Winch Experts wanted

We all know "cheap" is a relative word. Cheaper than a Skylaunch leaves
a lot of ground. Just like any design project, we need to start with
some goals.

Reality is that a 2 drum winch probably is the peak in operational
efficiency coupled with simplicity of design. Piggot's book recommends
multiple 2 drum winches over winch designs with more than 3 drums.
Safety for the operator is paramount and clearly we need to be providing
enough power to handle a glider on a Black weak link. In general this
design should keep cost in mind, but surely as any club or group starts
to embark on construction they will have a lot of latitude as to how
they control costs. Do they buy a crate motor for $3-4k or buy that
little old lady's Cadillac for $500.

However, the first thing needs to be a forum off of RAS where we can
work. Ulrich started this, so I'll defer to his preferences. The Yahoo
groups are free, offer file sharing (I think) and it's easy to set up
topics to be voted on by the members. With that, we can start nailing
down the design goals.

Bill Daniels wrote:
"Ian Forbes" wrote in message
...

Mark Zivley wrote:


This project should probably be moved to a slightly different forum
like a yahoo group where people interested in participating can do so
without
filling up RAS. This also allows the sharing of files and even voting
on ideas as the project starts to take shape. We're definitely onto
something here, lets get started. We should start by doing some
deciding as to what will be designed. 1 or 2 or more drums.....

Now you are talking!

Lets get the fundamentals right. We want a design that is easy to build,
not too expensive, simple to operate, easy to maintain and with safety
standards to meet current best practice. Performance should be capable
of launching a glass 2 seater trainer to a hight not less than 1/3 of
the runway length in zero wind conditions.

I vote for a big block V8 petrol motor powering a double drum winch. For
the guys who want to talk about exotics electric winches and diesels
with modified ECU's - go for it but lets separate the threads. I think
the successful 'one design' winch is going to run on petrol and will be
made from readily available hardware. If we have any spare cash left in
the budget we will spend it on plasma rope.

As a starting point, lets get some specs on winches that have been built
already together with performances achieved. We need to start off with
parameters like engine capacity and size, drum dimensions, final drive
ratios, gearbox/torque converter details and the source make and model
of the components used.

Then we need detail engineering drawings for the clever bits. Winch drum
axle mods, guillotines, guide pulleys. These should best be based on
proven designs. Details for a Skylaunch like throttle control would be
nice. Good engineering detail for the safety items like the operator's
cage and cable guards might save a few home builders from unexpected
injury.

The engineering should accommodate a choice of cables. Single strand,
multistrand or plasma. We need to spec those too.

We should also put together a "bill of materials" for anybody planning
on establishing a winching operation. I am thinking of a comprehensive
list of things like weak links, rings, 'chute, snake, signal lights,
radios, cable retrieve vehicle... That in itself would at least allow
for drawing up a proper budget.

As for a forum - if we are going to move off RAS, Al's gliderforum.com
might be a good home. If we want to run off an e-mail list, I can
probably make a plan to host it. We will also need a repository for
information - a web site - perhaps a "wikki".

Finally we need to establish some ground rules regarding copyright and
ownership of the design. My vote is to follow the "Open Source" model
used by Linux etc. Publish everything and allow anybody to use it - but
under the condition they publish details of what they build and how
well it works.

Who's in?

Ian



Ian. I admire your enthusiasm and support your ideas, but the economics need
a bit of discussion.

Winches are VERY profitable. The operational cost is less than $2US per
launch and most people will find $10 is a reasonable launch fee. That's a
500% profit with a volunteer crew in a club setting. The Return On
Investment for a $30,000 winch is just 63 operating days figuring an average
of 60 launches a day. A dual drum winch in a training environment can do a
LOT more than 60 launches a day.

After the club has its ROI it can buy a new glider every year with the
profits. That's the REAL secret of how those European clubs own all that
nice glass. They put their money into gliders instead of air tow fees.

My concern is that by focusing on the "build it cheap" aspect, the
productivity of the machine will be lost. That's where American winches
have gone wrong in the past. Just a couple of weekends lost to winch
repairs is significant. If the "Hassle Factor" is too large, people will go
back to air tow.

Build it right, make it reliable and as productive as possible no matter if
it costs more to build. If a diesel engine is more productive than a spark
ignition engine then pay the extra money for one. If Spectra improves the
operation by reducing cable breaks and tangles then pony up for it. The ROI
comes very quickly. Almost ANYTHING that increases the number of launches
per day or makes the whole operation easier and more pleasant is worth the
investment.

Bill Daniels

In my experience, one drum is pretty adequate.

Most fields in the US are limited in length, so the launch height is usually
just enough for a pattern. I find with one drum I can launch a ship, retrieve
the chute, and have be back at the launch point just as the glider lands. We
turn the glider around (usually lands cross wind), and we're ready to go with
another. We achieve about 6-7 launches per hour this way at my field..until
two or three other people turn up (with little experience but they're BS'ed the
membership into thinking they know what they're doing) and our rate goes down
to about 3 an hour.

Jim Vincent
CFIG
N483SZ
illspam

"Jim Vincent" wrote in message
...
In my experience, one drum is pretty adequate.

Most fields in the US are limited in length, so the launch height is
usually
just enough for a pattern. I find with one drum I can launch a ship,
retrieve
the chute, and have be back at the launch point just as the glider lands.
We
turn the glider around (usually lands cross wind), and we're ready to go
with
another. We achieve about 6-7 launches per hour this way at my
field..until
two or three other people turn up (with little experience but they're
BS'ed the
membership into thinking they know what they're doing) and our rate goes
down
to about 3 an hour.

Jim Vincent
CFIG
N483SZ
illspam

Jim, with one glider, one drum works fine. The length of the field doesn't
matter since with a longer field, the glider goes higher and stays up longer
so the wire is still back at the launch site in time for the glider landing
if the retrieve driver hustles. If you are launching from grass, all those
wire retrieves are sure tearing up the turf.

My most recent winching is with 5000 feet of wire and 2000 feet AGL is a
common release height. If there are any thermals, the glider will contact
one 3 out of 4 launches and soar away. In the western US there are many
runways 7000 feet or longer where winching is possible. You're talking
3000' AGL launches with that much room.

With a gaggle of gliders waiting to be launched you need the efficiency of
multiple drums or multiple winches. The real issue is often not how many
launches you can make in a day, it's how fast can you get everybody launched
when the thermals start. I've read of several winch operations that achieve
a sustained launch rate of one every two minutes.

Bill Daniels

I second the yahoo groups.

Frank Whiteley

"Mark Zivley" wrote in message
news
We all know "cheap" is a relative word. Cheaper than a Skylaunch leaves
a lot of ground. Just like any design project, we need to start with
some goals.

Reality is that a 2 drum winch probably is the peak in operational
efficiency coupled with simplicity of design. Piggot's book recommends
multiple 2 drum winches over winch designs with more than 3 drums.
Safety for the operator is paramount and clearly we need to be providing
enough power to handle a glider on a Black weak link. In general this
design should keep cost in mind, but surely as any club or group starts
to embark on construction they will have a lot of latitude as to how
they control costs. Do they buy a crate motor for $3-4k or buy that
little old lady's Cadillac for $500.

However, the first thing needs to be a forum off of RAS where we can
work. Ulrich started this, so I'll defer to his preferences. The Yahoo
groups are free, offer file sharing (I think) and it's easy to set up
topics to be voted on by the members. With that, we can start nailing
down the design goals.

Bill Daniels wrote:
"Ian Forbes" wrote in message
...

Mark Zivley wrote:


This project should probably be moved to a slightly different forum
like a yahoo group where people interested in participating can do so
without
filling up RAS. This also allows the sharing of files and even voting
on ideas as the project starts to take shape. We're definitely onto
something here, lets get started. We should start by doing some
deciding as to what will be designed. 1 or 2 or more drums.....

Now you are talking!

Lets get the fundamentals right. We want a design that is easy to build,
not too expensive, simple to operate, easy to maintain and with safety
standards to meet current best practice. Performance should be capable
of launching a glass 2 seater trainer to a hight not less than 1/3 of
the runway length in zero wind conditions.

I vote for a big block V8 petrol motor powering a double drum winch. For
the guys who want to talk about exotics electric winches and diesels
with modified ECU's - go for it but lets separate the threads. I think
the successful 'one design' winch is going to run on petrol and will be
made from readily available hardware. If we have any spare cash left in
the budget we will spend it on plasma rope.

As a starting point, lets get some specs on winches that have been built
already together with performances achieved. We need to start off with
parameters like engine capacity and size, drum dimensions, final drive
ratios, gearbox/torque converter details and the source make and model
of the components used.

Then we need detail engineering drawings for the clever bits. Winch drum
axle mods, guillotines, guide pulleys. These should best be based on
proven designs. Details for a Skylaunch like throttle control would be
nice. Good engineering detail for the safety items like the operator's
cage and cable guards might save a few home builders from unexpected
injury.

The engineering should accommodate a choice of cables. Single strand,
multistrand or plasma. We need to spec those too.

We should also put together a "bill of materials" for anybody planning
on establishing a winching operation. I am thinking of a comprehensive
list of things like weak links, rings, 'chute, snake, signal lights,
radios, cable retrieve vehicle... That in itself would at least allow
for drawing up a proper budget.

As for a forum - if we are going to move off RAS, Al's gliderforum.com
might be a good home. If we want to run off an e-mail list, I can
probably make a plan to host it. We will also need a repository for
information - a web site - perhaps a "wikki".

Finally we need to establish some ground rules regarding copyright and
ownership of the design. My vote is to follow the "Open Source" model
used by Linux etc. Publish everything and allow anybody to use it - but
under the condition they publish details of what they build and how
well it works.

Who's in?

Ian



Ian. I admire your enthusiasm and support your ideas, but the economics
need
a bit of discussion.

Winches are VERY profitable. The operational cost is less than $2US per
launch and most people will find $10 is a reasonable launch fee. That's
a
500% profit with a volunteer crew in a club setting. The Return On
Investment for a $30,000 winch is just 63 operating days figuring an
average
of 60 launches a day. A dual drum winch in a training environment can
do a
LOT more than 60 launches a day.

After the club has its ROI it can buy a new glider every year with the
profits. That's the REAL secret of how those European clubs own all
that
nice glass. They put their money into gliders instead of air tow fees.

My concern is that by focusing on the "build it cheap" aspect, the
productivity of the machine will be lost. That's where American winches
have gone wrong in the past. Just a couple of weekends lost to winch
repairs is significant. If the "Hassle Factor" is too large, people
will go
back to air tow.

Build it right, make it reliable and as productive as possible no matter
if
it costs more to build. If a diesel engine is more productive than a
spark
ignition engine then pay the extra money for one. If Spectra improves
the
operation by reducing cable breaks and tangles then pony up for it. The
ROI
comes very quickly. Almost ANYTHING that increases the number of
launches
per day or makes the whole operation easier and more pleasant is worth
the
investment.

Bill Daniels

F.L. Whiteley wrote:
I second the yahoo groups.

I've created a new Yahoo group "Winch Design" in the "Soaring" category.
To subscribe send an email to ,
or visit the group page at:

http://groups.yahoo.com/group/winchdesign/

I am the list owner, I'll limit my moderation activities to making sure
that new members are, in fact, glider pilots or other interested
parties. Otherwise, have at it...

Marc

At 04:48 24 March 2004, Bill Daniels wrote:

Jim, with one glider, one drum works fine. The length
of the field doesn't
matter since with a longer field, the glider goes higher
and stays up longer
so the wire is still back at the launch site in time
for the glider landing
if the retrieve driver hustles. If you are launching
from grass, all those
wire retrieves are sure tearing up the turf.

My most recent winching is with 5000 feet of wire and
2000 feet AGL is a
common release height. If there are any thermals,
the glider will contact
one 3 out of 4 launches and soar away. In the western
US there are many
runways 7000 feet or longer where winching is possible.
You're talking
3000' AGL launches with that much room.

With a gaggle of gliders waiting to be launched you
need the efficiency of
multiple drums or multiple winches. The real issue
is often not how many
launches you can make in a day, it's how fast can you
get everybody launched
when the thermals start. I've read of several winch
operations that achieve
a sustained launch rate of one every two minutes.

Bill Daniels

Bill

Flying from a grass/winch site, the wire does little
damage to the grass, the biggest problem is the cable
retrieve vehicle creating tracks.

We use a Landrover with low pressure tyres.

I agree with the last paragraph on efficiency and launching
a gaggle of gliders when the soaing starts, but what
is also require is an efficient method of delivering
the cables to the launch point. If the winch driver
does it then you have to wait for him to return to
the winch. The longer the airfied the longer the wait.

If the lanch crew are switched on then by the time
the retrieve driver gets back to the winch, the cables
should have been used.

This ties up one man for as long as there are gliders
waiting to be launched it is as big a factor as having
a good winch and driver. Maybe one reason why clubs
prefer aerotowing, it requires less man power.

The retrieve vehicle driver always wants to stop at
the launch point and chat rather than return to the
winch end to wait.

The Long Mynd use a retrieve winch which with a good
crew is very efficient and can work with a single drum
winch.

Efficiencey rates vary but with a switched on crew
periods one launch every 4-5 minutes can be sustained
for several hours average. This can be speed up slightly
and some UK will claim better that this, but for normal
club operations a higher rate is rarely required.

Still better than one tug where the tow to 2000 feet
takes about 7 minutes.

Dave

"Dave Martin" wrote in message
news:c3rjqe$2bh8m7
The Long Mynd use a retrieve winch which with a good
crew is very efficient and can work with a single drum
winch.

Dave



A visit to Long Mynd is on my "must do" list.

It has been my impression that while a retrieve winch works well when
launching from a ridge top where the height gained in the winch launch is
unimportant, lifting the retrieve wire is a hindrance when launching from
flatland where every foot of release height is very important.

What I don't know is how much hindrance. Do you think a retrieve winch
would be a good idea with 6000 feet of winch cable? If so, what is the
longest wire where a retrieve winch is practical?

Bill Daniels

At the Mynd being a hill-top site does not always help with soaring, and
height gain is often just as important as at a flat site.

When using the retrieve winch a cable parachute is not used, and any height
lost because of the retrieve winch wire is considered well worth while
because of the rapid launch rate.

The retrieve winch is very easy to drive. The main winch is more difficult
to drive than with a cable parachute system, the critical bit is immediately
after the cable comes off the glider, when the main cable has to be kept
from going slack and then the power cut as the retrieve cable starts to
pull.

At the Long Mynd almost all the driving is by professionals who also
maintain the equipment. There is a very short list of amateurs who have
been trained to drive. Very little aerotowing is done, and practically
none mid-week when gliding courses are run.

There are two problems which make it very difficult or impossible for most
sites to use a retrieve winch.

1./ There is always a wire between the glider and the retrieve winch, so
there must be no risk whatever of a glider (or aircraft) flying or landing
between the two winches at any time when a launch is in progress.

2./ Once the launch has started the cable and ironmongery which links the
two cables is going to drop without being restrained by a cable parachute.
There must be no risk whatever of any person or object being underneath when
it drops; and if it drops onto a runway or taxiway it will almost certainly
be damaged.

If you look at "Gliding and Motorgliding International"
http://www.glidingmagazine.com/ , go to "Photos" and enter the word Mynd in
the search facility, you will find three photos of a K21 being launched on
the Mynd system. In the photo captioned "our oldest K21" you can see the
retrieve cable in the right lower part of the picture.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Bill Daniels" wrote in message
news

"Dave Martin" wrote in message
news:c3rjqe$2bh8m7
The Long Mynd use a retrieve winch which with a good
crew is very efficient and can work with a single drum
winch.

Dave


A visit to Long Mynd is on my "must do" list.

It has been my impression that while a retrieve winch works well when
launching from a ridge top where the height gained in the winch launch is
unimportant, lifting the retrieve wire is a hindrance when launching from
flatland where every foot of release height is very important.

What I don't know is how much hindrance. Do you think a retrieve winch
would be a good idea with 6000 feet of winch cable? If so, what is the
longest wire where a retrieve winch is practical?

Bill Daniels

"Bill Daniels" wrote in message ...
"Dave Martin" wrote in message
news:c3rjqe$2bh8m7
The Long Mynd use a retrieve winch which with a good
crew is very efficient and can work with a single drum
winch.

Dave



A visit to Long Mynd is on my "must do" list.

It has been my impression that while a retrieve winch works well when
launching from a ridge top where the height gained in the winch launch is
unimportant, lifting the retrieve wire is a hindrance when launching from
flatland where every foot of release height is very important.

What I don't know is how much hindrance. Do you think a retrieve winch
would be a good idea with 6000 feet of winch cable? If so, what is the
longest wire where a retrieve winch is practical?

Bill Daniels



Hi Bill!

I checked out the German Sky Launch Site, and found a nice Cable
retrieve winch there, with a lot of info. Also, they offer kits, for
their winches that go down to half the price of a complete one, if I
remember correctly. Everyone can check the prices even if not familiar
with the language...

I canot figure out why these people want to re invent the wheel, when
all those beautiful winches can be bought for less than the price of a
glider?.....Now when flying season starts. Possibly the southern
hemisphere, freight would be high?

The retrieve winch uses a 2.5 mm cable, there seems to be no limit to
the lenght of either cable.....Bill. The loss they claim, is not more
than 2 % in hight. Will have to recheck that. The way I see it, with
the new ropes, it should not be a problem at all. The shute is not
neccesary with that application, which evens things out.

The retrieve winch seems to be not used much yet in Germany, possibly
because they somehow done well without it and are slow to change? I
know a soaring site in Germany, where they sometimes have 3 winches
next to each other. A retrieve winch could make this operation look
much better!

Rather than starting to tinker with winch building, I would suggest
for some teams to visit those winch manufacturers and get demos,
including Retrieve winches. As I said before. The problems in winch
operations are not the winches alone, but the know how in using them!

In addition to that, again, like I said before is the real estate!
Winches can hardly be used on public airports, possibly with a
retrieve winch? With winch operations, have to come relatively (long
runway) private gliderports.

Wonder whether Tonapah or Ely would alow a winch operation? Possibly
somone will build a hotel and buy the winching equipment......and have
a going business?

Think Up!

Dieter Bibbig
Gliders Of Aspen

soarski wrote:
I canot figure out why these people want to re invent the wheel, when
all those beautiful winches can be bought for less than the price of a
glider?.....Now when flying season starts. Possibly the southern
hemisphere, freight would be high?

That beautiful Skylaunch III kit will cost close to $60,000 once you add
an engine, shipping, and the miscellaneous parts needed to complete it.
I doubt there are more than one or two clubs or commercial
gliderports in the US that could justify that kind of expenditure, given
their current levels of operation.

This is a bootstrapping problem. Until one can prove there is a viable
market for proper winch operations in this country, no one is going to
risk a large amount of capital to find out. This isn't about cloning a
Skylaunch, it is about finding a way to build a decent quality winch for
a cost, in time and money, that a small group of people or a club would
be willing to risk.

If we ever get to the point where there are several US gliderports doing
100+ winch launches a weekend, then you'll no doubt start seeing
Skylaunches arrive on this shore.

In addition to that, again, like I said before is the real estate!
Winches can hardly be used on public airports, possibly with a
retrieve winch? With winch operations, have to come relatively (long
runway) private gliderports.

Yes, I know of large underutilized public and private airports in
California and Nevada where we would be allowed (and in some cases
encouraged) to winch launch. Most of the private gliderports in the
area would also likely be willing to give it a try.

The point is to try to grow the sport by cutting the cost of training
(probably by half), adding an element of excitement, and being able to
operate closer to urban areas without generating noise complaints.
Maybe it will work, maybe it won't...

Marc