Pretensioning cables

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

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.

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.

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

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.

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

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