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Cable Tensions for 601XL?
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mountain4don

Joined: 18 Jan 2006
Posts: 29

Posted: Tue Nov 11, 2008 3:21 pm Post subject: Cable Tensions for 601XL?

I am in the rigging stage for my 601XL, and can't find any references to what the cable tensions are supposed to be in the plans or manual.  What are all the cables supposed to be tensioned to and where may I find this information on the 601XL plans or specifications?



Don Mountain



         [quote][b]

_________________
Zenith 601XL, tail done, working on wings

amyvega2005(at)earthlink.
Guest

Posted: Tue Nov 11, 2008 7:33 pm Post subject: Cable Tensions for 601XL?

check the page with the cable rigging, its says 30 lbs. that is inch lbs i believe, or 4 ft lbs.



Juan



--

Ron Lendon

Joined: 10 Jan 2006
Posts: 685
Location: Clinton Twp., MI

Posted: Tue Nov 11, 2008 7:37 pm Post subject: Re: Cable Tensions for 601XL?

They just posted a great guide on the builder site at zenith.  



Go to the Zenith Aircraft Builder Pages, click on 



"for important notices and other building and flying information." 



then click on the link next to Zenair Safety Alert



"Photo guide: How to check the control cable tension of your Zodiac"



I would like to just post the link but I promised Zenith I wouldn't.

_________________
Ron Lendon
WW Corvair with Roy's Garage 5th bearing
CH 601 XLB
N601LT - Flying
http://www.mykitlog.com/rlendon
Corvair Engine Prints:
https://sites.google.com/site/corvairenginedata/

psm(at)att.net
Guest

Posted: Tue Nov 11, 2008 7:48 pm Post subject: Cable Tensions for 601XL?

Hi Juan,



I think you are confusing cable tension with torque.



My take on 30 pounds of tension is the amount of tension (pull) you 

get when the cable is holding up a 30 pound weight.



I just got the tensiometer shown in the AD from Aircraft Spruce and 

measured the rudder and elevator cables I already have installed (my 

wings are not yet on the plane).  My results setting the cable 

tension with no instruments at all were very close to the desired 

ones.  The rudder was 7 pounds high and the elevator was 2 pounds 

low.  Perhaps that is why Chris Heintz originally suggested we didn't 

really need the fancy instrument to rig the cables.



Paul

XL getting close

At 07:32 PM 11/11/2008, you wrote:



 	  Quote: 	
		  check the page with the cable rigging, its says 30 lbs. that is inch 

lbs i believe, or 4 ft lbs.



Juan

jmaynard

Joined: 27 Feb 2008
Posts: 394
Location: Fairmont, MN (FRM)

Posted: Tue Nov 11, 2008 10:43 pm Post subject: Cable Tensions for 601XL?

On Tue, Nov 11, 2008 at 10:32:35PM -0500, Juan Vega wrote:

 	  Quote: 	
		   check the page with the cable rigging, its says 30 lbs. that is inch lbs i

 believe, or 4 ft lbs.


	


No, that's 30 pounds cable tension, not torque (what would it be torque

*on*?).

-- 

Jay Maynard, K5ZC, PP-ASEL           http://www.conmicro.com

http://jmaynard.livejournal.com       http://www.tronguy.net

Fairmont, MN (KFRM)                        (Yes, that's me!)

AMD Zodiac CH601XLi N55ZC http://www.tronguy.net/N55ZC.shtml

_________________
Jay Maynard, K5ZC
AMD Zodiac XLi N55ZC

n801bh(at)netzero.com
Guest

Posted: Wed Nov 12, 2008 4:17 am Post subject: Cable Tensions for 601XL?

Sabrina.  

Since you built the plane I would hope you know it better then anyone else. When someone, ie, A&P / IA, friend etc, suggests a concept you must speak up and either allow the change or contest it.  On my 801 the cable tension on all controls are 30 lbs +/- 5 lbs.  You are correct in that because of the geometry of the front gear the tension will increase as the gear unloads, you would figure someone who is FAA certified should be able to look at the set up and derive the same conclusion. The 801 has  a rigid connection between the rudder peddles and the gear but passes through several pulleys and guide blocks on the way to the tail. Also the bearing surface on the rudder pivot is a simple but crude set up. It works fine but when loaded to 40+ lbs of tension I would become very leary of the weak points in the rudder cable path. The point I am trying to make is, 1- You know the plane bettter then anyone, Don't let them do something that could hurt or kill ya,  In my opinion when one sets the cable tension too high on a Zenith aircraft the damage could be greater then one set too loose.. YMMV. 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "Sabrina" <chicago2paris(at)msn.com> wrote:

--> Zenith-List message posted by: "Sabrina" <chicago2paris(at)msn.com>



Hello all... update on my cable tensions... my rudder cable tensions had to be adjusted today... although my IA set the aileron and elevator tensions to the high range of the AD/service letter,  he left the rudder tension alone at 27 pounds--his notes seemed to indicate the tension got less as the prop was placed in a sling.  The tension should increase not decrease.



I checked the tensions today and they were 27 with weight on the nose, 33 with the prop lifted by hand and nearly 40 with the nose gear stop plate at rest.



Now, they have been adjusted to 25 with the stop plate at rest, but only 12-13 sitting on the tarmac.   The O-200a with a metal prop is fairly heavy so the nose gear stop plate (for those of us with the older nose strut) is raised about 3/4" at rest.  



Thanks to all who questioned my last posting of rudder tension numbers off line.  



Happy Veteran's Day to all of you veterans out there--thank you for giving my generation the opportunities we enjoy.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=213631#213631===============================================sp;                       &nb========================================================================;           &nbsp============================================

 



_____________________________________________________________

Criminal Lawyers - Click here.

   [quote][b]

wjones(at)brazoriainet.co
Guest

Posted: Wed Nov 12, 2008 7:34 am Post subject: Cable Tensions for 601XL?

Hello group ,I have been reading the posts concerning the cable tensions 

,this should help in correcting the flutter problem (if there is one) .While 

building my 601XL I did not even consider installing aileron trim .Yes I did 

use elevator trim .Don't know if this qualifies me in any way ,however I 

have been flying/maintaining and building planes for 48 years have A/P/ and 

I/A ratings .We were always taught to rebalance control surfaces after 

painting .If a little paint will add to flutter what would the weight of an 

added trim + servo+ hinge do for the balance .It may pay for the readers of 

this post to break out their AC 43.13-1B acceptable methods techniques, and 

practices and read  4-36 flutter and vibration precautions . I am certain 

several will disagree with my post but I urge you to read the AC43.13-1B .

Wade  Jones  South Texas

601XL Franklin 0-235

---

wjones(at)brazoriainet.co
Guest

Posted: Wed Nov 12, 2008 9:35 am Post subject: Cable Tensions for 601XL?

I knew someone would ask ,if no aileron trim why elevator trim .My answer 

how many elevator failures has the 601XL had .

Wade  Jones  South Texas

601XL Franklin 0-235

---

ihab.awad(at)gmail.com
Guest

Posted: Wed Nov 12, 2008 9:43 am Post subject: Cable Tensions for 601XL?

Out of curiosity --



On Wed, Nov 12, 2008 at 7:29 AM, Sabrina <chicago2paris(at)msn.com> wrote:

 	  Quote: 	
		   

 The problem here is that I am sending someone else up in my aircraft every time

 I authorize a new test flight.


	


So you are having someone else fly off your 40h? Sounds good but,

since you have a PPL, why?



 	  Quote: 	
		   Although I know my particular airframe "at rest" better than anyone, and had

 to defend my modifications to it during hours of meetings last December and

 January ...


	


Again out of curiosity: what meetings?



Cheers,



Ihab



-- 

Ihab A.B. Awad, Palo Alto, CA

stormyflight(at)yahoo.com
Guest

Posted: Wed Nov 12, 2008 9:49 am Post subject: Cable Tensions for 601XL?

Sabrina,



I have to agree with Wade.  Every aircraft's control system is different and and the fact that the ailerons have a balance cable really does not impact its flutter characteristics because flutter is not really a control surface deflection that originates from the stick.  The deflection comes from a flexing of the system that then stores the spring energy.  This flexing and storing of energy and then releasing that energy as the surface unflexes is a primary driver in the creation of the flutter effect.  That is why stiffer is better when it comes to control systems.



That being said, a flutter situation can occur in any of the control surfaces.  As the XL has had several reported instances of aileron flutter, it seems to be the most prevalent flutter mode.  I have not heard of any report instances of elevator  flutter.  Also, any additional weight at the trailing edge of a control surface will absolutely reduce the flutter speed.  I'm not saying that the XL with aileron trim is unsafe, but it does have less flutter margin than one without the trim system.



I decided to go with a bungee type trim if required for the the ailerons.



Jim Machin

601XL, 0-200

Almost done!



--- On Wed, 11/12/08, Sabrina <chicago2paris(at)msn.com> wrote:

[quote]From: Sabrina <chicago2paris(at)msn.com>

Subject: Re: Cable Tensions for 601XL?

To: zenith-list(at)matronics.com

Date: Wednesday, November 12, 2008, 8:24 AM



[quote]--> Zenith-List message posted by: "Sabrina"

<chicago2paris(at)msn.com>



"I did use elevator trim."



Wade,



Personally, the elevator trim weight bothered me more than  the aileron trim.  

The ailerons, by their nature of one being up and one down, should, if properly

tensioned, be easier to dampen in flight than a fluttering elevator.  So too, a

builder can easily adjust an XL's horizontal stabilizer for proper cruise

configuration since it sits so high off the longerons.    The aileron trim was a

much easier call for me than the elevator trim.  If no aileron trim under Par.

4-36, why elevator trim?



As to Par 4-36(c) was it the Cardinal that used foam in the elevator trim tab

that took on water/ice and threw it off balance?



Has anyone had to drill a weep hole in their elevator trim tab to make sure ice

does not build up?   I ended up gust-locking my elevator in the up position

rather than down to keep the ice out.





Read this topic online            [quote][b]

craig(at)craigandjean.com
Guest

Posted: Wed Nov 12, 2008 10:18 am Post subject: Cable Tensions for 601XL?

 	  Quote: 	
		   There has to be a reason why Zenith added 6T3-8


	


Has anyone asked Caleb?



-- Craig



--

psm(at)att.net
Guest

Posted: Wed Nov 12, 2008 10:43 am Post subject: Cable Tensions for 601XL?

If that is the part I am thinking of, it was added to comply with the 

consensus standard for LSA.  I was told it was optional, but I 

installed it anyway.



Paul

XL getting close

do not archive



At 09:56 AM 11/12/2008, you wrote:

 	  Quote: 	
		  There has to be a reason why Zenith added 6T3-8, the elevator horn 

reinforcing strap, to the design.  At some point, some aerodynamic 

action was pulling the two horns apart in flight on the aircraft 

that was the basis for the design change.   6-T-3 08/05

stormyflight(at)yahoo.com
Guest

Posted: Wed Nov 12, 2008 10:51 am Post subject: Cable Tensions for 601XL?

I'm not sure I agree.  The discussion was whether or not that addition of the trim system had an impact on the flutter characteristics and whether the impact was greater on the ailerons or the elevator.  I am not really sure of all the details surrounding the crash due to the down elevator input, but the structural testing Zenith did (negative load test of the wing) and the subsequent recommendation of reducing the down elevator travel indicates to me that flutter was not suspected in that case.  



 I still stand by my statement that the addition of the aileron trim system reduces the flutter margin on 601 XL's.  As aileron flutter is the primary concern (at least today's most popular culprit) not installing a non-essential system that reduces the margin would seem prudent.



Jim



--- On Wed, 11/12/08,  Sabrina <chicago2paris(at)msn.com> wrote:

[quote]From: Sabrina <chicago2paris(at)msn.com>

Subject: Re: Cable Tensions for 601XL?

To: zenith-list(at)matronics.com

Date: Wednesday, November 12, 2008, 9:56 AM



[quote]--> Zenith-List message posted by: "Sabrina"

<chicago2paris(at)msn.com>



I strongly disagree, elevator input is suspect in more than one fatal crash. 

Even if an elevator remains in place, we don't know if the elevator got away

and overstressed some other component.   We just assume the pilot moved the

stick too abruptly.  It could be that we are only hearing about the aileron

flutter because it can be dampened and the pilot can survive. 



There has to be a reason why Zenith added 6T3-8, the elevator horn reinforcing

strap, to the design.  At some point, some aerodynamic          [quote][b]

gburdett

Joined: 05 Aug 2008
Posts: 13

Posted: Wed Nov 12, 2008 11:00 am Post subject: Re: Cable Tensions for 601XL?

DO NOT ARCHIVE

Last edited by gburdett on Thu Nov 13, 2008 6:20 am; edited 3 times in total

stormyflight(at)yahoo.com
Guest

Posted: Wed Nov 12, 2008 11:10 am Post subject: Cable Tensions for 601XL?

Well, in my opinion, all flutter is very bad.  There is something called limit cycle flutter which is a type of flutter that can be overcome, typically referred to as a control surface "buzz". To me, this situation is a kin to standing on the edge of a cliff with the edge crumbling away.  And yes, reducing speed and changing the aerodynamic loading can stop it.  There are other types of flutter that can be catastrophic in a very short period of time and there is nothing you can do to stop it.  The particular flutter mode dictates which kind you get.



Also, there are absolutely no benefits to adding weight of any kind to a trailing edge.  The goal is always to reduce the mass behind the hingeline.



--- On Wed, 11/12/08, Sabrina <chicago2paris(at)msn.com> wrote:

[quote]From: Sabrina <chicago2paris(at)msn.com>

Subject: Re: Cable Tensions for 601XL?

To: zenith-list(at)matronics.com

Date: Wednesday, November 12, 2008, 10:39 AM



[quote]--> Zenith-List message posted by: "Sabrina"

<chicago2paris(at)msn.com>



Craig,



Caleb, No, Roger, Yes.

Mr. Machin,



I think we are talking apples and oranges.   You and Wade are worried about

flutter.  I am worried about flutter that cannot be overcome.  I was taught to

dampen aileron or wing flutter by a firm climb combined with a firm bank as one

reduces power.     I know of no way to dampen elevator flutter other than by

reducing power.   You talk about the benefits of adding weight to the trailing

edge of an elevator being a lower frequency of oscillation but the added mass

increases your chances of entering into the situation in the first            [quote][b]

Joe Kidd

Joined: 01 Aug 2008
Posts: 15
Location: TN

Posted: Wed Nov 12, 2008 11:50 am Post subject: Cable Tensions for 601XL?

Sabrina, 

<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />  

Just for the sake of mentioning it have you gone over each of the bearing surfaces in your ailerons, flaps and rudder? Also with respect to your cable runs through your fuselage is there a remote possibility that something has induced friction or drag? While I don¢t have the engineering background back ground or resources your family and EEA chapter are blessed with I have found a solution is always present, one simply has to research or experiment until they find it.  

Since it is unlikely you have access to a wind tunnel for a full on ground systems test do you have access to a stationary airplane engine test stand? If so you can secure your airplane to the runway and get enough airflow across the wing and aileron and rudder surfaces to test your aircrafts control surfaces for action and reaction. It¢s not very scientific and admittedly is rather crude but it¢s worked well for me in the past on other projects I can¢t discuss.  

  

Best 

  

JWS 

  

Do not arcive please 



 

   From: Sabrina <chicago2paris(at)msn.com>

To: zenith-list(at)matronics.com

Sent: Wednesday, November 12, 2008 11:56:19 AM

Subject: Re: Cable Tensions for 601XL?



--> Zenith-List message posted by: "Sabrina" <chicago2paris(at)msn.com (chicago2paris(at)msn.com)>



I strongly disagree, elevator input is suspect in more than one fatal crash.  Even if an elevator remains in place, we don't know if the elevator got away and overstressed some other component.  We just assume the pilot moved the stick too abruptly.  It could be that we are only hearing about the aileron flutter because it can be dampened and the pilot can survive. 



There has to be a reason why  Zenith added 6T3-8, the elevator horn reinforcing strap, to the design.  At some point, some aerodynamic action was pulling the two horns apart in flight on the aircraft that was the basis for the design change.  6-T-3 08/05





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=213769#213769

[b]http://www.                   -Matt DrallList" target=_blank>http://www.matronics.com/Navigator?Zenith-List

         [quote][b]

jaybannist(at)cs.com
Guest

Posted: Wed Nov 12, 2008 12:09 pm Post subject: Cable Tensions for 601XL?

Sabrina,

 

 FWIW:   I asked the test pilot that first flew my 601XL if he used the elevator trim.  He said "Definitely!"  He said that he virtually flew the airplane with elevator trim.  To my thinking, that makes a pretty good case for the elevator trim.  I don't have aileron trim, either.

 

 Jay in Dallas

 

   

 

   

 

 --

notsew_evets(at)frontiern
Guest

Posted: Wed Nov 12, 2008 12:36 pm Post subject: Cable Tensions for 601XL?

Butting in here but,,,,

In my Experimental airplane adventures, I ve found that pitching up under 

power and then pitching down with reduced power is an indication of the 

engine mount not being set at the correct angle........

Steve W.



---

jaybannist(at)cs.com
Guest

Posted: Wed Nov 12, 2008 12:48 pm Post subject: Cable Tensions for 601XL?

Sabrina,

 

 My horizontal stabilizer is parallel to the upper longeron, as called for in the plans.  My engine is a Corvair, so, yes it could be considered a heavy engine.

 

 Jay in Dallas

 Do not archive

 

   

 

   

 

 --

amyvega2005(at)earthlink.
Guest

Posted: Wed Nov 12, 2008 1:33 pm Post subject: Cable Tensions for 601XL?

"Throttle is for climb and decent, you trim for speed"  A plane that is trimmed at a set speed wil climb or decend with a change in throttle rpm or power setting,  so angle on engine is more for p factor/ torque than anything, relavant on a limitted basis to level flight.



Juan



--

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