SAFE Winch Launching

Chris,

Nothing special required, except that the rollers or pulleys should be
smoothed out and polished if they have been used for steel cable. Some
types of drum may need to be reinforced as Dyneema can slip and tighten on
the drum to the extent that it get crushed.

What type of winch do you have?

Derek Copeland


At 23:50 22 July 2009, Chris Nicholas wrote:
Has anybody in the good old US of A developed a printed, available,
specification for the pay-on gear for Dyneema etc. rope =96 like low
weight (aluminum? - note USA spelling!) rollers, low friction and low
inertia bearings, anything special needed for the drum , etc.?

I suspect that there is scope for saving inventing too many wheels
twice over.

(And for the avoidance of doubt, I am NOT going to get into the Bildan/
DC/DJ etc. spats =96 you are all welcome to keep those among
yourselves.)

Chris N.

Thanks for answers so far.

Derek, we have two ex-ATC winches (Eagle or Wild – not sure which), re-
equipped with USA-made V8’s and auto gearboxes. Both run on LPG or
similar. One has a completely new cab, the other a modified cab.

We bought the basic winches in about 1991 at auction, cost less than
£1000 (say $1600) each. First was modified by ourselves at very low
cost, with an ex-Ford Tow truck 5.6L V8 and associated auto
transmission. The second we used a winch-builder at another gliding
club who had built their Tost winch, and he modified ours including
new big V8 and auto transmission, and the completely new cab. I think
we spent about £14000 on the conversion, and completed a bit ourselves
at very modest extra cost.

Chris N.

Chris Nicholas wrote:
Thanks for answers so far.

Derek, we have two ex-ATC winches (Eagle or Wild – not sure which), re-
equipped with USA-made V8’s and auto gearboxes. Both run on LPG or
similar. One has a completely new cab, the other a modified cab.

We bought the basic winches in about 1991 at auction, cost less than
£1000 (say $1600) each. First was modified by ourselves at very low
cost, with an ex-Ford Tow truck 5.6L V8 and associated auto
transmission. The second we used a winch-builder at another gliding
club who had built their Tost winch, and he modified ours including
new big V8 and auto transmission, and the completely new cab. I think
we spent about £14000 on the conversion, and completed a bit ourselves
at very modest extra cost.

Chris N.


I can add that I've launched from at least one of those winches, and had
very nice launches. Probably down to the driver, though there's clearly
nothing wrong with the winch(es).

Hint for US clubs who go for a winch - pilots should always thank the
winch driver for good launches, and explain what went wrong if a launch
is not satisfactory. This feedback helps the driver to improve, and also
means that your own foibles might be catered for in future launches!
Poor launches are often the pilot's own fault, and winch drivers like to
know that it wasn't their poor driving.

On Jul 23, 12:45*am, Derek Copeland wrote:
Chris,

Nothing special required, except that the rollers or pulleys should be
smoothed out and polished if they have been used for steel cable. Some
types of drum may need to be reinforced as Dyneema can slip and tighten on
the drum to the extent that it get crushed.


More spectacularly bad advice from Del C.

Smoothing and polishing rollers will NOT work since the rope slides in
a helical path on the roller if the wrap angle is not exactly at right
angles to the roller. All roller designs used with 'plastic rope'
show rings of melted plastic when used with Plasma Rope. The rope
itself shows severe damage from melting. Using rollers with Plasma
Rope is an expensive mistake

Plasma Rope (Spectra/Dyneema) should have swiveling pulleys with
specific pulley groove geometry. I have a tested design for fairlead
pulleys with a Plasma specific guillotine that I'll let anybody use to
make their own. E-mail me and I'll send the drawings.

I assume that Bill's comment is intended to be yet another thinly veiled
attack on Skylaunch, who make an excellent winch! There is no hard
evidence that rollers are any less Dyneema friendly, and in any case
Skylaunch can supply and fit swivelling pulleys if you think they are
better. Our new Skylaunch winches at Lasham are so fitted.

Again the rollers he is talking about are as fitted to antiquated US
Gerhlein winches, and his Ford Model T analogy is about right.

The guillotine issue is more relevant. For some reason hardened steel
blades that will chop steel cable many times are instantly blunted when
used on any type of UHMWPE synthetic cable. I believe the fix is to
replace the anvil with a bronze component. So much for modern materials
and technology!

Derek Copeland

At 23:39 23 July 2009, bildan wrote:
On Jul 23, 12:45=A0am, Derek Copeland wrote:
Chris,

Nothing special required, except that the rollers or pulleys should be
smoothed out and polished if they have been used for steel cable. Some
types of drum may need to be reinforced as Dyneema can slip and
tighten
o=
n
the drum to the extent that it get crushed.


More spectacularly bad advice from Del C.

Smoothing and polishing rollers will NOT work since the rope slides in
a helical path on the roller if the wrap angle is not exactly at right
angles to the roller. All roller designs used with 'plastic rope'
show rings of melted plastic when used with Plasma Rope. The rope
itself shows severe damage from melting. Using rollers with Plasma
Rope is an expensive mistake

Plasma Rope (Spectra/Dyneema) should have swiveling pulleys with
specific pulley groove geometry. I have a tested design for fairlead
pulleys with a Plasma specific guillotine that I'll let anybody use to
make their own. E-mail me and I'll send the drawings.

On Jul 22, 5:50*pm, Chris Nicholas wrote:
Has anybody in the good old US of A developed a printed, available,
specification for the pay-on gear for Dyneema etc. rope – like low
weight (aluminum? - note USA spelling!) rollers, low friction and low
inertia bearings, anything special needed for the drum , etc.?

I suspect that there is scope for saving inventing too many wheels
twice over.

(And for the avoidance of doubt, I am NOT going to get into the Bildan/
DC/DJ etc. spats – you are all welcome to keep those among
yourselves.)

Chris N.

Yes, I have and I'll send anyone the CAD files free. The unit has
been built and tested on an old Gerhlein winch and it shows no
degradation of the Plasma Rope.

On Jul 22, 12:48*pm, tommytoyz wrote:
Bill,
How much did the Gehrlein overhaul cost? Perhaps this could process
can be replicated several times over. My guess is that once small
scale winch launching grabs a foothold via Gehrlein winches and it
becomes more popular and more pilots get winch certified, that demand
will grow and we'll see the need for more productive multiple drum
winches. Perhaps we can then use the Gehrleins as retrieve winches at
that point.

Launch costs can be brought down so low, as to stimulate soaring in
this country. I myself am tired of paying $50 for one single aerotow -
it's nuts. Nothing will stimulate soaring more than to bring the costs
down and winch launching not only does that but makes soaring more
challenging and fun too!

I know, I'm preaching to the choir. So, choir, we need a cheap initial
solution to get things moving - to demonstrate and get people
certified - before we can realistically talk about expensive, albeit
more productive, winches.
Tom

I've worked pretty hard helping small winch operations get going with
refurbished winches. You're right. Once people get familiar with
winch launch, they'll want better equipment.

On Jul 22, 12:48*pm, tommytoyz wrote:
Bill,
How much did the Gehrlein overhaul cost? Perhaps this could process
can be replicated several times over. My guess is that once small
scale winch launching grabs a foothold via Gehrlein winches and it
becomes more popular and more pilots get winch certified, that demand
will grow and we'll see the need for more productive multiple drum
winches. Perhaps we can then use the Gehrleins as retrieve winches at
that point.

Launch costs can be brought down so low, as to stimulate soaring in
this country. I myself am tired of paying $50 for one single aerotow -
it's nuts. Nothing will stimulate soaring more than to bring the costs
down and winch launching not only does that but makes soaring more
challenging and fun too!

I know, I'm preaching to the choir. So, choir, we need a cheap initial
solution to get things moving - to demonstrate and get people
certified - before we can realistically talk about expensive, albeit
more productive, winches.
Tom

So far, it's probably in the $4000 - $5000 range but this particular
winch was well worn out and, in it's original form, not really
usable. Winch works now but refurbishing is still underway.

1. Replaced engine with a GM rebuilt long block for about $1400. New
ignition, carburetor added another $600.

2. Rebuilt the '57 Chevy rear end with 3:55 gears for about $700 with
new wheel bearings. (Better idea: put '57 Chevy parts on e-Bay and
use proceeds to buy new winch.)

3. Sawed off old roller box and replaced it with a "Spectra friendly"
pulley/guillotine assembly for about $1000. Drawings available.

6. A Bunch of other bits like electric radiator fans.