Question below:

"Brian Whatcott" wrote in message
...

snipped for brevity

I looked over the test description again, more carefully this time.
The description mentioned a
"C. Sherman Johnson Co. swaged terminal, with the swaged wire assembly
professionally made."

and also mentioned that in all cases, the other end was secured with
two nicopress swaged ferrules and a bolted clamp back up.

In no case, was damage to the nicopress end noted, so I have to
conclude that the double Nicopress fixing was superior to both
roller-swaged, and swageless terminals, and remarkably cheaper.

Is this reasonable, in your view?

Brian Whatcott Altus OK

No, not reasonable. I'm not great at explaining things but I'll try.
The
double nicopress fittings could support the load imposed in the tests
only
because they were clamping an eye that was passed around a 3" dia. pipe.
Some of the load on the wire was passed to each nicopress fitting but
most
was carried by the friction inherent in the eye passing around the 3"
pipe.
Think of a rope around a bollard tied back to itself.

Hmmm....you feel that the upper wire end was essentially locked to a
pipe by friction.

And so, I presume, you feel that the pipe was prevented from
rotating, because if your explanation is correct, there would be a
turning couple on the pipe.

Actually, the turning couple on the pipe is counter balanced by an equal
turning couple inmposed by the dead end continuing down the other side back
to the nicopress fitting.

Actually, light aircraft use double Nicopress swages, but a preferred
setup is to leave a slight loop before the second swage, in order to
observe the onset of slipping failure in the first Nicopress.
Others paint a mark at a joint.

I know it doesn't sit well with people who feel they need to pay ??$80
a fitting, but Nicopress are strong and reliable enough to be used in
a more demanding role than sailboat rigging. My opinion, naturally.

Brian W

I think I'm missing something here. Are you suggesting instead of using
swaged or other ends on wire terminations we use a couple of nicropress
sleeves and a large enough thimble to allow the wire to turn back on itself
without weakening it by bending it too severely? (This is how all the
terminations are done on a Laser II for instance but in that case the wires
are rather small.) Note that in the test they felt they needed a 3"
diameter pipe so as to not bend the cable too abruptly.
What then goes through the thimble to retain the end terminated thus? A pin
large enough in diameter to prevent the thimble from collapsing under load?
Or are there thimbles available, strong enough to retain their shape under
load with a small pin passing through like the one in a turnbuckle fork?
The turnbuckle fork would have to be wider than usual to accommodate the
thimble. Wouldn't this make for a rather bulky termination? We are talking
about rigging sized wire, not skinny little cables like the type used on a
light aircraft's controls.
--
Ken Heaton, Cape Breton Island, Canada
kenheaton AT ess wye dee DOT eastlink DOT ca