Getting the Kolb trimmed out works best making no more than one change at a

time.



All MKIII's I am aware of have adverse yaw and require a rudder trim tab to

correct.



john h

mkIII

Titus, Alabama

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

russk50(at)gmail.com
Guest

Posted: Mon Apr 28, 2014 5:03 am Post subject: Uncoordinated flight help!

Adam

You may have a hard-to-diagnose problem, but you've also got a lot of advice.

I would certainly take off the trim tab and all other 'fixes' and fly it to see what the basic problem is. Then add things one at a time & fly it again

And good luck

Russ K 



On Apr 27, 2014, at 2:17 PM, Adam Canterbury wrote:

 

 	  Quote: 	
		   

 

 A lot of great information here. I think that I will take the trim tab off and start from scratch. My problem is not a roll problem. Just yaw.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422467#422467

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Mon Apr 28, 2014 5:42 am Post subject: Uncoordinated flight help!

 Which brings up a point.  Duct tape works greatduring the initial testing of trim tabs on aileron, elevator, and rudder, until it is determined what size and where you place them permanently, if atall.

 



I used "cleeko's" for mine. Worked well with no sitckey residue.

 Larry



On Mon, Apr 28, 2014 at 5:57 AM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:

  	  Quote: 	
		  --> Kolb-List message posted by: "John Hauck" <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)>

  

 

 

 --> Kolb-List message posted by: "Adam Canterbury"

 --> <canterbury.adam(at)gmail.com (canterbury.adam(at)gmail.com)>

 

 I think I would be well suited to model a new trim tab like yours and go

 from there. Thanks so much!

 

 

 

 

 Adam C/Kolbers:

 

 The latest edition of the Kolb Extra wanted to fly right wing low during

 initial flight testing.  Was the weirdest feeling I have ever had in an

 airplane.  It did not want to continue to roll right once it got into its

 right wing low position.  Could not wait to land and try to figure out what

 was going on.  Taped a trim tab on the rudder and she flew straight and

 level the next flight.  Which brings up a point.  Duct tape works great

 during the initial testing of trim tabs on aileron, elevator, and rudder,

 until it is determined what size and where you place them permanently, if at

 all.

 

 Getting the Kolb trimmed out works best making no more than one change at a

 time.

 

 All MKIII's I am aware of have adverse yaw and require a rudder trim tab to

 correct.

 

 john h

 mkIII

 Titus, Alabama

 

 

 

 

 

 ===========

 " target="_blank">http://www.matronics.com/Navigator?Kolb-List

 ===========

 MS -

 k">http://forums.matronics.com

 ===========

 e -

           -Matt Dralle, List Admin.

 t="_blank">http://www.matronics.com/contribution

 ===========

 

 

 

 	




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If you forward this email, or any part of it, please remove my email address before sending.

 

 

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ceengland7(at)gmail.com
Guest

Posted: Mon Apr 28, 2014 7:42 am Post subject: Uncoordinated flight help!

On 4/28/2014 6:01 AM, racerjerry wrote:

 	  Quote: 	
		   



 You might want to identify the source of your problem before applying band-aids.  See if you can borrow a digital protractor to check the wings for mounting at different angles, but also for wing twist along the span.  Tape the protractor to a straight furring strip (1 x 2) that will span the leading and trailing edges of the wing and run it along the underside of the wing to see how much variation you have.  Digital protractors are accurate to one tenth of a degree and also you can zero them at any point to make readings / comparison extremely easy.  Nothing is perfect, but corrections are much better made after you identify the source of the problem.



 I hate to say this, but if you purchase a digital protractor from a home store that has a liberal return policy…

 Well, the darned things work so well that you will probably want to keep it anyway.



 --------

 Jerry King



Most newer smart phones & tablets have free apps available that work 
	


just as well as an expensive digital level. If your device re-orients 

the screen as you turn it from vertical to horizontal, you can probably 

get a digital level app for it. I've been using one on my iphone 4 to 

check all kinds of stuff during my RV-7 build. Not quite as convenient 

as a dedicated tool, but the price is right.



When you check the wings, don't forget to check the ailerons & elevators 

for twist, also. On the planes I normally fly (faster homebuilts), twist 

there can have almost as much effect as a big trim tab.



Charlie

John Hauck

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

Posted: Mon Apr 28, 2014 8:47 am Post subject: Uncoordinated flight help!

Adam C/Kolbers:



Keep it simple.



If it was my airplane, I'd pull off the incorrectly attached rudder trim tab.



Flight test the Kolbra without the tab, then tape on a tab in the correct position.  Continue to adjust the tab and flight test until happy as a lark the adverse yaw problem has flown away.  



I would not concern myself with "rerigging" the airplane until I eliminated the adverse yaw.



john h

mkIII

Titus, Alabama



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

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Wed Apr 30, 2014 2:58 pm Post subject: Uncoordinated flight help!

Adam, Attached is the Kolb factory trim tab drawing.



Rick Girard



On Sun, Apr 27, 2014 at 8:08 PM, Adam Canterbury <canterbury.adam(at)gmail.com (canterbury.adam(at)gmail.com)> wrote:

  	  Quote: 	
		  --> Kolb-List message posted by: "Adam Canterbury" <canterbury.adam(at)gmail.com (canterbury.adam(at)gmail.com)>

  

 I think I would be well suited to model a new trim tab like yours and go from there. Thanks so much!

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=422478#422478

 

 

 

 

 

 

 

 ===========

 " target="_blank">http://www.matronics.com/Navigator?Kolb-List

 ===========

 MS -

 k">http://forums.matronics.com

 ===========

 e -

           -Matt Dralle, List Admin.

 t="_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

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John Hauck

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

Posted: Wed Apr 30, 2014 4:12 pm Post subject: Uncoordinated flight help!

Rick G/Kolbers:

 

I'll be darn.  That factory trim tab looks just like the one I posted a few days ago.

 

john h

mkIII

Titus, Alabama

 

 

 

Adam, Attached is the Kolb factory trim tab drawing.

 



Rick Girard

 



 

  [quote][b]

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

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Wed Apr 30, 2014 7:30 pm Post subject: Uncoordinated flight help!

John, I took the tab off "The Plane from Hell" and tried to fly it. It was okay, if you like flying sideways or getting a big cramp in your left leg trying to make the airplane fly straight. Put it back per the Kolb plans and the aircraft was once again easy to fly and keep the yaw string centered. I only wish I'd been able to put my engine on it and test that configuration. 



Rick



On Wed, Apr 30, 2014 at 7:12 PM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:

  	  Quote: 	
		  

Rick G/Kolbers: 

 

I'll be darn.  That factory trim tab looks just like the one I posted a few days ago. 

 

john h 

mkIII

Titus, Alabama 

 

  

 

Adam, Attached is the Kolb factory trim tab drawing. 

 



Rick Girard 

 



  

   	  Quote: 	
		  



get="_blank">http://www.matronics.com/Navigator?Kolb-List

tp://forums.matronics.com

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-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

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