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.