Towertalk
[Top] [All Lists]

Re: [TowerTalk] Why galvanized crank up cables instead of stainless?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Why galvanized crank up cables instead of stainless?
From: K8RI <K8RI-on-TowerTalk@tm.net>
Date: Tue, 09 Oct 2012 13:58:57 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 10/9/2012 10:27 AM, K7LXC@aol.com wrote:
t/>  Having just replaced my crank up cables (in case they  migh
be rusted internally), I am wondering why stainless steel
cables  aren't used.  It would seem that they would avoid
the latent rust  issue.  I realize that they are not as strong,
but they could simply be  sized appropriately.  Is it the
case that they may still rust, just more  slowly?  Would
they somehow wear out and break internally?  It  would be
great to merely have to inspect the cables for obvious  broken
strands and never have to replace them on a preventative basis.
Can  someone explain this?  Don't airplanes use SS cables?

     Sure, but they don't go thru the forces and cycles  of crank-up cables.

Agree with everything except the cycles. Aircraft control cables (rudder, ailerons, and elevator) are in an almost constant state of motion while in flight and the bending takes place over very short spans on each of the cables where the pulleys are located. OTOH they are not heavily loaded nor under much tension. They must be replaced at any sign of strand failure which is rare. They are "supposed" to be inspected during the annual (yearly) inspection.

I do not know if they are impregnated with lube.

73

Roger (K8RI)



     IMO there are 2 factors. One is cost since  everything is determined by
it. And the second is the fact that worked SS cables  under load will gall.
That is, pieces of the material will be deposited on other  strands and
eventually you have a hard spot in the cable. This might be  prevented by
REGULAR cable lubrication but I don't think it's worth the  potential problem.

     SS nuts and bolts will also gall. That's why you  have to use some sort
of non-seize on the threads.

Cheers,
Steve    K7LXC
TOWER TECH
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>