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biglar

Joined: 14 Jan 2006
Posts: 457

Posted: Wed Nov 29, 2006 4:37 pm Post subject: Dual Elevator Cables

While thinking on this topic, I'll refer you to a page of my website.  Take 

a look about 1/2 way down the page.............



http://www.biglar.homestead.com/STARTINGTHECABIN.html



Larry Bourne

Santa Fe, NM

www.gogittum.com



---

_________________
Larry Bourne
Palm Springs, CA
Building Kolb Mk IIIC
"Vamoose"

jindoguy(at)gmail.com
Guest

Posted: Thu Nov 30, 2006 6:29 am Post subject: Dual Elevator Cables

Larry, Does your extra elevator cables also work as trim cables like the original early Mk 3's, or do you just run them double from bell crank to bell crank? 

As I documented here last summer, the early system of returning the elevator cable to the trim lever made for handling I didn't like. The airplane seemed to hunt for a pitch attitude all the time. The reason is that when you pull on some trim the elevator cable would go slack. Now each pitch input goes through the trim spring. I'd pull back just a bit, I usually fly with index finger and thumb wrapped around the bottom of the stick grip, and nothing would happen. Pull back just a smidge more and oops now we're gaining a bit, ease off the stick pressure and we're diving again. In my early days of extreme ham handedness, when I had my whole hand wrapped around the stick grip, I drove myself nuts. There were times when I could not tell if it was the aircraft or me causing PIO's. We would just slide through the sky making a gentle, shallow sine wave. Eventually I got pretty good at compensating, but there was never a time when I could just relax and trim the airplane out. 

Unfortunately, unlike others, who can report on the effect of going to the new style rigging, I'm still fooling around with a new electrical system for my Mk 3 and won't be flying for several weeks. As soon as I get her airborne again, I'll report on the change. 

Incidentally, when I told Travis of the rigging I found, he said the guys at TNK hadn't seen it done like this, so the change occured sometime before they took over. My Mk 3 is serial # 43.



Rick



 On 11/29/06, Larry Bourne <biglar(at)gogittum.com (biglar(at)gogittum.com)> wrote:[quote] --> Kolb-List message posted by: "Larry Bourne" <biglar(at)gogittum.com (biglar(at)gogittum.com)>



While thinking on this topic, I'll refer you to a page of my website.  Take

a look about 1/2 way down the page............. 



http://www.biglar.homestead.com/STARTINGTHECABIN.html



Larry Bourne

Santa Fe, NM

www.gogittum.com 



---

John Hauck

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

Posted: Thu Nov 30, 2006 7:52 am Post subject: Dual Elevator Cables

| Larry, Does your extra elevator cables also work as trim cables like 

the

| original early Mk 3's,

|

| Rick

Rick:



Believe you are mistaken on the dual up elevator cables and mkIII's. 

I have serial number M3-011, was at the factory working when the first 

mkIII kit was sitting on the shipping dock to be picked up by Rudy 

Doctor.  Forced pitch trim system with springs attached to the 

elevator bell crank has always been that way on mkIII's.



The Twinstar used a cable operated elevator trim tab.  So maybe the 

mkII is the Kolb that used redundant up elevator cables.



You speak of the aircraft not wanting to settle down in pitch trim. 

My mkIII was that way during experimentation with my adjustable 

leading edge on the horizontal stabilizers, until I found the sweet 

spot.  Now it behaves its self.



Take care,



john h

mkIII

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

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Thu Nov 30, 2006 8:32 am Post subject: Dual Elevator Cables

I had the same problem with it not wanting to settle down. In my case, 

having a flap handle with three settings in the "up" position was the cure. 

Regular "up", about 3 degrees more "up", and about three degrees down from 

regular "up." That's the nice thing about the MKIII, no matter how you skin 

the cat, you get good results.

Richard Pike

MKIII N420P (420ldPoops)

DNA



---

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

John Hauck

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

Posted: Thu Nov 30, 2006 8:51 am Post subject: Dual Elevator Cables

In my case,

| having a flap handle with three settings in the "up" position was 

the cure.

 | Richard Pike

Richard:



One of these days I would like to have infinite flap adjustment on my 

mkIII.  I think it would be fun to experiment with, and much, much 

simpler than adjusting push/pull tubes each time a change was desired. 

Main reason I never got around to doing a lot of experimentation with 

reflexed flaps, pain in the butt set up in the normal configuration.



Eventually, I may get around to it.  The old flap mechanism is showing 

its age.  Vibration has worn down the tabs an 1/8" or so over the 

years.



Take care,



john h

mkIII

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

jindoguy(at)gmail.com
Guest

Posted: Thu Nov 30, 2006 3:12 pm Post subject: Dual Elevator Cables

John, perhaps my description was lacking. On my Mk. 3 the pitch trim cable and the up elevator cable were two ends of the same long wire. From the spring on the trim handle there was a multihole link of flat sheet metal and the wire started there, went back to the aft elevator bell crank and then forward to the forward elevator bell crank in the cockpit.  

The forward bell crank differs from the current one shown in the plans and does not have the tab and hole to hook up the trim wire coming from the spring to the forward bellcrank. 

My solution was to use a tang salvaged from my friend Jeff Johnson's 1975 Eipper-Formance FlexiFlyer Rogallo attached with the same bolt as the push rod coming from the stick. The circuit is now the same as plans stock in function, but I get to carry a piece of Jeff along with me from now on. 

When I first recounted this last summer, I thanked another lister (sorry forgot your name again) who had recounted a similar setup and published a warning about it. Perhaps it was a mod endorsed by a small community of builders, back when. 

Once again assume made an ass of me. 



Rick



On 11/30/06, 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)>



 In my case,

| having a flap handle with three settings in the "up" position was

the cure.

 | Richard Pike

Richard:



One of these days I would like to have infinite flap adjustment on my 

mkIII.  I think it would be fun to experiment with, and much, much

simpler than adjusting push/pull tubes each time a change was desired.

Main reason I never got around to doing a lot of experimentation with

 reflexed flaps, pain in the butt set up in the normal configuration.



Eventually, I may get around to it.  The old flap mechanism is showing

its age.  Vibration has worn down the tabs an 1/8" or so over the

 



	


-- 

Rick Girard

"Ya'll drop on in"

takes on a whole new meaning

when you live at the airport.  [quote][b]

biglar

Joined: 14 Jan 2006
Posts: 457

Posted: Thu Nov 30, 2006 4:01 pm Post subject: Dual Elevator Cables

It's hard to remember and the plane is 800 miles away.   Seems like I ran the trim cable to a separate anchor point on the elevator horn,  to make 2 completely separate systems.  I saw a couple of ideas that used a  common anchor point, and didn't think too much of them, cause you've still  really got the effect of just one actual cable.  If that connection  failed, all the cables in the world wouldn't  help.                             Lar.

  

 Larry Bourne

Santa Fe, NM

www.gogittum.com

 [quote]   ---

_________________
Larry Bourne
Palm Springs, CA
Building Kolb Mk IIIC
"Vamoose"

John Hauck

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

Posted: Thu Nov 30, 2006 4:37 pm Post subject: Dual Elevator Cables

Hi Gang:



Anybody know of a yahoo breaking a 3/32" aircraft cable on an elevator 

on a mkIII?  That cable has a breaking strength of 920 lbs.



If you double your 3/32" cable you will end up with about 1840 lbs.



If you go to a single 1/8" cable you will have to exert 1700 lbs to 

break that cable.



Tell me, please.  How the hell is anyone going to exert that much load 

on that little bitty elevator???



Another note.  Don't think Homer Kolb would have put us in jeopardy by 

using a cable that was not strong enough to do the job.  I am not a 

mathematician or an engineer, so I don't know how much load is 

possible to apply to the elevator.  I have an idea though, that those 

little 5/16" aluminum tubes in the elevator are going to bend and 

break long before one overloads the cable.



Since I have a habit of breaking Homer's airplanes, I used a single 

1/8" cable on my up elevator.



Of note is my pitch trim system cable which is 1/16" cable.  1/16" 

cable has a breaking strength of 480 lbs.  That is what we used for 

tail wire bracing on the Ultrastar.  Normally, my nose up trim is 

carrying the up elevator flight load.  That tiny cable has been doing 

all that work for more than 2500 hours without as much of a whine.



But........if it makes you feel better, make'em redundant.



Let's see.  The Piper Cubs and other small Piper aircraft all use 1/8" 

elevator cable.  Taylorcraft, same same.  Wonder why the FAA did not 

make them go redundant?



Take care,



john h

mkIII

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

Eugene Zimmerman

Joined: 10 Jan 2006
Posts: 392

Posted: Thu Nov 30, 2006 5:54 pm Post subject: Dual Elevator Cables

Hey John relax,



The issue is most certainly NOT cable strength.



I believe you are the one who reminded us in the past that everything  

has a life span or life cycle.

I believe most cables have a life span longer than even the youngest  

pilot.



but,



some cables break in flight,

some kolb wings break in flight.



Remember most kolbs are built by uncertified amateurs and flown by  

fallible humans.



Gene Z

On Nov 30, 2006, at 7:37 PM, John Hauck wrote:



 	  Quote: 	
		    Hi Gang:



 Anybody know of a yahoo breaking a 3/32" aircraft cable on an elevator

 on a mkIII?  That cable has a breaking strength of 920 lbs.



 If you double your 3/32" cable you will end up with about 1840 lbs.



 If you go to a single 1/8" cable you will have to exert 1700 lbs to

 break that cable.



 Tell me, please.  How the hell is anyone going to exert that much load

 on that little bitty elevator???

flykolb(at)pa.net
Guest

Posted: Thu Nov 30, 2006 6:06 pm Post subject: Dual Elevator Cables

John,



I don't think that even you could break an elevator cable.  If you could

pull hard enough to exert the necessary force to break the cable, the cable

would stretch enough so you would run out of travel.  



With a straight run like the Mark-III has for the elevator, there is little

to fatigue it.  The flight loads alone would not be sufficient to fatigue

it.  Running over a pulley adds more stress than anything else, but there

are no pulleys in the M3 elevator system.



Dennis



--

jcooley380(at)hughes.net
Guest

Posted: Thu Nov 30, 2006 7:05 pm Post subject: Dual Elevator Cables

Dennis S.,



Is there a reason that the MK 3 trim system wasn't set-up similar to the

Twinstar MK II? I know a lot of other planes use a cockpit adjustable trim

tab on the elevator surface to control trim. 

Another plus, unless I'm thinking wrong, is that if something did happen to

the up elevator cable or other control mechanism, you can still control

pitch with a cockpit adjustable trim system on the elevator.



Later,

John Cooley



Do not archive   




John,



I don't think that even you could break an elevator cable.  If you could

pull hard enough to exert the necessary force to break the cable, the cable

would stretch enough so you would run out of travel.  



With a straight run like the Mark-III has for the elevator, there is little

to fatigue it.  The flight loads alone would not be sufficient to fatigue

it.  Running over a pulley adds more stress than anything else, but there

are no pulleys in the M3 elevator system.



Dennis



--

Earl Zimmerman

Joined: 13 Jan 2006
Posts: 35
Location: Elizabethtown, PA

Posted: Thu Nov 30, 2006 8:01 pm Post subject: Dual Elevator Cables

Eugene Zimmerman wrote:

 	  Quote: 	
		   I know of two of at least two kolb planes and two pilots that  

 experienced sudden complete tearing or breaking of rudder cables  while 

 in-flight.

 One was our own Mk II with my son Earl as the pilot taking off at the  

 Father's day fly-in in a pretty good cross wind.

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

 	  Quote: 	
		  > Remember most kolbs are built by uncertified amateurs and flown by  

> fallible humans.

> 

> Gene Z

As I remember it the cable in question was exposed to some heat while 

gas welding a pulley bracket with the cable was installed. The fresh 

replacement cable has nearly 500 hrs. without a problem.

I agree with John. I don't think Dave's cables failed! There could be 

nothing else that would hold the elevator up in the crash pictures that 

were posted. Sure would love to know what DID happen!

                 ~Earl

nandrand(at)xtra.co.nz
Guest

Posted: Fri Dec 01, 2006 3:00 am Post subject: Dual Elevator Cables

Hi List. Is it the cable it's self that breaks, or the crimping??   John H. 

is right, it's hard to break "The Cable"in normal use!!!  There is a 

possability that the cable at, or in, the crimp could "work harden" over 

time and snap a number of strands, thus reducing the strength. Just my 

$0.02.  Fly safe.   Noel

---

pj.ladd(at)btinternet.com
Guest

Posted: Fri Dec 01, 2006 3:46 am Post subject: Dual Elevator Cables

Sure would love to know what DID happen>>



Hi Earl,



isn`t there an automatic FAA investigation in the case of an accident, 

particularly a fatal one. There would here in the UK so that in the case of 

a mechanical or structural failure being found a mod. or a warning could be 

circulated. In the worst case of course all planes of that type would be 

grounded until the cause of the crash was determined.



Pat



do not archive

David.Lehman

Joined: 10 Jan 2006
Posts: 265
Location: "Lovely" Fresno CA

Posted: Fri Dec 01, 2006 5:19 am Post subject: Dual Elevator Cables

Pat...

  

 It works a little differently here...  The FAA does indeed investigate most "N" numbered accidents, but because amateur-built aircraft are not built to a "standard" like "store bought" aircraft, they don't issue airworthiness directives and/or "ground" amateur-builts... 

  

 In the past, the NTSOB hasn't hands-on investigated amateur-built aircraft accidents (unless they were high exposure, ala John Denver), but lately there seems to be a little more interest in them...

  

 DVD

  

 do not archive...



 

 On 12/1/06, pat ladd <pj.ladd(at)btinternet.com (pj.ladd(at)btinternet.com)> wrote: [quote]--> Kolb-List message posted by: "pat ladd" <pj.ladd(at)btinternet.com  (pj.ladd(at)btinternet.com)>



Sure would love to know what DID happen>>



Hi Earl,



isn`t there an automatic FAA investigation in the case of an accident,

particularly a fatal one. There would here in the UK so that in the case of 

a mechanical or structural failure being found a mod. or a warning could be

circulated. In the worst case of course all planes of that type would be

grounded until the cause of the crash was determined.



Pat 



do not archive



[b]

_________________
Ã´Â¿Ã´

"Both optimists and pessimists contribute to the society. The optimist invents the aeroplane, the pessimist the parachute."

--- George Bernard Shaw

pj.ladd(at)btinternet.com
Guest

Posted: Fri Dec 01, 2006 8:12 am Post subject: Dual Elevator Cables

because amateur-built aircraft are not built to a  "standard" like "store bought" aircraft, >>

  

 Hi David,

  

 does that mean that anyone can build a plane  (within the ultralight limits) and just fly it?  No one checks the validity  of the design or the workmanship?

  

 Here the CAA has devolved inspection/certification  etc to the Popular Flying Assoc. Roughly like the EAA. You can certainly build  your own design if you wish but the plans will have to be passed by the PFA and  the building will be checked at intervals by an PFA Inspector. In the  case of ulralights by the British Microlight Assoc.

 No one can just build and fly what they like if it  has an engine. If you want to build a glider and have a large farm then you can  get away with it.

  

 Cheers

  

 Pat

   [quote][b]

David.Lehman

Joined: 10 Jan 2006
Posts: 265
Location: "Lovely" Fresno CA

Posted: Fri Dec 01, 2006 8:41 am Post subject: Dual Elevator Cables

Pat...

  

 The FAA says that you're building it for your "education and recreation"...  Want to use garage doors for wings, no problem, but your operating limitations will probably state that your test time/area will be 100 hours within a 1 mile radius of Nowhere...  The EAA did an excellent job of lobbying the CAA/FAA to allow builders to be creative, the FAA's primary concern in this arena is to protect persons (not particularly the pilot) and property from the aircraft, therefore the limitations... 

  

 All that said, I'm referring to "N" numbered aircraft, ultralights all but don't exist in the FAA's eyes...  Ultralights have to live within our Part 103 regulations, but the FAA doesn't expend much of their resources to check compliance... 

  

 DVD

  

 do not archive



 

 On 12/1/06, pat ladd <pj.ladd(at)btinternet.com (pj.ladd(at)btinternet.com)> wrote: [quote]  because amateur-built aircraft are not built to a "standard" like "store bought" aircraft, >>

  

 Hi David,

  

 does that mean that anyone can build a plane (within the ultralight limits) and just fly it?  No one checks the validity of the design or the workmanship?

  

 Here the CAA has devolved inspection/certification etc to the Popular Flying Assoc. Roughly like the EAA. You can certainly build your own design if you wish but the plans will have to be passed by the PFA and the building will be checked at intervals by an PFA Inspector. In the case of ulralights by the British Microlight Assoc. 

 No one can just build and fly what they like if it has an engine. If you want to build a glider and have a large farm then you can get away with it.

  

 Cheers

  

 Pat



[b]

_________________
Ã´Â¿Ã´

"Both optimists and pessimists contribute to the society. The optimist invents the aeroplane, the pessimist the parachute."

--- George Bernard Shaw

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Fri Dec 01, 2006 8:46 am Post subject: Dual Elevator Cables

That is correct. We can build and attempt to fly anything we like, as long  as it meets the specs of FAR 103. Our government still allows us the freedom to  do what we want (even be stupid) as long as we don't hurt someone else in the  process. And I guess it is working - How many innocent bystanders/uninvolved  third parties have been taken out by a legal ultralight? Some? A few?  None?

  

 Richard Pike

 MKIII N420P (420ldPoops)

 [quote]   ---

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

slyck(at)frontiernet.net
Guest

Posted: Fri Dec 01, 2006 8:47 am Post subject: Dual Elevator Cables

I think we could carve an airplane from a block of cheese and pass 

inspection

if it had a good W &B.  Don't have to meet noise standards like in Yurp.

No emissions requirements either although Limburger might offend the 

neighbors.

-vermont sharp cheddar lover

do not archive



On 1, Dec 2006, at 11:10 AM, pat ladd wrote:



 	  Quote: 	
		   because amateur-built aircraft are not built to a "standard" like 

 "store bought" aircraft, >>

  

 Hi David,

  

 does that mean that anyone can build a plane (within the ultralight 

 limits) and just fly it?  No one checks the validity of the design or 

 the workmanship?

  

 Here the CAA has devolved inspection/certification etc to the Popular 

 Flying Assoc. Roughly like the EAA. You can certainly build your own 

 design if you wish but the plans will have to be passed by the PFA and 

 the building will be checked at intervals by an PFA Inspector. In the 

 case of ulralights by the British Microlight Assoc.

 No one can just build and fly what they like if it has an engine. If 

 you want to build a glider and have a large farm then you can get away 

 with it.

  

 Cheers

  

 Pat

FS2Kolb(at)aol.com
Guest

Posted: Fri Dec 01, 2006 9:38 am Post subject: Dual Elevator Cables

In a message dated 12/1/2006 9:14:42 A.M. Mountain Standard Time,  pj.ladd(at)btinternet.com writes:

  	  Quote: 	
		  does that mean that anyone can build a plane (within the    ultralight limits) and just fly it?  No one checks the validity of the    design or the workmanship? 	


 

 That's right..

 God Bless American, land of the free.

  [quote][b]

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