Winch Experts wanted

On Thu, 18 Mar 2004 20:42:21 GMT, "mat Redsell"
wrote:

And in part I do think that we have taken a wrong road with high wing
loading. for example with the Monarch we are able to tow it aloft with 160
lbs of tension at a speed of about 15 mph with a wind down the runway of
about 10 mph. This requires a very small rope and small horsepower.

Nothing better than runing 125 kts between clouds with a 50 kg/m^2
wing loading in my ASW-27 after a $2 winch launch on my club's 280 hp
Diesel winch. vbg


Bye
Andreas

On 18 Mar 2004 10:35:33 -0800, (Ulrich Neumann)
wrote:

I think the biggest problem to overcome is the mind-set that the winch
has to be built (cobbled together) in one weekend from parts supplied
exclusively from the local junk-yard. Lets apply some sound
engineering, craftsmenship and parts, that are commercially available
for years to come.

Sounds like a vacation in Germany might be a good idea... many good
examples of more or less well-engineered winches available here.
Typically each club has its own design, and nearly all of them seem to
be working well enough.

Bye
Andreas

Ulrich,
See if you can find a contact at "The Soaring Centre", Husbands
Bosworth in UK.
Some years ago they built their own 4-drum winch. I saw it a few years
ago, and it was a most impressive machine.
Unfortunately I don't have any contact info for them, but they do have
a web site at: http://www.thesoaringcentre.co.uk/index.htm

Cheers, John G. (Australia)
"Ulrich Neumann" wrote in message
om...
"mat Redsell" wrote in message
...
I really think this idea has merit.... but should we also consider
lowering
the wing loading so that the horsepower requirements are much
less? I also
think that the future of soaring is rather bleak without winch
alternatives.

Mat,

I don't think that the road-block for whole winch idea is
horse-power.
Horse-Power is available in abundance at a reasonable cost - see
Bill
Daniels' write-up on this subject. Even with a high HP winch, older,
smaller and lighter gliders can be launched. It is only when you
have
a fully watered open ship or heavy double seat trainer on the other
end of the cable when you need the extra uhmpf!
I think the biggest problem to overcome is the mind-set that the
winch
has to be built (cobbled together) in one weekend from parts
supplied
exclusively from the local junk-yard. Lets apply some sound
engineering, craftsmenship and parts, that are commercially
available
for years to come.

Ulrih Neumann

mat Redsell wrote:
My statement was very confusing... what I really meant was without the winch
I think that we will be in troubles down the road for affordable tows....

And in part I do think that we have taken a wrong road with high wing
loading. for example with the Monarch we are able to tow it aloft with 160
lbs of tension at a speed of about 15 mph with a wind down the runway of
about 10 mph. This requires a very small rope and small horsepower.

http://www.continuo.com/marske/
look under articles for : ultralight design parameters design parameters of
the ultralight glider

I'd love to see a winch design that uses a 100hp or less engine,
can be easily bolted on the back of an old pickup, and has engine
and parts that are low maintenance and (especially engine) easy
to acquire (either locally or via shipping).

Alternately, how about a "spare tire" that is really a winch drum.
a stable sturdy "jack" and some way to route the cable
to ensure it winds up nice.

Might not work (thoughts of side loads tipping my car
over come to mind!), but it sure is fun to play with the
thuoght!
--

------------+
Mark Boyd
Avenal, California, USA

"Mark James Boyd" wrote in message
news:405aa3e8$1@darkstar...

I'd love to see a winch design that uses a 100hp or less engine,
can be easily bolted on the back of an old pickup, and has engine
and parts that are low maintenance and (especially engine) easy
to acquire (either locally or via shipping).

Alternately, how about a "spare tire" that is really a winch drum.
a stable sturdy "jack" and some way to route the cable
to ensure it winds up nice.

Might not work (thoughts of side loads tipping my car
over come to mind!), but it sure is fun to play with the
thuoght!
--

------------+
Mark Boyd
Avenal, California, USA

Mark, unfortunately, the physics of a winch launch says that it takes about
1 kWh or 3,600,000 Joules to launch a glider. The peak power demand places
yet another constraint on the minimum HP that must be available. Those
numbers point to a 400 to 500 HP engine to be able to provide launch service
to any glider in the existing fleet. Although the initial cost of a well
engineered winch is high (nearly as much as a tow plane) the long term costs
are only a few percent as much a tug.

The good news is that the total energy consumed for one launch (About 1
liter of diesel fuel equivalent) is tiny compared to any other launch method
except bungee launch. (Excluding, of course, the beer you have to provide
the bungee crew.)

A glider winch is a highly specialized piece of machinery that needs the
kind of engineering Ulrich is asking for. Please avoid the temptation to
cobble some junk together to make a barely workable winch. That sort of
thing has given winch launch a bad name in the USA.

A well run winch operation is very attractive to newcomers to the sport. It
shows a lot of ground activity that is visible to the onlookers and the
rides are a real thrill. Lets get winching!

Bill Daniels

Bill,

I think you need to revisit your numbers.

Here at Nympsfield (UK) we have a Supacat winch with
a 250 horse Diesel that easily provides enough power
for the biggest gliders on site (DG505, DuoDT, Nimbus3DT)
(And pretty scary in a Libelle if the winch driver
is *over enthusiastic*)

The previous engine was 180 HP, this was a bit marginal
for the Heavy Glass, but more than enough for any single
seat

(We have a 1000m field & regularly get 1500', even
nil wind)

:-)

KN

At 15:36 19 March 2004, Bill Daniels wrote:

Mark, unfortunately, the physics of a winch launch
says that it takes about
1 kWh or 3,600,000 Joules to launch a glider. The
peak power demand places
yet another constraint on the minimum HP that must
be available. Those
numbers point to a 400 to 500 HP engine to be able
to provide launch service
to any glider in the existing fleet.

(Mark James Boyd) wrote in message news:405aa3e8$1@darkstar...
mat Redsell wrote:
My statement was very confusing... what I really meant was without the winch
I think that we will be in troubles down the road for affordable tows....

And in part I do think that we have taken a wrong road with high wing
loading. for example with the Monarch we are able to tow it aloft with 160
lbs of tension at a speed of about 15 mph with a wind down the runway of
about 10 mph. This requires a very small rope and small horsepower.

http://www.continuo.com/marske/
look under articles for : ultralight design parameters design parameters of
the ultralight glider

I'd love to see a winch design that uses a 100hp or less engine,
can be easily bolted on the back of an old pickup, and has engine
and parts that are low maintenance and (especially engine) easy
to acquire (either locally or via shipping).

Alternately, how about a "spare tire" that is really a winch drum.
a stable sturdy "jack" and some way to route the cable
to ensure it winds up nice.

Might not work (thoughts of side loads tipping my car
over come to mind!), but it sure is fun to play with the
thuoght!

Mark,

a 100HP or less winch? What are you trying to launch - kites or RC
gliders? The Europeans are replacing their winches powered
traditionally by Detroit's finest with big rig Diesels, because ...?
Lets get real here. As nice as it sounds to have your own personal
winch in the trunk, the reality looks more like you could haul your
car around with the winch.

But keep the ideas coming.

Ulrich Neumann

On Fri, 19 Mar 2004 08:24:24 -0700, "Bill Daniels"
wrote:


"Mark James Boyd" wrote in message
news:405aa3e8$1@darkstar...

I'd love to see a winch design that uses a 100hp or less engine,
can be easily bolted on the back of an old pickup, and has engine
and parts that are low maintenance and (especially engine) easy
to acquire (either locally or via shipping).

Alternately, how about a "spare tire" that is really a winch drum.
a stable sturdy "jack" and some way to route the cable
to ensure it winds up nice.

Might not work (thoughts of side loads tipping my car
over come to mind!), but it sure is fun to play with the
thuoght!
--

------------+
Mark Boyd
Avenal, California, USA

Mark, unfortunately, the physics of a winch launch says that it takes about
1 kWh or 3,600,000 Joules to launch a glider. The peak power demand places
yet another constraint on the minimum HP that must be available. Those
numbers point to a 400 to 500 HP engine to be able to provide launch service
to any glider in the existing fleet. Although the initial cost of a well
engineered winch is high (nearly as much as a tow plane) the long term costs
are only a few percent as much a tug.

The good news is that the total energy consumed for one launch (About 1
liter of diesel fuel equivalent) is tiny compared to any other launch method
except bungee launch. (Excluding, of course, the beer you have to provide
the bungee crew.)

A glider winch is a highly specialized piece of machinery that needs the
kind of engineering Ulrich is asking for. Please avoid the temptation to
cobble some junk together to make a barely workable winch. That sort of
thing has given winch launch a bad name in the USA.

A well run winch operation is very attractive to newcomers to the sport. It
shows a lot of ground activity that is visible to the onlookers and the
rides are a real thrill. Lets get winching!

Bill Daniels

If you have a diesel driving through a fluid flywheel you don't need
that much power: we have a Supacat with a 245 hp Deutz V8 aircooled
industrial diesel and torque converter (no gearbox). This can launch
an ASH-25 or just about any Nimbus. With a 15 m glider, K-21 or Grob
you'd expect 1200-1400 ft on a 1000m run in calm conditions and over
2000 ft if its blowing a bit.

I'd agree with everything you've said about the specialised nature of
a glider winch, the heavy duty engineering and the costs.

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

Martin Gregorie wrote:
If you have a diesel driving through a fluid flywheel you don't need
that much power: we have a Supacat with a 245 hp Deutz V8 aircooled
industrial diesel and torque converter (no gearbox). This can launch
an ASH-25 or just about any Nimbus. With a 15 m glider, K-21 or Grob
you'd expect 1200-1400 ft on a 1000m run in calm conditions and over
2000 ft if its blowing a bit.

I think the difference is that Bill is considering operating at much
higher density altitudes. In the western US, there are many glider
operations where summer density altitudes are in the 8000+ foot range.

Marc

You have to remember folks that these are American horsepower units. About
2:1 is a good ratio against proper European horses!

:-)

Ian

"Kevin Neave" wrote in message
...
Bill,

I think you need to revisit your numbers.

Here at Nympsfield (UK) we have a Supacat winch with
a 250 horse Diesel that easily provides enough power
for the biggest gliders on site (DG505, DuoDT, Nimbus3DT)
(And pretty scary in a Libelle if the winch driver
is *over enthusiastic*)

The previous engine was 180 HP, this was a bit marginal
for the Heavy Glass, but more than enough for any single
seat

(We have a 1000m field & regularly get 1500', even
nil wind)

:-)

KN

At 15:36 19 March 2004, Bill Daniels wrote:

Mark, unfortunately, the physics of a winch launch
says that it takes about
1 kWh or 3,600,000 Joules to launch a glider. The
peak power demand places
yet another constraint on the minimum HP that must
be available. Those
numbers point to a 400 to 500 HP engine to be able
to provide launch service
to any glider in the existing fleet.