Winch Experts wanted

"Bruce Greeff" wrote in message
...
Hi Bill

I respect your views but there are some differences in the way we see
things he

Firstly please note that I am not advocating underpowered winches. I do
however
maintain that power is not the most important safety issue in winch
launching,
and that - for our fleet where the highest wingloading is relatively
modest, and
the heaviest glider is a Blanik L13 - a winch with 220Hp is adequate.
(maybe 250
would be better)

Bill Daniels wrote:
We have had several people writing that they have launched heavy glider
X
with a low powered winch. I have done it and so have many others, but
this
is still not a good idea. There are serious dangers involved.

Too low power is dangerous, and we agree entirely that more power is
desirable.
Interestingly the most recent National Safety meeting addressed winch
launching
as the primary theme.

There were 25 Safety Officers and at least ten Chief Flying Instructors
as well
as the SSSA Exco present. One thing that became apparent was that there is
no
optimal power winch. In particular - when launching old designs that are
light,
high wing with the hook at a considerable vertical displacement from the
wing,
there have been numerous dangerous launches where the initial acceleration
exceeds the control authority on the glider. The example given was
launching a
Ka8 with the stick hard against the forward stop for most of the launch.

Too much acceleration is as dangerous as too little.

The best way to look at it is to consider power demand and supply. The
winch engine should be able to supply all the power the glider demands.
If
the glider demands more power that is available by pulling up hard, the
airspeed will decay quickly. If the pilot knows this is going to
happen, he
can manage it by controlling the pitch attitude carefully. If he
doesn't
expect it, the airspeed will decay so quickly that a very dangerous
situation will develop.

Agreed, and all of our pilots have to learn to control their demands on
the
winch before going solo. In this respect it would be safer and better to
have
more power for perhaps 30% of our fleet. Conversely, any piulot who relies
on
the generous power reserve of the winch to compensate for pulling back too
hard
is dangerous. I am all for the speed decay to warn the pilot. That way,
when the
winch falters, he will compensate automatically because he will be used to
monitoring and controlling airspeed carefully.

The attempt to launch gliders with a low powered winch gets into who is
in
control of the launch. I think it goes without saying that who controls
the
launch should not be in doubt. The majority view is clearly that the
winch
driver should be in charge.

Here I differ, the pilot is always in control of his / her destiny. Our
process
is that the launch marshal controlls the launch process, and the winch
driver
and pilot must work together. A skilled winch driver is in control at all
times
within the parameters dictated by physics. If we have a pilot who over
rotates
and "bends the pole" a number of things will happen.
With the exception of the Blanik with its flaps deployed the winch driver
will
be able to keep the glider above stall speed with full throttle.
The winch driver is still in control and may decide that the probability
of a
maximum tension cable break is dangerously high and elect to reduce power
until
the pilot takes the pressure off the cable. (even if it results in a low
release)
If the pilot is being ham fisted the cable will probably break resulting
in a
dangerous recovery and the possibility of landing damage. This probability
is
directly proportional to the instantaneous force on the cable, here a
powerful
winch is a distinct liability.
In any event an overzealous pilot is going to get a lecture from the
CFI...


With a low powered winch, the winch driver is in charge early in the
launch
but as the glider steepens the climb, the power demand exceeds supply
and
speed control shifts to the glider pilot who now must control airspeed
with
pitch since the winch is at full throttle. As the glider rises still
further and power demands lessen, airspeed control shifts back to the
winch
driver who must reduce power to prevent over speeding the glider.
There
are lots of ways this scenario can go badly wrong.

The other area where a low powered winch can cause problems is in the
initial acceleration. The German Aero Club specifies the maximum
distance
that a glider can use to reach flying speed to determine the minimum
winch
power. Specifically, under all conceivable wind, density altitude and
weight conditions, a glider must reach Vr (rotation speed) in 40 meters
or
less - there is no minimum specified. This is a very intelligent
specification. The concern driving this spec is that should a glider's
wing
drop to the ground before reaching flying speed, the resulting ground
loop
will be very ugly and quite possibly fatal for the glider pilot.

These concerns and the desire to get the highest launch possible, has
driven
winch horsepower higher and higher in recent years. Shortening the
accelerate to Vr distance has a powerful effect on the launch height
achievable. Many powerful winches have shortened this to less than 20
meters.

IF we were launching twin Astirs, or K21s or other heavy two seater I
would
concur that you would want more power. But bear in mind that the Blue weak
link
is easily overcome by a 200-250Hp winch. If that is the heaviest weak link
specified you are wasting your time on more power.

Again I agree that more initial acceleration is desirable - I HATE slow
acceleration launches in my Cirrus because the chance of a wing drop is
higher.
TO overcome this we use gearing on the winch that increases the effective
torque
available.

To summarize, I am advocating generous power reserves to permit the
winch
driver to maintain control of the launch and to insure the glider
reaches
flying speed before a wing can drop.

Bill Daniels


Generous power reserves are desirable. I am just not convinced that the
use of
very powerful winches imnproves safety. My experience is that an
adequately
powerful winch that is tractable and predictable is safe, even if there
are
compromises on height and initial acceleration. In our mixed vintage and
glass
setting it would be challenging to have a super powerful winch.

My conclusion is that it is desirable to have generous power reserves and
good
torque for fast acceleration of the heaviest aircraft on the fleet. It is
also
imperative that the control be adequately calibrated so that power output
can be
modulated easily for all of the gliders the winch could be expected to
launch.

Bruce

Bruce, good points all.

I probably should have emphasized that with large power reserves, it becomes
imperative to have extremely precise control of that power.

I am in absolute agreement that there are gliders with inadequate down
elevator authority to cope with high initial acceleration. Your example of
a K8 is a good one.

If you would allow me, I will restate your objections thusly. 'Very
powerful winches with inadequate power controls, launching lighter wing
loading gliders possibly with inept winch drivers/pilots is a very dangerous
situation.' 'Given this situation, a less powerful winch is safer.' 'With
less power, the winch driver can just hold the throttle wide open and let
the glider pilot control airspeed with pitch.' I agree with this.

The only objection I can raise is that the launch will necessarily be
sub-optimal in that the glider could have utilized more power had it been
available and thus achieved a greater height.

Let me dream a little.

I think we all have noticed that once in a while, things just go perfectly
and the glider achieves a launch height that is perhaps 25% higher than the
norm. I'd like to make this the norm rather than a fortunate accident.

To achieve the control precision needed with powerful winches the winch
driver and pilot need more information. Just as a tow pilot controls the
glider's airspeed by reference to the tug's airspeed indicator, a winch
driver should have the gliders airspeed displayed as well as the glider's
acceleration in G's. The pilot should have the cable tension, measured at
the weak link, displayed on the panel.

I know some will say that a good winch driver can judge the glider's
airspeed by watching the cable sag. If Spectra is utilized instead of heavy
steel it will be as straight as a bow string and provide no information to
the winch driver.

My goal is that the responsibility should be divided as follows. The winch
driver should control the glider's acceleration and its airspeed throughout
the launch by reference to panel displays in the winch. The pilot should
control the cable tension with backpressure on the stick by reference to a
tensiometer on the panel while monitoring the airspeed. In this scenario,
the glider's initial acceleration and airspeed are held to the precise
values requested by the pilot and the tension at the weak link is a precise
value that the pilot feels comfortable with. The pilot is in complete
control and the launch is totally optimized and very safe.

If the pilot knows from experience that in a particular glider he can manage
1.1 G and feels that under the existing conditions, 60 knots would be
optimum, then 1.1G and 60 knots it shall be. If, during the launch, he
feels that a cable tension of 80% of the weak link breaking strength is
safe, then 80% it shall be. If the pilot is flying a K8 and knows the
maximum acceleration he can manage is 0.6 G and that 54 knots is optimum
given a 15 knot headwind then so it shall be. Beyond this, there is nothing
that could be done operationally that would improve the launch process.

Bill Daniels

Bruce and Bill,

these were very insightful contribution to this subject. I think that
nobody in his right mind would set out to purposely build an
underpowered winch. I think you cannot have too much power, as long as
it is controlable. The ECU's of modern big rig diesels would allow you
to have a preset power setting for each glider with an available
override. I remember one incident where an L-Spatz took off and as
soon as he rotated, the spoilers popped out. No radio and an oblivious
pilot left the winch operator no choice than to 'floor'it. We had a
360cuin V8 powerplant, which fortunately was capable to jank the Spatz
up even with the spoilers open. Had this been our K-21 or Janus-C, the
outcome would have certainly been different.
Don't get me wrong, I don't intend to design a winch capable of
converting a glider into a dragster by puling the fuselage from
between the wings, but power (read torque) is a good thing here.

Keep the discussion going - we have two more winter months to cover
;-)

Ulrich Neumann




Bruce Greeff wrote in message ...
Hi Bill

I respect your views but there are some differences in the way we see things he

Firstly please note that I am not advocating underpowered winches. I do however
maintain that power is not the most important safety issue in winch launching,
and that - for our fleet where the highest wingloading is relatively modest, and
the heaviest glider is a Blanik L13 - a winch with 220Hp is adequate. (maybe 250
would be better)

Bill Daniels wrote:
We have had several people writing that they have launched heavy glider X
with a low powered winch. I have done it and so have many others, but this
is still not a good idea. There are serious dangers involved.

Too low power is dangerous, and we agree entirely that more power is desirable.
Interestingly the most recent National Safety meeting addressed winch launching
as the primary theme.

There were 25 Safety Officers and at least ten Chief Flying Instructors as well
as the SSSA Exco present. One thing that became apparent was that there is no
optimal power winch. In particular - when launching old designs that are light,
high wing with the hook at a considerable vertical displacement from the wing,
there have been numerous dangerous launches where the initial acceleration
exceeds the control authority on the glider. The example given was launching a
Ka8 with the stick hard against the forward stop for most of the launch.

Too much acceleration is as dangerous as too little.

The best way to look at it is to consider power demand and supply. The
winch engine should be able to supply all the power the glider demands. If
the glider demands more power that is available by pulling up hard, the
airspeed will decay quickly. If the pilot knows this is going to happen, he
can manage it by controlling the pitch attitude carefully. If he doesn't
expect it, the airspeed will decay so quickly that a very dangerous
situation will develop.

Agreed, and all of our pilots have to learn to control their demands on the
winch before going solo. In this respect it would be safer and better to have
more power for perhaps 30% of our fleet. Conversely, any piulot who relies on
the generous power reserve of the winch to compensate for pulling back too hard
is dangerous. I am all for the speed decay to warn the pilot. That way, when the
winch falters, he will compensate automatically because he will be used to
monitoring and controlling airspeed carefully.

The attempt to launch gliders with a low powered winch gets into who is in
control of the launch. I think it goes without saying that who controls the
launch should not be in doubt. The majority view is clearly that the winch
driver should be in charge.

Here I differ, the pilot is always in control of his / her destiny. Our process
is that the launch marshal controlls the launch process, and the winch driver
and pilot must work together. A skilled winch driver is in control at all times
within the parameters dictated by physics. If we have a pilot who over rotates
and "bends the pole" a number of things will happen.
With the exception of the Blanik with its flaps deployed the winch driver will
be able to keep the glider above stall speed with full throttle.
The winch driver is still in control and may decide that the probability of a
maximum tension cable break is dangerously high and elect to reduce power until
the pilot takes the pressure off the cable. (even if it results in a low release)
If the pilot is being ham fisted the cable will probably break resulting in a
dangerous recovery and the possibility of landing damage. This probability is
directly proportional to the instantaneous force on the cable, here a powerful
winch is a distinct liability.
In any event an overzealous pilot is going to get a lecture from the CFI...


With a low powered winch, the winch driver is in charge early in the launch
but as the glider steepens the climb, the power demand exceeds supply and
speed control shifts to the glider pilot who now must control airspeed with
pitch since the winch is at full throttle. As the glider rises still
further and power demands lessen, airspeed control shifts back to the winch
driver who must reduce power to prevent over speeding the glider. There
are lots of ways this scenario can go badly wrong.

The other area where a low powered winch can cause problems is in the
initial acceleration. The German Aero Club specifies the maximum distance
that a glider can use to reach flying speed to determine the minimum winch
power. Specifically, under all conceivable wind, density altitude and
weight conditions, a glider must reach Vr (rotation speed) in 40 meters or
less - there is no minimum specified. This is a very intelligent
specification. The concern driving this spec is that should a glider's wing
drop to the ground before reaching flying speed, the resulting ground loop
will be very ugly and quite possibly fatal for the glider pilot.

These concerns and the desire to get the highest launch possible, has driven
winch horsepower higher and higher in recent years. Shortening the
accelerate to Vr distance has a powerful effect on the launch height
achievable. Many powerful winches have shortened this to less than 20
meters.

IF we were launching twin Astirs, or K21s or other heavy two seater I would
concur that you would want more power. But bear in mind that the Blue weak link
is easily overcome by a 200-250Hp winch. If that is the heaviest weak link
specified you are wasting your time on more power.

Again I agree that more initial acceleration is desirable - I HATE slow
acceleration launches in my Cirrus because the chance of a wing drop is higher.
TO overcome this we use gearing on the winch that increases the effective torque
available.

To summarize, I am advocating generous power reserves to permit the winch
driver to maintain control of the launch and to insure the glider reaches
flying speed before a wing can drop.

Bill Daniels


Generous power reserves are desirable. I am just not convinced that the use of
very powerful winches imnproves safety. My experience is that an adequately
powerful winch that is tractable and predictable is safe, even if there are
compromises on height and initial acceleration. In our mixed vintage and glass
setting it would be challenging to have a super powerful winch.

My conclusion is that it is desirable to have generous power reserves and good
torque for fast acceleration of the heaviest aircraft on the fleet. It is also
imperative that the control be adequately calibrated so that power output can be
modulated easily for all of the gliders the winch could be expected to launch.

Bruce

Marc Ramsey wrote in message .com...
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


So?
Our setup: 222kW (300hp) turbocharged diesel, 6 drums, 1000m of steel
cable. This winch has handled everything including a 4DM. Even a
slight tailwind and a ASH25 are no real problem.
Samedan, the highest airport in Europe at over 5600ft MSL, has the
same winch with four drums. No problems at all. It's heaven compared
to the voluminous petrol monster they had before.
BTW these winches use an average of 0.4 litres of Diesel per launch.

Marcel Duenner wrote:


So?
Our setup: 222kW (300hp) turbocharged diesel, 6 drums, 1000m of steel
cable. This winch has handled everything including a 4DM. Even a
slight tailwind and a ASH25 are no real problem.
Samedan, the highest airport in Europe at over 5600ft MSL, has the
same winch with four drums. No problems at all. It's heaven compared
to the voluminous petrol monster they had before.
BTW these winches use an average of 0.4 litres of Diesel per launch.

How much petrol per launch did the previous winch use? Is there a big
price difference between the two fuels?
--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

(Ulrich Neumann) wrote in message om...
Bruce and Bill,

these were very insightful contribution to this subject. I think that
nobody in his right mind would set out to purposely build an
underpowered winch. I think you cannot have too much power, as long as
it is controlable. The ECU's of modern big rig diesels would allow you
to have a preset power setting for each glider with an available
override.

True today's electronic can be programed to various power outputs.
However it is not possible to do this in a way that would be useful
in the winch application. At least not through the engines computer.
To reprogram the engine you first have to be trained and then have
access to the OEM codes. Only dealers and certified shops get these
codes and then it varies engine by engine as to specific results.
Also to time consuming and not able to make small enough adjustments
to be useful in winch launching. However an external system such
as Bill has proposed could tell the engine "give me more or give me
less". Until a system such as this is built and proven there is
no substitute for the human bean, er brain.

I remember one incident where an L-Spatz took off and as
soon as he rotated, the spoilers popped out. No radio and an oblivious
pilot left the winch operator no choice than to 'floor'it. We had a
360cuin V8 powerplant, which fortunately was capable to jank the Spatz
up even with the spoilers open. Had this been our K-21 or Janus-C, the
outcome would have certainly been different.
Don't get me wrong, I don't intend to design a winch capable of
converting a glider into a dragster by puling the fuselage from
between the wings, but power (read torque) is a good thing here.

Keep the discussion going - we have two more winter months to cover

Two months- NO WAY four knotters all over the place in West Texas
yesterday. Our winch is already getting a workout. Yipee !!

Craig-

Ulrich Neumann




Bruce Greeff wrote in message ...
Hi Bill

I respect your views but there are some differences in the way we see things he

Firstly please note that I am not advocating underpowered winches. I do however
maintain that power is not the most important safety issue in winch launching,
and that - for our fleet where the highest wingloading is relatively modest, and
the heaviest glider is a Blanik L13 - a winch with 220Hp is adequate. (maybe 250
would be better)

Bill Daniels wrote:
We have had several people writing that they have launched heavy glider X
with a low powered winch. I have done it and so have many others, but this
is still not a good idea. There are serious dangers involved.

Too low power is dangerous, and we agree entirely that more power is desirable.
Interestingly the most recent National Safety meeting addressed winch launching
as the primary theme.

There were 25 Safety Officers and at least ten Chief Flying Instructors as well
as the SSSA Exco present. One thing that became apparent was that there is no
optimal power winch. In particular - when launching old designs that are light,
high wing with the hook at a considerable vertical displacement from the wing,
there have been numerous dangerous launches where the initial acceleration
exceeds the control authority on the glider. The example given was launching a
Ka8 with the stick hard against the forward stop for most of the launch.

Too much acceleration is as dangerous as too little.

The best way to look at it is to consider power demand and supply. The
winch engine should be able to supply all the power the glider demands. If
the glider demands more power that is available by pulling up hard, the
airspeed will decay quickly. If the pilot knows this is going to happen, he
can manage it by controlling the pitch attitude carefully. If he doesn't
expect it, the airspeed will decay so quickly that a very dangerous
situation will develop.

Agreed, and all of our pilots have to learn to control their demands on the
winch before going solo. In this respect it would be safer and better to have
more power for perhaps 30% of our fleet. Conversely, any piulot who relies on
the generous power reserve of the winch to compensate for pulling back too hard
is dangerous. I am all for the speed decay to warn the pilot. That way, when the
winch falters, he will compensate automatically because he will be used to
monitoring and controlling airspeed carefully.

The attempt to launch gliders with a low powered winch gets into who is in
control of the launch. I think it goes without saying that who controls the
launch should not be in doubt. The majority view is clearly that the winch
driver should be in charge.

Here I differ, the pilot is always in control of his / her destiny. Our process
is that the launch marshal controlls the launch process, and the winch driver
and pilot must work together. A skilled winch driver is in control at all times
within the parameters dictated by physics. If we have a pilot who over rotates
and "bends the pole" a number of things will happen.
With the exception of the Blanik with its flaps deployed the winch driver will
be able to keep the glider above stall speed with full throttle.
The winch driver is still in control and may decide that the probability of a
maximum tension cable break is dangerously high and elect to reduce power until
the pilot takes the pressure off the cable. (even if it results in a low release)
If the pilot is being ham fisted the cable will probably break resulting in a
dangerous recovery and the possibility of landing damage. This probability is
directly proportional to the instantaneous force on the cable, here a powerful
winch is a distinct liability.
In any event an overzealous pilot is going to get a lecture from the CFI...


With a low powered winch, the winch driver is in charge early in the launch
but as the glider steepens the climb, the power demand exceeds supply and
speed control shifts to the glider pilot who now must control airspeed with
pitch since the winch is at full throttle. As the glider rises still
further and power demands lessen, airspeed control shifts back to the winch
driver who must reduce power to prevent over speeding the glider. There
are lots of ways this scenario can go badly wrong.

The other area where a low powered winch can cause problems is in the
initial acceleration. The German Aero Club specifies the maximum distance
that a glider can use to reach flying speed to determine the minimum winch
power. Specifically, under all conceivable wind, density altitude and
weight conditions, a glider must reach Vr (rotation speed) in 40 meters or
less - there is no minimum specified. This is a very intelligent
specification. The concern driving this spec is that should a glider's wing
drop to the ground before reaching flying speed, the resulting ground loop
will be very ugly and quite possibly fatal for the glider pilot.

These concerns and the desire to get the highest launch possible, has driven
winch horsepower higher and higher in recent years. Shortening the
accelerate to Vr distance has a powerful effect on the launch height
achievable. Many powerful winches have shortened this to less than 20
meters.

IF we were launching twin Astirs, or K21s or other heavy two seater I would
concur that you would want more power. But bear in mind that the Blue weak link
is easily overcome by a 200-250Hp winch. If that is the heaviest weak link
specified you are wasting your time on more power.

Again I agree that more initial acceleration is desirable - I HATE slow
acceleration launches in my Cirrus because the chance of a wing drop is higher.
TO overcome this we use gearing on the winch that increases the effective torque
available.

To summarize, I am advocating generous power reserves to permit the winch
driver to maintain control of the launch and to insure the glider reaches
flying speed before a wing can drop.

Bill Daniels


Generous power reserves are desirable. I am just not convinced that the use of
very powerful winches imnproves safety. My experience is that an adequately
powerful winch that is tractable and predictable is safe, even if there are
compromises on height and initial acceleration. In our mixed vintage and glass
setting it would be challenging to have a super powerful winch.

My conclusion is that it is desirable to have generous power reserves and good
torque for fast acceleration of the heaviest aircraft on the fleet. It is also
imperative that the control be adequately calibrated so that power output can be
modulated easily for all of the gliders the winch could be expected to launch.

Bruce

"Craig Freeman" wrote in message
om...
(Ulrich Neumann) wrote in message
om...
Bruce and Bill,

these were very insightful contribution to this subject. I think that
nobody in his right mind would set out to purposely build an
underpowered winch. I think you cannot have too much power, as long as
it is controlable. The ECU's of modern big rig diesels would allow you
to have a preset power setting for each glider with an available
override.

True today's electronic can be programed to various power outputs.
However it is not possible to do this in a way that would be useful
in the winch application. At least not through the engines computer.
To reprogram the engine you first have to be trained and then have
access to the OEM codes. Only dealers and certified shops get these
codes and then it varies engine by engine as to specific results.
Also to time consuming and not able to make small enough adjustments
to be useful in winch launching. However an external system such
as Bill has proposed could tell the engine "give me more or give me
less". Until a system such as this is built and proven there is
no substitute for the human bean, er brain.


I have it on "pretty good" authority that these ECU's are simple to hack or
reverse engineer. Several gray market operations have already done it and
offer replacement ECU's with extensive user controls accessible through a
serial port from a laptop running special software. The market demand seems
to be coming from the participants in tractor pull competitions.

I would tend to think that the maximum power setting of the ECU would be
best used as a safety limit set to , say, 10% over the expected power
demand. With 3000 + foot pounds of torque available on these large diesels,
a winch driver sneeze at just the wrong time might produce interesting
results. If we go to a "full authority" autolaunch system, having a
separate power limiting safety net seems like a good idea.

You know, there is another "feel good" thing about diesels. There is a
rapidly expanding supply of renewable "biodiesel" fuel whose source is
vegetable oils produced domestically. Since CO2 went into growing the crop
that produced the oil, releasing it back into the atmosphere results in no
net increase in atmospheric CO2. With biodiesel fuel, a diesel runs
better, lasts longer and sure smells better. It's a little more expensive
than petroleum based diesel but at .4 liters of fuel per launch, you aren't
going to use much of it.

Bill Daniels

"Craig Freeman" wrote in message
om...

True today's electronic can be programed to various power outputs.
However it is not possible to do this in a way that would be useful
in the winch application. At least not through the engines computer.
To reprogram the engine you first have to be trained and then have
access to the OEM codes. Only dealers and certified shops get these
codes and then it varies engine by engine as to specific results.
Also to time consuming and not able to make small enough adjustments
to be useful in winch launching. However an external system such
as Bill has proposed could tell the engine "give me more or give me
less". Until a system such as this is built and proven there is
no substitute for the human bean, er brain.

Craig-

I am a parts person at an International Trucks (Navistar) dealer. We are
full service dealers for International, Cummins, Detroit Diesel, and
Caterpillar engines. It is certainly possible to reprogram the ECU's of
these diesels. We do it every day. Simple and easy enough for high school
drop outs to do. I sell the software for reprogramming the engines. Shrink
wrap stuff, just like at the computer store. That said, it would probably
be possible to just replace the TPS (Throttle Position Sensor, "electronic
foot pedal") with a microprocessor circuit and get the thing to do what you
need. I am not a computer nerd, so I don't know the details...
-Bob Korves

"Bill Daniels" wrote in message
...
demand. With 3000 + foot pounds of torque available on these large
diesels,

3000+ foot pounds?? Bill, you really are talking "big"! Is that just in
case a Horsa, CG-4a, or Gotha 242 shows up looking for a tow?

You know, there is another "feel good" thing about diesels. There is a
rapidly expanding supply of renewable "biodiesel" fuel whose source is
vegetable oils produced domestically.
Bill Daniels


International Trucks has "Green Diesel" technology that uses biodiesel.
These vehicles are out there in small numbers in the field already
throughout the U. S. and seem to work just fine. The exhaust smells like
french fries.

Off topic, perhaps, but a while back a prototype truck was in our dealership
that had no camshaft. The valves were electronically controlled and
hydraulically actuated, the same way that injectors are controlled on many
newer engines. This system allows unlimited options of valve timing and
different schemes of timing at different loads, running the engine on less
than all cylinders, etc. The valves also had no springs -- they were both
opened and closed hydraulically.
-Bob Korves

Have you ever smelt a diesel running on used vegetable oil?

It's just like standing in the local Fish and Chip shop!

Ian

"Bill Daniels" wrote in message
...

"Craig Freeman" wrote in message
om...
(Ulrich Neumann) wrote in message
om...
Bruce and Bill,

these were very insightful contribution to this subject. I think that
nobody in his right mind would set out to purposely build an
underpowered winch. I think you cannot have too much power, as long as
it is controlable. The ECU's of modern big rig diesels would allow you
to have a preset power setting for each glider with an available
override.

True today's electronic can be programed to various power outputs.
However it is not possible to do this in a way that would be useful
in the winch application. At least not through the engines computer.
To reprogram the engine you first have to be trained and then have
access to the OEM codes. Only dealers and certified shops get these
codes and then it varies engine by engine as to specific results.
Also to time consuming and not able to make small enough adjustments
to be useful in winch launching. However an external system such
as Bill has proposed could tell the engine "give me more or give me
less". Until a system such as this is built and proven there is
no substitute for the human bean, er brain.


I have it on "pretty good" authority that these ECU's are simple to hack
or
reverse engineer. Several gray market operations have already done it and
offer replacement ECU's with extensive user controls accessible through a
serial port from a laptop running special software. The market demand
seems
to be coming from the participants in tractor pull competitions.

I would tend to think that the maximum power setting of the ECU would be
best used as a safety limit set to , say, 10% over the expected power
demand. With 3000 + foot pounds of torque available on these large
diesels,
a winch driver sneeze at just the wrong time might produce interesting
results. If we go to a "full authority" autolaunch system, having a
separate power limiting safety net seems like a good idea.

You know, there is another "feel good" thing about diesels. There is a
rapidly expanding supply of renewable "biodiesel" fuel whose source is
vegetable oils produced domestically. Since CO2 went into growing the
crop
that produced the oil, releasing it back into the atmosphere results in no
net increase in atmospheric CO2. With biodiesel fuel, a diesel runs
better, lasts longer and sure smells better. It's a little more expensive
than petroleum based diesel but at .4 liters of fuel per launch, you
aren't
going to use much of it.

Bill Daniels

Bill Daniels wrote:

"Craig Freeman" wrote in message
om...

(Ulrich Neumann) wrote in message

om...

Bruce and Bill,

these were very insightful contribution to this subject. I think that
nobody in his right mind would set out to purposely build an
underpowered winch. I think you cannot have too much power, as long as
it is controlable. The ECU's of modern big rig diesels would allow you
to have a preset power setting for each glider with an available
override.

True today's electronic can be programed to various power outputs.
However it is not possible to do this in a way that would be useful
in the winch application. At least not through the engines computer.
To reprogram the engine you first have to be trained and then have
access to the OEM codes. Only dealers and certified shops get these
codes and then it varies engine by engine as to specific results.
Also to time consuming and not able to make small enough adjustments
to be useful in winch launching. However an external system such
as Bill has proposed could tell the engine "give me more or give me
less". Until a system such as this is built and proven there is
no substitute for the human bean, er brain.



I have it on "pretty good" authority that these ECU's are simple to hack or
reverse engineer. Several gray market operations have already done it and
offer replacement ECU's with extensive user controls accessible through a
serial port from a laptop running special software. The market demand seems
to be coming from the participants in tractor pull competitions.

I would tend to think that the maximum power setting of the ECU would be
best used as a safety limit set to , say, 10% over the expected power
demand. With 3000 + foot pounds of torque available on these large diesels,
a winch driver sneeze at just the wrong time might produce interesting
results. If we go to a "full authority" autolaunch system, having a
separate power limiting safety net seems like a good idea.

You know, there is another "feel good" thing about diesels. There is a
rapidly expanding supply of renewable "biodiesel" fuel whose source is
vegetable oils produced domestically. Since CO2 went into growing the crop
that produced the oil, releasing it back into the atmosphere results in no
net increase in atmospheric CO2. With biodiesel fuel, a diesel runs
better, lasts longer and sure smells better. It's a little more expensive
than petroleum based diesel but at .4 liters of fuel per launch, you aren't
going to use much of it.

Bill Daniels

Bill, I know one of the sources of raw material for biodiesel is
useddeep-frier grease. What a great way to get teenagers into the
sport. They follow the smell of french fries and find gliders instead!

Cheers,
Shawn