Eric, George Moore of Spokane is working on exactly the approach you
suggest. Electric drive offers a seamless CVT drive that lets a computer
control the launch to a degree of precision no human winch driver can
approach. That precision allows the use of much higher rope tension with
much greater safety than the old automobile V8 and non-electronic 4-speed
transmission.

The key enabler for electric winches is the frenetic work being done on
electric, and electric hybrid cars. The required parts are available now
but not at attractive prices. The hope is that once these vehicles are in
mass production in 5 - 10 years, the component prices will drop
substantially.

Oh yes, I should mention the rather elegant ESW-2B from Germany which uses
50 car starting batteries as a buffer to store enough power for ~20
launches. This winch is usually connected to the grid to keep the huge
battery pack topped up but it can also use a diesel generator. A grid tap
or a generator adds substantially to the cost but where electricity is
available or where there are extremely noise sensitive airfield neighbors,
it's a viable choice.

So, the concept of an electric winch is very elegant but not quite
economically attractive at this point. It's worth point out that diesel -
hydrostatic drive (Hydraulic pumps and motors) achieves the same degree of
controllability and the components are almost a commodity. My guess is that
hydrostatic drive is the near term solution and electric is a good bet for
the middle future if the component prices can drop below hydrostatic
components.

Bill Daniels

"Eric Greenwell" wrote in message
news:wlRcj.2733$si6.2097@trndny08...
Bill Daniels wrote:
Let me predict that in the near future, one and perhaps two US based
manufacturers will be offering a FAR better winch design than the
Skylaunch at a similar price. Hang tight.

What's the winch community's opinion on a "hybrid" winch, which uses an
electric motor and batteries to do the launch, and a generator to keep the
batteries charged? That might give a more easily controlled, possibly
automated, power system, but retain the indpendence of a gas/diesel winch.

Lighter weight gliders, coupled with smaller, lower cost winches that are
dead simple to operate (or can perform the launch automatically) might do
more for growing the sport than a somewhat cheaper version of the gliders
we fly now.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org