Winch Hardware - To swivel or not swivel

John G. Harte wrote:

Our club is fortunate enough to have a winch, and a large number of ground
launch endorsed pilots.

We use a steel cable and encounter some kinking and twisting at the glider
end of the setup. Last weekend we installed a swivel in line before the
cg hook and were initially pleased with the first several launches;
however, after several more, we encountered even more twisting and
kinking, but, alas, the kinking and twisting occurred in that portion of
the cable that was descending after release.

Has anyone had experience with swivel installations?

Input would be greatly appreciated.

jgh
Tost recommends that the swivel only be used when pulling out the wire rope,
not under launch tension.

I've found that putting a 'set' into the wire rope when new and every few
hundred launches also helps. We attach the wire rope to a vehicle and give
it a good hard static load.

Frank

F.L. Whiteley writes
Has anyone had experience with swivel installations

I'm no expert, and I'm sure somebody else from my club will correct me
if I'm wrong, but I believe we use three locking swivels in our setup,
one between the plastic-sheathed strop and the thick connecting rope,
another between the rope and drogue chute, and the third between the
drogue and the stranded steel cable used by our Skylaunch winches.

I do know, within my experience at least, that the setup appears to be
very effective in that we don't have any problems with twisting or
kinking in the cables.

--
Bill Gribble
http://www.scapegoatsanon.demon.co.uk
- Learn from the mistakes of others.
- You won't live long enough to make all of them yourself.

Bill Gribble wrote:
F.L. Whiteley writes

Has anyone had experience with swivel installations


I'm no expert, and I'm sure somebody else from my club will correct me
if I'm wrong, but I believe we use three locking swivels in our setup,
one between the plastic-sheathed strop and the thick connecting rope,
another between the rope and drogue chute, and the third between the
drogue and the stranded steel cable used by our Skylaunch winches.

I do know, within my experience at least, that the setup appears to be
very effective in that we don't have any problems with twisting or
kinking in the cables.


I believe the swivel on our winch cables lock under tension, i.e. locked
during a launch but free once the glider is off the cable to allow the
drogue chute to rotate without twisting the cable when winding in.

Nick Hill

From the Tost homepage:

"Use swivel only if necessary, and then only for unwinding cable, never
while launching."

Stefan