Kite Strings

https://youtu.be/SpYdb-aIn6I

I am very happy to report that it has worked flawlessly for 20 tows and expect it to work the same in the future.
I feel confident enough now to recommend it for the following reasons.

#1 Hands Free Operation
* Instant release from lockout with both hands on control bar.
* Instant launch cart release with both hands gripping hold down tubes to abort tow while on ground.

#2 Works With A 2 Point Setup
* Pitch down control is improved with the use of a 2 point bridle. (Shoulders AND Keel)

#3 Normally Open
* If for some reason you are "given the rope" and don't know it. (Think about it)

#4 Reliability
* These releases have previously proved themselves in 1 point tow configurations (sometimes called Pro-Tow)

The original release you get is on top and you can get them here...
http://mouthrelease.com



To make a 2 point one you need about 6' of SPIRAL WOUND cable housing. (Not SIS type) & with a Teflon liner.
A standard bicycle derailleur cable.
And a spray can of Teflon lubricant is recommended like Tri-Flow.

Start with a long cable and test fit by directing it under your arm pit.
Run the cable inside your shoulder strap.
Cut to fit & reassemble.

The cable adjustment is dependent on the amount of bend you have in the housing.
Adjust the inner cable length when you are in your flying position to assure proper release activation.

https://youtu.be/SpYdb-aIn6I

Can we flip the settings on that video so's it embeds/displays here? When I tried:
http://www.youtube.com/watch?v=SpYdb-aIn6I
I got:

I am very happy to report that it has worked flawlessly for 20 tows and expect it to work the same in the future.

Twenty tows. Wow. The standard aerotow weak link worked flawlessly for, quite literally, HUNDREDS OF THOUSANDS of tows. Only downside... A bit of inconvenience every now and then. BFD. I think you're nuts flying a new piece of equipment with a track record as short as that. If this thing actually worked in reality dontchya think everybody would be using it already? But I guess some people just enjoy being test pilots. The extra risk must really make that kinda flying extra attractive to them.

But seriously, folks...

For off the shelf, or close to it, two point solutions I'd still recommend Joe Street's:

http://www.getoffrelease.com/


The Kaluzhin DOES have a bit of an edge over Joe's down in the kill zone but one very unlikely to make a difference. Downside is that you've gotta keep holding it in your teeth after you've gotten to a safe altitude and until you've topped out. Upside, on the other hand... You don't hafta install it if you're regularly switching between AT and mountain.

For one point - which is a bad idea that you can probably get away with, 'specially if you're using a release that doesn't stink on ice - yeah, this is the better option.

And for one point surface towing - which virtually all surface towing is - this release is a total no brainer.

Thanks much for the work on this Dave. Really nice to see stuff that isn't mainstream commercial shit getting into circulation.

Tad Eareckson wrote:For off the shelf, or close to it, two point solutions I'd still recommend Joe Street's:

I have one I'll sell you cheap.

I heard of a failure to release malfunction regarding the Joe Street device.

John Alden of WesMar Aerodrome reported that he quit using his after the "fishing pole thread wrap" used to secure the cable housing to the quick link failed.
This allowed the housing to slip toward the barrel release and prevent activation.

Tad Eareckson wrote:The Kaluzhin DOES have a bit of an edge over Joe's down in the kill zone but one very unlikely to make a difference.

Imposter!!!...Untie Tad and give him back his MacBook.

I'm also an auto racer and as auto racers do, we spend many hours in the garage looking for very, very small edges.

I have one I'll sell you cheap.

He sells them pretty damn cheap as it is - I'd guess at about cost. He never embarked on that project to make a buck - just to get a decent piece of equipment into circulation. Pretty good case to be made that it's already reduced the number of fatalities in a tandem crash from two to one.

I heard of a failure to release malfunction regarding the Joe Street device.

Tell us about these things as soon as possible. If we've got problems we need to put out advisories immediately and deal with things.

John Alden of WesMar Aerodrome reported that he quit using his after the "fishing pole thread wrap" used to secure the cable housing to the quick link failed.

And thank you so very much John Alden of WesMar Aerodrome for properly reporting that on a known public venue where people interested in what's going on are gonna be able to see it and do something about it. Shows us just how much you really care about people who aren't either you or people riding with you.

This allowed the housing to slip toward the barrel release and prevent activation.

Which is a potential fatal - a problem that's killed a pretty substantial number of people before.

Questions... Was this unit abused to precipitate the failure and, regardless of whether or not it was, was it preflighted on the day of the failure? I'm having a hard time believing that the wrap was in fine shape that morning and failed in flight that afternoon.

On the afternoon of 2015/08/23 Rafi Lavin died right after launching when a 3/32 inch sidewire failed. But we didn't all suddenly swap out for eighth inch on all our gliders.

I DO see this as a serious issue. Release designs should be robust enough to not require careful inspections more than once or twice a season. That's why I consider Peter Birren's award winning and universally praised Linknife a mostly useless piece o' junk. It can be and has been neutralized by a few stems of grass. But Joe's design concept is solid and if this is a legitimate problem - and it probably is - it can be addressed. Use a wire wrap instead of Dacron thread or whatever he's using.

At this point I'll continue saying they're both good solutions for two point aero - the best by far off the shelf - and they both have minor noncritical relative pluses and minuses. And if you go with an existing release of Joe's preflight it like you're supposed to preflight critical components at appropriate intervals.

And if the fuckin' useless goddam manufacturers would do their jobs and build these things into their planes the way sailplane manufacturers do...

Imposter!!!...Untie Tad and give him back his MacBook.

Nah, I don't have a dog in this fight. I'm just recommending what would be my choice between the two options. And I'm saying the differences ain't big fuckin' deals.

I'm also an auto racer and as auto racers do, we spend many hours in the garage looking for very, very small edges.

Comp is different from utility/recreational. If I were flying in a comp and there were no rule mandating two point releases I'd pull my two point components out of the airflow and fly one point - knowing and accepting the additional but fairly microscopic risk for the first twenty seconds of the tow for the advantage of better performance for the rest of the flight. For recreational flying - no thanks, the tradeoff isn't worth it. Grade school arithmetic shows us very clearly that fairly microscopic risks taken hundreds or thousands of times start progressing to near certainties.

And if you're gonna spend many hours on THIS particular two point AT issue looking for edges that are pretty substantial you're gonna reinvent my built-in two point release system. And it's gonna look a lot like ALL VG systems 'cause damn near all the time we reach natural and obvious design plateaus.

If you've been watching the glider's themselves you'll have noticed that they got the performance/handling plateau maxed out a decade and a half ago and the gliders that they sell and people wanna buy and fly are just about all stepped a good bit down from that level.

Based upon the photo of Joe's release I would think that if the housing were allowed to slip toward the barrel it wouldn't matter.

If the tension on the base of the unit is greater than the force of the spring then the housing serves only as a guide, No?
If tension is less than the spring and the housing slips then the release would function as soon as the housing makes contact with the flange on the aft end of the unit, Yes?

That sounds right to me. Could the two flanges being out of alignment prevent or restrict actuation?

Basically it does this...

http://c1.staticflickr.com/5/4433/35531445133_87c70f9bdf_o.png


Imagine now, where the bare cable is in this picture, there is in its place the housing that has slipped forward.

Easy fix really...
Weld a cable stop to the quick link.

Another bit I'd like to see is an easy way to take the cable out and lubricate it.
Cables have a nasty habit of corroding.
He is using JagWire CEX housing which is pretty good.
Also maybe a smoother stranded cable for less friction like the kind used for bicycle derailleurs.

It still isn't a hands free device
We could discuss improvments to the Ford Pinto if you like.

Oh crap. Glad I didn't post what I was about to before seeing that photo and reading your explanation.

Yeah, that's a serious problem. Bums me out 'cause Joe put that out after a lot of work, refinement, help from Yours Truly and with the best of motivations and intentions.

Déjà vu...

http://www.flickr.com/photos/aerotowrelease/8322130138/


I put an ENORMOUS amount of time and effort in trying to help Tim Hinkel get his baby up to snuff and finally said to myself, "WHAT THE FUCK AM I DOING??? I've already invented and engineered the best wheel possible. Why am I wasting my time on this hexagonal piece o' well intentioned crap?"

Weld a cable stop to the quick link.

Yeah, that would do it but...

Another bit I'd like to see is an easy way to take the cable out and lubricate it.
Cables have a nasty habit of corroding.
He is using JagWire CEX housing which is pretty good.
Also maybe a smoother stranded cable for less friction like the kind used for bicycle derailleurs.

11-01210
http://farm1.staticflickr.com/550/19439582466_5d57c5c98d_o.png

Tad Eareckson - 2011/01/04 12:04:39 UTC

I despise cable.

It still isn't a hands free device

Neither are the brake levers on bicycle handlebars or:

http://www.aviaavtomatika.com/image/catalogue/work.007.3b.jpg?mtrrgt


But... I have to concede that your mostly off-the-shelf solution for two point (read safe and legal) AT is the only safe one out there. And I have zero doubt that Aleksey will make that release available with whatever cable length one cares to specify.

But THIS:

http://www.flickr.com/photos/aerotowrelease/8318603266/


http://www.flickr.com/photos/aerotowrelease/8306300488/

CANNOT be improved on. It DOES require a minimal amount of hand movement but not any compromise of control worth mentioning. There is no record of an incident in which two inches of inboard hand slide is gonna turn a save into a crash.

Having a cable out in the airflow velcroed to a downtube is gonna cost a glide point - according to Rob Kells' guesstimate. And it's gonna be a bit worse hanging down in the middle of the control frame. And I'd say that you're more likely to get into a situation in which you really need the glide point than to get into a situation in which your really need the advantage of an actual release over an easily reachable one - let alone the advantage of a bite controlled over a hand twitch release.

We've gotta look at the whole picture and evaluate the tradeoffs - like there's no such thing as an oversized wheel when you're landing or an oversized (slower opening, reduced shock) parachute when you're in an Adam Parer freefall.

And, regardless of what I feel, people who've paid zillions of dollars for high performance gliders and racing harnesses aren't gonna use two point systems at the price of putting unstowable cable into the airflow. If we wanna get stuff into widespread circulation it's gotta be clean. And I'm guessing auto racers have similar mindsets. They're not gonna put anything on the car that's gonna pretty much guarantee that they won't win the race.

Imagine now, where the bare cable is in this picture, there is in its place the housing that has slipped forward.

Thanks for the photo and explanation, Dave. I'm a little bit embarrassed that I didn't realise what could happen if the housing slipped forward toward the barrel.