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 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 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.

On Jul 22, 11:16*pm, Frank Whiteley wrote:
On Jul 22, 6:38*pm, sisu1a wrote:



On Jul 22, 4:50*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.

While I'm sure there *are such documents handy, if your goal is
'saving wheels' one can (and is better off...) doing away with the
level wind mechanism altogether, which is itself a source of
additional hassle in most operations. The trick is to use a high
enough aspect drum and have a long enough run between the fairlead
assy and the drum, somewhere around 1:18 I believe, comparing drum
width to run length between the two mechanisms according to German
DAeC.

Assuming a bigblock/TH400/truck rearend setup is what you're leaning
towards, final drive gearing needs to be selected based on drum
diameter, since larger diameter drums call for higher gear ratios in
the rearends... a small price to pay considering. There are
spreadsheets and other files covering all this on winchdesign BTW

-Paul

PS. join the winchdesign group and comb the postings and files there
as well as keeping up on new ones...http://groups.yahoo.com/group/winchdesign/*-that is if you can
handle more episodes of the Derek/Bill show *

The ratio of drum width to feed is 10:1 for unassisted level winding.
So an 8-inch wide drum needs 80 inches. *The Gehrlein Model 62
distance is about 88 inches from axle to rollers. *The drum I had
built is 8.5 inches wide. *A high ratio can only make it more
effective.

That said, the winch at Littlefield, TX, uses a simple level wind that
is easy to maintain and works very well on their wide drum. *The wide
drum advantage is the there is a small shift in the torque arm as the
drum loads.

Frank Whiteley

The German DAeC winch recommendation calls for an 18:1 ratio between
fairlead pulleys and the drum width. However, that's for steel
cable. "Plastic Rope" seems to spread out nicely so even 8:1 seems to
work.

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.

On Jul 22, 10:30*am, Dave Martin wrote:
So what are you saying Bill?

That old technology actually works and being brought up to date
does the job people want?


Well, not really. You could say a Model T "works" but you wouldn't
want to take one on a California Freeway. They're good enough to get
started but I really hope to see them quickly replaced with far, far
better equipment.

You have to put the word "works" in quotes since a refurbished
Gerhlein winch only works as well as it did in the '50's - except for
the Plasma Rope which is light years ahead of steel cable. There's a
technology gulf of more than half a century between the technology in
an old Gerhlein and state-of-the-art winches like the Hydrowinch.

These old winches are highly dependent on skilled winch operators and
benign operating conditions. They can still deliver some big
surprises under non-optimum conditions. There are virtually no
safeguards against operator error or really much protection for the
winch operator. Even under optimum conditions, one launch is rarely
like the one before.

On Jul 21, 4:12*pm, tommytoyz wrote:
Perhaps the way to go is just buy a good used winch from a European
club. What was the offered price again for that old Tost winch at
Lasham?

My German contacts recommend against buying an old Tost winch since
the parts they are made from are no longer available. In many ways
they share the same technology as the old Gerhleins.