PDA

View Full Version : Learning to use a Hi-Start to launch your glider


AEAJR
07-30-2006, 04:22 AM
LEARNING TO USE A HI-START
by Ed Anderson
aeajr on the forums

I think one of the reasons we don't see more people flying unpowered
sailplanes/gliders is that they don't understand how the planes are
launched. Once someone tells them about a hi-start or a winch, they
shy away, again, because they don't understand.

I LOVE hi-start launching my Spirit 2 meter and my Sagitta 600 2 meter and
even my 3 meter Airtronics Legend. It is such a thrill to see the plane
climb up to the sky then just silently float off the line like a sailboat.
I find the hi-start easier than the club winch and I get great launches. If
I can do it, you can do it.

These links may be helpful for background about hi-starts.

What is a Hi-Start
http://www.labyrinth.net.au/~learmont/HiStart.html (http://www.labyrinth.net.au/~learmont/HiStart.html)

This product review of the AVA RES Sailplane has some good photos of a
hi-start launch and a video of an actual launch.
http://www.rcgroups.com/articles/liftzonemag/2004/mar/ava/Ava1.wmv (http://www.rcgroups.com/articles/liftzonemag/2004/mar/ava/Ava1.wmv)

Videos of actual hi-start launches
http://portfox.rchomepage.com/gallery/movies/Stepp3-launch.wmv (http://portfox.rchomepage.com/gallery/movies/Stepp3-launch.wmv)

By comparison, this is a strong winch launch
http://static.rcgroups.com/gallery/data/500/7716mono.mpg (http://static.rcgroups.com/gallery/data/500/7716mono.mpg)


HI-START LAUNCHING - Getting Ready

First, let's be clear, what I will be focused on is NOT competition
launches. I am talking about safe sport launches. I am sure someone
will comment about maximum altitude and such. I just want to help
you get in the air safely.

Second, if possible, get a coach/instructor if one is available and ignore
all of this. This is ONLY intended for someo ne who is unable to get help
and must learn on their own.

Third, your plane must already be well trimmed and flying straight and even
from a hand throw. If you have been having problems with getting good hand
launches, ask questions here. It isn't hard but there is a definite
techniques to it. Getting good at hand launches is important to good
hi-start launches. Fail to do this and the hi-start will turn your plane to junk!

Fourth and very important, make sure your tow hook is in the forward most
hole that your plane has. If you only have one tow hook location check to see
that it is a little in front of the CG of your plane. about 1/4" to 1/2" is a
good starting point. This will give you a more controlled launch than the more
rear, competition positions. You can move it back later, once you become
comfortable with the hi-start.

OK? We understand the goal here? Safe and gradual build up. Our goal
is control, not ultimate height! That will come later.


STARTING SMALL

I don't know what hi-start you have or how big it is, but if it is a "full
size" hi-start it probably has 30 meters/100 feet of elastic, usually latex
rubber tubing, and 100-125
meters/300-400 feet of line. There is no reason why you can't start right
in with this full size unit. However, if you feel this is an awful big thing
to handle on initial launches without a coach you can start smaller. You can
either get an up-start which is a smaller version of a hi-start, or take
your big hi-start and only use part of it for your inital launches.

SHORTENING YOUR HI-START

Remember, this shortening step is optional.

To take a large hi-start and only work with part of it, we will reduce the
length of the line and elastic that will be involved in the launch. You can
cut the line, or replace it with a smaller piece during the training phase.
DON'T CUT THE TUBING! We want to preserve the tubing, or other elastic, as
a single piece as it will work better when you are ready to use all of it. We
will just change how it is secured so we are only using part of it.

First the line. You can either cut the line, or buy another piece of line
that is shorter. Line is cheap and it can be useful to have line of
different lengths, so I will suggest you pick up some masons line, or any
braded nylon or Dacron line at any hardware store. You want something
with a working strength of 50 pounds or more. Nylon mason's line is typically
around 100-150 pounds working strength. Bright colors will make it easier
to find the line in the grass. Mine are hot pink and hot orange.
You can also use 50 pound test monofilament fishing line for your 2 meter
plane but it will be harder to find in the grass than mason's line. I
suggest you make up a couple of 50 foot lengths. As we progress you can
join them using a knot, or I like to use heavy duty fishing snap swivels.

To shorten the elastic I simply loop the elastic over the spike 2-3 times at
some reduced length. Works fine.

LAUNCH INTO THE WIND!

Always launch into the wind. Whether it is a sailplane on a hi-start, a
parkflyer or a Boeing 747, we always launch into the wind.

For learning purposes I would say calm air to 5 mph would be a good starting
range. Gusty or swirling wind that changes direction a lot is going to
complicate learning. Once you are accomplished, these will be much less of
an issue. I have spent whole days hi-start launching in 15 mph winds which can
really help take the plane high. Launches will be higher with a breeze
than dead calm air.

One of the advantages of a hi-start over a winch is that it is easy to
adjust your launch related to the wind. When your plane is in your hand,
check the wind direction and move left or right so your launch will be as
directly into the wind as possible. You can move right or left to adjust to
a changing wind direction.


SETTING UP THE HI-START

Now we want to get to deploying the hi-start in preparation to launch your
sailplane. You are going to stake one end of the hi-start into the ground
using a 10-16 inch spike, large tent peg, screw in dog chain anchor or some
other method. Make sure the stake that you put into the ground is secure
and has a large enough washer on it so that the ring on the hi-start will not
pull off the stake. As extra insurance, you can also loop the elastic over the
spike for extra security. I usually do this.

If you start small, say 15' of elastic and 50' of line it might feel a lot
easier to control, and the launch will be lower and the energy smaller.
Again, this is just an assisted hand throw. We will use this length
combination for this discussion. Remember that I am assuming your plane
is well balanced and trimmed and that you can reliably hand throw it and
control that hand throw from your radio. (If you are not a master of the hand
throw, put this down and go work on that!)

If your plane is flying well from a hand launch and your tow hook is a
little in front of the CG then I am going to suggest that you launch with all
controls at neutral trim, or whereever the plane flies best from the hand
throw. Remember you don't use the elevator to take the plane up, the lift
of the wings will do that. In fact, as we will discuss later, if you have
problems with pop-offs, you can put in 3-4 clicks of down elevator to slow
down the rotation of the plane on the initial launch. Just don't forget to
take it out once you are off the hi-start.

If you get your wings out of level on the launch, the plane will tend to go
right or left when you throw it, just like a bad hand throw. Use the rudder
to get it back to center and work on getting a level throw.

It is easy to control the launch force of a hi-start by how far back we pull
it, which will determine the stretch on the elastic and the energy of the
pull Do exactly what you would do on a hand throw. Basically flat firm throw
with level wings. The hi-start will continue the pull to accelerate the plane
giving the equivalent of a strong hand throw. However as the hi-start will
pull it faster than a hand throw, it will start to climb. This is what we
want.


TIME TO LAUNCH

Be sure your receiver and radio are turned on. Complete your range check
and make sure all surfaces are moving in the right direction. Now you can
hook the line to your plane's tow hook and pull back a distance equal to the
length of the elastic, 15 feet in our example. You should feel a pull on
the line, but should have no trouble holding the plane in one hand. I like to
grip my plane under the wings and hold it with the wings over my head.

Now, check to make sure all of your controls are working again. If
necessary, use your mouth to move the sticks and see that everything is
working. Check the trims on your radio to make sure you have not bumped
them out of place. Do this on EVERY launch ... forever!

Stand firm, don't walk or run with it, and just give it a straight. firm,
flat throw, controls at neutral just like a hand throw. Get your hands to
the controls on the radio ready to guide the plane, but don't over control it.
The plane should go out just like a hand launch, only with more speed.
It should naturally climb a little. It should just fly off the end of the
line. Let it glide out and drift down naturally, just as you would on a hand
throw, just further. Be sure you have enough space in front of the
launch to allow it to do this. You don't want to have to turn on you first
hi-start to avoid hitting things.

You just completed your first hi-start launch.

How did that go? If it went left or right, you tipped the wings when you
threw it or your plane is not trimmed to fly straight. Work on it at this
length until you go out level and true every time.

Build up the strength of the pull over several launches. Pull back one
length of the elastic. Launch from this until you are comfortable. Then
pull it back 1 1/2 lengths of the elastic. Then try it at twice the length of the
elastic. Make sure you are going out straight and level. For a 15 foot
piece of elastic that would be a 30 foot pull.

Then slide another 15-20 feet of tubing into the working area of the
hi-start and add another 50 feet of line. You are now in up-start range
with 25-40 feet of tubing and 100 feet of line. The plane will launch
higher with this arrangement. You change nothing, let the hi-start do the
work. Just don't forget to get the plane a strong push/throw as you release
it. Don't just let go.

Keep adding elastic in whatever increments you like till you get to the full
length. Add 3-5 times as much line as elastic till you add it all back.
Again a typical full size hi-start is 60 to 100 feet of elastic 250-400 feet
of line.

How far back you want to pull depends on the make and diameter of the tubing
on your hi-start. If this is a commercial hi-start, read the makers
recommendations and follow them. In general, with 1/4 -5/16 OD latex
tubing, pulling back two to three times the length of the tubing should be
plenty for your 2 meter plane and should not over stress the tubing. If you are
using bungee cord you will likely not be able to pull back that far as the cloth
covering constrains it and bungee is typically much stronger than the latex
tubing.

If you are using heavier tubing such as 3/8", 7/16" or 1/2", a pull of 1
1/2 times the tubing length may be all you would want to do with a 2 meter
plane. My hi-start rubber is 3/8" and I only pull back about 1 to 1 1/2
times the length of the tubing to launch my 2 meter planes. At that pull I can barely
hold the plane. I measured it once at 14 pounds of pull which is stronger
than needed for a Spirit, for example. If you feel like measuring, a pull
of 3-5 times your model's weight is a good target, or 6-10 pounds for the
typical 2 meter starter plane. I have launched my Spirit at up to 14 pounds
of pull, as measured with a fisherman's scale.

Pop-Offs:

A pop-off occurs when the plane rotates so much during the launch that it
releases the line early and "pops off" the line. This can happen anywhere
but I have usually seen it within the first 150 feet of the launch. Pop offs can be
tricky to control. The plane may fly up at an extreme angle then stall and
want to dive for the ground. More often it will pop off and go into a loop
to the rear, behind you. I have found that most of the time, if this
happens, you are best served to just help the plane finish the loop rather than
trying to prevent it. Fighting the loop often takes so much energy out of
the plane that it will stall and you are fighting to keep it from crashing to
the ground.


If the plane starts popping off too soon, try putting a
click or two of down elevator on the trim before you launch. Also make sure
your tow hook is in FRONT of the CG. About 1/4-1/2 inch is enough. The
likelihood of a pop off will increase with the power of the launch due to
the rotation of the plane from level to climb, so let's get it under control
early. That is why we build up slowly.

As the pull gets stronger, the plane will fly out faster and the lift of the
wings will take it higher naturally. No need to throw it up, it will go up
on its own. You can launch the plane at a more elevated angle as you become
more comfortable with the hi-start and get to know how your plane launches.
Up to a 45 degree angle works well. Just remember that the steeper the angel
the more important the throw. Don't just let go, give it a good push.

I have over 450 launches with my Spirit, Sagitta and Legend. I launch at 20
to 45 degree up angle with neutral controls and the forward tow hook
position. My planes climb beautifully and I don't give up much to the winch,
if anything.

Using my smaller launcher (25' tubing and 100' line) I get 100+ feet
launches depending on the wind, without a zoom at the end. With the larger
hi-start (100' 3.8" tubing and 400' line) I estimate I go up 350-500 foot
launches, depending on the wind, and can zoom off of the end to gain more
height if I want.

I was afraid of the hi-start but now I really enjoy it. If you have someone
to coach you through the first few launches you will be fine. If you don't,
try this method.

Sailplanes are Wonderful!
http://www.rchangout.com/forums/showthread.php?t=5356 (http://www.rchangout.com/forums/showthread.php?t=5356)

That plane was made to fly. Fly it!

rwmson
08-03-2006, 12:19 AM
Excellent article Ed - nicely done!

Sky Sharkster
08-03-2006, 01:15 AM
Thanks, Ed, great article!
Ron

TLyttle
08-03-2006, 02:45 AM
Yup, all info is correct.

Once you have your model trimmed for histart launch, ya get kinda arrogant about it (or at least I did).... I seldom pull back any more than 20 paces if there is ANY wind, set the trims and just let go. I have done this with the TX sitting on the ground, no input required until the model floats off the line. If I want to get into light lift, I trim in a bit of up, until the model is at the end of the line indicating a thermal, then zoom off the line.

In light winds, I annoy the experts by zigzagging up the line, gaining height with every sweep. Try this with a model you are familiar with, it really is fun!

AEAJR
08-03-2006, 05:45 AM
[quote=TLyttle;92931]
Once you have your model trimmed for histart launch, ya get kinda arrogant about it (or at least I did).... I seldom pull back any more than 20 paces if there is ANY wind, set the trims and just let go. I have done this with the TX sitting on the ground, no input required until the model floats off the line. If I want to get into light lift, I trim in a bit of up, until the model is at the end of the line indicating a thermal, then zoom off the line.
quote]

This may be a cute stunt but I would not endorse doing this at any time with any model.

TLyttle
08-10-2006, 02:50 AM
Yeah, I guess it was a stunt, but the point to the beginners was that launching off a histart is NOT all that complicated. The lesson was not wasted, and it made the beginners more relaxed about the process.

Quite often, I would use the same "stunt" with their own models once they were trimmed. That is my point: proper TRIMMING allows you to use a histart without fear or stress, either to the model or the modeller, and allows a lot of latitude in a launch.

AEAJR
10-03-2006, 10:39 PM
Do you avoid contests because they are flown off winches and you practice on a hi-start? Let me give you a different prospective. If you don't fly contests you are missing out on a lot of fun.


Our club contests and our Eastern Soaring League contests are all done off
winches. However anyone can have their plane launched for them off the
winch if they are not talented on a winch. I did this for several Novice
class flyers at a recent ESL event. In my first ESL contest others launched the plane for me.

Are you at a competitive disadvantage if you don't have a winch to practice on? Sure, but compete anyway!

There is no question that a super strong ship can achieve greater height off
a winch than a hi-start. And there is no question that a typical sport
class plane can not take the stress of the extreme zooms that the super
competition class planes can handle.

Having said that, I say, who cares? I compete in club and Eastern Soaring
League contests. I may never win either but I have so much fun at the
competitions it really doesn't matter if I win. And I get so much support
and good coaching from the advanced pilots that I would have to be a fool
not to compete. These are flying lessons from the best!

I share what I learn with those who want it. They can use it in whatever
way they wish. But the idea that you can't compete because you don't have a
super ship just does not cut it with me.

I was at my first Eastern Soaring League with a Sagitta 600 2M RES glider.
The only 2 meter in the contest. I finished dead last, but I finished.
Some others did not finish. I had a grand time and I was a better flyer for
it.

I did most of my practice flying off a Hi-start! At the contest other flyers launched my plane off the winch for me. Worked out fine and they were happy to do it.

I then got a 15 year old Airtronics Legend that flies like a tank. 4
contests on that one. It is now my back-up plane. I have managed to move up to NEXT to last. Having a frickin ball!

On the Legend, I practiced on the winch and on the hi-start.

Now I have a PoleCat Thermal Dancer. Still not an Icon or a Supra or a
Sharon. Maybe I can achieve mid pack. That would be nice, but frankly I am always flying for my personal best. Perhaps someday that will get me a prize. But when I make a personal best, it always makes me smile. Hitting the center of the landing circle is such a high!

I encourage you and other flyers to enter contests for the fun, for the
friendship and for the learning. And, if you are an active contest pilot, I
encourage you to take that hand of a reluctant flyer and bring them into the
contest fold. Believe me they will thank you.

Clear Skies and Safe Flying!

AEAJR
10-03-2006, 10:52 PM
Maximizing Launch Height Using a Hi-Start
by Ed Anderson
aeajr on the forums

While the winch is the preferred method to get the most height on a launch,
you can get awesome launches off a hi-start if you know what to do. The
advantage the winch has is that you can control the pull throughout the
launch. With a hi-start, the pull is maximum on initial release then
decreases throughout the launch. But that does not mean that you can not use the same techniques the winch launchers use to gain extra height.


ELEVATOR AND CG

The further back the CG, the easier it is for nose to come up during the
launch. If your plane tends to launch fairly flat and you find you need up
elevator to get it to rotate, try moving the CG back slightly. Then fly the
plane. It will be more responsive and will read lift better. You may find
that you have to add some down trim after moving the CG back. This is
because you have been using up trim to hold up that heavy nose. This
process will reduce drag and make for a better flying plane.

I usually start my gliders at the most forward CG recommended by the MFG,
then over a series of flights, I move it back till it gets too twitchy to
handle, then I move it forward a little till it gets stable enough for me to
fly it. Many competition pilots have the CG so far back that I can not
handle their planes.

If you have a computer radio, try adding some expo. This will soften the
response around the center of the controls making it easier for you to
manage smooth flight with a plane that has a more rearward CG.

You should not have to apply any elevator during the launch. If you are,
then you are introducing drag which reduces speed and does not increase
lift. Try working your CG back and see how it flies. It will launch better
when the CG is further back and you will need little or now elevator to get
the nose up. The placement of the tow hook will likewise impact the need
for elevator on launch. I cover that next.


HOOK AND THROW

Hook placement will make a big difference in your launch height. The closer
the hook is to the CG, the steeper the rotation of the plane during launch.

The optimum situation is that your plane climbs at about a 70-80 degree
angle presenting the most resistance to the contraction of the rubber. This
takes the plane through the largest arch and produces the longest time of
launch, extracting more energy from the pull and translating it to height.
If there is a breeze and your launch angle is steep enough, the rubber may
never fully contract during the launch giving you the greatest height
possible. You will use that remaining tension in the line when I cover the
zoom, later in the discussion.

When you launch initially, if you have enough pull on the line, throw the
plane up at about a 30 to 45 degree angle rather than out flat. This gets
the plane through the rotation faster getting it into this max lift position
sooner. The throw really makes a difference. It gets you up to flying
speed faster which is important the closer you have the hook to the CG.
Typical hook position is about 1/4" in front of the CG, but having it closer
will usually give you higher launches.

Note that , as you move the CG back, as advised above, you are moving
further and further away from the hook, so you may need to adjust hook
position just to maintain your current hook/CG position. Also note that the
further back the hook placement, the closer to the CG, the harder the plane
is to control on launch. It will stall easier on initial release, so it is
vitally important to give it a good throw and not just let go.

When moving your hook back, you may wish to have someone help you during this adjustment phase by either throwing the plane for you, or working the radio. This way the hands are on the sticks at all times. If the throw goes bad or if you have moved it back too far, you will be better able to respond. If the plane stalls on the launch, a little down elevator for a moment will help it gain speed and you may be able to save the launch. Once you have it where you like, you should be able to launch it by yourself.


ZOOM

It is possible to "zoom" off a hi-start, in a similar fashion to what is
done with a winch. The bounce is not as dramatic, but still, you can gain
additional height if you get the timing right.

When the model is about 80% through its arc, and while there is still
tension on the line, rather than just flying off the line, you nose down for
less then a second, then pull up hard. The weight of the hi-start, and any
remaining tension, will help to accelerate the model to a higher speed. The
down/up pull then translates this speed into altitude. I do this with all
my planes. The Spirit, the most fragile of my gliders, picks up at least 50
feet this way. With a moderate breeze and a fast plane, you can do even
better. If you have an aileron plane or aileron/flaps, and a computer radio
that will allow you to reflex the wing, this can help you gain even more
height.


CHANGING THE WING

If you have flaps, deploy them on launch. If you have ailerons and a
computer radio, then drooping the ailerons also will add even more lift upon launch.

By creating more under camber, more bottom curve, you create an airfoil that
produces more lift. It also produces more drag, but during the launch, when
you have the pull of the hi-start, you can afford this drag to gain the
lift. This will create a longer arc and a higher launch.

Launch - Flaps or flapperons down for initial launch: Usually 10-20 degrees
is enough, but every plane is different, you have to experiment. I have seen
launch positions as high at 45 degrees on the flaps. If you have the
ability, droop the ailerons too.

Throw the plane hard with the nose up at around 45 degrees or higher.

Mid arc - If you have a computer radio and can set a reflex position, about
70% up the line you switch to reflex. This is where the ailerons/flaps are
actually moved up slightly from their normal position. On most airfoils,
the RG15 foil being a know exception, this creates a high speed/low
drag/lower lift setting that is great for gaining speed. Now you want to
accelerate the glider to gain speed.

Zoom - Around 80% though the arc you do the down/up while at maximum speed,
still in reflex. The down lasts less than a second and the up is strong.
Go for a climb angle of 60-90 degrees, depending on the plane and the pilot.
You have to experiment to see what works best for you.

Level - As it climbs it will lose speed. Before the plane loses all its
speed, you level the plane, go to normal wing position and start your hunt.
If you are stalling at the top of the launch, resulting in a drop in the
nose and loss of height, then you are waiting too long to level the plane.
It should look like the plane just leveled onto a table with no drop of the
nose. This is your best launch height.

You can still zoom with a simple 2 channel plane, but if you can change the
airfoil during the launch, you can gain even more height. If you have
flaps but no computer radio, you can still go though this sequence using the
flaps. Where I call for reflex, just move the flaps to normal flying
position. Ahhhh, the joy of computer radios.

Using a winch, this sequence can gain 150-300+ feet, if you have a strong
plane. It can be quite dramatic.

Using a full size hi-start with enough pull, you can do about 25-50% of
that. The limiting factor is that you can't increase the power at the end
of the launch like you can on a winch. However you are also unlikely to
overstress the wings off a hi-start. I have seen planes fail on zoom, using
a winch, when the pilot was too aggressive on the zoom. I have never seen a
plane fail when zooming off a hi-start, but I am sure it can be done.


GIVE IT A TRY!

If you go through all the steps above, you may find that you are getting
higher launches without the zoom. This is great!

Then you can try adding the zoom, but tune the CG and hook positions first
as these are more important. But you can try a zoom on any plane, the
benefits will just not be as great as when the plane is tuned properly.

If your plane drops at 100 feet per minute during its glide, and you can
gain 50 feet on the launch, you just gained 30 seconds of flight time. And
thermals tend to be larger in radius the higher you go, so you have a larger
target. If you can gain 100 feet, the flying experience can be quite
different.

The more sophisticated the plane and the more flexible the radio, the more
you can tweak the launch. The longer and stronger the hi-start, within
reason, the higher your launches.

Even with a simple R/E plane, you can improve your launch height by going
through these steps. You will get higher launches, longer glides and likely
find more thermals than you did before.

Other resources can be found in the handbook. I hope this has been
helpful.

The New Glider Pilot's Handbook
http://forums.flyesl.com/topic.asp?TOPIC_ID=251

AEAJR
12-20-2006, 12:09 AM
We are thinking of trying a new approach for our hi-start. This involves using a pully at the other end of the field, like the one used on a winch.

You spike the hi-start near your end of the field, run the string through the pully then back toward the launch point. Hook it to the plane, then walk back.

This stretches the rubber toward the pully. Now, when you launch, the rubber stays on the ground and the plane does not have to carry the weight of the rubber into the sky.

Let you know how well it works.

jooNorway
12-20-2006, 12:02 PM
Very interesting AEAJR!

One of my (many) attempts to "make" more sailplane-pilots in my club began one-and-a-half year ago, using my "fullsize" rubber hi-start (30 meter rubber, 120 meter line) and I asked everyone to try my new EasyGlider for a flight. A short instruction and away they flew. I did throw the plane, but didn`t touch the radio.
Soon i discovered that the EasyGlider were to slow and lightweight for the big hi-start, and tried to make a mini-version for the next day. 10 meter rubber, 60 meter line and then it worked much better. The lightweight planes like EasyGlider didn`t like the heavy weight of so much rubber, and lost height because the newbies didn`t have the skill to pull hard enough, and of course not to zoom.
The "small" bungee is often used, and there are half a dozen EasyGlider pilots in my club today who are not afraid of launching their gliders ;)

Your idea sounds great, reducing the weight in the "airborne" line/rubber sounds like success in my ears!

AEAJR
12-20-2006, 02:14 PM
We launch Easy Gliders off full size hi-starts all the time, but they are 2M hi-starts. The plane is so light that it will get ahead of a heavier hi-start and just fly off hte line.

Also, the stock hook position is not optimized for a hi-start, it is optimized for a tow launch using a string and a runner. Move the hook back and you will get better, higher launches with it.

We also launch the EG off the winch with good success.

WillKrash
12-27-2006, 12:50 AM
Ed...get a chance to try the hi-start with the turnaround pully? Results?

Mike

AEAJR
12-27-2006, 03:09 AM
No I haven't. It is pretty cool weather around here and I normally don't like to put out the hi-start under 50 degrees. Add that to the fact that I have a winch and there is no reason to risk damage to the rubber. It will probably wait till spring.

Up&Away
01-03-2007, 04:46 PM
Maximizing Launch Height Using a Hi-Start
by Ed Anderson
aeajr on the forums


... If you have ailerons and a
computer radio, then drooping the ailerons also will add even more lift upon launch...

However, if your ailerons are only at the tip of the wing (like my Filip600Sport) the lowered ailerons can also induce tipstal.

flyranger
01-13-2007, 03:14 PM
Ed, I am slowly moving into "pure" gliders from electric motor gliders. I am a scratch builder, preferring balsa over foam and other exotic materials. What I need, if you or some of the other readers have it, is a pic of the actual "hook" installation in a 2m glider? How much internal bracing is needed? How big is the hook? Thanks in advance.

AEAJR
01-13-2007, 03:55 PM
Tow Hooks
http://www.hobby-lobby.com/towing.htm

http://www.hilaunch.com/

Tow hook
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKAM9&P=7

Spirit Manual
http://www.greatplanes.com/parts/index.html


The photos below show the interior of my Spirit. Ignore the battery. That was an experiment I did with adding a power pod to the plane. It worked but I prefer it as a pure glider.

There is a piece of 1/8 ply that has 3 blind nuts embedded in it. They are about 1/2" in front of the CG, about 1/4" in front of the CG and one on the CG, or something like that. That is one approch. You can use one of the hook kits above, or just buy a blind nut, and thread a 6 or 8 penny finishing nail to fit it.

The ply can be a bit larger if you are not sensitive to weight. It is just there to spread the load so your hook mount does not pull through the balsa.


Sometimes they cut a slot in the bottom of the fuselage, about an inch long, back it with a piece of ply, then embed the blind nut in a piece of 1/4" ply or basswood that you can slide back and forth along the slot to adjust your hook position.


If you are new to hi-start launching, put the hook about 1/2 inch in front of CG. That won't give you the highest launches, but the launches will be more stable. Then move it back as you get better. The further back you get it, the steeper the angle of climb, but the harder it is to control and more prone to stalling, so the throw becomes enven more important.


Hope that is what you needed. :)

Lip84
02-26-2007, 03:01 AM
subscribe!

You guys are a freaking GOLD MINE of information. Its like reading a 2000 year old manual for life or something...

Great stuff!

TLyttle
02-27-2007, 04:41 AM
Add all the experience of these guys together, and it IS 2,000 years!

I find that those T-nuts don't add significant weight; put in a row of them if you like, just like AEAJR said, from the c/g to well near the l.e. and pick the one you like. Back when I had hair, we used to have adjustable towhooks that allowed up to an inch or more adjustment (EK? seems that is what I used), now you have to innovate unless you can find a good supplier. There ain't a lot of mystery to this, just some common sense and a bit of experience.

AEAJR
02-27-2007, 01:23 PM
Add all the experience of these guys together, and it IS 2,000 years!

I find that those T-nuts don't add significant weight; put in a row of them if you like, just like AEAJR said, from the c/g to well near the l.e. and pick the one you like. Back when I had hair, we used to have adjustable towhooks that allowed up to an inch or more adjustment (EK? seems that is what I used), now you have to innovate unless you can find a good supplier. There ain't a lot of mystery to this, just some common sense and a bit of experience.

IF you take one of those T-nuts/blind nuts and mount it in a piece of 1/4" plywood, you can cut a 1" slot in the bottom of the plane starting 1/4" behind the CG going forward. Now you can slide the hook back and forth to adjust the CG. Start with it all the way forward. Get comfortable and work it back over time and watch the height of your launches increase, jsut by moving the tow hook. :)

nicklanigan
04-01-2007, 06:15 AM
Hi there.

Am brand new to flying gliders, but have had a very successful first day out today! (ie, nothing broken). Followed the guidance in this forum re hi-start.

Only problem I had was some difficulties with the hi-start.

Managed to get the glider up in the air everytime, but the hi-start seemed to struggle a bit.

I was using it in long grass (I have a farm). The nylon part seemed to easily snag in the long grass, causing the lift to end abruptly.

The stake in the ground holding the hi-start was also about 1-2m (3-6 foot) above the launch spot, making the snagging worse. Field has long very gentle slope in it.

I don't think I ever had the tubing off the ground, so the launches were pretty low in altitude. Because I was learning I didn't want too much pressure on the line, and it didn't matter that much.

Is this a normal problem? I do have the option of mounting the hi-start anchor to the top of a fence post, which would probably allow me to get the whole hi-start off the ground when I'm ready to launch.

Look forward to your advice,

Thanks,

Nick. (New Zealand).

Sky Sharkster
04-01-2007, 12:54 PM
Hello Nick, Welcome to Wattflyer!
Good to hear you're having sucess with your glider, once you catch a thermal it's really addicting!
Having the line snag is a fact of life with hi-starts, most glider sites have the grass cut short for this very reason. If this is not possible, sometimes "whipping" the line side-to-side just before the launch will clear it. I've never tried raising the stake end, that might work also, but the rubber end is so heavy it will drag the line down (near the stake) before launch.
As far as actually lifting the tubing off the ground, this usually only occurs in very windy conditions. The tubing wieghs more than the glider, so the lift from the acceleration (wing lift) can only do so much. Also, the time when you need to lift the tubing (at the top of the arc) is also the slowest part of the climb.
How long is the line part of your hi-start? For 2 meter gliders I use 400' of line and the tubing is (I believe) 75'. The 400 foot altitude, even without a "zoom" launch, is high enough for a few circuits of the field.. If there's lift around, you should have several minutes to find it.
So, you might lengthen the line portion of the high-start, perhaps move the towhook back a small amount and accelerate at the end of the launch to zoom off. Each of these, done carefully, should help maximize the altitude. A little more "stretch" of the line before launch can help also, but this eventually becomes a "wing stress test" and you only get one chance to be wrong!
Good Luck!
Ron

AEAJR
04-01-2007, 01:25 PM
Hi there.

I don't think I ever had the tubing off the ground, so the launches were pretty low in altitude. Because I was learning I didn't want too much pressure on the line, and it didn't matter that much.

Is this a normal problem? I do have the option of mounting the hi-start anchor to the top of a fence post, which would probably allow me to get the whole hi-start off the ground when I'm ready to launch.

Look forward to your advice,

Thanks,

Nick. (New Zealand).

Nick,

I was very pleased to read your post. Welcome to silent flight. You are going to love this.

I belive I can help you on all points as I have similar problems with grass. our field is not cut often and at times i have launched with the grass 3 feet high.

You need to lay the grass down if you can. This can be accomplished in several ways.

First, try to pick a spike point that will give you the clearest path to the launch spot. Avoid bushes, sticks, tufts of grass and the like.

If you walk to the spike point several times, retracing your path carefully, that will typicaly lay the grass down. Or if you can run your car up and down to the spike, that is even better. Use the weight of the car to lay the grass down. The path doesn't have to be wide but the wider the better.

When you walk out to get the chute, again, walk that line to the spike, then turn 90 degrees to go to the chute. Then walk back to that line and walk that path over and over. This will get the grass out of your way.

Another approach would be to use a weed wacker to cut a path in the grass that will fee up the line. Again, you don't need a lot, but the more the better.

As for height and picking up the rubber, there are many factors that impact how the line rises. Most of the energy for the launch comes from the rubber. The rest comes from your throw and from the wind.

If you don't pull very far you won't get a lot of energy. So you may not have had enough pull in order to lift the rubber. Or your rubber may not be strong enough.

On hi-start launches I lift most of the rubber off the ground every time. If there is a bit of a head wind and the plane is well matched to the rubber, you can lift it all and get REALLY high launches.

Your hi-start rubber and hook position will dramatically impact how high you launch and how much of the rubber you can lift. Also your CG setting will impact the launch. If the plane is nose heavy you will get a fairly flat launch. You will find with thermal duration gliders that, over time, you want to try and move the CG back which allows the nose to rise more easily on launch and makes the plane more responsive in the air. But for your early flights, set it according to the plans/instructions.

I don't think having the spike higher than the launch point will matter, except that it will help keep the line and rubber out of the grass to some degree. Try it on top of a fence post. When you tension the line, it sould raise most of the line out of the grass and that should help.

The following info would help:

What plane are you using, including wing span?

If this is a ready made hi-start, please provide a link to info. If you made it yourself, we need the following info:

What are the lengths of the hi-start rubber and string.
How thick is the rubber? Is it hollow? Give OD and ID of the tube.
Is it fabric covered bungee? That makes a HUGE difference.
What kind of line are you using?


Where is your tow hook placed relative to the CG?

If you can get a scale, like a fish scale, measure the pull you are placing on the rubber. You need at least 3X the weight of the plane to get a good launch and 4X or 5X are typically better except for VERY light planes.

For example, a GP Spirit is about 2.5 pounds so I need about 7.5 pounds of pull for a good launch. If I have 10 pounds of pull I will get a higher launch.

Without this info, we really know nothing about your launches or how to improve them.

TeslaWinger
04-02-2007, 12:01 AM
I didn't see mentioned that to be CAREFUL when you are walking it back and your hand is sweaty. Keep your face out of the path between the plane and that force. It'll rip yer face off if your hand slips!

The most frustrating part of a Hi Start is that when thermals come cycling thru they change the wind direction and you find the line to be now 45 degrees or more off the wind direction!

Making a steep turn on launch to get into line with the wind before the dash to the top is a trip! Its like flying a 2 line stunt kite! Once you experience a good high launch (wind helps a lot!) you will be hooked! After my first 30 minute soaring flight from such a launch I am now a believer.

AEAJR
04-02-2007, 12:13 AM
The most frustrating part of a Hi Start is that when thermals come cycling thru they change the wind direction and you find the line to be now 45 degrees or more off the wind direction!

Making a steep turn on launch to get into line with the wind before the dash to the top is a trip! Its like flying a 2 line stunt kite! Once you experience a good high launch (wind helps a lot!) you will be hooked! After my first 30 minute soaring flight from such a launch I am now a believer.

If you have the room, the best thing to do in this circumstance is to just change your launch point so that you are facing into the wind. This is one of the advantages of the hi-start over a winch. It is easy to move with a hi-start. Of course if your field is narrow or something is in the way, this doesn't work too well. However my field is large and I can just walk sideways to align with the wind.

You are right about holding the hi-start. When I hi-start my larger planes, where the pull will be over 25 pounds, I hook the plane, then tuck the nose under my arm and walk back facing away from the peg with the plane facing toward the peg. one wing is across my body. Pretty hard for it to get away, but turning round can be tricky. Good ot have your radio on a neck strap so both hands are free.

nicklanigan
04-02-2007, 02:38 AM
Thanks for the advice - I was kind of hoping you weren't going to say the grass needed to be flattened - it's a long way!

To answer your queries -

It's a Tower Hobbies Vista - 2m wingspan - an ARF. I have actually built and flown a glider before - about 15 years ago! Was a kit glider, with a motor system. Unfortunately lasted about 10 seconds. Took 15 years to recover from it! I remain convinced to this day that the problem was the motor system - too much to worry about on a first flight. I feel I've proven this by having no major problems with this new glider! (and I'm not trying to start a debate about motor systems!).

I figured this time I'd get an ARF that is mighty cheap as I'd have little "invested" in it should the worst happen again. You can imagine my relief at it all going well.

Tow hook location is the most forward hole, well in front of the CG.

Hi-start is a dynaflite heavy duty model. http://www.dynaflite.com/accys/dyfp8301.html

I know I didn't need this model hi-start for this glider, but it only cost $5 more than the standard one, and will presumably be fine once I graduate to something bigger.

The glider seemed to do all the right things - went up in the air in a hurry, and went pretty much straight up without needing much in the way of rudder control. I did notice that it didn't really drop the line properly - this may have been because of the nylon snagging? Tended to have to waggle the elevator up and down a bit to drop the line off. I'm guessing that this may have been me trying to get the plane off too early? The nose seemed to be still pointing upwards at this point - in hindsight I think I probably felt that it was stalling and I needed to get it off the line?

I don't know how much tension I was launching with, but it was getting a fair pull on it. It wasn't particularly easy to hold it while my 2 year counted down from 10 to a launch. I'm not sure if this tension went right to the anchor though - given the snags only part of the line may have been under tension. Hope this makes sense. Will get a fishermans scale to measure next time.

While I'm writing, I'd appreciate advice on what would be a good 2nd plane.

Reason I'm writing this now is I appreciate it takes a fair while to build a kit, and am thinking about starting soon - we're heading towards winter in the southern hemisphere. I'm keen to get a reasonably priced kit, and it's easiest if someone major stocks it - like Tower Hobbies. Shipping can be a problem from smaller places to NZ.

AEAJR
04-02-2007, 11:21 AM
The Dynaflite HD would the the right model for that plane. I don't recommend the Dynaflite standard for 2M planes regardless of what they advertise. It is adequate, but I feel th HD is much better. I would not even try a 3 M plane with that HS even thought they say it will launch it. Maybe a real light weight 3M like a bird of time, but not much more.

At 3X pull I think that HS will give you about 10 pounds of pull which is plenty for the Vista.

If you are snagging the rubber it will eventually cut it up, so I would try to clear the path to some extent.

WillKrash
04-09-2007, 02:14 AM
Ed....have you had a chance to try the turnaround with the histart?

nicklanigan
04-10-2007, 08:59 AM
Hi all.

3 successfull flight sessions so far, still absolutely no damage, despite some somewhat hairy landings.

A question though - the field I have available is too short for a 6x launch force. It is long enough for a 3x launch force though.

Am I better off sticking with a 3x launch force, with the use of the entire hi-start length, or shortening the hi-start (nylon part) to allow a 6x launch force?

Which option would give the higher launch?

My guess is that shortening the nylon and increasing the force would give a higher launch, but this is just a hunch.

Much appreciated,

Nick.

AEAJR
04-10-2007, 12:58 PM
Hi all.

3 successfull flight sessions so far, still absolutely no damage, despite some somewhat hairy landings.

A question though - the field I have available is too short for a 6x launch force. It is long enough for a 3x launch force though.

Am I better off sticking with a 3x launch force, with the use of the entire hi-start length, or shortening the hi-start (nylon part) to allow a 6x launch force?

Which option would give the higher launch?

My guess is that shortening the nylon and increasing the force would give a higher launch, but this is just a hunch.

Much appreciated,

Nick.

Nick, you have confused pull length ( feet and inches ) with pull power ( pounds of force )

When I say 3X launch force I am talking about a pull force of 3 times the weight of your model in pounds, not 3X the length of your hi-start rubber in feet. To get to 6X launch force you MIGHT pull further if you have a strong hi-start or a light model but more likely you need a stronger hi-start.

The Aerofoam Hosemonster is the only hi-start that I know of that claims to go to 6X pull length without damage, but that says NOTHING about the force of the pull. The force would depend on the thickness of the rubber. Only the most expensive hi-starts can sustain a 5X+ pull length. Most hi-starts will be damaged or break beyond 4X.

That means a 100 foot piece of rubber is stretched 3X its length, a stretched length of 400 feet. Any more than that and you will likely damage or destroy it.

Since that hi-start would likely have about 400' of line on it, the fully extended length of the rubber plus string would be 800 feet. So we say you need about 800 feet of space to use a typical full sized hi-start.

I will give you some typical numbers to illustrate. All of these would be at a pull of 3X the length of the rested rubber. They are all very approximate.

1/4" od latex tube - about 4-7 pounds ( typical 1M-2M hi-start )
5/16" od latex tube - about 8-14 pounds ( typical 2M-3 hi-start )
3/8" od latex tube - about 12-18 pounds ( typical 3M+ hi-start )
7/16" od latex tube - 15-25 pounds ( perhaps a competition 3M hi-start)
1/2" od latex tube - about 30+ pounds ( typical 4M hi-start )

All are 3X pull. Those are VERY approximate. A lot depends on the quality of the rubber, the thickness of the tube wall, etc. Typical wall thickness can vary from 1/32 to 3/32 and some are solid rubber.

I have a hi-start that I think is 3/8 rubber with a 3/32 wall. At 1.5X pull I get about 12-14 pounds of pull to launch my Spirit, Sagitta 600 and similar ships at 5-6X their weight. At 2.5X pull I get about 25 pounds pull to launch my Airtronics Legend at 5X its weight. At that pull I can barely hold the plane. IT is supposed to be able to launch 4M planes of maybe 8-10 pounds.

For the Spirit, a much better match would be a 5/16" tube with a 1/16" wall. It would provide a pull similar force but I could pull it out 3X its length in order to deliver that force over a longer period of time. That would yield a better climb and less stress on the plane.

I hope that clarifies things. Length of pull and power/force of pull are related but not the same. It varies a lot depending on the strength of your hi-start, but typically pulling the rubber more than 3X will damage it.

None of these numbers relate to fabric covered bungee which typically can not stretch this far due to the fabric covering. I don't like, don't use and don't recommend fabric covered bungee/shock cord for launching planes, but some people use it.

AEAJR
04-10-2007, 01:01 PM
Ed....have you had a chance to try the turnaround with the histart?

No I have not. It has been too cold most of the time. And, frankly, I rarely use my hi-starts for launching these days as I have access to a winch.

Winches are very expensive, about $400-$800. If I was not part of a club, I would not have a winch available and would be using a hi-start to launch.

nicklanigan
04-11-2007, 12:26 AM
Thanks Ed, I didn't have the 2 things confused (force vs length stretched), but didn't make the explanation clear enough.

Basically, if I stretch the hi-start the full length of the field available, I get a force of about 9 pounds - about 3x the weight of the plane.

To get 18 pounds of force - 6x weight of plane, I'd have to shorten the nylon, then stretch the hi-start the length of the field again, as the field is a fixed length.

My question relates to which of these 2 scenarios would give the higher launch height?

AEAJR
04-11-2007, 12:46 AM
Getting the right balance of line is important. A stronger pull will allow you to carry more line giving you a higher launch.

When I adjust I look at how the plane goes up. If it travels a nice arch and lifts the line and most of the hi-start, I have a good balance of pull vs. line. The pull continues throught the whole climb.

If it seems to run out of gas about 2/3 of the way up, I have too much line. Basically the pull is running out before the plane hits the top of the arc. Then you drop off some line.

When there is a breeze, say 5 mph or better, you can typically add line as the plane will act as a kite and resist the contraction of the rubber. Get a 10 mph wind and you can add a lot of line. The more wind, the more line you can add.

On my practice hi-start I have 25 feet of 7/16 rubber. Max pull is about 12 pounds. With a 3M 70 ounce plane, I have to shorten it to about 75 feet. With a light 36 ounce plane I can put on 125 feet. If there is a 5+ mph wind I can add about 25 feet to either of these and still get that good arch and have the plane climbing well all the way up.

With a good wind and a good balance of line you can pick up almost the whole hi-start and release almost over the spike.

If you get real good, you can even lean to zoom off the hi-start and add 50-150 feet to your launches.

Also go back and reread post 8
http://www.wattflyer.com/forums/showpost.php?p=108520&postcount=8

IFlyTailies
04-14-2007, 04:17 AM
Nice 4m Multiplex ASH-26. Look for the launches during Hi-Start...

Because of the field setup the owner chose to launch downwind, ROG was not possible because of high grass. As you can see the plane was stalling during launch, but luckily it picked up speed fast enough...
The tail dropping was a combination of a couple things. The stab is small relative to the wing and relies on a long moment arm. This only works when there is enough air speed for the stab to function. When the plane pitches upward during launch, the stab is in the stalled turbulent wake of the wing, so it still has nothing to work with.
The main solution is to switch to a pair of hooks right under the wing
on the sides of the fuselage. The owner of the ASH is currently working on that... Enjoy the video...

http://www.youtube.com/watch?v=T-sYXc9gbUE

AEAJR
04-14-2007, 05:25 AM
The stab was not really an issue.

Down wind = stall

The person throwing was trying to give that last push and was pulling the back of the fuse down. Hard to avoid.

A bridal under the wings, or move the hook forward a bit and it would handle that launch situation a little better. But considering it was a down wind launch, it went OK. Lucky he did not crack it up.

I would love to see how it launches into the wind.

Any idea what hi-start he was using and how far he pulled it?

rc_flyboy1
05-25-2007, 03:32 PM
I'm new at soaring although I've been flying glow power for 9 years now. I got hooked on gliding, believe it or not with my electric slow stick. We had a fun fly at my club and one of the events was climb and glide. I took my slow stick up as high as I could, Powered back and started my glide. I don't know if I hit a thermal or what but the plane just kept going up. I flew for about 20 mins. before I finally touched down. Ever since then I have been flying my stick that way. All the other guys like to fly low and do combat with their slow sticks. This too is fun but I got tired of repairing prop tears in my wings. I decided to buy a sailplane and a hi-start and give that a try. I'm not use to trimming a plane from a hand launch which resulted in a "Yard Dart" crash. It only broke the bulkhead in front of the wing which was an easy repair. I learned that you must keep the plane straight and level to trim it. I have it pretty well trimmed now and I'm ready now for my first hi-start launch. I have been a little scared to try it up till now but with all the advice given in this thread I think that I'm ready. My hi- start has a 30' rubber and a 200' line. I think that I will try my first launch with the full length. I have ample room to do this so I think that it would be best to start out that way. If anyone has any more advice for me, I'm all ears. No one in my club flies sailplanes so I guess I'm on my own.

AEAJR
05-25-2007, 04:10 PM
Welcome to soaring. You have a great time ahead of you.

What you have would typically be called an up-start, or a small hi-start.

What plane are you flying?
What does it weigh, approximately?

Do you have a fish scale to test the pull of your upstart? Not required, just a helpful tool.

Where is your tow hook placed relative to the CG?

Remember to give it a good hard throw so it can get up to flying speed quickly.

Always launch into the wind!

Good luck and may the lift be abundant!

rc_flyboy1
05-25-2007, 05:23 PM
Thanks for your reply. I have a Tower Hobbies Vista 2 meter. I wanted to start out with something cheap. It floats good with just a hand launch. I have the tow hook in the foward most position and the weight is approx 32 ozs. I do not have a fish scale. Funny because I'm an avid fisherman. lol. I have tried to locate other glider pilots in my area with no luck as of yet. I live in South Western Virginia near Bristol. Hopefully someone that reads this post may live in the same area and offer some help.

AEAJR
06-01-2007, 12:15 AM
Check the Eastern Soaring League web site, www.flyesl.com (http://www.flyesl.com) then click on the about the ESL button and you will find a list of member clubs. Maybe one is near you.

AEAJR
08-24-2007, 04:17 AM
Thanks for your reply. I have a Tower Hobbies Vista 2 meter. I wanted to start out with something cheap. It floats good with just a hand launch. I have the tow hook in the foward most position and the weight is approx 32 ozs. I do not have a fish scale. Funny because I'm an avid fisherman. lol. I have tried to locate other glider pilots in my area with no luck as of yet. I live in South Western Virginia near Bristol. Hopefully someone that reads this post may live in the same area and offer some help.

How are you doing with your Vista? Did you find a club, or hook up with some other glider pilots?

How are you and your hi-start getting along?

montanacos
02-06-2008, 05:12 AM
I would love to get into gliders and slope soaring. I also would love to build a 2 +/- meter glider that would work for this. Do you know of any plans that would make a good trainer, and yet give years of good enjoyable soaring?

Thanks in advance.

Tim

AEAJR
02-06-2008, 11:32 AM
I can name many kits and ARFs. I am not generally a plans builder. However the AMA has a plans service.

AMA Plans Service
http://www.modelaircraft.org/plans.aspx


This thread is about learning to use a hi-start so I don't want to get into a big discussion about slope planes and kit. However if you start a thread on the topic and post the link, I will join it.

Ed

Sky Sharkster
02-06-2008, 12:40 PM
Hello Tim, Welcome to Wattflyer!
Ed is correct, you will have better luck if you start a specific thread for your question. Something like "Good 1st Glider from plans" or "Scratch-Built Glider, any suggestions?" etc.
In the meantime, you can check out the links on the sticky at the top of this Forum; http://www.wattflyer.com/forums/showthread.php?t=28303
And any of the "Plans Services" here;
http://www.wattflyer.com/forums/showthread.php?t=14868
Under "Gliders" or "Sailplanes".
Depending on your building experience, you might be better off with a kit or ARF. For kits, a couple I would recommend are the "Gentle Lady" from Carl Goldberg or the "Riser 2M" from SIG Mfg.
Also, take a look here; http://www.skybench.com/
Most of these are "Nostalgia" glider kits and partial (short) kits of gliders from the 1970's, in other words, all-balsa, (usually) polyhedral wing, rudder/elevator (some have spoilers added) and a few have aileron control. These were designed and flown before that introduction of composite construction and are sometimes called "Woodies", "Gasbags" or "Floaters" as a reference to their light weight and somewhat fragile construction.
Most gliders, regardless of their construction, last a long time. Unless there's a flyaway or total loss of control- high speed crash, they rarely need major repair. Because of the low flight speeds, light wing loading and gentle flying characteristics, it's not often they self-destruct.
Good Luck and Thermals!
Ron

montanacos
02-06-2008, 03:56 PM
Thanks for the advice, and I will start a thread on plans for a first glider. Thanks alot

Tim

AEAJR
04-12-2008, 10:49 AM
What model hi-starts are people using and what planes are you launching. Let's get some user experience reports if we can.

AEAJR
10-09-2008, 08:24 AM
PLAYING WITH YOUR LAUNCH SETTINGS

A few weeks ago we were flying in about 12 MPH winds with gusts to 20. Lift
was there and we were having fun. However the winch battery gave out.

No more fun? Not a chance!

I always carry my hi-start in my car just in case we have a winch problem. So
out comes the hi-start. This was going to be the first time I had launched my
Supra off a hi-start. This is a NE Sailplanes XL hi-start so it is very strong,
giving me about 24 pounds of pull on the launch, or about 6X my 4 pound plane.

With a 12+ mph breeze I expected a good launch.

I hit my launch setting and just as I threw the plane the wind speed picked up.
The Supra went up at about an 80 degree angle but the wind was pushing back
against the hi-start. The plane was now slightly behind me as it climbed and, as
luck would have it, directly in the sun. It was an interesting launch, to say
the least, and I got pretty good height. But I can do better!

Next time I launched I left the launch mix off. I did this twice. The climb was
not quite as steep but it was faster. I actually got a better launch and a
little zoom at the end. But I can do better.

For the next series I launched without the launch mix, throwing up at about 45
degrees, then once the plane was about 50 feet up, moving quickly, I flipped on
the launch mix. With the greater speed and the later application of the flaps my
launch was higher still. Before I went for the zoom I switched to reflex,
gained speed and up it went! This is the same zoom techniques I use on the
winch. It did not match the super zoom of the winch, but this was my highest
launch.

After a couple more launches like this I was getting pretty high launches off
this 100 feet of rubber and 400 feet of line. But I can do better!

So I added another 100 feet of line to the hi-start. I continued to add the
launch mix at about 50 feet. The wind carried the extra line with no problem
and I got the highest launch yet. I also tried leaving the launch mix off and
using my thermal camber mix instead. That was an improvement over no launch mix
but I am not sure if it was as high as the late application of my flap/aileron
launch mix.

By time I had completed about 12 launches with various settings and line
configurations I think I was getting about 80% of my winch launches. Basically I
lacked some the powerful zoom that I can get out of Supra when using the winch.
But I was very satisfied with the experience and learned a lot about the effect
of when and how to use the launch mix for best effect.

The net net of this story? Experiment! Play! Try new things and see what
works for you. And if you find a good combination, please post it here so
others can give it a try.

Clear skies and safe flying!

AEAJR
07-09-2009, 06:22 PM
Any new glider pilots launching with a hi-start?

Share your experience as well as any tips.

AEAJR
11-02-2009, 11:46 AM
THE EFFECT OF CG ON HIGH-START LAUNCHING

Let me share an experinece I had yesterday to illustrate a point. And I am going to take you through my thought processes as I discovered and corrected the problem.

My main planes are a Supra and an AVA. I use these for contest flying in the Eastern Soaring League where I launch off winches. My Thermal Dancer has been relegated to a back-up plane position. I had not flown it in months, but I had it out yesterday. What I relate here was experienced on a winch, but it applies to HS launching as well. What we are giont to discuss is the impact of moving the CG.

Before I launched the plane, I did a hand throw. Seemed it needed a couple clicks of up to give me the glide I wanted. Having done that and completing a good range check, it was time to launch. Well I popped off 3 times in a row. Once I did get the plane in the air, it was flying very poorly. A dive test indicated the plane was nose heavy.

I have done several repairs to the nose and fuselage area of the Thermal Dancer over the time I have owned it. This has resulted in the plane becoming somewhat nose heavy. Since I have no removeable weight in the nose, I added 1/4 oz of lead to the tail over a year ago.

After some trial and error, I realized the tail weight was missing and added it back. I added 7 grams, about 1/4 oz, right in front of the verticle fin. This would be like taking about 3/4 to 1 oz of weight out of the nose. This sifted the CG back, giving my plane a much better balance. Several hand throws confirmed this and allowed me to adjust the elevator trim, removing several clicks of up trim. Now I was getting a nice smooth glide.

Now I was getting great launches and the plane was flying much better. WHY????

Because the plane was nose heavy, this CG was shifted forward, as compred to my normal CG. This effectively moves the hook position rearward in relation to the CG. I may have actually had the hook behind the CG. The further back the hook, relative to the CG, the more unstable the plane becomes on launch. Most people have the hook 3/8 to 1/8 inch in front of the CG. On my competition planes I have it right on the CG. But having it behind the CG makes for extremely difficult to control launches and a great tendency to pop-off.

By putting that weight on the tail, I effectively shifted the CG rearward. Now the hook was back in its proper position relative to the CG and the launches were as I expected them to be, straight, steep and high.

The second issue that comes up is that a nose heavy plane requires a lot of up elevator trim. That up trim on the elevator can become very effective at the speeds that a hi-start produces during the launch. This can lead to pop-offs. By shifting the CG back, I was able to remove some of that up trim, thus removing my tendancy to over rotate and pop-off.

I share these experiences because they apply equally to the hi-start and to the winch. The position of the hook, relative to the CG is critical to a smooth, high launch. If you change the CG of your plane, be aware of how this will change the relative position of the hook.

If you have a high tendency to pop-off on launch, consider that your plane might be nose heavy. Or, if you like the balance of your plane, consider setting up a launch mix that adds a few clicks of down elevator during the launch. This will prevent that over rotation during the critical first 50 feet of the launch. You can flip that mix off somewhere along the arch of the launch.

eastbay
02-01-2010, 12:03 AM
Any new glider pilots launching with a hi-start?

Share your experience as well as any tips.

Well I'm about ready to try it but I'm afraid I'll destroy my first glider I built a couple weeks ago, because I'm not getting good hand launch flights yet. So I have some questions. The plane is an EasyGlider Pro, built without a motor.

When I hand launch, if I give it a good throw, the plane noses up, stalls, and crashes immediately. I've trimmed the elevator down and put the battery as far forward as it will go, and it still behaves like this. I don't know if this is a problem with the way I'm throwing it or with the way it's trimmed or what.

Also, the plane tends to roll and yaw left significantly. By trimming the rudder and ailerons, I've been able to compensate this mostly, but the trim seems excessive. I've looked quite a bit at how true and straight the plane is put together, and if anything, it looks to me like the slight curve in the body which is visible when you sight down the underside of the plane should cause yaw in the opposite direction. So I'm not sure what's going on with that, either.

Any advice for me? I'm afraid to hi-start without a plane that seems to behave well under hand launch (as duly warned), and I'm not sure if I'm there yet or not.

Thanks for any advice!

AEAJR
02-01-2010, 02:34 AM
Also, the plane tends to roll and yaw left significantly.

By trimming the rudder and ailerons, I've been able to compensate this mostly, but the trim seems excessive. I've looked quite a bit at how true and straight the plane is put together, and if anything, it looks to me like the slight curve in the body which is visible when you sight down the underside of the plane should cause yaw in the opposite direction. So I'm not sure what's going on with that, either.

!

If you have a twist in the fuse you have almost no hope of getting a good launch or a good flight. You have to fix it.

I suggest you start a thread asking for help to straighten out the Easy Glider Pro.

Take a lot of pictures. Try to get the shots such that we can see the twists. Make sure you get shots of the h-stab placement. Then we can get some idea of how to fix them.

Don't post them here, start a new thread focused on your plane.



When I hand launch, if I give it a good throw, the plane noses up, stalls, and crashes immediately. I've trimmed the elevator down and put the battery as far forward as it will go, and it still behaves like this. I don't know if this is a problem with the way I'm throwing it or with the way it's trimmed or what.

Thanks for any advice!

Once you have it straight, then start over.

1) Make sure all surfaces are even with the wing, v and h stabs. These should be centered with the radio trims centered. Remember you have to do this with the radio turned on.

2) Make sure the CG is set where the instructions say it should be. If you were moving the battery forward to resolve this problem, but doing that will actually make things worse.

3) Make sure the surface throws are set to the throws recommended in the instructions.

NOW you are ready to try the throw again. Let's go over the throw.

A) Calm conditions and certainly no more than 5 mph breeze. Any more than that and you will not get a true reading.

B) I like to do these first throws over tall grass, or the softest area I can find so if it goes badly the damage is minimized.

C) Make sure all surfaces are moving properly. Since you are having a dive problem, tripple check the elevator. Pull sthe stick and make sure that surface goes up.


Now the throw.

FLAT FLAT FLAT - Don't throw up, not even a little bit. Throw it firmly, into the wind and throw it flat. Think darts, not baseball.

The best is to have someone else throw it for you so you can be ready on the sticks. It should glide out straight and pretty flat for 100 feet or so.

If it should nose up, then be ready to level it to slightly down so that it does not lose speed.

If this doesn't work, I hope you can find an experienced pilot who can check over the plane?

eastbay
02-01-2010, 03:18 AM
If you have a twist in the fuse you have almost no hope of getting a good launch or a good flight. You have to fix it.

I suggest you start a thread asking for help to straighten out the Easy Glider Pro.


Really appreciate the detailed feedback. I will start a new thread as you've suggested.

Thanks!

Huffy01
02-19-2010, 08:22 AM
Would there be many or any danger's attaching a high start to the tow bar on the car?!?!?!

Nitro Blast
02-19-2010, 03:57 PM
Would there be many or any danger's attaching a high start to the tow bar on the car?!?!?!


That depends on if the car is moving or stationary.

If moving (and I would personally qualify that idea as dumb):

The first problem is that it will take too long to 'get to speed'

The next problem is that the car will create a huge turbulance in the air right in front of the glider.

Another problem is: Who is flying the glider while someone is driving the car?


If stationary, and you are just using the car as a anchor... no issues at all. A parked car is the same as a nail in the ground, anchored to a brick, tied to a tree, or duct-taped to the nearest modern art-sculpture
.

Huffy01
02-19-2010, 11:59 PM
Well ,I really did mean "stationary" but you did reminded me once some one told me if I had a R/C car I could launch a gider from it.
For some reason ,it really became a thinker, How heavy the car would have to be?, what speed you would have to do? , How smooth the ground would have to be? If the car went over a bump/jump would it rip the plane in half? etc.

TDisaster
02-20-2010, 12:53 AM
The next problem is that the car will create a huge turbulance in the air right in front of the glider.

Well I guess then we couldn't aerotow either, huh?

The turbulence wouldn't even be noticeable. The plane would be much higher than the car, almost instantly...

But I agree, with the car moving it wouldn't be too smart. Just using a stake would be best. If something happens on launch, and the glider doesn't go up, it could get expensive. :p>

Lets not go tying high starts to trees either. That might be in the bad idea range of ideas...

soar-ne
02-20-2010, 03:46 PM
Probably shouldn't admit this but my brother and our kids launched a Oly 650 and a 2M Gnome many times some years ago being towed from a little Honda 3 wheeler ATV. We used about 400 feet of braided fishing line in a large pasture. Dont need extreme speed just a jogging pace into a little breeze. After the glider popped off the ATV driver just circle around us and we grabbed the line with leather gloves and he went out and waited for the tow up again. Kids got to drive the ATV and we got to fly, Win Win situation!!!!!!!!

Bob

AEAJR
02-20-2010, 10:52 PM
Works for me!

Huffy01
04-02-2010, 03:56 AM
I haven't used a high-start before but I have some 8mm silicone bugee and a 'chute on order at the LHS.
Last night I bought my second unpowered sailplane.
I don't know what brand it is but it's a 3m ,4 channel a/r/e/s .
My other sailplane is a full house Great Planes Spirit Elite.
Which sailplane should I start learning with??

AEAJR
04-02-2010, 04:06 AM
I haven't used a high-start before but I have some 8mm silicone bugee and a 'chute on order at the LHS.
Last night I bought my second unpowered sailplane.
I don't know what brand it is but it's a 3m ,4 channel a/r/e/s .
My other sailplane is a full house Great Planes Spirit Elite.
Which sailplane should I start learning with??

Have you ever flown an RC Airplane?

My recommended first glider would be a Multiplex Easy Glider.

Huffy01
04-02-2010, 04:13 AM
I have had a Parkzone Radian for about 1 year and 4 months.
The only other R/C I have going at the moment is an Eflite MCX S300.
I also have a Phoenix simulator.

Huffy01
04-02-2010, 04:16 AM
http://www.wattflyer.com/forums/showthread.php?t=54889
Here's the link to the 3m sailplane that I bought last night

AEAJR
04-02-2010, 10:38 AM
OK, now I know what hi-start to recommend.

I believe Stepp is the name of the plane. I will see if I can find some info on the plane and post it in your other thread. What is important here is that I now know it's weight at 78 ounces. You want a 3M hi-start to launch that plane. It will also launch the Spirit Elite just fine.

Get the NESail Pinnacle Large - $90
http://www.nesail.com/detail.php?productID=874

Or

the Aerofoam Hosemonster
http://www.aerofoam.com/hosemonster.html
3Meter/50 foot rubber 250' Line $130.00
3Meter/100 foot rubber 500' Line $165.00

Many say the hosemosters are the best HS around. I used a 2M model once and it seemed very nice, had a nice stretch and a good release. I have been very happy with my Pinnacle, so I can recommend that too.

Follow the instructions in the thread on learning to use a hi-start and you should have no problem. Pay close attention to the recommendation that you MUST be able to get a good hand glide before trying to launch this on a hi-start of a winch. If your plane will not glide out nicely from a hand launch then you could have a disaster on the hi-start.

Also get the fish scale, as I recommend. You will only use it a few times to help you get the feel of the desired pull, but it is a good investment. This is especially tru for you as you have two planes of very different weighst, so you want to get the right pull for the best launch for each plane.

If the Elite is built properly and has no damage it will take all the power this hi-start can provide so don't be afraid of too much pull. More important is to be sure you have enough. I assume your Elite will be in the 44 to 48 ounce range. So you will want to launch at 9-15 pounds of pull once you are ready for a full launch.

I don't know what sort of wing rod and spar system you have in the 3M plane but, again, I would not expect it to have any problem with handling the hi-start. That plane is almost 5 pounds so you will want at least 15 pounds when you go for a full launch and 25 pounds would not be too much. I think that hi-start can provide at least 20 pounds so it should be a good match for that plane.

When you are ready to go to full pull launches, you may wish to get some help for the first launch or two so you can be ready on the radio, in case something goes wrong. Holding a glider with the hi-start pulling and you trying to handle the radio in the other hand can be a bit akward at first, but once you get the hang of it, it will be no problem.

The topic of this thread is "Learning to Use a Hi-start" and I would like to keep it focused on that. I will jump in on your other thread, in case you need some set-up help.

Huffy01
05-05-2010, 04:27 AM
I got the rubber for my high start yesteday ,it's not latex its silicone rubber ,alot cheaper than latex .
It comes in 10m lengths so I need 2 joins to make the final 30m for the high start.
I remember that a wooden dowel is used to join the lengths together but I can't remember if a screw or a thread is used as well.
I know glue isn't used because the tube has so much elasticity it will break a glue joint.

AEAJR
05-05-2010, 12:34 PM
I am not sure of the grip character of silicone rubber but with latex rubber you can just slip a wooden dowel into the tube. As you stretch it the grip gets tighter.

I have never joined rubber sections, but what I have read is that people recommend you use a hardwood dowel that requires you to stretch the tube a bit to slide it in. I would try to get it into the tube at least 3 inches, then test the grip. If you cut some shallow circles around the tube, or perhaps some cross hatches, this will give the tube something to grab on the dowel as it tightens.

I have not tried this, but if you are able, try to fold the tube back over itself for 3-4 inches. Then position the dowel at the end of the tube and try to roll the folded tube over the dowel. If that works, it will probably be the easiest way to get the dowel in that far, especially with the rings or cross hatching cut into it.

Now, spike down one end. Tie a string to the other end that is at least 100 feet long and try some test pulls.

With latex rubber you can usually stretch it 3X the rested length. Not sure about silicone, so you will have to experiment. Using a fish scale you can measure the pull. The pull should go up as you stretch it. If the pull suddenly starts to jump a lot with very little additional stretch you are at or maybe a bit past the safe limit ... stop.

What's the outside diamater, OD of the tube as well as the ID of the tube? Where did you buy it?

I think the typical 5/16" latex tube with a 1/16 wall will give you 12-15 pounds of pull on a 3X stretch. This is your typical hi-start for 1.5-3M planes. Good for 1.5-4.5 pound planes which covers a large range of planes.

3M+ hi-starts often use 3/8" which will go to about 20 pounds, roughly. Good for 2 to about 6 pounds.

4M+ might use 1/2" that will give about 35 pounds of pull. Good for 3 to about 10 pound planes.

Actual numbers will vary by wall thickness and formulation, but these should give you some target ideas. I would be interested to see what you get with the silicone rubber.

Huffy01
05-05-2010, 02:29 PM
I order the tube from my local hobby store ,I think it was sourced from the US.
Sorry, I dont know the equivalent imperial measurement but the outside diameter is 8mm and the inside diameter is 5mm.
I just had a try at rolling the tube back and didn't have much luck.
Silicone isn't as good as Latex but 30 metres cost me $40 compaired to $150+ for Latex tube!

AEAJR
05-05-2010, 05:20 PM
That would be about 3/8 inch, so you can compare to the list I made. I will be very interested to see what your pull tests reveal.

AEAJR
06-05-2010, 09:08 PM
I order the tube from my local hobby store ,I think it was sourced from the US.
Sorry, I dont know the equivalent imperial measurement but the outside diameter is 8mm and the inside diameter is 5mm.
I just had a try at rolling the tube back and didn't have much luck.
Silicone isn't as good as Latex but 30 metres cost me $40 compaired to $150+ for Latex tube!

Have you had a chance to try out your new hi-start?

Huffy01
06-06-2010, 10:00 AM
I haven't done anything at the moment.
I bought some 6mm dowel and have tested it and it seems to be the right size.
It's only 1mm bigger than the inside diameter of the silicone rubber.
I pushed the dowel in about an inch and a half . It is stuck in firmly and cant get it out.
I still have to buy some key rings and some kind of strong line.
I also have to workout how to attach the line to the rubber.
But by far the biggest reason why I haven't built the high start is I don't have a plane yet to launch from it.
I could safely say I will launch the Great planes spirit elite. I am still waiting on some iron-on covering which is on back-order.
The Stepp-Upp is far from being finished.

AEAJR
06-06-2010, 11:06 AM
I haven't done anything at the moment.
I bought some 6mm dowel and have tested it and it seems to be the right size.
It's only 1mm bigger than the inside diameter of the silicone rubber.
I pushed the dowel in about an inch and a half . It is stuck in firmly and cant get it out.
I still have to buy some key rings and some kind of strong line.
I also have to workout how to attach the line to the rubber.

snip ....


You can try key rings, but remember that there is going to be quit a pull on them, so use very strong ones.

Better to use solid welded rings like these.
http://www.homedepot.com/h_d1/N-5yc1vZ1xgk/R-100121681/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

I think I usually use about about a 1.5" to 2" welded ring for the rubber on the end where I will spike it down. Just slip it through the ring and tie a knot.

Then I use a steel spike for the ground, usually with a washer.
http://www.homedepot.com/h_d1/N-5yc1vZ1xgk/R-100124434/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

As for the airplane end, if you buy a commercially available parachute then the rings are already attached. I provide these as examples.
http://www.nesail.com/detail.php?productID=2625
http://www.4mrkite.com/Chutes.html

The parachute works with the wind to bring the line back toward you and makes it easier to find in the grass. The brighter the color the better. Mine are pink or orange.

Or you can just tie a steel ring onto the airplane end. Take your fuse to the hardware store and see what will fit ver loosely into the gap between the hook and the fuse. If you are not going to use a chute you might tie a brightly colored streamer to the airplane end, say something 1" wide and 1 foot long, to help you find the end in the grass.

I use pink Mason's line. It is strong and easier to spot in the grass than monofiliment.
http://www.homedepot.com/h_d1/N-5yc1vZ1xgk/R-100318178/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Others use monofiliment fishing line. Antying over 40 pound test should be strong enough for the pull and to stand up to some abuse. It is lighter than the Mason's line but harder to see in the grass. Here is an example.
http://www.cabelas.com/cabelas/en/templates/pod/standard-pod-wrapped.jsp?id=0018813&navCount=1&parentId=cat600392&masterpathid=&navAction=push&parentType=index&indexId=cat600392&rid=&cmCat=netcon&cm_ven=netcon&cm_cat=Bing&cm_pla=monofilament%20fishing%20line&cm_ite=netcon&rid=2146251080

Huffy01
06-06-2010, 04:27 PM
I have a parachute ,fluro pink with fluro yellow thread.
I didn't even think about a solid steel ring .
I live on a property at the moment so I was thinking of using an old 4x4 paddock basher to attach the high-start too.
I think I could find an old star dropper and shape it with an angle grinder.

Rockin Robbins
06-06-2010, 07:20 PM
Go, man, go! You're going to love launching with a high start. Suggested accessory, a young kid who loves to run after and retrieve the parachute. You can then easily retrieve the high launch, anchor it to a large nail in the ground and be ready for instant relaunch on hand catch. That is absolutely fun.:D

AEAJR
06-06-2010, 08:09 PM
If I don't have the kid to chase the chute, and if the field is open, where I would not interfere with anyone, I use the chute as my landing target. So as I am flying I walk to the chute. Then, when I land I try to put the nose of the plane on the chute.

Then I pick up the plane, the chute and stretch off for another launch. :)

Huffy01
09-24-2010, 04:56 PM
Well, I've been shopping and bought some steel/galv rings some 80lb/150m fishing line and some huge 74kg swivels.
I've got to do some wire work on the swivels,I have one on the bungee/fishing line end and one to go from the fishing line to the parachute.
The steel rings I bought I'm going to use on the stake end but they are too heavy for the end of the parachute.
I have joined up the 3x10 metre silicone with wood dowel , I guess I cut them about 2 inches long and on seem to hold well.
I have bought a luggage scale so sometime I will get a rating.
Nothing's going my way at the moment .All my money has been going towards fixing cars and it has been about 4 months waiting for one roll of covering to finish my Sirit Elite.

Rockin Robbins
09-26-2010, 09:37 PM
Just be very careful that you use stakes on both ends that cannot be pulled out of the ground by the hi-start. If you were to use a steel spike that was too short, it becomes a LETHAL spear, flying through the air at 50-100 mph. People have been killed that way.

AEAJR
09-27-2010, 12:48 AM
Typically you have the stake, then 100' rubber then 400 feet of line. It would be a miracle for the stake to come out and travel 500 feet much less have the power to hurt anyone.

I doubt anyone has ever been killed by a hi-start spike.

Rockin Robbins
09-27-2010, 02:32 AM
I forgot where I read the story but it was recently. There was a person close to the anchor spike, not the flier of the plane, who would be too far away for the spike to reach. Basically it was a person who should have been prevented from being in the area. I would imagine if you had 100' of elastic stretched to 300 or 400 feet, anyone standing from halfway of the length of the elastic to the spike could be in danger of being stricken by a very fast-moving spike.

Under normally controlled circumstances there wouldn't be anyone in the danger zone at all. And I agree that the flier would not be in danger because he is isolated from the spike and elastic by a length of non-stretchable line extending a hundred to 400' depending on the hi-start's size.

Huffy01
09-27-2010, 06:50 AM
I am intending to make a stake out of a fencing dropper but I have a 4wd van and a station wagon that are not register for the road so depending on the weather I'll just use a tow bar.
I am on 90+ acres of land so there will be little chance of hitting someone with a spike.

AEAJR
09-27-2010, 12:50 PM
Humm, I had not thought of that. Actually it is not unusual, when several pilots are sharing the hi-start, for one to be out in the field, perhaps 1/2 way to the stake to pick-up the chute and bring it back for the next launch.

But despited any debate, YES, make sure that stake is long and strong. I typically use a 12 inch spike which I pound in at about a 30 degree angle away from the pilot with about an inch sticking up to take the ring/washer attachment and to allow it to swing as the hi-start is adjusted for the wind.

With this angle, as the pull increases the tendency is for the rubber to pull down toward the ground rather than up. and any pull pressure will tend to be distributed along the length of the spike into and against the ground.

Never had one come loose.

Rockin Robbins
09-27-2010, 08:04 PM
I also used a 12" spike driven the same way. Never had one pull loose even in the Florida sand.

I used a 24" stake in beach sand though. Then I was using elastic only with no fishing line, with parachute fastened to the ring on the end of the elastic. I had less spectator control there and was taking no chances.

Huffy01
10-09-2010, 06:40 AM
Fianlly spring has arrived, one month late. It gave me sometime betwwen races at Bathurst.
The first pull I only got to 2.17kg before one of the joints failed.
After replacing the dowel with a longer piece of dowel I got to 3.67kg before the other dowel joiner failed.
I haven't got anything to measure the distance so I had to pace it out.
The silicone bungee is about 32 paces long and managed to stretch it 65.5 paces.
So that's 97.5 paces from the anchor point at 3.67kg.
Is this going to be good enough to launch my 3.2m Stepp Upp its all up weight was 2.2kgs????

Nitro Blast
10-09-2010, 04:10 PM
Fianlly spring has arrived, one month late. It gave me sometime betwwen races at Bathurst.
The first pull I only got to 2.17kg before one of the joints failed.
After replacing the dowel with a longer piece of dowel I got to 3.67kg before the other dowel joiner failed.
I haven't got anything to measure the distance so I had to pace it out.
The silicone bungee is about 32 paces long and managed to stretch it 65.5 paces.
So that's 97.5 paces from the anchor point at 3.67kg.
Is this going to be good enough to launch my 3.2m Stepp Upp its all up weight was 2.2kgs????

Sorry if I missed it, but you dont describe a high start that I'm used to. The typical hi-start rig is 1/3 bungee, and 2/3 string.

If your 'all up' distance is only 97 paces, once that tubing begins to shrink, the altitude gets compromised. Plus, the heavy tubing will weigh it down.

If you have the long string attached, the 3+ kg is plenty of pull.

Huffy01
10-09-2010, 05:20 PM
I haven't attached the line yet. I was just stretching the bungee.
I have 150m of 80lbs fishing line and a hot pink parachute to go on the end.
I just need a descent ring to go at the end of the parachute.
I did buy some from the hardware store but they are about 28mmX5mm and solid zinc coated steel.

AEAJR
10-11-2010, 02:23 AM
As stated earlier in this discussion, typically for a thermal duration glider with the hook placed near the CG, you want a pull of at least 3 times the weight of the glider. Less than that and you are not likely to get a relable launch except in a strong breeze. Even then it would be as high as you would like.

Also, my hi-starst have 3 to 5 times as much string as rubber. So a 30 meter hi-start would have 90 to 150 meters of line.

AEAJR
06-29-2011, 03:20 PM
Sources for hi-starts and hi-start rubber
This needs to be updated from time to time.

My favorite, NESailplanes seems to be in trouble. No one seems to be able to get in touch with them, so forget the Pinnacle hi-starts.


OTHER SOURCES

Hobby-Lobby - hi-start rubber or full hi-start packages - well known for quality products
http://search2.hobby-lobby.com/psear...-start&x=0&y=0 (http://search2.hobby-lobby.com/psearch/svc/search.php?uid=2&q=hi-start&x=0&y=0)


Aerofoam - Hosemonster - rubber alone or full packages
reputed to be the best
http://www.aerofoam.com/hosemonster.html (http://www.aerofoam.com/hosemonster.html)


HobbyKing - rubber only. I don't know much about these. 30 foot pieces only so you would have to join them for a larger HS.
http://www.hobbyking.com/hobbyking/s...wer_Search.asp (http://www.hobbyking.com/hobbyking/store/uh_power_Search.asp)


I found this e-bay listing for theraband
http://cgi.ebay.com/ws/eBayISAPI.dll...m=190544596819 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190544596819)
I posted a question to see if the spools are 100 feet continous or if it is pieces. 100 foot of green is $53 including shipping. A guestimate would be that red would be good for 2M, Green for typical 3M, Black for extra strong or larger than 3M. Anyone have actual pull measurements for this stuff?


Tower Hobbies - Low cost - they work but I only recommend these for people on a very very tight budget. Use the HD for 2M or above. Probably Ok to 100" wing span. Standard is for under 2M gliders.
http://www3.towerhobbies.com/cgi-bin...EARCH=hi-start (http://www3.towerhobbies.com/cgi-bin/WTI0095P?FVSEARCH=hi-start)


General guidelines

You can buy latex rubber tubing on e-bay or from other sources, just make sure that whatever length they offer is one piece. You can see offers for 100 feet but it comes as a bunch of 5' sections which would be common use for this stuff. You can join pieces but I would not want more than two joiners on a 100 foot hi-start. There are joiners that can be split so having multiple pieces could be an advantage if you fly on varying length fields.

Assuming you find 30, 50 or 100 foot pieces here are the size breakdowns as I have seen them used. Others may provide different advice. I tend to like my HS a little stronger. You can always pull a little less but if you need more pull and you don't have it you are stuck.


5/16" OD - Standard HS good for about 1.7M up to about 3M or about 65 ounces.

3/8" OD - HS for up to about 3.5M or about 80 ounces. Fine for 2M planes, just don't pull as far.

1/2" OD - Good for up to about 4M or about 100 ounces. May not be good for 2M planes.

Note that if you are going to hi-start launch a 80 to 100 ounce plane, about 5-8.25 pound planes, your high-start will be pulling at 25 to 40 pounds. That would be difficult for one person to handle so it would be best to have someone handle the plane while someone handles the radio. Planes of this weight are better suited to a winch, but you can hi-start launch them.

Rockin Robbins
06-29-2011, 04:12 PM
I used a Dynaflite Heavy Duty from Tower for over 10 years with no problems. It's 25 years old now and the rubber is shot, but with new elastic I could use it tomorrow. I flew 2 meter planes with it.

Having never flown a higher quality one, what is the difference? There isn't a whole lot of difference in price either if you were also considering one from Hobby Lobby.

TM4197
06-29-2011, 04:27 PM
I now use shock cord "bungee". Its very weather proof and very strong, you can actually roll it up wet and it will not degrade it. You have to adjust your pullback distance compared to the rubber tubing distance. But I have had great success with this stuff..and its last a very long time. You can get about 300feet of it for around 40 bucks.

AEAJR
06-29-2011, 07:13 PM
I used a Dynaflite Heavy Duty from Tower for over 10 years with no problems. It's 25 years old now and the rubber is shot, but with new elastic I could use it tomorrow. I flew 2 meter planes with it.

Having never flown a higher quality one, what is the difference? There isn't a whole lot of difference in price either if you were also considering one from Hobby Lobby.

The HD is great for 2 to 2.5M and light 3M gliders, but once you get above about 60 ounces it just doesn't have the umph you need. One of our members has one and it hardly luanched is 58 ounce Bird of Time.

Rockin Robbins
06-29-2011, 08:09 PM
Okay, so it's good for what its real capabilities are but Heavy Duty should be "Heavy Duty" in quotations with a smile. I'm not surprised there. Thanks!

AEAJR
03-31-2014, 05:17 PM
A few more examples of hi-start launches:

https://www.youtube.com/watch?v=JghL7LRFQoo (https://www.youtube.com/watch?v=JghL7LRFQoo)

https://www.youtube.com/watch?v=tUHykiGOOyU (https://www.youtube.com/watch?v=tUHykiGOOyU)

Hi-starts are not just for little woodies. The Nan Shadow is a high end composite competition glider
https://www.youtube.com/watch?v=RGHcya0WPEQ (https://www.youtube.com/watch?v=RGHcya0WPEQ)


Mike Smith is a world class competition pilot.
https://www.youtube.com/watch?v=mTd3PGC8zOs (https://www.youtube.com/watch?v=mTd3PGC8zOs)

solentlife
03-31-2014, 06:09 PM
Here's back in 1980's ......

Apologies for video quality but it's 8mm cine converted ...

http://www.youtube.com/watch?v=rU0Ke1Fbmvk

Nigel

AEAJR
11-20-2014, 02:26 PM
Just came across a hi-start at Horizon hobby. FYI
http://www.horizonhobby.com/parkzone/hi-start-450-2-3m-efla650

Includes a good video on how to use a hi-start
https://www.youtube.com/watch?v=ru0tyLi6L74#t=43

Mkrusz98284
07-03-2015, 08:15 PM
Do you avoid contests because they are flown off winches and you practice on a hi-start? Let me give you a different prospective. If you don't fly contests you are missing out on a lot of fun.


Our club contests and our Eastern Soaring League contests are all done off
winches. However anyone can have their plane launched for them off the
winch if they are not talented on a winch. I did this for several Novice
class flyers at a recent ESL event. In my first ESL contest others launched the plane for me.

Are you at a competitive disadvantage if you don't have a winch to practice on? Sure, but compete anyway!

There is no question that a super strong ship can achieve greater height off
a winch than a hi-start. And there is no question that a typical sport
class plane can not take the stress of the extreme zooms that the super
competition class planes can handle.

Having said that, I say, who cares? I compete in club and Eastern Soaring
League contests. I may never win either but I have so much fun at the
competitions it really doesn't matter if I win. And I get so much support
and good coaching from the advanced pilots that I would have to be a fool
not to compete. These are flying lessons from the best!

I share what I learn with those who want it. They can use it in whatever
way they wish. But the idea that you can't compete because you don't have a
super ship just does not cut it with me.

I was at my first Eastern Soaring League with a Sagitta 600 2M RES glider.
The only 2 meter in the contest. I finished dead last, but I finished.
Some others did not finish. I had a grand time and I was a better flyer for
it.

I did most of my practice flying off a Hi-start! At the contest other flyers launched my plane off the winch for me. Worked out fine and they were happy to do it.

I then got a 15 year old Airtronics Legend that flies like a tank. 4
contests on that one. It is now my back-up plane. I have managed to move up to NEXT to last. Having a frickin ball!

On the Legend, I practiced on the winch and on the hi-start.

Now I have a PoleCat Thermal Dancer. Still not an Icon or a Supra or a
Sharon. Maybe I can achieve mid pack. That would be nice, but frankly I am always flying for my personal best. Perhaps someday that will get me a prize. But when I make a personal best, it always makes me smile. Hitting the center of the landing circle is such a high!

I encourage you and other flyers to enter contests for the fun, for the
friendship and for the learning. And, if you are an active contest pilot, I
encourage you to take that hand of a reluctant flyer and bring them into the
contest fold. Believe me they will thank you.

Clear Skies and Safe Flying!

I was on a 1,500 mile bike ride and took a break at a park that was doing a glider competition. Back then they used a starter from a old Chevy with a foot switch. The poor people used a bike with the rear tire removed, upside down. They only made ten speeds during that era. Everything was balsa paper and dope. Now it's foam. The good old days!:D

Mkrusz98284
07-03-2015, 08:25 PM
I haven't attached the line yet. I was just stretching the bungee.
I have 150m of 80lbs fishing line and a hot pink parachute to go on the end.
I just need a descent ring to go at the end of the parachute.
I did buy some from the hardware store but they are about 28mmX5mm and solid zinc coated steel.

Try using key rings. The string is just to keep the stake from hitting the control guy in the event the stake comes out of the ground or the tubing breaks. Make sure the key rings are strong but will come off the plane. I have the instructions and a hi start. The knots were the hard part for me.

Mkrusz98284
08-28-2015, 06:38 PM
Throw the plane hard with the nose up at around 45 degrees or higher.

It took some time to get my wife out of the house to launch for me but she's under five feet tall and doesn't seem to understand keeping the wings level during launch. I started with her flying flat and worked it up on each launch to around 45%. When I got back home she said the best launches were just tilt to the angle and let go. 450' of line with a parachute, 1/4 tubing, 3/4 string. That's just to keep the stake from going between the eyes if it were to come out of the ground. So I am told. We had nine great launches. Some were hard to recover from on that boost. One I was stuck on the high start. It didn't want to let go so I did a dive and hard up. It came loose and it was fun too.

How do you feel about launching at a 45% angle with no toss? Just tenshion on the line and let it go to make sure the wings are level?

Some minor repairs and I'll be ready to launch again. Trial and error seems to be my downfall. :D


Maximizing Launch Height Using a Hi-Start
by Ed Anderson
aeajr on the forums

While the winch is the preferred method to get the most height on a launch,
you can get awesome launches off a hi-start if you know what to do. The
advantage the winch has is that you can control the pull throughout the
launch. With a hi-start, the pull is maximum on initial release then
decreases throughout the launch. But that does not mean that you can not use the same techniques the winch launchers use to gain extra height.


ELEVATOR AND CG

The further back the CG, the easier it is for nose to come up during the
launch. If your plane tends to launch fairly flat and you find you need up
elevator to get it to rotate, try moving the CG back slightly. Then fly the
plane. It will be more responsive and will read lift better. You may find
that you have to add some down trim after moving the CG back. This is
because you have been using up trim to hold up that heavy nose. This
process will reduce drag and make for a better flying plane.

I usually start my gliders at the most forward CG recommended by the MFG,
then over a series of flights, I move it back till it gets too twitchy to
handle, then I move it forward a little till it gets stable enough for me to
fly it. Many competition pilots have the CG so far back that I can not
handle their planes.

If you have a computer radio, try adding some expo. This will soften the
response around the center of the controls making it easier for you to
manage smooth flight with a plane that has a more rearward CG.

You should not have to apply any elevator during the launch. If you are,
then you are introducing drag which reduces speed and does not increase
lift. Try working your CG back and see how it flies. It will launch better
when the CG is further back and you will need little or now elevator to get
the nose up. The placement of the tow hook will likewise impact the need
for elevator on launch. I cover that next.


HOOK AND THROW

Hook placement will make a big difference in your launch height. The closer
the hook is to the CG, the steeper the rotation of the plane during launch.

The optimum situation is that your plane climbs at about a 70-80 degree
angle presenting the most resistance to the contraction of the rubber. This
takes the plane through the largest arch and produces the longest time of
launch, extracting more energy from the pull and translating it to height.
If there is a breeze and your launch angle is steep enough, the rubber may
never fully contract during the launch giving you the greatest height
possible. You will use that remaining tension in the line when I cover the
zoom, later in the discussion.

When you launch initially, if you have enough pull on the line, throw the
plane up at about a 30 to 45 degree angle rather than out flat. This gets
the plane through the rotation faster getting it into this max lift position
sooner. The throw really makes a difference. It gets you up to flying
speed faster which is important the closer you have the hook to the CG.
Typical hook position is about 1/4" in front of the CG, but having it closer
will usually give you higher launches.

Note that , as you move the CG back, as advised above, you are moving
further and further away from the hook, so you may need to adjust hook
position just to maintain your current hook/CG position. Also note that the
further back the hook placement, the closer to the CG, the harder the plane
is to control on launch. It will stall easier on initial release, so it is
vitally important to give it a good throw and not just let go.

When moving your hook back, you may wish to have someone help you during this adjustment phase by either throwing the plane for you, or working the radio. This way the hands are on the sticks at all times. If the throw goes bad or if you have moved it back too far, you will be better able to respond. If the plane stalls on the launch, a little down elevator for a moment will help it gain speed and you may be able to save the launch. Once you have it where you like, you should be able to launch it by yourself.


ZOOM

It is possible to "zoom" off a hi-start, in a similar fashion to what is
done with a winch. The bounce is not as dramatic, but still, you can gain
additional height if you get the timing right.

When the model is about 80% through its arc, and while there is still
tension on the line, rather than just flying off the line, you nose down for
less then a second, then pull up hard. The weight of the hi-start, and any
remaining tension, will help to accelerate the model to a higher speed. The
down/up pull then translates this speed into altitude. I do this with all
my planes. The Spirit, the most fragile of my gliders, picks up at least 50
feet this way. With a moderate breeze and a fast plane, you can do even
better. If you have an aileron plane or aileron/flaps, and a computer radio
that will allow you to reflex the wing, this can help you gain even more
height.


CHANGING THE WING

If you have flaps, deploy them on launch. If you have ailerons and a
computer radio, then drooping the ailerons also will add even more lift upon launch.

By creating more under camber, more bottom curve, you create an airfoil that
produces more lift. It also produces more drag, but during the launch, when
you have the pull of the hi-start, you can afford this drag to gain the
lift. This will create a longer arc and a higher launch.

Launch - Flaps or flapperons down for initial launch: Usually 10-20 degrees
is enough, but every plane is different, you have to experiment. I have seen
launch positions as high at 45 degrees on the flaps. If you have the
ability, droop the ailerons too.

Throw the plane hard with the nose up at around 45 degrees or higher.

Mid arc - If you have a computer radio and can set a reflex position, about
70% up the line you switch to reflex. This is where the ailerons/flaps are
actually moved up slightly from their normal position. On most airfoils,
the RG15 foil being a know exception, this creates a high speed/low
drag/lower lift setting that is great for gaining speed. Now you want to
accelerate the glider to gain speed.

Zoom - Around 80% though the arc you do the down/up while at maximum speed,
still in reflex. The down lasts less than a second and the up is strong.
Go for a climb angle of 60-90 degrees, depending on the plane and the pilot.
You have to experiment to see what works best for you.

Level - As it climbs it will lose speed. Before the plane loses all its
speed, you level the plane, go to normal wing position and start your hunt.
If you are stalling at the top of the launch, resulting in a drop in the
nose and loss of height, then you are waiting too long to level the plane.
It should look like the plane just leveled onto a table with no drop of the
nose. This is your best launch height.

You can still zoom with a simple 2 channel plane, but if you can change the
airfoil during the launch, you can gain even more height. If you have
flaps but no computer radio, you can still go though this sequence using the
flaps. Where I call for reflex, just move the flaps to normal flying
position. Ahhhh, the joy of computer radios.

Using a winch, this sequence can gain 150-300+ feet, if you have a strong
plane. It can be quite dramatic.

Using a full size hi-start with enough pull, you can do about 25-50% of
that. The limiting factor is that you can't increase the power at the end
of the launch like you can on a winch. However you are also unlikely to
overstress the wings off a hi-start. I have seen planes fail on zoom, using
a winch, when the pilot was too aggressive on the zoom. I have never seen a
plane fail when zooming off a hi-start, but I am sure it can be done.


GIVE IT A TRY!

If you go through all the steps above, you may find that you are getting
higher launches without the zoom. This is great!

Then you can try adding the zoom, but tune the CG and hook positions first
as these are more important. But you can try a zoom on any plane, the
benefits will just not be as great as when the plane is tuned properly.

If your plane drops at 100 feet per minute during its glide, and you can
gain 50 feet on the launch, you just gained 30 seconds of flight time. And
thermals tend to be larger in radius the higher you go, so you have a larger
target. If you can gain 100 feet, the flying experience can be quite
different.

The more sophisticated the plane and the more flexible the radio, the more
you can tweak the launch. The longer and stronger the hi-start, within
reason, the higher your launches.

Even with a simple R/E plane, you can improve your launch height by going
through these steps. You will get higher launches, longer glides and likely
find more thermals than you did before.

Other resources can be found in the handbook. I hope this has been
helpful.

The New Glider Pilot's Handbook
http://forums.flyesl.com/topic.asp?TOPIC_ID=251

fhhuber
08-28-2015, 09:14 PM
Actually depends a bit on the plane and the power of the High-Start.

A light plane with just a little wind and a good High-Start can do fine with the 45 up angle and let go.

A heavier model that will stall it and it will spin in then get dragged and shredded. Heavy models (especially with a lighter pull High-Start and no wind) need a strong toss aimed at the stake, gain a little speed then pull.

There is no one technique that is guaranteed to be right every time... Adjust for the model, the High-Start and the wind.

AEAJR
08-28-2015, 09:23 PM
Throw the plane hard with the nose up at around 45 degrees or higher.

It took some time to get my wife out of the house to launch for me but she's under five feet tall and doesn't seem to understand keeping the wings level during launch. I started with her flying flat and worked it up on each launch to around 45%. When I got back home she said the best launches were just tilt to the angle and let go. 450' of line with a parachute, 1/4 tubing, 3/4 string. That's just to keep the stake from going between the eyes if it were to come out of the ground. So I am told. We had nine great launches. Some were hard to recover from on that boost. One I was stuck on the high start. It didn't want to let go so I did a dive and hard up. It came loose and it was fun too.

How do you feel about launching at a 45% angle with no toss? Just tenshion on the line and let it go to make sure the wings are level?

Some minor repairs and I'll be ready to launch again. Trial and error seems to be my downfall. :D

The four factors that impact launch:

Weight of the glider
Pull of the hi-start
Position of the tow hook
Amount of wind

You can launch at whatever angle works best for you. This thread is about learning and during learning I would say you should do your first launches flat with the tow hook well in front of the CG and let the glider rotate on its own. Then you can gradually work your way up on angle until you find the angle that works best for you. Then you can consider whether you want to move the tow hook back, assuming you have an adjustable tow hook.


No matter how I launch my Supra, it will rotate almost vertically because of where I have the tow hook, which is optimized for the winch, not the hi-start. I have to be careful not to stall it on the launch even though my hi-start is quite strong.

Kasperwing
04-22-2017, 10:44 PM
Hi Everyone! Been away from flying for a number of years. I have been flying the EF Laser60 ( electric) and some foamies. BUT...My heart is in sailplanes!! Heck I used to own a 2 place Lark so many years ago. I have read this entire thread and lots of other things over the last few months. Since I am semi retired, out of work and have time, I thought I would get back into RC. I flew in an electric glider contest using the Calypso last year and performed very well. I want to get back into silent flight for most of my flying. I have been vacillating between Electric sailplanes and pure gliders. When I watch someone hand laugh the Explorer and find lift, it excites me the way few things can ( for this old man). So I am thinking that to get a good sailplane with a small low power high start, kind of like a super strong arm, would just be loads of fun. Also I would not have to spend $300 ~ $500 on electrics. So the idea of getting a explorer or a shadow ll or a dragonfly-strong.... and using a low power high start seems like a good way to go. Money is scarce these days. So I am wondering how well would a Dragonfly ( soaring USA) do with a high start and how much would I be giving up buying that VS a Sharron or Shadow or Explorer?

Kasperwing
04-22-2017, 11:01 PM
the planes I am looking at weigh about 60 to 70 ounces with 3.5 to 4 m wing spans.
Would this UP start work? http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYXK7&P=0

where could i find a little better for not a big increase in cost?

BTW, I am doing this for the fun and challenge. As of now, no one flies gliders around here.

AEAJR
04-23-2017, 12:11 AM
Not that upstart would not work. It is too light.

At 70 ounces, about 4.5 pounds, you will need about 14 pounds of pull to launch that glider.

You need about 3X the weight of the glider, minimum. That would call for a hi-start with about 5/16" outside diameter rubber, minimum. I would recommend 3/8 rubber.

Kasperwing
04-23-2017, 12:18 AM
Thanks Ed! Did not expect such a quick response. Any ideas where I could get 3/8" rubber latex/ silicone/ un-obtainium glider launching gear?
and.. would an Up start work well enough to find lift?

Kasperwing
04-23-2017, 12:24 AM
Another question please. Since this thread first started, a large number of improvements have taken place with motors and batteries. It seems to me that many of these planes need ballast.... and to that end why not just add electric propulsion. It looks like the ballast and electric add the same weight?

I think the electric would offer one to make another approach and possibly lessen the chance one would damage the plane ( when you have no more altitude). Thoughts please!!??

AEAJR
04-23-2017, 12:41 AM
Best on the market
https://www.aerofoam.com/complete-highstarts.html

This one will get you 12 to 13 pounds as I recall.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYXK5&P=7

Kasperwing
04-23-2017, 02:01 AM
Best on the market
https://www.aerofoam.com/complete-highstarts.html

This one will get you 12 to 13 pounds as I recall.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYXK5&P=7

Thank you Ed!

1. Did anyone ever try the "turn-around" pulley system for high starts? I remember reading that you were going to try, but it was to cold and you had use of a wench. It seems like such a good idea!

2. I went to the Aerofoam site. What would be the experience of using the Highstart vs their "zip-start"?

Sincerely,
Dave
South Louisiana

AEAJR
04-23-2017, 02:36 AM
I never did try the pulley hi-start system.

Zip starts, as he is using it, are also called upstarts, basically short hi-starts. Note that some of his are very very strong and will tear the wings off of non-competition gliders. You could use the first one, 15' of 3M rubber but it is going to give you a very short launch.

Based on the planes you mentioned you want the 3M model. Remember you don't have to pull it all the way back. You can do a partial pull to get lower tension but if that is not enough and you are already at 3X pull, you are sunk.

Since you seem to want a shorter one, get the 50 foot rubber option. You will pull that 150 feet at full pull or 100 feet at partial pull. He includes 250 feet of line. If that is too much you can cut it and put in a 75 pound snap swivel so you can have less or more line.

In my full size hi-start I have 100 feet of rubber with 250 feet of line, snap swivel, 150 feet of line, snap swivel, 100 feet of line. This way i can adjust to the size of the field.

Kasperwing
04-23-2017, 03:51 AM
Is there a cheap way to do a wench or do used ones ever come available?

If I am just flying for fun, maybe I do not even need a wench...? Thoughts?

AEAJR
04-23-2017, 04:51 AM
Do used ones ever become available? Of course. I would check Craig's list, e-bay and the buy/sell area of www.rcgroups.com as they have a large sailplane community.

New ones are typically around $500, I think. Then you need a car battery, turn around, pedal, line. I have my own so I have not been in the market.

http://www.irfmachineworks.com/lbwinch/
http://www.mgertech.com/COMET-WINCHES.htm
https://www.soaringusa.com/AC-NN-WINCH.html

What is wrong with a hi-start?

Kasperwing
04-23-2017, 04:23 PM
Do used ones ever become available? Of course. I would check Craig's list, e-bay and the buy/sell area of www.rcgroups.com as they have a large sailplane community.

New ones are typically around $500, I think. Then you need a car battery, turn around, pedal, line. I have my own so I have not been in the market.

http://www.irfmachineworks.com/lbwinch/
http://www.mgertech.com/COMET-WINCHES.htm
https://www.soaringusa.com/AC-NN-WINCH.html

What is wrong with a hi-start?

I do not think anything is wrong with a HS. I guess I am looking at all of my options.

When NE sail ( :censor: ) was around, I bought a Graphite from Sal ( :censor: )
This was in the mid 90's. I did this with my son back in those days. I actually don't remember much, but from what I do remember we had very little success. So then we motorized the beast. The then very expensive motor did not last that long. I think it was an Aveox. We also had the extreme displeasure of fighting ni-cads, poor chargers. Not to mention the added weight of the batteries and motor. Oh, sure it worked, but I do not remember much success finding a thermal. The Graphite seemed very fragile because the least amount of up elevator at speed and the wings would bend. I seem to remember having to walk alot. I know compared to now, I knew nothing about the art of flying a sailplane. When I got into discuss launch in ~ 2002 time frame, I then had access to the internet. With all of that information, I had success with the DLG. 3D was just starting and we both became good at it. There were very few ( VERY FEW) electric planes. We flew 45 size YS motors on tuned pipes attached to the Morris Hobby Sudohkoi (sp). Great fun and we flew several times a week. I so wanted success with gliders, but after Sal's questionable advise, the fact that I just spent north of $4,000. to soar, I did not feel like the Eagle I envisioned... more like a Turkey did I feel.

I guess when it comes to a HS vs Wench, they will both use up space at the flying club. Its a small club with less than 25 members. Most of them fly pattern and not that often. So I often have the field to myself, specially since I can go anytime, and not just weekends.

I think I should look on RC groups since they have a large glider contingent and weight the pro's and con's of all methods of launch.

I am thinking that with todays electric set-up's, and since ballast is required anyway, the electric would solve all of the issues if the plane's ability to stay aloft does not suffer from adding the electric motor. Talking to Soaring USA only causes more questions. I wonder how much are they trying to sell gear vs looking at all options.
There are no gliders with in a 5-8 hour hour drive. So the only way I can find answers is via threads like this. I also do not have money to just try different things. I have to make the best decision that works for me. Thank you for your help!
Sincerely,
Dave

Kasperwing
04-23-2017, 05:05 PM
Thanks for the links to the wench's. The LBW seems to be the best choice considering costs and completeness. I am MUCH MUCH more inclined to go with a HighStart from Aerofoam. OK... here is my line of thought... please tell me where i am wrong ( or right) as the case may be.

Todays top gliders, Pike, Explorer, Shadow, Sharon ( who else am I missing?) can be simply hand launched and sometimes find lift then soar to ones heart content. Well anyway from what I have found on You Tube. So with a modest boost from a HS to 100 to 200 feet, soaring WILL happen ( unless conditions are NON soar PERIOD).

In the 1990s and early 2000's Lipo and motor-combo that weigh less than ballast did not exist. So wouldn't a motor/lipo set up set up solve everything. That is unless the glider will come down sooner with the motor.... all things being equal.

AEAJR
04-23-2017, 11:06 PM
Hand throwing those gliders to catch lift would be an enormous effort but I have seen it done. I will never attempt it as a main lanuch method. Those are winch planes and hi-start second.

If you want to hand launch gliders then get a DLG, discus launched. Tons of fun and made for hand launching.
https://www.soaringusa.com/DLG-HLG/

As for 3-gliders, that is a fast growing segment of the soaring hobby. today's modern e-gliders are extremely good and thermal very well.