aeajr

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I came across a highly portable (5 lb) launch system that could be an alternative to a hi-start or an electric winch. It can be used to launch HLG through Unlimited sizes.

roaddog2

Bookmarked it! Tnx!
RD

aeajr

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aeajr

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I hope to get a LOT of time on the Onewinch tomorrow. I have asked the club to bring planes and I hope someone brings a video camera. We gonna use and abuse this baby to see what it can do.

I will have my Thermal Dancer (3.2m bagged wing) out there again but I will be launching it by myself and I will play with various launch mixes.

I am also bringing my 3.4M Graphite which is the hardest pulling, most winch stalling plane I have. I have yet to see noticeable flex in the Graphite's wings when I stand on the pedal of an ESL winch. I will likewise be playing with mixes on this one.

I have a 2 day ESL contest next weekend, so the Supra, my main plane, stays in the hanger. These are my back-up contest planes. 


I hope to have a detailed report for you, some photos, and maybe some video too. And I plan to bring it to Virginia to the ESL contest at CASA. I have been requested to bring it. The contest pilots are dying to give it a try. When I had it out at the Boston ESL contest I had an audience.

ARUP

Pretty cool!

aeajr

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FIELD REPORT ON THE ONEWINCH
More detail here if you are interested
http://www.rcgroups.com/forums/showthread.php?t=1473778&page=9


We spent 8 hours at the field yesterday. About 5 of that was spent
with the Onewinch.

Bottom Line - winner! This thing works as advertised and I like it.
Note that I own a FLS winch and two hi-starts so I have a full range
of tools for comparison. And I am a member of a glider club that has 4
club winches. Some members have sport winches and we have a variety of
hi-starts. We launch gliders by various methods all the time.

What it is not - The Onewinch is not a replacement for a Ford Long
Shaft based competition winch. The Onewinch simply can not generate
the 200+ pounds plus of pull that a FLS winch can generate. And it is
not advertised as a replacement for a FLS winch.
What it is - A clear alternative to a hi-start and maybe an electric
sport winch.

What I learned.

Conditions - Clear, 78 degrees. Breeze was about 3-5 mph in the
morning going to about 10 in the afternoon.

* The Onewinch is easy to use
* Just like alternative launch methods, you have to work on your
technique
* Proper tuning of the plane to the launch method will improve
results.
* The average guy can easily manage the pull and the coordination
* I was launching in fairly rapid succession and I did not feel overly
fatigued
* More fatigue was probably from the walk to get the chute than the
launch
* There is a lot less walking than when using a hi-start
* You can use it on a shorter field than a hi-start and get a full
launch
* shortening the length is very easy if you don't have room for the
full set of line
* You get similar power to a hi-start but you can control/sustain it
throughout the launch
* Hook position is the critical factor to success - more on this at
the link above.

Three planes were used. A Radian that has had the motor removed and a
hook attached. Several of our members have done this. Works quite
well. This amazing little glider has been launched with hi-starts and
with a winch, so putting it up on the Onewinch was a valid test. Net
results were very good.

My Thermal Dancer, which I have launched on the Onewinch before,
launches great on the Onewinch. My techique is getting better and I am
starting to get a good feel for when and how to use my launch mixes.

My Graphtie, a 3.4M built up competition plane, had problems. The
problems were caused by the hook position, not the launch method.

What I learned is that it is not the plane that is the difference, it
is the set-up of the plane. This is a critical factor to understanding
where and how the Onewinch fits into the range of launch options we
have for string launched gliders.

The Graphite is set-up for all out competition climb on a FLS
competition winch. When I launch it I strain the winch to tension the
line and when I throw it it goes almost straight up on a full pedal
launch. I have the hook set so the plane rotates hard and immediately.
I have broken 200 pound test line with the Graphite. I can not
duplicate this launch power with the Onewinch so the Graphite's set-up
is not optimum. If I moved the hook forward a bit it would launch much
better on the OneWinch.

As a result the Graphite, in the current configuraion, tends to stall
on launch. I have to really run back fast with the One Winch to try
and generate enough speed and tension to keep it from stalling as it
tries to climb straight up. After 3 attempts I finally got a full
launch but if I were to use the OneWinch as my main launcher for the
Graphite I would move the hook forward a bit so it would take a less
agressive angle and could pick up speed more easily.

Note that I have the same issue with the Graphtie and my Supra when
launching on my 3M hi-start. My hi-start is strong, providing 24
pounds of pull at launch and both of these planes tend to stall on
launch with that hi-start unless I have a breeze to help. It is not
the weight of the Graphtie (60 ounces) or the Supra (65 ounces) it is
the hook position.

The Thermal Dancer wings are not as strong as the Graphite's so I have
the hook placed less aggressively, a little more forward. When I
launch on the FLS winch I don't tension up as much and I tap it up the
line. The hook position on the Thermal Dancer is much closer to
optimum for the Onewinch. It gains speed easily and climbs nicely.

Conclusion: The setting of the tow hook is a critical factor in the
success of launching with the Onewinch. If your plane is set up to
launch well off your hi-stat it will launch well off the Onewinch. If
you have it set up for aggressive launch on a FLS winch, it is going
to be tough to get it to launch well with that hook position. Move it
forward a bit and it will launch well.

But it was a good day and my friends seemed to like the Onewinch. I
hope to get some of their comments too,

Ed Anderson
President, LISF
Newsletter Editor ESL

ray foley

hi there from Toledo

Magnificent! A truly fair and comprehensive evaluation of a distinct departure in sailplane launch technology.

Bravo, well done!!! Keep up the good work.

ciao -rjf

BMatthews

Nice report. I wonder if we'll soon be seeing some home built alternatives after a little while when folks try to achieve the advantages at a lower price point. But to do that they'd have to deal with line control to avoid tangles or bunching when the line is slack in all the pulleys.

Could you also link to the video in this thread? I'm sure we're all interested to see if it was truly as easy as shown in the company vids.

aeajr

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I will be posting some video and photos tonight.

Digger3612

Will the new videos be linked to this topic?
I don't see anything here yet.
Tks.

OK, just did a search on youtube and found a few clips that you posted.
I needed sunglasses for the one clip. Ow, right into the sun. :-)

aeajr

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The quality of the videos is pretty poor but you will get the idea.

I have to say that as the flow of the Onewinch launch becomes more familiar I become less aware of the step-back. In the videos I pull back farther than I realized but it becomes clear where I hit the tension up point where I do little more than hold tension.

In these videos I launch my 122" 60 ounce Thermal Dancer. These are from my early launches of the day, when I had help to take the videos. As I get the technique down the launches get higher and better. By the end of the day I had the line going pretty much straight up and getting some zoom at the end.

While the plane is not easily visable on the video, it is quite high. And remember we were launching with about 50 feet of the line removed due to space constraints.

http://www.youtube.com/watch?v=3iZB7bIy3qw

Here you see that when I throw the Thermal Dancer it rotates quickly and climbs pretty steeply, though not as steeply as some of my other gliders. I hit the tension point sooner as we had about a 5 mph breezed during this launch. Once you hit tension you basically just hold that tension as the glider climbs, taking the occasional step back to keep the tension up. The more breeze the sooner you hit that tension point.

http://www.youtube.com/watch?v=5Lk-xBPdYak

Note that I do most of my sailplane launching off powerful electric winches. My standard stance is to have the plane back behind me, like a Javeline thrower. You can see this in the photo below as I prepare to launch my Graphite. I step on the pedal of the winch and tension up the line till the winch is almost stalled, then throw it hard. So you see some of that in how I hold and throw the Thermal Dancer, tensioning up the line and establishing as much tension on the line as I can before I launch. The heavier the plane and the more agressive the tow hook position the more important the pretensioning of the line. In the videos below you see Trevor does not use this hold or stance but gets successful launches with his light weight Radian.

aeajr

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On earlier launches, when we returned the launch line to the lanch point the sled got tangled in the lines.   But there is a little coil on the front that holds the line straight so the sled slides without getting tangled in the lines.

This would be less of an issue on smooth ground, but over irregular grass having the lines in that loop really makes the retrun of the chute and the sled to the launch point highly automatic

Note that the lines extend straight from the front of the sled. 
http://www.youtube.com/watch?v=T1BaxAsVsrg

aeajr

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In these videos we are working with a Parkzone Radian that has had the motor removed and a tow hook added.  It is now a pure glider.  The launches are being done by people with no experience with the Onewinch so you will see an advancing level of success and coordination. 

First we see some two man launches.   Neither person has ever done this before.

This was the first attempt.   The pilot, Trevor,  and the puller, Lee,  were not yet coordinated. 
http://www.youtube.com/watch?v=WupKyoUx6_I

Getting the hang of controlling the tension for best launch.  We found that the maximum tension is not always the best approach.  The Onewinch gives you very good control of tension so even a soft winged foam glider can be launced successfully as you regulate the tension.

http://www.youtube.com/watch?v=io4LqGJRF9c

Trevor is doing these launches by himself.

In the first one he appears to launch it like a hi-start.  He did not do much to pretension the line and did not back-up once it was launched, so the chute came off the hook.   If you have never done this before it is easy to forget to step back the first time or two.    Trevor uses a hi-start and is learning to use a regular winch.

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

http://www.youtube.com/watch?v=OMl-rBK5TyA

Getting the hang of controlling the tension for best launch

http://www.youtube.com/watch?v=W-BwDpJ-XXU

Launching into about a 7 mph breeze - very little walk back required for the Radian.

http://www.youtube.com/watch?v=Nu_ePg6nhTc

aeajr

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Digger3612

OK. I'm an old, 4 channel, nitro flyer who is looking to getting into sailplanes. Therefore, a lot of what you experienced glider-guiders are talking about is new to me. What exactly is a "launch mix" and what is it's advantage?
Tks, Ron

aeajr

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If you have a glider that has full span ailerons, or ailerons and flaps, you can change the shape of the wing by raising or lowering the trailing edge. One of the stuations where you would do this is on launch.

When you lower the trailing edge you increase the lift of the wing which can be advantageous at launch. It creates a lot of drag too, but during the launch when the glider is being towed, the drag ma not be an issue.

No different from a power plane lowering its flaps for take-off. That would be his "launch mix". Pure gliders don't take-off, they are launched.

Jets take off from a runway, but they are launched from an aircraft carrier because the are "thrown", so to speak by the catapult..

aeajr

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The OneWinch is getting a lot of interest on other forums, so I will bump this thread back up for the benefit of sailplane pilots who have not read about this.