Winch rope 1/4 inch poly

On Mon, 12 Jan 2004 20:35:06 +1300, Bruce Hoult
wrote:

In article ,
Martin Gregorie wrote:

On Fri, 2 Jan 2004 17:39:28 +1300, "goneill"
wrote:

We are not talking a huge effect here

Agreed. I was watching launches at Auckland a few weeks ago and didn't
notice any gross bungee effects. All the launches I saw looked pretty
smooth.

I took a couple of winch launches at Puhipuhi in a Janus on I think poly
rope last week. Seemed pretty smooth, and I didn't notice bad effects
from stretching. Not that I got much height from my own pathetic
attempt (less than 1000 ft), but it was enough to get away...

I cheated last time I flew: poly rope all right, but attached to a
Cessna 182, not a winch. We got away too, thanks to being dropped at
2500 on a ridge across the valley from Omarama. I was in the DG-1000
and spent the next three hours learning the first steps to mountain
flying from Hugh. Fantastic! Worth every penny.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

(Doug Taylor) wrote in message . com...
Vectran would not be a very suitable winch rope. It tends to fatigue
relatively rapidly with bending. It is useful as standing rigging on
sailboats but isn't used for running rigging. Technora is about the
same tensile strength and modulus (both have very high modulus)
without the fatigue problem. I don't have any proof of this but was
told this by someone who appeared to know quite a lot about all the
various new fibers being used in rope.


Gary,

Thanks for the information. Now, if the poly could be spliced ~50/50 or so
with something like 1/8" Validator 12
http://www.samsonrope.com/admin/data...dator12_LR.pdf ,
(Vectran) http://www.pelicanrope.com/peli05c.htm both the bungee and sag
effects could be reduced with some cost benefits. This could be a solution
for long runs. When we launched with 1000ft of Spectra on the end of the
wire rope, we didn't pull the Spectra through the rollers. Two synthetics
with a reasonable join might work well as a hybrid solution.

Vectran is stronger than Spectra with a higher critical temperature, but
with somewhat less abrasion resistence.

There are some interesting 1/4" vectran sheathed products
http://www.pelicanrope.com/new04.htm
for improved abrasion resistence.

And Plasma 12
http://www.cortlandcable.com/psrope/...PlasmaRev9.pdf
Spectra in a variety of sizes.

Frank Whiteley
Colorado

OK, I can see that their are many ideas & successes on the polyrope.
Can anyone give me an idea as to the height advantage. For example.
Four thousand foot runway no wind. With wire we usually climbed to
1000 feet and with poly we averaged 1200? Does anyone know of a web
site where this info may have been posted?

Robert Curry
Ohio

Your heights seem to be a bit low off 4000ft on poly ,I would have
expected 1500 as an average
On 3300ft we are averaging 1300-1600ft with single seaters
Have you adapted the launch profile to take advantage of the rope.
gary
"Robert Curry" wrote in message
om...
(Doug Taylor) wrote in message
. com...
Vectran would not be a very suitable winch rope. It tends to fatigue
relatively rapidly with bending. It is useful as standing rigging on
sailboats but isn't used for running rigging. Technora is about the
same tensile strength and modulus (both have very high modulus)
without the fatigue problem. I don't have any proof of this but was
told this by someone who appeared to know quite a lot about all the
various new fibers being used in rope.


Gary,

Thanks for the information. Now, if the poly could be spliced ~50/50
or so
with something like 1/8" Validator 12
http://www.samsonrope.com/admin/data...dator12_LR.pdf ,
(Vectran) http://www.pelicanrope.com/peli05c.htm both the bungee and
sag
effects could be reduced with some cost benefits. This could be a
solution
for long runs. When we launched with 1000ft of Spectra on the end of
the
wire rope, we didn't pull the Spectra through the rollers. Two
synthetics
with a reasonable join might work well as a hybrid solution.

Vectran is stronger than Spectra with a higher critical temperature,
but
with somewhat less abrasion resistence.

There are some interesting 1/4" vectran sheathed products
http://www.pelicanrope.com/new04.htm
for improved abrasion resistence.

And Plasma 12
http://www.cortlandcable.com/psrope/...PlasmaRev9.pdf
Spectra in a variety of sizes.

Frank Whiteley
Colorado

OK, I can see that their are many ideas & successes on the polyrope.
Can anyone give me an idea as to the height advantage. For example.
Four thousand foot runway no wind. With wire we usually climbed to
1000 feet and with poly we averaged 1200? Does anyone know of a web
site where this info may have been posted?

Robert Curry
Ohio