Pretensioning cables

[Gig 601Xl Builder]

Anyone have a good method for pretensioning cables. There has been some
issues of late with 601Xl control cables getting loose after the first
few flights.

I'm looking for info on ways to pretension 1/8" galvanized cables that
are tensioned between 22 and 40 lbs.

[Gregory Hall]

"Gig 601Xl Builder" > wrote in message
m...
> Anyone have a good method for pretensioning cables. There has been some
> issues of late with 601Xl control cables getting loose after the first few
> flights.
>
> I'm looking for info on ways to pretension 1/8" galvanized cables that are
> tensioned between 22 and 40 lbs.

Pre-tensioning cables is not possible. You must mean post-tensioning?

--
Gregory Hall

[[email protected]]

On Nov 18, 10:33*am, Gig 601Xl Builder >
wrote:
> Anyone have a good method for pretensioning cables. There has been some
> issues of late with 601Xl control cables getting loose after the first
> few flights.
>
> I'm looking for info on ways to pretension 1/8" galvanized cables that
> are tensioned between 22 and 40 lbs.

Only once have I seen a pair of cables go slack soon after
installation, and I think (just an opinion) that there was a lot of
the heavy, waxy oil in the cable that squeezed out and let the strands
come together under tension. That would let them relax some. All the
other cables we've ever installed stayed tight. Are you sure there's
no deformation taking place in the control system? Or maybe they're
being tensioned in a warm shop, then the airplane goes out into the
cold and the aluminum shrinks more than the steel cable and they'll go
a little loose.

Dan

[jan olieslagers[_2_]]

Gregory Hall schreef:
> "Gig 601Xl Builder" > wrote in message
> m...
>> Anyone have a good method for pretensioning cables. There has been some
>> issues of late with 601Xl control cables getting loose after the first few
>> flights.
>>
>> I'm looking for info on ways to pretension 1/8" galvanized cables that are
>> tensioned between 22 and 40 lbs.
>
> Pre-tensioning cables is not possible. You must mean post-tensioning?

Must mean post-installation but pre-crash.

[Gig 601Xl Builder]

wrote:
> On Nov 18, 10:33 am, Gig 601Xl Builder >
> wrote:
>> Anyone have a good method for pretensioning cables. There has been some
>> issues of late with 601Xl control cables getting loose after the first
>> few flights.
>>
>> I'm looking for info on ways to pretension 1/8" galvanized cables that
>> are tensioned between 22 and 40 lbs.
>
> Only once have I seen a pair of cables go slack soon after
> installation, and I think (just an opinion) that there was a lot of
> the heavy, waxy oil in the cable that squeezed out and let the strands
> come together under tension. That would let them relax some. All the
> other cables we've ever installed stayed tight. Are you sure there's
> no deformation taking place in the control system? Or maybe they're
> being tensioned in a warm shop, then the airplane goes out into the
> cold and the aluminum shrinks more than the steel cable and they'll go
> a little loose.
>
> Dan


Thanks Dan for the only straight answer. Am I sure there isn't any
deformation? No I'm not, because it hasn't happened yet to a plane I
have had access to. The people that have have said that no there is no
deformation.

In one case a plane was flown recently from Florida to South Carolina.
On arrival in SC the aileron counter balance cable was so slack that it
was unmeasurable with a tension gauge. From building the same design I
would have to think that enough deformation to loosen the cable that
much would be clearly visible.

This is an extreme example. Most is the reports are in the neighborhood
of 10-12 lbs change in tension.

[cavelamb himself[_4_]]

wrote:

> On Nov 18, 10:33 am, Gig 601Xl Builder >
> wrote:
>
>>Anyone have a good method for pretensioning cables. There has been some
>>issues of late with 601Xl control cables getting loose after the first
>>few flights.
>>
>>I'm looking for info on ways to pretension 1/8" galvanized cables that
>>are tensioned between 22 and 40 lbs.
>
>
> Only once have I seen a pair of cables go slack soon after
> installation, and I think (just an opinion) that there was a lot of
> the heavy, waxy oil in the cable that squeezed out and let the strands
> come together under tension. That would let them relax some. All the
> other cables we've ever installed stayed tight. Are you sure there's
> no deformation taking place in the control system? Or maybe they're
> being tensioned in a warm shop, then the airplane goes out into the
> cold and the aluminum shrinks more than the steel cable and they'll go
> a little loose.
>
> Dan


It is pretty amazing how much pressure a person can exert with their feet.

I believe the 601 control horns are 6061T6 extruded angle(?)

Just to be sure, make a careful inspection of the rudder and horns.
Make sure the attachments are still secure.


--

Richard

(remove the X to email)

The democracy will cease to exist when you
take away from those who are willing to work
and give to those who would not.

Thomas Jefferson

[[email protected]]

On Nov 20, 3:17*pm, cavelamb himself > wrote:
"It is pretty amazing how much pressure a person can exert with their
feet."

My thoughts exactly!

It depends on the design of the control system (Independent pedals
vs a rudder bar). "Way back when", I had an issue with finding myself
putting way to much foot pressure on the rudder pedals. Finally
switching to something with toe brakes cured me fast!

Vaughn

[Gig 601Xl Builder]

cavelamb himself wrote:

>
> It is pretty amazing how much pressure a person can exert with their feet.
>
> I believe the 601 control horns are 6061T6 extruded angle(?)
>
> Just to be sure, make a careful inspection of the rudder and horns.
> Make sure the attachments are still secure.
>
>

Yep 6061T6. BUT the problem isn't showing itself in the rudder cables it
is in the ailerons.

[Morgans[_2_]]

"Gig 601Xl Builder" > wrote

> Yep 6061T6. BUT the problem isn't showing itself in the rudder cables it
> is in the ailerons.

Wood wings, or metal?
--
Jim in NC

[cavelamb himself[_4_]]

Morgans wrote:
> "Gig 601Xl Builder" > wrote
>
>
>>Yep 6061T6. BUT the problem isn't showing itself in the rudder cables it
>>is in the ailerons.
>
>
> Wood wings, or metal?

The 601s are all aluminum.
Zodiac designed by Chris Heinz.

Break

Gig, you better dig into that.

It sounds like something has "adjusted" it's position.
It might innocent, but you need to know for sure WHY the change.

My next door neighbor on the airport built an 601-HDS.
It looked pretty solid.

The cables just are not long enough to show any significant stretch.
Not at 40 pounds tension.

Check for a loose pivot point?
Or a bent support?

Or?

Or the cable ends! Thimbles in place?
Have they changed shape any at all?

Check the nicopress collars with a go/no go gage?

Any detectable wear in the connection tangs?

Does this airplane have the hingless aileron hinges?
(Althought I seem to think there was a pushrod to the aileron)



--

Richard



(remove the X to email)

The democracy will cease to exist when you
take away from those who are willing to work
and give to those who would not.

Thomas Jefferson

[Gig 601Xl Builder]

Morgans wrote:
> "Gig 601Xl Builder" > wrote
>
>> Yep 6061T6. BUT the problem isn't showing itself in the rudder cables it
>> is in the ailerons.
>
> Wood wings, or metal?

Metal... also 6061-T6

[Gig 601Xl Builder]

cavelamb himself wrote:
> Morgans wrote:
>> "Gig 601Xl Builder" > wrote
>>
>>
>>> Yep 6061T6. BUT the problem isn't showing itself in the rudder cables
>>> it is in the ailerons.
>>
>>
>> Wood wings, or metal?
>
> The 601s are all aluminum.
> Zodiac designed by Chris Heinz.
>
> Break
>
> Gig, you better dig into that.
>
> It sounds like something has "adjusted" it's position.
> It might innocent, but you need to know for sure WHY the change.
>
> My next door neighbor on the airport built an 601-HDS.
> It looked pretty solid.
>
> The cables just are not long enough to show any significant stretch.
> Not at 40 pounds tension.
>
> Check for a loose pivot point?
> Or a bent support?
>
> Or?
>
> Or the cable ends! Thimbles in place?
> Have they changed shape any at all?
>
> Check the nicopress collars with a go/no go gage?
>
> Any detectable wear in the connection tangs?
>
> Does this airplane have the hingless aileron hinges?
> (Althought I seem to think there was a pushrod to the aileron)
>
>
>

You are right and it could be any of those things but as I mentioned
this hasn't happened yet to my yet to be completed airplane so as I
mentioned I don't have access and the people who have mentioned the
problem SAY they don't see any problems. And you also right that there
is a short push rod between the bell crank and the aileron.

[Gig 601Xl Builder]

Bryan Martin wrote:

Bryan, I'd not noticed you on RAH before. You know the issue I'm asking
about. Maybe you can add something that I've left out that could help.

[cavelamb himself[_4_]]

>
> You are right and it could be any of those things but as I mentioned
> this hasn't happened yet to my yet to be completed airplane so as I
> mentioned I don't have access and the people who have mentioned the
> problem SAY they don't see any problems. And you also right that there
> is a short push rod between the bell crank and the aileron.


So what do we have in the cable route?

One pulley on each side???


--

Richard

[Gig 601Xl Builder]

cavelamb himself wrote:
>>
>> You are right and it could be any of those things but as I mentioned
>> this hasn't happened yet to my yet to be completed airplane so as I
>> mentioned I don't have access and the people who have mentioned the
>> problem SAY they don't see any problems. And you also right that
>> there is a short push rod between the bell crank and the aileron.
>
>
> So what do we have in the cable route?
>
> One pulley on each side???
>
>

Nope straight line from the stick to the aileron bell crank. The cable
balance side of the bell crank makes a turn through fair leads made from
some pretty tough nylon.

[John[_9_]]

On Nov 18, 12:33*pm, Gig 601Xl Builder >
wrote:
> Anyone have a good method for pretensioning cables. There has been some
> issues of late with 601Xl control cables getting loose after the first
> few flights.
>
> I'm looking for info on ways to pretension 1/8" galvanized cables that
> are tensioned between 22 and 40 lbs.

I have been working on a well known VlJ that recently declared
bankruptcy. It is the first aircraft that I have ever worked on that
discusses pretensioning cables. Basically they tension the cables to a
figure well above nominal. Then back off and retension to nominal.

John Dupre

[Stealth Pilot[_2_]]

On Sun, 30 Nov 2008 18:35:29 -0800 (PST), John >
wrote:

>On Nov 18, 12:33*pm, Gig 601Xl Builder >
>wrote:
>> Anyone have a good method for pretensioning cables. There has been some
>> issues of late with 601Xl control cables getting loose after the first
>> few flights.
>>
>> I'm looking for info on ways to pretension 1/8" galvanized cables that
>> are tensioned between 22 and 40 lbs.
>
>I have been working on a well known VlJ that recently declared
>bankruptcy. It is the first aircraft that I have ever worked on that
>discusses pretensioning cables. Basically they tension the cables to a
>figure well above nominal. Then back off and retension to nominal.
>
>John Dupre

The humble old Cherokee 140 has an interesting pretensioned control
run ...to the ailerons I think.
the cables run from the surfaces via the usual pulleys then terminate
in sections that look for all the world like bicycle chain. these are
run up past two sprockets which are bolted together. the positions
that the sprockets are in when bolted determine the amount of cable
tension in the outer runs. past the sprockets the run to the yolk is
actually almost untensioned completely.
this allows the cables to, in effect, be used in a pretensioned state
while the yolk controls feel light and friction free.

it is a damn cunning arrangement that works superbly.
Stealth Pilot