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Old Sep 12, 2011, 07:09 AM
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South Korea
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Ed,

I had a chance to fly in one thermal contest and that was the CASA Memorial in 2009, exactly 2 years ago!

For my One Winch maiden, I was flying a custom made 60" pure glider. I definitely agree with you on the need for more practice and I am certainly willing as the prospect of catching thermals with the One Winch seem higher than with my hi-starts. I will also get some more sturdy stakes to support more tension that I suspect will be in order for my 3 meter birds.

Now that I have tried it out by myself without embarrassing myself in front of my friends, I will take it out to Xevious RC Club flying site at the next opportunity and show it off to Korean RC glider pilots.

sam
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Old Sep 12, 2011, 10:32 PM
3 Sons - Legos and Lift
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Grand Rapids, MI
Joined Apr 2004
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Originally Posted by Correa View Post
Thanks to Ed, I saw this mentioned in RCSE and quickly ordered one. It arrived last week and I finally got time to test it out today - Chuseok in Korea or Harvest Moon Festival in China when families gather to celebrate, eat rice cakes and give thanks similar to US Thanksgiving Holiday.

Yes. Set up takes longer than hi-start but not having to pull against the hose and keep that potential energy under control is well worth the extra time.

I used the full length of string that came with the spool but the highest launch that I was able to get after much practice was somewhere between a hi-start and a winch without the zoom.

The cordless drill adapter for reeling in the line worked like a charm!

The best part that makes me give a thumbs up on this One Winch is that at the last launch I was able to catch a thermal! This rarely happened in my hi-start experience. That slight extra launch height may be what made the difference. I am quite hopeful that with more practice and more wind, I will be more likely to catch thermals with this than my hi-starts.

I did have some difficulty getting the turnarounds into my field. It is a grass-covered softball field with gravel just under the grass. The stakes bent as I tried to hammer them in with a 2x4. I used the tie-down stakes to pre-drill a hole in the ground and then gently pushed the pulley stakes into the ground at the cost of some pain in my palms. I am looking for some heavy duty stakes to modigy the two pulley stakes.
Sam,

Thank you for the report. I'm glad the OneWinch is working well for you.

I have a suggestion on getting the stakes into very hard ground. Rather than modifying the turnaround, it will be a lot easier to get bigger stakes for the hold down rope. 8" or 10" pole barn spikes should be tough enough to pound into any soil but solid rock. If these are secure, with the heads angled away from the turnaround, and the safety lines are tight down to where the safety stakes enter the ground, the turnaround will not be overstressed. Creating a pilot hole with a safety stake is a great idea, and the turnaround stake doesn't have to go all the way in.

You need not worry about strengthening the system for 3m planes. We have done many launches of 3m planes with the supplied stakes and turnaround.

Also - if you're launching a 60" plane, I expect with a little more practice and wind you'll getting some pretty good zooms.

Tim
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Old Sep 13, 2011, 07:43 AM
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South Korea
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Thanks, Tim. I agree. A set of 4 stakes that are long enough to create a hole for deep enough for the two pulley stakes and strong enough to not bend with hammering should be sufficient. I also need to let everyone know that the sled worked very well also. As I was walking back with the parachute I could see the sled moving towards the launch point at a fraction of the distance I was traveling.

A question. I was pulling with the belt myself and found the release to be a bit awkward while I was hurrying to piloting the plane. I had the buckle at the small of my back. I suppose I could move the buckle to my side so that my hand won't have to reach back so far. How do you release the buckle after the walking/leaning backward is done and the plane is off the hook?

sam
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Old Sep 13, 2011, 08:10 AM
3 Sons - Legos and Lift
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Grand Rapids, MI
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Originally Posted by Correa View Post
Thanks, Tim. I agree. A set of 4 stakes that are long enough to create a hole for deep enough for the two pulley stakes and strong enough to not bend with hammering should be sufficient. I also need to let everyone know that the sled worked very well also. As I was walking back with the parachute I could see the sled moving towards the launch point at a fraction of the distance I was traveling.

A question. I was pulling with the belt myself and found the release to be a bit awkward while I was hurrying to piloting the plane. I had the buckle at the small of my back. I suppose I could move the buckle to my side so that my hand won't have to reach back so far. How do you release the buckle after the walking/leaning backward is done and the plane is off the hook?

sam
Sam,

The best place for the buckle is next to the sled handle on the left side. There's a small sketch of this in the instructions. You can keep your right thumb on the joystick and unbuckle with the left. Put the female end of the buckle at the front. When you press the release tabs the male side will fall away and behind you. The front/female side will stay in your hand with the sled hanging from it. Then just set the sled down.

This sounds a little complicated, but it works very well.

I hope this helps.

Tim
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Old Sep 13, 2011, 11:57 AM
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Which line is which?


The braided line goes on the bottom.

The mono goes to the glider.

Tim is going to better annotate the instructions but it is not clearly stated anywhere that I could find. I had three guys look over the instructions so that we could be sure we were doing it right.

In the end we "figured" the mono probably went to the plane.

So, your "top line" or your "parachute line" is the mono.

the knot between mono and braided needs to be on the bottom line so that it does not go through the pully on every launch.


Just in case anyone is as confused as I was.


BTW, I will post video tonight. Got it out of the camera. Quality is not good but you can see what is going on. Shot the video with my still camera.
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Old Sep 13, 2011, 04:58 PM
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Would my Oly III be too big to work with this system? It's about an 11 foot span and about 5 lbs.

Thanks,
Bob
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Old Sep 13, 2011, 09:18 PM
3 Sons - Legos and Lift
2motheus's Avatar
Grand Rapids, MI
Joined Apr 2004
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Originally Posted by Bflat View Post
Would my Oly III be too big to work with this system? It's about an 11 foot span and about 5 lbs.

Thanks,
Bob
Hi Bob,

As a matter of fact, at the NATS this year we launched this exact plane several times.
http://www.skybench.com/images/slnost/scully_olyiii.jpg

The owner told me he had built it for looks, not lightness, so it ended up heavy. But based on the Skybench spec of 59 ounces, I doubt it weighs 5 pounds (80 ounces). It did put up a good fight, and I wouldn't recommend a plane this big as your first OneWinch launch.

Tim
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Old Sep 14, 2011, 04:51 AM
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Originally Posted by Bflat View Post
Would my Oly III be too big to work with this system? It's about an 11 foot span and about 5 lbs.

Thanks,
Bob
As I stated earlier, the hook position is the key factor, in my opinion. Not sure if a 5 pound plane would be a challenge as a first plane on the Onewinch. You are going to need a good strong throw to get it flying, then keep that tension up as you walk back. That would also be true on a hi-start.

I owned an Airtronics Legend, 82 ounces and 2.9 meter wing. I found it a bit tricky to launch from a hi-start. My Hi-start pulls 24 pounds but the plane was difficult to handle and needed a real strong push to get it going or it would stall.

If you can easily launch your Oly III on a 3M hi-start I would say you could launch it off the Onewinch.
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Old Sep 14, 2011, 05:19 AM
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Onewinch videos

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.

Onewinch - TD launch with narration.avi (0 min 39 sec)



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.

Onewinch - TD launch - Ed.avi (0 min 39 sec)



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.
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Old Sep 14, 2011, 05:21 AM
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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.
Onewinch sled return with strings in loop (0 min 35 sec)
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Old Sep 14, 2011, 05:37 AM
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Launching a Parkzone Radian

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.
Onewinch radian failed launch (0 min 25 sec)


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.

Onewinch radian pulled with less tension (0 min 26 sec)




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.

Onewinch radian not enough tension (0 min 3 sec)



Onewinch radian launch a (0 min 17 sec)


Getting the hang of controlling the tension for best launch

Onewinch - radian launch - watching Trevor.avi (0 min 45 sec)



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


Onewinch - radian launch.avi (0 min 28 sec)
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Old Sep 14, 2011, 06:07 AM
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I hope the videos were of sufficent quality that you can tell what is going on.

I focused more on the pilot than the planes. The planes launch, so that is not a big deal. But people ask about the technique and what the pilot does so I focused on the pilot.

I tried to post the videos in the order they were flown so you can see the growing confidence and improving performance.

I have about 15 launches to date. Trevor had about 6 with the Radian.

You can see my other comments in my earlier posts.

So, to summarize AGAIN, I like the Onewinch and plan to keep using it as one of my launch methods. In fact it may replace my hi-starts for launching when I don't have my winch with me. It needs a lot less space, requires a lot less walking and I don't have to make that 300 foot walk to stretch the rubber.


*We got good launches with planes from 24 to 60 ounces and from 2M to 3.1 M wing spans. If I wanted to adjust the hook positions I am sure my 3.4M Supra and Graphtie would launch just fine.

*Pretensioning prior to release builds up energy in the line which helps get the plane up to flying speed.

*If there is a breeze, the walk back will be less than if it is calm.

*With a small breeze, once you hit the "tension point" there really does not seem to be much value in fighting to keep the line moving. Just hold tension and the glider will climb.

* The hook position would be the primary tuning point for successful launches, in my opinion.

* If you want to play with launch mixes, try applying the mix at about 50 feet or once the plane is flying and climbing nicely. I found it better to launch neutral and then apply a launch mix. This is the same way I fly my hi-starts.

Clear skies and safe flying!
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Old Sep 14, 2011, 03:43 PM
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Joined May 2010
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Ed,

I think you hit on a great way to get someone acclimated to using the OneWinch quickly:
  1. Pick a day with wind.
  2. Use a Radian or similar foamy sailplane. You'll be able to read how much pressure you're putting on the wings just by looking at how much they are bowing back.
  3. Start by having someone else pull while you launch and fly the plane.
  4. Make your first launches, where you pull, when there is a headwind. You won't have to move much and can just keep your mind on maintaining tension (and flying the plane).
I preferred launching using the OneWinch by myself, rather than having someone else pull. I liked to be able to control the tension during a launch just by walking backward. I was getting continuous feedback from the pull of the belt and I didn't need to do a tap dance on a foot pedal and guess at how much the wing was being stressed like with a winch.

Today would've been a perfect day to be launching using the OneWinch; the rubber on my Hi-start got driven over at least twice. Once was by someone who was trying to avoid it. You can't replace the rubber in a Hi-start like you can the line in the OneWinch.

Trevor
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Old Sep 14, 2011, 04:20 PM
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Thanks Trevor. you are free to borrow the Onewinch anytime.
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Old Sep 14, 2011, 07:28 PM
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Aeajr Thanks nice work I enjoyed watching the vids,and I think that will work better than a high start at my field.
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