On 5/5/2010 2:30 AM, Ian White GM3SEK wrote:
> AI4WM Bill wrote:
>
>> Wal-mart, Lowe's, ACE& Home Depot sell the same thing for about
>> $3.00. They work fine.
>>
>>
>
> I've had very good experience with larger rope grips using the same
> 3-ball system, which gives a very firm hold on a 3-twist rope.
Problem is I try to avoid that kind of rope when working with rigging
and towers. They should have the "twist" in capitol letters. The stuff
is terrible at getting ... well twisted and tangled up. I use braided
rope with very little stretch.
BTW those things take a real grip on Phillystran as long as they aren't
made of plastic The metal ones I use can stand a "comealong" pulling at
400 to 600# tension. Thing is that kind of tension on that kind of
device will weaken the guy line. However getting back to the original
use for the OP they would get by just fine with the braided poly rope
sold by TheRFConnection, Davis (Orion Wire) and a number of others as
they probably won't be running over 60 - 100# tension which I believe in
his case would be sufficient. To top it off the 3/16" which is about
850# test, or the 1/4" @ 850@#, or 5/16" at 1000# test is 10 to 15 cents
per foot. The strength may vary between vendors.
Be wary of the cast pulleys with what look like brass inserts and a
swivel mount. Many of them are rated for very little tension.
73
Roger (K8RI)
> They
> really are superb... but they are also 50% bigger than the ones we're
> talking about here, all metal and built to NATO specs.
>
> The same grips made to 'home hardware specifications' could have several
> points of failure, starting probably with the bent wire bail. Would
> anyone in the USA care to try a destructive test?
>
>
>
>
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