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mdnanwelch7(at)hotmail.co
Guest

Posted: Sun Dec 02, 2007 10:46 pm Post subject: Elevator trim tab information needed

Hello Kolb guys and girls,



   I have a question regarding the elevator trim on a MkIII.  Is there anyone that actually built a trim tab INTO the elevator?  (Rather than adding it on!)



  What I'm getting at is, I am seriously considering building a "built-in" elevator trim tab, most likely with electric adjustment.  Has anyone done this already?  And, does anyone have an idea of the dimensions that a MkIII elevator trim tab would need to be?



  As I have recommended in the past, the motorcycle exhaust servo motor could make a perfect electric trim motor.

Some come with cable assemblies, and mounting tabs.  These are very durable, high torque, 12volt, small servo motors.  I have one similar to this.  It would be very easy to attach the cables to a bellcrank.

http://cgi.ebay.com/ebaymotors/06-GSX-R1000-GSX-R-exhaust-servo-motor-engine_W0QQitemZ310002541330QQihZ021QQcategoryZ35591QQssPageNameZWDVWQQrdZ1QQcmdZViewItem



  Any thoughts on the subject would be much appreciated.       Mike Welch  MkIII



BTW.  Many thanks to the people that offered lots of advice regarding cutting and drilling Lexan (especially Rick G.'s drill bit drawing)  I am happy to say, I am virtually finished with all the "glass" (Lexan).  OMG, THAT was a lot of work!!!   Cleco it on.  Uncleco, sand it some.  Cleco it back on, check for fit, again, uncleco it, etc, etc, etc, etc.  



  

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ElleryWeld(at)aol.com
Guest

Posted: Sun Dec 02, 2007 11:21 pm Post subject: Elevator trim tab information needed

Mike 

 I  Built a trim tab into one of the elevators on my Firestar like your talking about it worked great  it was 3"X 12" controllable in flight, I sold the Plane to a Guy in Minnesota but I think I have a pic somewhere of the modification I did on it.

 I think theirs PICS in the archives I did of this mod.

 I could us the trim alone to land the plane  of course in perfect conditions no gusting x winds 

  

 Ellery In Maine Building MK3Xtra

  

 do not archive



hottest products and top money wasters of 2007.

  [quote][b]

mdnanwelch7(at)hotmail.co
Guest

Posted: Mon Dec 03, 2007 7:02 am Post subject: Elevator trim tab information needed

Hi Ellery,



   Thanks for the reply on the trim tab.  Was the one you built on the Firestar electrically operated?  Do you plan the same type of tab on the Xtra you're building?  Why was the trim tab on Crystal's MkII so huge?  



  I will check the archives.  If you come across that photo of the tab you built, I'd sure appreciate it if you sent it to me.  Do you think 3" X 12" would be big enough for a MkIII, of should it be more like 4" X 14"?  Or whatever?



                                                 Thanks,   Mike Welch





________________________________



From: ElleryWeld(at)aol.com

Date: Mon, 3 Dec 2007 02:20:52 -0500

Subject: Re: Elevator trim tab information needed

To: kolb-list(at)matronics.com



Mike



I  Built a trim tab into one of the elevators on my Firestar like your talking about it worked great  it was 3"X 12" controllable in flight, I sold the Plane to a Guy in Minnesota but I think I have a pic somewhere of the modification I did on it.



I think theirs PICS in the archives I did of this mod.



I could us the trim alone to land the plane  of course in perfect conditions no gusting x winds



Ellery In Maine Building MK3Xtra



do not archive



________________________________



hottest products and top money wasters of 2007.





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cartejy(at)mtn-state.com
Guest

Posted: Mon Dec 03, 2007 7:45 pm Post subject: Elevator trim tab information needed

Mike,I have a Firestar,,,with built in Electric Trim....works real 

well,,very efective & easyto manage. I will put some info & pics out to you 

on the site. 503...KXP & located in East :Liverpool Ohio,I will get some 

photos & how done & what. get at it soon as can..hope it helps. Jay Carter 

N90485..Firestar Exp --

olendorf

Joined: 06 Jul 2006
Posts: 140
Location: Schenectady, NY USA

Posted: Tue Dec 04, 2007 6:02 am Post subject: Re: Elevator trim tab information needed

Jay,  That's some Firestar you have there!  How does that RAMJET engine perform?  Must be a blast.    



Here is the aircraft info from airport-data.com



Aircraft N90485 Profile



Aircraft (FAA)

Manufacturer: Washburn Ron 

Model: FIRESTAR KXP    Search all Washburn Ron FIRESTAR KXP 

Year built: 1991 

Serial Number (C/N): 297 

Mode S Code: 53100626 

Aircraft Type: Fixed wing single engine 

Amateur-Built: Yes 

Number of Seats: 1 

Number of Engines: 1 

Engine Type: Ramjet 

Engine Manufacturer and Model: Ama/expr UNKNOWN ENG

_________________
Scott Olendorf
Original Firestar, Rotax 447, Powerfin prop
Schenectady, NY
http://sites.google.com/site/kolbfirestar/

mdnanwelch7(at)hotmail.co
Guest

Posted: Tue Dec 04, 2007 7:07 am Post subject: Elevator trim tab information needed

Jay, 

  

   Thanks for whatever info you can send.  Scott O. refers to "nice looking plane", but I didn't see any photos, or a link to photos.

  

   I'm also considering making the trim tab adjustable with possibly a cable like Ellery suggested.

  

   Thanks,   MIke Welch  MkIII   (I'll go look at the Kolb list photo site, to see if they're there) 

  

  

  

  

  

  

 

[quote] Mike,I have a Firestar,,,with built in Electric Trim....works real 

 well,,very efective & easyto manage. I will put some info & pics out to you 

 on the site. 503...KXP & located in East :Liverpool Ohio,I will get some 

 photos & how done & what. get at it soon as can..hope it helps. Jay Carter 

 N90485..Firestar Exp 

Connect and share in new ways with Windows Live. Connect now!   	  Quote: 	
		  [b]

John Hauck

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

Posted: Tue Dec 04, 2007 7:39 am Post subject: Elevator trim tab information needed

Mike W:

  

 Thought you may be interested in the following NTSB  fatal accident report:

  

 http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001211X11253&key=1

  

 Standard forced pitch trim works well on the  MKIII.

  

 For what it is worth,

  

 john h

 hauck's holler, alabama

  

  

 [quote]     

  I'm also considering    making the trim tab adjustable with possibly a cable like Ellery    suggested.

 

  Thanks,   MIke Welch     MkIII   (I'll go look at the Kolb list photo site, to see if they're    there) 

 

[b]

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

mdnanwelch7(at)hotmail.co
Guest

Posted: Tue Dec 04, 2007 8:02 am Post subject: Elevator trim tab information needed

Wow.  Thanks, John, for the article on the trim accident.  I guess that is basically my concern, which is: how effective and accurate is the adjustment on the present design?



  Maybe I should leave well enoungh alone.                             Mike



Do Not Archive





________________________________



From: jhauck(at)elmore.rr.com

To: kolb-list(at)matronics.com

Subject: Re: Elevator trim tab information needed

Date: Tue, 4 Dec 2007 09:38:50 -0600



Mike W:



Thought you may be interested in the following NTSB fatal accident report:



http://www.ntsb.gov/ntsb/brief.asp?ev_id 001211X11253&key=1



Standard forced pitch trim works well on the MKIII.



For what it is worth,



john h



hauck's holler, alabama



  I'm also considering making the trim tab adjustable with possibly a cable like Ellery suggested.



  Thanks,   MIke Welch  MkIII   (I'll go look at the Kolb list photo site, to see if they're there)



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JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Tue Dec 04, 2007 8:46 am Post subject: Re: Elevator trim tab information needed

I am also going to add electric trim to my Kolb MK-III Xtra.   As shown in the accident report you need to be careful, but there is no reason not to do it.  Many experimental / Ultralight airplanes have "Real" trim tabs, I like this a lot better than the spring adjustment, as almost all certified aircraft prove, this is the better way to trim an airplane.  On a kolb it also gives you the ability to trim down and it also gives a back up to broken elevator cables, attachments etc.



Number one, I will be adding counterweights to my elevators when I add the trim tab, similar to the ones on the ailerons to eliminate the possibility of flutter.   Stock, the elevator cables act as the counterbalance for the elevator and keep it from fluttering, but this may not be enough with the added weight of a trim tab and actuator.



Having a trim tab come free in flight can be disastrous, and induce flutter, it has happened on certified airplanes plenty of times.   There is a purpose built electric trim actuator for experimental aircraft made by Ray Allen company, I have flown with it on another experimental similar to the Kolb ( Skyboy ) with these electric trim on both the rudder and elevator and its WONDERFUL !!!   Its just so nice to do patterns, and just move the hat switch for trim in both axis and fly hands off whenever you like, like a real airplane !



Given the critical nature of trim tabs, and the possibility of disastrous results, I would highly recommend using trim tabs that are designed for aircraft.   They are expensive, but not unreasonable.  You can look at them at the link below.



http://www.rayallencompany.com/products/trimsystems.html



Mike Bigelow

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

Kolb MK-III Xtra, 912-S

capedavis(at)yahoo.com
Guest

Posted: Tue Dec 04, 2007 9:51 am Post subject: Elevator trim tab information needed

Mike , I had a firestar KXP with a trim tab sold to me for around 100 dollars by Rans it was an alum formed tab which I cut down from 24x 4 inches to about b14x4inches  and it was adjusted by cable with a wheel about 6 inches in diameter mounted iin the cockpit , mine was on the cockpit frame just ahead of the throttle and was adjusted like the trim on my Dads 1959 Cessna 172 , Roll it forward the  nose went down , Roll it backward the nose comes up , and I was taking alot of Aeriel Photos and I could set the trim at any throttle setting to fly hands off , it worked for me for about 500 hrs . Hope this info is helpful , I don't know if  Rans still offers this but the installation and the use of it was an easy lesson in aircraft construction. Chris



 ---

herbgh

Joined: 10 Jan 2006
Posts: 145

Posted: Tue Dec 04, 2007 9:55 am Post subject: Elevator trim tab information needed

near as I know,.,,horizontal trim tab does not have to be on the

elevator... that would likely be the most effective spot however...



   Stick it on the vertical stab.. or on the horizontal stab..outboard

end on the side that creates a bit of drag to assuage the p factor...??

Herb 

On Tue,  4 Dec 2007 08:46:51 -0800 "JetPilot" <orcabonita(at)hotmail.com>

writes:

 	  Quote: 	
		   

 

 I am also going to add electric trim to my Kolb MK-III Xtra.   As 

 shown in the accident report you need to be careful, but there is no 

 reason not to do it.  Many experimental / Ultralight airplanes have 

 "Real" trim tabs, I like this a lot better than the spring 

 adjustment, as almost all certified aircraft prove, this is the 

 better way to trim an airplane.  On a kolb it also gives you the 

 ability to trim down and it also gives a back up to broken elevator 

 cables, attachments etc.

d-m-hague(at)comcast.net
Guest

Posted: Tue Dec 04, 2007 11:19 am Post subject: Elevator trim tab information needed

At 12:52 PM 12/4/2007, herbgh(at)juno.com wrote:

 	  Quote: 	
		  



near as I know,.,,horizontal trim tab does not have to be on the

elevator... that would likely be the most effective spot however...



    Stick it on the vertical stab.. or on the horizontal stab..outboard

end on the side that creates a bit of drag to assuage the p factor...??


	


A trim tab mounted to a fixed surface needs to be much larger.  When you 

put the tab on the elevator, the tab moves the elevator, and the elevator 

does the work of trimming the plane, so the tab is relatively small.  When 

the tab is mounted to a fixed surface (or separately mounted like the early 

Taylorcrafts and the Smith Miniplane), the tab has to do all the work 

directly and thus must be much larger.



-Dana

--

  Why are there Interstate highways in Hawaii?

John Hauck

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

Posted: Tue Dec 04, 2007 12:03 pm Post subject: Elevator trim tab information needed

> Wow.  Thanks, John, for the article on the trim accident.  I guess that 

is basically my concern, which is: how effective and accurate is the 

adjustment on the present design?

 	  Quote: 	
		  

  Maybe I should leave well enoungh alone.                             Mike


	




Mike W:



It would be interesting to know how many successful hours of flight have 

been put on the MKIII design since it was first produced in late 1991.  For 

that matter, it would also be interesting to know how many Kolbs have been 

built, how many were flown successfully, and how many are being flown 

successfully now, and for how long.



My mkIII is serial number M3-011.  It was the first complete cage Brother 

Jim welded up when we were staying with Homer and Clara Kolb last of 1990 

and early part of 1991.  I personally inspected the first 40 or 50 MKIII 

fuselages that came off the line, was part of my daily chores during the 

time we spent building my MKIII during the evening hours.



I can assure you the pitch trim system of the MKIII is more than adequate 

and safe.  If it wasn't, I would not be flying my MKIIII with it, and you 

would be hearing the screaming and moaning of those unhappy souls who were 

having problems with it.



I am continually amazed at people who are redesigning their Kolb aircraft 

when they have little or no time flying it of any other Kolb.  I never 

changed a thing on any of the three Kolb airplanes I built before I had 

flown and gained good solid experience in them, enough experience to know 

what was needed and how to go about accomplishing the task that was 

required.



One point on adding "stuff" to the trailing edge of the elevators.  The Kolb 

elevator is hinged on the leading edge and not at all balanced.  Why they do 

not have a tendency to flutter, I do not know.  However, in the case of the 

fatality I referenced, he had added more weight to the trailing edge which 

probably got him into trouble with flutter before the trim tab seperated. 

The original Twinstar used this elevator trim system.  It was changed to the 

present system used on the MKIII because it was proven to be a better 

design.



Take care,



john h

mkIII 2,700+ hours

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

planecrazzzy
Guest

Posted: Tue Dec 04, 2007 2:47 pm Post subject: Re: Elevator trim tab information needed

Jet Pilot is a big fat moron

.

.

.

Last edited by planecrazzzy on Thu Jul 31, 2008 12:36 pm; edited 1 time in total

John Hauck

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

Posted: Tue Dec 04, 2007 3:31 pm Post subject: Elevator trim tab information needed

Hi Mike B:



Interesting post on trim tabs.



 "Stock, the elevator cables act as the counterbalance for the elevator and 

keep it from fluttering,"



You will have to explain the above to me a little bit better.  I do not 

understand how cables counter balance the elevators.



"> I have flown with it on another experimental similar to the Kolb ( 

Skyboy ) with these electric trim on both the rudder and elevator and its 

WONDERFUL !!!   Its just so nice to do patterns, and just move the hat 

switch for trim in both axis and fly hands off whenever you like, like a 

real airplane !"



I use a fixed rudder trim tab and have no requirement for an adjustable one. 

Same was true with my FS and US.  Far as I know my MKIII still flies like a 

"real" airplane without the luxury of Chinese Hat trim switch.  



Take care,



john h

mkIII

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

planecrazzzy
Guest

Posted: Tue Dec 04, 2007 4:25 pm Post subject: Re: Elevator trim tab information needed

Jet pilot is a moron

.

.

.

.

Last edited by planecrazzzy on Thu Jul 31, 2008 12:35 pm; edited 1 time in total

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Tue Dec 04, 2007 7:08 pm Post subject: Re: Elevator trim tab information needed

An electric trim does not cause flutter.   A failure that would drive an electric motor back and fourth is unheard of, they may run away to one stop or the other, but rapidly back and fourth no.  Even on the billion to one chance you could induce a back and fourth failure in electric trim, the mechanism is not capable of moving the trim tab anywhere near fast enough to cause flutter.  Bottom line is this is never going to happen. What does cause flutter in a trim tab is it coming loose from its actuator.   A free floating trim tab will induce flutter very quickly, and has happened many times in both certified and experimental.



Mounting a trim tab on the end of the vertical or horizontal stab is a nothing short of a horrible idea.  First you add stress to the outboard of those surfaces, the worst place structurally that you possibly can.  The tabs would also be very inefficient, big, and heavy.  There is a very good reason that you never see come crazy setup like this on certified airplanes.



Trim tabs on control surfaces work very well, and when you have an electric actuator on the stick, it makes a very ergonomic nice to fly airplane.   Before adding trim tabs though, you do need to do your homework and make sure you are not going to make a mistake that is going to kill you.   The electric trim tabs on the Skyboy that I flew were not in the design, but they were well worth the effort and made a very nice flying airplane out of it.   The work was done by some airline mechanics that knew what they were doing.  I will be copying their installation on my plane.  I have gotten every bit of information on trim tabs that I can, and am confident that my Kolb would be a much nicer airplane to fly with them.   John H is correct, modifying a known design is risky and not done correctly could be fatal, so I would recommend that no one try this type of modification unless they do proper research and have the ability to do it correctly.



Mike Bigelow

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

Kolb MK-III Xtra, 912-S

slyck(at)frontiernet.net
Guest

Posted: Wed Dec 05, 2007 6:00 am Post subject: Elevator trim tab information needed

The first time I laid eyes on the MkIII trim system I also thought it  

was a goofy looking contraption.

But being much too busy rebuilding the plane, I was willing to give  

it a try.



Works perfect. I think the reason for no flutter problems is that the  

entire horizontal assembly,

including the elevator is under load.  If you used a tab you might  

actually reduce that load

in the wrong place and end up with flutter.



Looks better too without extra crap hanging outside.

BB, plowed out from one foot of white stuff.

planecrazzzy
Guest

Posted: Wed Dec 05, 2007 4:01 pm Post subject: Re: Elevator trim tab information needed

Oooooh,

             I see , you know everything....and "I'm" a liar



     Whatever...

.

.

 Gotta Fly...

.

.

.

 





 	  JetPilot wrote: 	
		  An electric trim does not cause flutter.   A failure that would drive an electric motor back and fourth is unheard of, 

Mike Bigelow

Michael Sharp

Joined: 10 Jan 2006
Posts: 118
Location: Oak Grove, MO (Kansas City)

Posted: Wed Dec 05, 2007 6:41 pm Post subject: Elevator trim tab information needed

No Mike, YOU ARE NOT!

   

  I've seen several of electric motors flutter back and forth... 

   

  Seems to me that if someone wants a "real airplane" maybe they should have bought one...

   

  Mike

  do not archive



planecrazzzy <planecrazzzy(at)yahoo.com> wrote:

  

Oooooh,

I see , you know everything....and "I'm" a liar



Whatever...

_________________
The air up there in the clouds is very pure and fine...And why shouldn't it be?-
--It is the same the angels breathe.
Mark Twain,
Roughing it' 1886

Mike

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