SAFE Winch Launching

At 14:52 12 July 2009, bildan wrote:

Do I have an emotional bias against crappy engineering? Damn right I
do - especially when it's being sold as the 'perfect' solution.

My club in New Jersey used to operate a winch. It was before my time
(hard to believe anything was before my time, but there you are). It was
made from a Model A Ford chassis. One rear axle was welded solid and a
drum (probably made from an old truck wheel) was mounted on the other axle
with the launch rope wrapped around it. They launched down the side of a
hill and had one helluva lot of fun doing it.

OK, this was back in the 1930s, as I've heard the tales.

We'd all like to have the ultimate winch to launch with. We'd also like
to all have Ferraris to drive. Most of us settle for what we can afford,
and try to avoid letting the perfect become the enemy of the good.

Jim Beckman

On Jul 13, 1:15*am, Derek Copeland wrote:
At 21:30 12 July 2009, David Chapman wrote:

But other nonsense posted here . please help me, *...

A standard car auto gearbox has some magic power to automatically adjust
the torque to the car wheels on reaching a hill, without changing gear,
road speed or engine setting? What magic is that?

David.

Bill Daniels has some very strange ideas as to how an automatic gearbox
works! As far as I am concerned, it is a device to allow a motor vehicle
to move off from rest, to smoothly change gears, and to stop without
stalling the engine, without a driver operated mechanical clutch. It is
not cruise control!

In that changing gear with a mechanical gearbox and clutch would give
dangerous short term losses of power, an automatic gearbox is an essential
component for any winch or towcar.

Derek Copeland

The only strange part is your inability to read and understand
technical manuals. No one except yourself used the term "cruise
control". Automatic transmissions are extremely complicated devices
with complex behaviors that cannot be understood in your simple terms.

On Jul 13, 2:45*am, Dave Martin wrote:
Bill

The arguments are now in an endless repetative cycle fired by the theories
you propose and the convenient practicalities of the European systems, also
used by older US winches *- still in use today.

There is only one solution the challenge is there -- get the winch built
with the new technology and at a competetive price and put it on the
market.

Like new glider technology if it works people will use it.

Sadly much as we would like to do it we cannot change overnight.

Look how long it has taken to get the EB28 technology into a practical
aircraft --- but at what cost and how many of us can actually afford it?

Dave

*At 07:15 13 July 2009, Derek Copeland wrote:

At 21:30 12 July 2009, David Chapman wrote:

But other nonsense posted here . please help me, *...

A standard car auto gearbox has some magic power to automatically
adjust
the torque to the car wheels on reaching a hill, without changing gear,
road speed or engine setting? What magic is that?

David.

Bill Daniels has some very strange ideas as to how an automatic gearbox
works! As far as I am concerned, it is a device to allow a motor vehicle
to move off from rest, to smoothly change gears, and to stop without
stalling the engine, without a driver operated mechanical clutch. It is
not cruise control!

In that changing gear with a mechanical gearbox and clutch would give
dangerous short term losses of power, an automatic gearbox is an
essential
component for any winch or towcar.

Derek Copeland

We are doing exactly that - and it's working! It's what has the Brits
so agitated.

After reading these cat fights for well over a year, and now that it
has spilled out into RAS, I think this public (and personal) argument
is doing harm to potential winch activity in the U.S. There are many
glider pilots in the U.S. who believe that winch launching is more
dangerous than aerotow… and this endless debate, about the merits of
one technology over another, just fuels that skepticism.

Engineers, by personality and training, want clear-cut black and white
answers to a problem. The fact is that there is a lot of gray involved
in what works with winch equipment. Regardless of the merits of new
winch technology, Europe has been effectively winch launching for many
decades with “traditional” mechanical technology. Setting the
engineering skirmish aside, the old technology is proven to work over
the course of hundreds of thousands of launches. Maybe the “new”
technology is better, but keeping it in context – it is a potential
alternative to the proven traditional technology, not *THE* definitive
answer. This is what is being lost in this ongoing point and counter-
point dialog.

There are many of us who believe in the merits of winch launching; and
that U.S. glider pilots would benefit from the widespread adoption of
the technique. However, from a management standpoint these ongoing
inscrutable arguments are a winch advocate’s public relations
nightmare. The fact is that traditional automotive-based winch
technology works, as proven by decades of successful use. The
developing new technology may be an improvement, but that in no way
negates the wide-spread use of lower cost existing technology.

It would benefit the soaring community if the polarized principals in
this personal disagreement would spend their time advocating winch
launching as a method, rather than publically arguing over technical
details that may or may not be relevant. For most of us involved in
winching, the debate is somewhat amusing (if not distressing), but
what is does do is to support anti-winch sentiment in the U.S.

Just as we can effectively train new pilots in a K-13 or a DG-1000, we
can effectively and safely winch launch with automotive-based hardware
or new technology hardware. If we could re-focus this obsessive, bias,
and argumentative dialog into promoting the use of ground launching it
would be of greater benefit to the soaring community at large.

Anyone agree?

Bob Lacovara
(Winch pilot, winch driver, winch advocate)

On Jul 13, 6:30*am, Del C wrote:
Unless Bill has invented a perpetual motion machine, you can't get more
power out of a mechanical device (such as an automatic gearbox) than you
put in. You can gear that power down to get more torque, but the Skylaunch
winch depends on supplying the right amount of power (related to throttle
setting) for the given glider type and headwind component. The automatic
gearbox is only useful to provide some extra torque at low revs to get the
glider moving at the start of the ground run without stalling the engine.

Derek Copeland

At 22:45 12 July 2009, bildan wrote:

On Jul 12, 3:30=A0pm, David Chapman
wrote:

But other nonsense posted here . please help me, =A0...

A standard car auto gearbox has some magic power to automatically
adjust
the torque to the car wheels on reaching a hill, without changing
gear,
road speed or engine setting? What magic is that?

That 'magic' is called a torque converter which begins to slip and
multiply torque under increasing load. *Stock units can double torque
to the wheels.

Modern transmissions use a torque converter locking clutch allowing an
even greater torque multipication factor after the clutch disengages
under load. *The effect can be 4:1 or greater.

For basic info, see:http://en.wikipedia.org/wiki/Torque_converter

In addition, automobile engine torque curves have peak torque lower
than cruise RPM. *As the vehicle encounters a load such as a hill, the
torque output actually increases as the RPM is pulled down by the
increasing load. *The typical V8 used in glider winches has a torque
peak at about 1800 RPM.

The engine/transmission combination acts in exact opposition to what
is needed in a glider winch.

In fact, with an automatic transmission in the drive line, it's
impossible to ever get the rope tension exactly right - certainly not
with something as simple minded as a throttle stop.

Most of what an automatic actually does in a glider winch is either
unnecessary or detrimental. Only the auto-clutch action at idle is
useful and there are far better ways to do that. The only
justification for using an automatic in a winch is that it's cheap and
comes with the engine.

The idea that low starting gears are necessary with a glider winch is
absurd. Tost gutted their automatics - even while saying automatics
were dangerous - to eliminate everything but the torque converter
leaving the box in it's straight through 1:1 ratio. Simple torque
calculations show that 3rd gear is capable of breaking the strongest
weak link during acceleration. Stepping through 1st and 2nd gears
only makes it more difficult to achieve accurate acceleration.

After watching this thread deteriorate, it reminds me why I stopped participating in the WinchDesign Yahoo news group. The discussions became personal, agressive, angry, and absent of civility.

I really wish this thread would change its' tone, or move back to the WinchDesign group.



..

When our Tost winches were fitted with 'one speed' (fixed in top)
automatic gearboxes, the ground run acceleration for the heavier two
seater was somewhat ponderous, although they could still rocket launch
lightweight K8 single seaters. They also tended to overheat the gearbox
oil, despite being fitted with big oil coolers with electric fans.

This was also why you had to apply full throttle to get the gliders moving
and then back off as the gliders entered the full climb, to avoid a huge
overspeed. From a winch driver's point of view, it was hard to get this
right, which was probably the cause of some of the awful launches we used
to have to endure in that era.

Derek Copeland


At 14:49 13 July 2009, bildan wrote:
On Jul 13, 6:30=A0am, Del C wrote:
Unless Bill has invented a perpetual motion machine, you can't get
more
power out of a mechanical device (such as an automatic gearbox) than
you
put in. You can gear that power down to get more torque, but the
Skylaunc=
h
winch depends on supplying the right amount of power (related to
throttle
setting) for the given glider type and headwind component. The
automatic
gearbox is only useful to provide some extra torque at low revs to get
th=
e
glider moving at the start of the ground run without stalling the
engine.

Derek Copeland

At 22:45 12 July 2009, bildan wrote:

On Jul 12, 3:30=3DA0pm, David Chapman
wrote:

But other nonsense posted here . please help me, =3DA0...

A standard car auto gearbox has some magic power to automatically
adjust
the torque to the car wheels on reaching a hill, without changing
gear,
road speed or engine setting? What magic is that?

That 'magic' is called a torque converter which begins to slip and
multiply torque under increasing load. =A0Stock units can double
torque
to the wheels.

Modern transmissions use a torque converter locking clutch allowing
an
even greater torque multipication factor after the clutch disengages
under load. =A0The effect can be 4:1 or greater.

For basic info, see:http://en.wikipedia.org/wiki/Torque_converter

In addition, automobile engine torque curves have peak torque lower
than cruise RPM. =A0As the vehicle encounters a load such as a hill,
the
torque output actually increases as the RPM is pulled down by the
increasing load. =A0The typical V8 used in glider winches has a
torque
peak at about 1800 RPM.

The engine/transmission combination acts in exact opposition to what
is needed in a glider winch.

In fact, with an automatic transmission in the drive line, it's
impossible to ever get the rope tension exactly right - certainly not
with something as simple minded as a throttle stop.

Most of what an automatic actually does in a glider winch is either
unnecessary or detrimental. Only the auto-clutch action at idle is
useful and there are far better ways to do that. The only
justification for using an automatic in a winch is that it's cheap and
comes with the engine.

The idea that low starting gears are necessary with a glider winch is
absurd. Tost gutted their automatics - even while saying automatics
were dangerous - to eliminate everything but the torque converter
leaving the box in it's straight through 1:1 ratio. Simple torque
calculations show that 3rd gear is capable of breaking the strongest
weak link during acceleration. Stepping through 1st and 2nd gears
only makes it more difficult to achieve accurate acceleration.

Yeah... well, my point exactly. Over and out.

Bob Lacovara

On Jul 11, 1:34*pm, johngalloway wrote:
On 11 July, 14:36, bildan wrote:



On Jul 11, 2:00*am, Derek Copeland wrote:

At my club we typically get about 1600ft in no wind and

2000ft launching into a 10 knot headwind. Our standard aerotows are 2000ft,
but you can go as high as you like, depending on your needs and the depth
of your wallet.

This week we were getting as high as 1900' from 3900 feet of rope at
9000 feet density altitude with little wind with the Hydrowinch. *With
no gear shifting at all, the Hydrowinch is MUCH smoother than any
winch with an automatic transmission.

Skylaunches are just like old Gerhleins with new paint - they use
exactly the same components. *They are not particularly well
controlled since they use road vehicle torque converters and automatic
transmissions free to shift gears when they please. *The old junk
Gerhleins around most US clubs are probably the only winches in the
world worse than a Skylaunch - but they are a LOT cheaper.

BTW, notice how Derek has to reply to himself to get any conversation
at all?

This account of the performance of the Skylaunch winch is, as Bill has
repeatedly been told previously elsewhere by pilots who actually
operate or launch on Skylaunch winches, utterly false and his
obsessive denigration of it is disgraceful. *Our club had a Skylaunch
winch for evaluation for six days a couple of weeks ago. *The
smoothness of launch is faultless and a vast improvement over Supacat
and Tost winches

The fact that the automatic transmission can shift gears "when they
please" is a complete non issue. *The gear changes up at the start of
the launch occur within the first 2-3 seconds (timed by me) and before
the glider has rotated into the climb. *The gear changes are
completely imperceptible in the glider. *None of numerous pilots on
the ground near the winch during launches note the upwards gear
changes without being prompted to listen out for them - an even then
there was soe debate about whether they could be detected.
Occasionally the autobox changes down to second during the mid launch
when under load but at no time was any of the many pilots launched
aware of any gear change.

The operational mechanisms of the Skylaunch are not designed to
"control" the launch so it is not surprising that it does not do so.
What it does have is an interconnected maximum throttle position guide
that takes into account the type of the glider and the headwind
component. *This means that each glider is effectively provided with a
winch with an appropriately powered engine for itself and the wind
conditions in the mid launch. *The winch driver still has to control
the start and end of the launch - by advancing the throttle control at
an appropriate rate at the start (about 3 seconds IMHO) and backing
off the power at the top. *The predictable response of the good old GM
V8 to load means that the plot can pull into a steep climb without
fear of overspeeding.

The new US winches may turn out to be brilliant but Bill's emotional
bias invalidates him as an objective reporter in my opinion.

John Galloway

Look, I didn't start this thread. You don't have a perfect winch and
neither does anybody else. There's a LOT of room for improvements in
every aspect of winch design. Keep an open mind.

If you think that automatic gear changes don't matter, put a tension
logger on yours for a few launches. The results will astonish you.

What gets my dander up is "emotional" opposition to all attempts at
innovation based on the idea that your domestic winch is 'perfect'.

At 15:01 13 July 2009, Wayne Paul wrote:
After watching this thread deteriorate, it reminds me why I stopped =
participating in the WinchDesign Yahoo news group. The discussions =
became personal, agressive, angry, and absent of civility.

I really wish this thread would change its' tone, or move back to the =
WinchDesign group.

I started this thread off trying to promote winch launching as a safe,
environmentally friendly and low cost means of launching gliders. Most
gliding clubs in Germany, Holland, the UK and the Eastern European
countries do the majority of their launches this way.

The problem is Bill Daniels. I have no idea what his true agenda is: Maybe
to build up a US winch building empire? However the BGA winching advisor,
who knows everything there is to know about winch launching, has also
given up posting on the Winch Design Group in disgust.

Derek Copeland