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In flight Adjustable Trim
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elleryweld(at)aol.com
Guest

Posted: Mon Feb 15, 2010 5:54 pm Post subject: In flight Adjustable Trim

Has anyone on the list ever thought of designing something to adjust the horizontal stabilizers like on a cub to trim a Kolb it just makes more sense to me because it would be a positive trim and not make more drag , the spring system just doesn't work as great as it should for me the air temps change so much  the springs are not consistent enough for me. 

   I rebuilt the elevators on my old firestar a few years ago and built a inflight trim tab into one of the elevators  with great results, but that would make more drag than a stabilizer trim system what are your opinions ?

    

   The reason I ask, I am working on a electric project to do just this on a Kolb Mk3 it might be a waste of my time but I have to try it  anyway thanks for your time and input.   

 

 Ellery Batchelder Jr.

    

   Kolb Mk3C

   N213, 582 Rotax

   Garmin AERA

   

 

 

   --

planecrazzzy
Guest

Posted: Tue Feb 16, 2010 7:38 am Post subject: Re: In flight Adjustable Trim

Wittman had a simple trim system that works... 



 Here's some pictures of mine... I can give you more details if you need them.

.

.

           Gotta Fly...

Mike & "Jaz"



Building Wittman "Buttercup" w/Lycoming 0-235

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Eugene Zimmerman

Joined: 10 Jan 2006
Posts: 392

Posted: Tue Feb 16, 2010 1:56 pm Post subject: Re: In flight Adjustable Trim

Ellery,



My experience at pitch trimming the kolb plane using adjustable horizontal stabilizers has been totally unsatisfactory. I believe the reason for this is because of the specific triangular shape of  stab which reduces the surface area of the stab to near zero at the outer point of the stab.



On my plane I needed more nose up trim, so I  tried lowering the leading edge of the stab. The result was totally unsatisfactory. It merely made the elevator have a natural  downward  deflection to remain aligned with the air flow as it passed over the stab. It actually now required even more  back stick pressure to keep the nose up and it was less efficient  because the stab and the elevator were now misaligned with a  combined camber that is opposite what is necessary for the downward direction of the force on the tail to raise the nose.



I attached an in-flight picture where you can see this opposite camber of the stab & elevator  necessary  to produce downward force of the tail. 



Against all intuition  I then raised the leading edge of the horizontal stab to align with the natural inflight position of elevator and much to my amazement it improved the trim greatly.



I did eventually add an in-flight adjustable tab to the elevator which is much more effective and efficient at aerodynamically changing pitch trim, though I'm not saying it is better than adjustable spring  tension to the mechanical linkage of the stock kolb elevator.



My conclusion is that trying to use adjustable stab incidence for pitch control on a Kolb is ineffective and a wast of time and effort.



Merely sharing my experience.



Gene Z

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Eugene Zimmerman

Joined: 10 Jan 2006
Posts: 392

Posted: Tue Feb 16, 2010 7:33 pm Post subject: In flight Adjustable Trim

Ellery,



My experience at pitch trimming the kolb plane using the horizontal stabilizers has been totally unsatisfactory. I believe the reason for this is because of the specific triangular shape of  stab which reduces the surface area of the stab to near zero at outer the point of the stab.

On my plane I needed more nose up trim, so I  tried lowering the leading edge of the stab. The result was totally unsatisfactory. It merely made the elevator have a natural  downward  deflection to remain aligned with the air flow as it passed over the stab. It actually now required as much or even more  back stick pressure to keep the nose up and it was less efficient  because the stab and the elevator were now misaligned with an opposite camber for the necessary direction control force to raise the nose.

I attached an in-flight picture where this opposite camber of the stab & elevator  to produce downward force of the tail can be seen. 

Against all intuition  I then raised the leading edge of the horizontal stab to align with the natural inflight position elevator and much to my amazement it improved the trim greatly.

I did eventually add an in-flight adjustable tab to the elevator which is much more effective and efficient at aerodynamically changing pitch trim, though I'm not saying it is better than adjustable spring  tension to the mechanical linkage of the stock kolb elevator.

Merely sharing my experience.

Gene Z

[img]cid:22C990AB-7E63-4C70-8CB3-3F688516F208[/img]

On Feb 15, 2010, at 8:51 PM, Ellery Batchelder Jr wrote:

 	  Quote: 	
		  Has anyone on the list ever thought of designing something to adjust the horizontal stabilizers like on a cub to trim a Kolb it just makes more sense to me because it would be a positive trim and not make more drag , the spring system just doesn't work as great as it should for me the air temps change so much  the springs are not consistent enough for me.

I rebuilt the elevators on my old firestar a few years ago and built a inflight trim tab into one of the elevators  with great results, but that would make more drag than a stabilizer trim system what are your opinions ?

 

The reason I ask, I am working on a electric project to do just this on a Kolb Mk3 it might be a waste of my time but I have to try it  anyway thanks for your time and input.   



Ellery Batchelder Jr.

 

Kolb Mk3C

N213, 582 Rotax

Garmin AERA

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elleryweld(at)aol.com
Guest

Posted: Tue Feb 16, 2010 7:40 pm Post subject: In flight Adjustable Trim

Eugene

   thanks for your input  that's the kind of info I was looking for, someone that has tried it. 

   I had my old firestar able to fly hands off long distance with a trim tab in the elevator I want to make my Mk3 fly as well ,if I let go of the stick it wants to take a dive  the way it is now and I don't like it that way i am just trying to figure out the best way to correct it.  

 

     Ellery Batchelder Jr.

 

 

 

   --

Dana

Joined: 13 Dec 2007
Posts: 1047
Location: Connecticut, USA

Posted: Wed Feb 17, 2010 4:17 am Post subject: In flight Adjustable Trim

I added prebent aluminum tabs to my UltraStar to trim for a slow cruise, then a bungee system to add more down elevator for normal cruise, and to compensate as fuel burns:



 http://img.photobucket.com/albums/v486/flyparafan/Kolb/elevator_trim.jpg



 When I move the fuel tanks from in front of to behind the seat I'm hoping I can back off on one or both of the tabs, but I'll keep the bungee arrangement for inflight adjustment.



 -Dana

 --

  The citizens of the United States are getting the government they deserve. The problem is that I'm also getting the government they deserve.    [quote][b]

zeprep251(at)AOL.COM
Guest

Posted: Wed Feb 17, 2010 4:51 am Post subject: In flight Adjustable Trim

Gene,

 Using your picture as a guide,it appears that reflexing the ailerons might be helpful in reducing that forward pitch tendency.

 G.Aman

 

   

 

  

   

 

   

 

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elleryweld(at)aol.com
Guest

Posted: Wed Feb 17, 2010 6:11 am Post subject: In flight Adjustable Trim

Nice looking ultrastar you have there  but theres  quite a difference from that to a MK3  I just want a more sufisticated way of triming my plane than a bungie 

     	  Quote: 	
		  	


 

 

     Ellery Batchelder Jr.

 

 

 

   --

John Hauck

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

Posted: Wed Feb 17, 2010 6:22 am Post subject: In flight Adjustable Trim

Ellery B/Gang:

  

 I fabricated a trim wheel for forced pitch trim.  Mounted  it just forward the throttle handle.

  

 Most mkIII's need nose up trim only.

  

 Only time my mkIII needs nose up trim is under cruise  power.  Lower power settings, the aircraft is about neutral with a 12  lb Maule Tundra Tailwheel and my main gear modification which moved the main  gear forward about 8 inches.

  

 I use Kolb Company recommended pair of heavy springs  on the up side and a very light spring on the down side, with 1/16" aircraft  cable from springs to trim wheel/pulley.

  

 I guess it still works.  Have flown about 5 hours since I  returned from Homer's funeral 19 July 2009.  

  

 Al Gump has screwed up our global warming in Alabama.   Hanging at 32F.

  

 john hauck

 mkIII

 Titus, Alabama

  

  

 [quote]    

Nice looking    ultrastar you have there  but theres  quite a difference from that    to a MK3  I just want a more sufisticated way of triming my plane than a    bungie 

       	  Quote: 	
		  	


      Ellery Batchelder    Jr.



 [b]

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

rickofudall

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

Posted: Wed Feb 17, 2010 7:03 am Post subject: In flight Adjustable Trim

Ellery, Check the aileron and flap rigging, the only have to be down a fraction of a degree to get that effect. Set the trim in the middle, fly, then adjust rigging to get neutral trim. Worked for me.



Rick Girard

 

On Tue, Feb 16, 2010 at 5:15 PM, Ellery Batchelder Jr <elleryweld(at)aol.com (elleryweld(at)aol.com)> wrote:

[quote]  Eugene

   thanks for your input  that's the kind of info I was looking for, someone that has tried it. 

   I had my old firestar able to fly hands off long distance with a trim tab in the elevator I want to make my Mk3 fly as well ,if I let go of the stick it wants to take a dive  the way it is now and I don't like it that way i am just trying to figure out the best way to correct it.  

  

     Ellery Batchelder Jr.

 

 

 

   

--

_________________
The smallest miracle right in front of you is enough to make you happy....

smlplanet(at)msn.com
Guest

Posted: Wed Feb 17, 2010 7:39 am Post subject: In flight Adjustable Trim

I had the same problem, flying solo I was fine hands off but duel I had to hold forward pressure on the stick and made landings tricky. I bought and adjustment from Kolb ( to expensive plus needs more position holes ) but did the trick so long as you remember to change the pin location. I have an elect. trim that I getting ready to install to be able to adjust for the extra weight of the larger fuel tank i'm installing. I am using a boat trim indicator so that I can always see where it is and adjust in flight as needed.     

Date: Wed, 17 Feb 2010 07:02:47 -0800

Subject: Re: Re: In flight Adjustable Trim

From: aslsa.rng(at)gmail.com

To: kolb-list(at)matronics.com

Ellery, Check the aileron and flap rigging, the only have to be down a fraction of a degree to get that effect. Set the trim in the middle, fly, then adjust rigging to get neutral trim. Worked for me.

Rick Girard

On Tue, Feb 16, 2010 at 5:15 PM, Ellery Batchelder Jr <elleryweld(at)aol.com (elleryweld(at)aol.com)> wrote:

[quote]  Eugene

   thanks for your input  that's the kind of info I was looking for, someone that has tried it. 

   I had my old firestar able to fly hands off long distance with a trim tab in the elevator I want to make my Mk3 fly as well ,if I let go of the stick it wants to take a dive  the way it is now and I don't like it that way i am just trying to figure out the best way to correct it.  

     Ellery Batchelder Jr.

--

Eugene Zimmerman

Joined: 10 Jan 2006
Posts: 392

Posted: Wed Feb 17, 2010 8:28 am Post subject: Re: In flight Adjustable Trim

Kolb pilot friends,



Yes, pitch trim may be adjusted via aileron rigging ,,,, but normally not while in-flight.   This means the airplane  is ideally  trimmed  for only one specific airspeed,  power setting, and payload.

Change any one of these conditions and the airplane becomes out of trim again. 

Hence the convenience of having adjustable  in-flight pitch trim.



Gene Z

John Hauck

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

Posted: Wed Feb 17, 2010 8:45 am Post subject: In flight Adjustable Trim

Hence the convenience of having adjustable  in-flight pitch trim.



Gene Z

Gene Z/Gang:



I lucked out with my Firestar.  I needed a little help trimming in pitch, 

roll, and yaw.  Did not know what the results would be when I fabricated 

fixed trim tabs from .015" 6061 aluminum sheet for the right aileron, left 

elevator, and rudder.  The thin sheet metal was easy to tweak to get the FS 

dialed in and trimmed up.  The result was, in fact, mind boggling.  My FS 

was always trimmed, not matter how it was loaded (I was doing a lot of long 

multi-day cross country flights with camping gear, clothes, etc., plus 18 

gal fuel, another 108 lbs) or what speed I flew.  It would hold a nice steep 

Kolb climb hands off on takeoff, zero stick pressure during cruise and other 

areas of flight.  Undoubtedly, the thin sheet metal would flex enough to 

compensate for airspeed.



Wish I could get Miss P'fer (P fer plane) my mkIII to trim out like that. 





john hauck

mkIII

Titus, Alabama

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

smlplanet(at)msn.com
Guest

Posted: Wed Feb 17, 2010 8:53 am Post subject: In flight Adjustable Trim

I agree but like some of the plane spraying and in my case XC the trim will change as fuel is used.

Now I have to land and change the adjustment to fly hands off ( with out appling pressure to the stick)  I like having my hands free when I have to ( drink coffee or use the camera and video)

I like flying low over  the Gulf of Mexico looking at the schools of fish, shark, rays and any thing of interest. 



[quote] Subject: Re: In flight Adjustable Trim

 From: etzimm(at)gmail.com

 Date: Wed, 17 Feb 2010 08:28:36 -0800

 To: kolb-list(at)matronics.com

 

 --> Kolb-List message posted by: "Eugene Zimmerman" <etzimm(at)gmail.com>

 

 Kolb pilot friends,

 

 Yes, pitch trim may be adjusted via aileron rigging ,,,, but normally not while in-flight.   This means the airplane  is ideally  trimmed  for only one specific airspeed,  power setting, and payload.

 Change any one of these conditions and the airplane becomes out of trim again. 

 Hence the convenience of having adjustable  in-flight pitch trim.

 

 Gene Z

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=286806#286806

 

 

 

 

 

 <=========

 

 

 

 		 	   		     	  Quote: 	
		  [b]

elleryweld(at)aol.com
Guest

Posted: Wed Feb 17, 2010 12:40 pm Post subject: In flight Adjustable Trim

Thanks I will give that a try before I go spending a bunch of time and money on other designs

 

     Ellery Batchelder Jr.

 

 

 

   --

Richard Pike

Joined: 09 Jan 2006
Posts: 1670
Location: Blountville, Tennessee

Posted: Wed Feb 17, 2010 1:02 pm Post subject: Re: In flight Adjustable Trim

 	  elleryweld(at)aol.com wrote: 	
		  Has anyone on the list ever thought of designing something to adjust the horizontal stabilizers like on a cub to trim a Kolb it just makes more sense to me because it would be a positive trim and not make more drag , the spring system just doesn't work as great as it should for me the air temps change so much  the springs are not consistent enough for me. 

   I rebuilt the elevators on my old firestar a few years ago and built a inflight trim tab into one of the elevators  with great results,ï¿½but that would make more drag than a stabilizer trim system what are your opinions ?

    

   The reason I ask, I am working on a electric project to do just this on a Kolb Mk3 it might be a waste of my time but I have to try itï¿½ anyway thanks for your time and input.   

 

 Ellery Batchelder Jr.    

   Kolb Mk3C

   N213, 582 Rotax

   Garmin AERA 

   -- 	




You might want to think about modifying the flap handle mechanism a bit. By being able to either reflex or slightly lower the flaps just a little, the rest of the trim system hardly has to work at all to get things in trim. I can carry a heavy passenger, and by reflexing the flaps up a notch at cruise, the up elevator trim is then only about 30% of normal.

Here is a link to how I did mine, but I would think that if you overlaid the standard curved piece of steel that has 3 big vertical slots cut in it with a new one that had multiple horizontal slots instead, and then attached a horizontal piece of steel to the flap handle that would click into the slots, you could do it even easier. (I tend to over complicate stuff, so there is probably an easier way...) As long as it doesn't tend to pop out of the slots, almost  any crude and simple system is ok.

http://www.bcchapel.org/pages/0003/pg3.htm

Richard Pike

MKIII N420P (420ldPoops)

elleryweld(at)aol.com
Guest

Posted: Wed Feb 17, 2010 7:22 pm Post subject: In flight Adjustable Trim

that gives me an Idea I have an electric actuator  now Im thinking I should install that and set it up so I can go a tad negative on the flaps and make the flaps electric, get two birds with one shot.  

   I really like this list even if it makes my mind go to another world once in a while you guys are always interesting,help full and full of things I cant seem to think of once in a while 

   and its really nice to not have any bickering 

 

     	  Quote: 	
		   	  Quote: 	
		  	
	


 

 

     Ellery Batchelder Jr.

 

 

 

   --

icrashrc

Joined: 16 Mar 2006
Posts: 247
Location: Mishawaka, In

Posted: Thu Feb 18, 2010 3:31 am Post subject: Re: In flight Adjustable Trim

You mean like this?



http://www.ill-eagleaviation.com/electric_flap_drive.htm



 	  elleryweld(at)aol.com wrote: 	
		  that gives me an Idea I have an electric actuator  now Im thinking I should install that and set it up so I can go a tad negative on the flaps and make the flaps electric, get two birds with one shot.  

   I really like this list even if it makes my mind go to another world once in a while you guys are always interesting,help full and full of things I cant seem to think of once in a while 

   and its really nice to not have any bickering 

 

    

     Ellery Batchelder Jr.

 

  

   --

_________________
Scott

www.ill-EagleAviation.com

do not archive

elleryweld(at)aol.com
Guest

Posted: Thu Feb 18, 2010 6:48 am Post subject: In flight Adjustable Trim

Thats what I have in my hand but the one I have is longer,  I have the website handy so I can get what I need if it needs to be a short one

     	  Quote: 	
		   	  Quote: 	
		  	
	


 

 

     Ellery Batchelder Jr.

 

 

 

   --

John Hauck

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

Posted: Thu Feb 18, 2010 6:48 am Post subject: In flight Adjustable Trim

You mean like this?



http://www.ill-eagleaviation.com/electric_flap_drive.htm

 Scott



Scott/Gang:



How fast is the actuator through full travel?



The MKIII doesn't like to climb with full or half flaps.  Climbs much better 

clean.



I like the almost instantaneous capability of going from full flaps in 

landing configuration to climbing out clean in a go around situation.



Infinite adjustment of flap angle might be fun to play with in the air.



Global warming is ruining my flying.  My airplane needs to be washed when 

the ice in the bucket and the hose thaws.



john hauck

mkIII

Titus, Alabama

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

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