Topband: Ends for older Phillystran

[Ashton Lee]

We sailors would wrap a line twice around the eye and then leave a longer tail and clamp that with some space between each clamp. The increased friction of 2 wraps around an eye/block/winch substantially reduces the pull on a knot, cleats or (in this case) clamps. It could be that the phillystran needs to be wrapped around something with a larger radius than the eye however… not sure of the engineering on that point. So you might  need a “thimble” in the set up.



On Jan 14, 2014, at 10:04 AM, Bill Wichers <billw at waveform.net> wrote:

> The bar idea would probably significantly reduce the allowable tension on the cable, similar to what knotting does, due to the force at each "bite point" weakening the cable. I suppose if the cable was sufficiently oversized this wouldn't pose a problem, but I'd certainly expect such a clamping method to effectively reduce the allowable tension significantly below the normal rated load.
> 
> I'm actually a little surprised a dead end / preform isn't supposed to be used with the straight-strand version of the cable. Those grips work by compression of the cable they are "grabbing", and it's a fairly even pressure over the length of the gripped area. If one could be found that was the correct diameter for the cable being used it might be worth a shot, but I completely agree with Tom -- TEST ANYTHING YOU TRY BEFORE USING IT FOR REAL!  He's also correct that dynamic loading is much worse than static loading. Wind causes vibration in towers and guys and that can cause your clamps  to loosen over time, especially if they were marginal to begin with.
> 
>   -Bill
> 
> 
>> Has anyone thought of a long rectangular bar with multiple champhered
>> holes, with the Phillystran woven through from side-to-side? With enough
>> weaves, this should self-tension with just a single clamp on the far end.
>> Regardless, I would test pull and see what breaks first at what tension.
>> 
>> 73 Tom
>> 
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