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Understanding Tow Releases

Postby Bob Kuczewski » Thu Feb 17, 2011 9:20 pm

Hi Tad,

Now that I'm living in flat land, I'd like to start understanding more about various towing and release systems (not that I'm committed to ever using them). Would you mind helping me understand them a little better?

Let's start with the one you use as your avatar. This is a picture I've seen posted:

Tads_Barrel_Release_small.jpg
Tads_Barrel_Release_small.jpg (7.71 KiB) Viewed 9231 times

I can't quite figure out what I'm looking at there ... or how it's supposed to work. Can you help?

I also found these pictures at that same site:

Tads_Barrel_Release_Frames.jpg
Tads_Barrel_Release_Frames.jpg (25.17 KiB) Viewed 9231 times

What are they telling me?

Thanks in advance, and sorry for the ignorance.
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Re: Understanding Tow Releases

Postby Bob Kuczewski » Thu Feb 17, 2011 10:25 pm

Actually, I think I've finally figured it out. As with most "Aha" moments, I now don't understand what was so hard about it.

Here's the photo that finally clicked with me:

Tads_Barrel_Release_top.jpg
Tads_Barrel_Release_top.jpg (19.02 KiB) Viewed 9225 times

Up until that point, the standard "avatar" photo wasn't making sense to me:

Tads_Barrel_Release_small_top_half.jpg
Tads_Barrel_Release_small_top_half.jpg (3.75 KiB) Viewed 9223 times

For some reason, it looked like the red rope became the mostly white rope behind the pin (and out of view). It wasn't until I saw the top view that I realized those are two separate ropes with two separate loops. Now it all makes sense.

From an engineering perspective that looks like a pretty clean way to separate the two ropes under a lot of tension with fairly little force. Since the distance between the ropes is very very small, they don't generate much torque to bind the pin in the barrel ... even with considerable tension.

Sorry about being so slow. I suppose it doesn't help that I've never even seen towing ... let alone experienced it.

Now just in case there's anyone else out there as slow as me, it might be helpful to generate an animated GIF to use for your avatar (or posts) which shows the deployment sequence. Here's one of my favorite animations of "Little Hawk":

LiteHawk_f128_20ms.gif
LiteHawk_f128_20ms.gif (194.94 KiB) Viewed 9224 times
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Re: Understanding Tow Releases

Postby Bob Kuczewski » Thu Feb 17, 2011 10:54 pm

By the way ... for anyone interested in towing discussions, there are a lot of informative posts at:

kitestrings.prophpbb.com

Here's their description:
Welcome / About This Forum

Posted by Zack C on Nov 22, 2010 11:23 pm

In September of 2010, hang gliding safety activist Tad Eareckson entered a discussion on the Houston Hang Gliding & Paragliding Association's discussion group that would result in his being banned from the group within two months. But despite the controversy over Tad's 'arrogance' and 'condescending tone,' I was impressed by his knowledge, logic, and respect for science, which included a great deal of his own research and experimentation. My attempts to carry out a rational discussion with him were continually sabotaged and eventually aborted by other group members, many with little interest in or comprehension of the discussion.

I wished to continue the discussion, and I knew others in the group were interested in it as well. But Tad had been banned from every group he entered to date, so we needed a place of our own where knowledge was prized over personality. And thus the idea for Kite Strings was born.

The purpose of Kite Strings is to foster serious discussion regarding the practices and technologies of modern hang gliding. This is a forum ruled by science, truth, facts, reason, and logic. Anyone with a respect for these principles and a willingness to learn and engage in rational discussion is welcome to participate.

The forum is still in its infancy, so we don't have much in the way of structure or posting rules. Until we're large enough to have a need for more, all topics will be under a single forum. As for rules, just keep it civil, stay on topic, keep topics in line with the forum purpose, and don't lie or misrepresent others' statements.

Note that you may subscribe to forums to receive email notifications of new posts. Also, the forum currently does not allow attachments (including images) to be uploaded with posts. However, you may display images by uploading them to a site like Photobucket or Flickr and linking to them using the Img button.

Zack

That's pretty cool and worth checking out. Thanks Zack!! :thumbup: :thumbup: :thumbup:
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Re: Understanding Tow Releases

Postby Free » Fri Feb 18, 2011 11:08 pm

Hey, I'm trying to get a good picture of this nail that I cut the head off and soldered a loop on the end..
Can't figure out where to put the film in this dad gummed camera!

:srofl:


Seriously, I think a lot of people can't really tell what is going on with all the release photos. Hence the resistance.
The photography is excellent, professional even, but a lot of people aren't able to get their mind around something like that without being able to see and touch it to make any sense. I'm fairly mechanical and it has me scratching my head.

A lot of people reject what they don't understand. It makes life so much simpler.
Self destructive but simpler..
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Re: Understanding Tow Releases

Postby Bob Kuczewski » Fri Feb 18, 2011 11:13 pm

Free wrote:Hey, I'm trying to get a good picture of this nail that I cut the head off and soldered a loop on the end..
Can't figure out where to put the film in this dad gummed camera!

That is funny. :srofl:

Free wrote:The photography is excellent, professional even, but a lot of people aren't able to get their mind around something like that without being able to see and touch it to make any sense. I'm fairly mechanical and it has me scratching my head.

Thanks Warren. I think you're making a good point, and I also think an animation would help a lot. Tad, if you'd like some help developing an animation for your system, I'd happily offer my services. Just let me know...
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Re: Understanding Tow Releases

Postby TadEareckson » Sat Feb 19, 2011 2:17 am

Jason Dyer - 2010/03/29
Alberta

I'll tell the tale of the barrel that stuck me on tow. It was no the same as this video but might save someone the same problem.

I am by default a DIY type person. Like most i can look at something and once i understand how it works I'm pretty handy and try and build it. The same with a barrel release. I used an old washout tube and flared the ends for the barrel, used rope doubled back for the bridle with a knot to keep the two halves together and threaded a pin on. The problem was the pin. I used a 3" box nail that I cut the head off, formed an end into a loop and silver soldered it together (no mig welder at the time). On tow (payout) I was exposed to high pressure mid way through that I expected the weak link to pop. I had the bar stuffed and I distinctly remember a short jerk. I assumed it was my quick link readjusting or something mundane not worth worrying about. When I topped out I pulled the release, nothing. Yanked, NOTHING!! The driver was still full tension I looked down and seen that the weld had given out and now the weak link was in the former loop with the bridle. Panic started to take over and grabbed for my hook knife. I took a moment to think about how to cut. See, I was still under pressure, I couldn't afford to cut only one side of the bridle, I couldn't reach the weak link and if I did manage to get them both my wrist would have been attached to the towline. I am thankful I took the time to think. I took the release line off my hand, and swung quick hoping to get both lines in one swipe. I did.

In hindsight I should have waited till the driver ran out of road, when the tension was off, reach down and unhook. I also now know that a 3" nail makes a fine pin, but you have to form the loop so the weld is not loaded, and a welded joint is much better than a soldered one

I made quite a few after, gave them out and still have a couple in my towing box, but I prefer the link knife. I like the fact that it takes the same pull to get off tow, no matter the pressure.

Don't know if that will help out any other DIYers but if you want any pictures I might have a few


Now tell me exactly just HOW funny.
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Re: Understanding Tow Releases

Postby Bob Kuczewski » Sat Feb 19, 2011 7:47 am

So what do you think about the idea of an animation to make releases clearer?

We could show how they work ... and how they fail - including the failure modes of the soldered nail rig.
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Re: Understanding Tow Releases

Postby TadEareckson » Sat Feb 19, 2011 1:40 pm

And I finally get caught up enough to respond to THIS thread.

I've developed and refined a lot of tow equipment technology that USHGA and the Flight Park Mafia has been happily ignoring and suppressing for about sixteen years. It was a lot of freaking painstaking work and I was afraid that if I were hit by a truck it would all be lost.

So I first created a text document - Mousetraps - describing the components in agonizingly precise detail so that anyone who really wanted to could reproduce what I had done - given a sufficient supply of aspirin.

Didn't get a digital camera before five years ago but then went to work illustrating the components to somewhat reduce the hellishness for someone undertaking the project.

The photography is excellent, professional even...

Thanks for noticing. After some clumsy starts I, if I do say so myself, got pretty good at setting up the shots and Photoshopping the crap out of them - literally down to the last pixel. A lot of them represent a long day's worth of setup and editing, some several.

I have no fond memories of any of that and I came to dread having better ideas which called for reshoots. (I'm feeling a bit queasy at the moment 'cause on Monday Joe Street of Ontario wired me about a very simple cable lanyard two point AT release he developed which makes everything else in the category look like the junk it is and at some point I'm gonna hafta stretch it out on the frame and set up the tripod.) But I figured that if I did the best photos humanly possible people might start suspecting that the work on the equipment might well be comparable. Of course that was before I got to better know the kind of a**holes that Jack and Davis cultivate on their fora.

From an engineering perspective that looks like a pretty clean way to separate the two ropes under a lot of tension with fairly little force. Since the distance between the ropes is very very small, they don't generate much torque to bind the pin in the barrel ... even with considerable tension.

Yeah. That's EXACTLY the kind of "Aha" moment I've been trying to trigger with all the Bailey Releasers. But instead I get comments like:

I can see how that "release" would not release at all, especially with 400lb of load.
-
Would/could not release at all. No better than any others.
-
When you pull your release and nothing happens , and you s*** your pants, then you will know how!

Doesn't matter that it blows seven hundred pounds of towline tension with a seventeen pound pull. Doesn't matter that it's gone up for tens of thousands of tandem tows with never the slightest problem. On the Oz Report you have unrestricted freedom of speech - as long as you line up with Davis. But I digress.

If you properly explore that site:

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

and the sets:

Aerotow Release System
Cache
temp

particularly the first one - it shouldn't be too much of a challenge to figure things out. You gotta click on things, blow up pictures, and read descriptions. Start with the overviews and understand how the detailed stuff fits into the big pictures. This ain't rocket science - it's barrel releases and a four-string letting go of bridle ends.

If you can follow the schematics for a VG system in a Wills Wing manual this should be a walk in the park. The primary / frame mounted release system IS pretty much a VG system.

A lot of people reject what they don't understand.

It's not really intended for a lot of people. It's intended for people like Paul Farina, Steve Kinsley, Craig Stanley, and Joe Street who want to develop sane equipment. (Don't wanna jinx anything but I think I'm on the verge of getting Zack to pick up a drill.) I thought I'd be looking at maybe one in a hundred - but I think it's more like one in a thousand.

Seriously, I think a lot of people can't really tell what is going on with all the release photos. Hence the resistance.

The resistance occurs 'cause the hang gliding public believes that if there were better ways of doing things the a**holes who've been running the flight parks for the past twenty years would already be doing them that way. They think that driving a Dragonfly up and down a hundred times a day makes someone a qualified engineer. They need to get to know Bo Hagewood a lot better and see the tragic effects of that much exposure to carbon monoxide.

So what do you think about the idea of an animation to make releases clearer?

I greatly appreciate the offer but here's the problem...

Students take lessons at flight parks and think their instructors are gods.

They're trained on and sold s*** by these bastards and - 'cause a Stockholm Syndrome thing kicks in - even if something smells like s***, if they're told it smells like roses they're gonna smell roses.

Thus the market is continually flooded with s***.

It generally takes about three things lining up wrong at the same time to kill a pilot.

One of those things is ALWAYS gonna be pilot error. You can get away with flying s*** equipment almost all the time if you adjust your dolly for proper pitch attitude, secure the VG cord, don't take off in too much of a crosswind, check the streamers along the runway before you give a thumb's up, keep your speed up after you lift off, maintain good position, and don't get into an oscillation cycle.

So when you set the dolly a notch nose high, get rolled by a thermal generated crosswind gust as you're lifting off, and have no means of aborting the tow with your Wallaby or Bailey release 'cause you need BOTH hands to fight the roll, Tracy or Mitch is gonna be able to say...

This is a terrible tragedy. John was such a genuinely wonderful person and all of us here at Cloud Quest are DEVASTATED. We all need to take away a lesson from this as I know John would have wanted us to. It's VITAL that you set that nose angle properly EVERY time. Get one of the crew to check if you're not sure. And ALWAYS check those ribbons before giving the go-ahead.

And then they can happily ignore the issue that the third factor which was necessary to turn a bent downtube event into a broken neck was added to the equation at the cash register ten months before the impact.

We could show how they work ... and how they fail - including the failure modes of the soldered nail rig.

We've known exactly how they fail for twenty years but it doesn't matter 'cause nobody ever goes to prison for negligent homicide and thus the people in position to make positive change on a significant scale have absolutely no incentive to do so.

How many spinnaker shackles were grounded after Robin was killed?
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Re: Understanding Tow Releases

Postby Bob Kuczewski » Sun Feb 20, 2011 6:49 am

A picture is worth a thousand words, and your photos are excellent. I went through the entire aerotow release set, and they are all immaculate.

But a video can be literally worth a thousand pictures ... because that's what it is. More importantly, an engineer can understand engineering drawings and create an image of the real thing in their brain. But most pilots are not engineers, and they may not easily understand what they're seeing.

In my case, I have an engineering degree, but after maybe a year of seeing your barrel release avatar, I still had no idea what it was. I think if you changed that avatar to an animation (or series of photographs) showing the actual release as the barrel was retracted, the pin swung free, and the ropes separated, it might have a lot more instant impact.

I think the easiest approach is to videotape an actual release at a relatively high frame rate, and then extract a few of those frames into an animated GIF to use as your avatar or to post on sites. Animated GIFs are relatively small compared to videos, and they're recognized by almost all browsers.

I've started reading your "Mousetraps.pdf" article, and I don't know when I'll finish it. But I noticed the word "Tost" which I believe should have been "Most". Was this article scanned in?

~02. Sailplanes
#01. Releases
Tost sailplane release mechanisms are mission specific, cost multiples of the price of their counterparts assembled from components designed to dump boat sails and stop bicycles, have no backup options, and do not fail.

I hope some of this is helpful. I can see that you've spent a lot of time considering and designing tow release systems. I don't think I can contribute too much to that body of knowledge. But maybe I can help make that information more widely understood (and possibly accepted) by a larger community. I'd be happy to help if I can.
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Re: Understanding Tow Releases

Postby TadEareckson » Sun Feb 20, 2011 2:59 pm

But most pilots are not engineers...

EXACTLY. This is an excellent summary of pretty much everything that's been wrong with hang gliding for the past forty years.

...and they may not easily understand what they're seeing.

That's fine. I gave up on the idea of pilots being able to understand anything about five years ago and if I weren't as clueless as I am I'd have thrown in the towel fifteen years before that. Pilots shouldn't be allowed to make decisions on what they're gonna go up in the air with. George Worthington ended any halfway intelligent debate on that issue on 1982/09/10.

These photos and documents are not for stupid pilots - like Bill Bryden, Peter Birren, and Tracy Tillman. They're for good engineers - like Mike Lake, Paul Farina, Steve Kinsley, Craig Stanley, and Joe Street. (Steve actually sucks as an engineer but his concepts are brilliant and can easily be modified and made to fly.)

Most pilots couldn't get working understandings of second class levers if you smashed their kneecaps in with baseball bats. You will recall my attempt at communication with Sam.

In my case, I have an engineering degree, but after maybe a year of seeing your barrel release avatar, I still had no idea what it was.

If you had aerotowed you WOULD be familiar with a Bailey Release. If you were familiar with a Bailey Release you should've understood what you were looking at. If you had explored the Aerotow Release System set at my photo site you should've been able to understand the barrel release and how it fits into the big picture.

I think if you changed that avatar to an animation (or series of photographs) showing the actual release as the barrel was retracted, the pin swung free, and the ropes separated, it might have a lot more instant impact.

If you go to:

http://www.flickr.com/photos/aerotowrel ... 066304861/

and run it as a slideshow you will pretty much see the animation you are describing. That sequence was intended to show the utter insanity of using a short bent pin as the lever in a mechanism that may be seeing two or three hundred pounds but it sure didn't prevent any of the a**holes who run the flight parks from continuing to flood the market with them.

I've started reading your "Mousetraps.pdf" article, and I don't know when I'll finish it.

Like I've told Zack, for the love of god don't read it - you'll go blind after about twenty minutes. Just skim it. Use it as a cross reference for the photos if you're really curious about anything.

But I noticed the word "Tost" which I believe should have been "Most".

Nope - TOST. As in Tost Flugzeuggeratebau.

http://www.tost.de/

If you wanna understand hang gliders you've gotta forget all the crap you've learned and understand sailplanes. If you wanna understand sailplanes you gotta go to Germany. If you go to Germany and wanna understand releases and weak links you gotta go to Tost. If you really wanna understand releases you gotta get buy an older model Tost sailplane release beyond its service interval and spend three days with a Mini Maglite and a magnifying glass trying to see how all those interacting levers work.

Was this article scanned in?

Nope. Every punctuation mark is original material - although I ripped off one of the better concepts in there from Steve.

I don't think I can contribute too much to that body of knowledge.

As an engineer you can understand it as well as possible (it ain't rocket science), look for weaknesses, and think about refinements.

But maybe I can help make that information more widely understood (and possibly accepted) by a larger community.

Jim Rooney - 2005/08/31

As with many changes in avaition, change is approached with a bit of skepticism. Rightfully so. There's something to be said for "tried and true" methods... by strapping on somehting new, you become a test pilot. The unknown and unforseen become your greatest risk factors. It's up to each of us to individually asses the risks/rewards for ourselves.

Jim Rooney - 2010/12/16

Notice how I'm not saying to not do it.
Go forth and experiment. That's great... that's how we improve things.
I'm just warning you of that chasm.

A few years ago, I started refusing to tow people with home made gear.

As long as the brain damaged scumbags that control the airports are able to flood the market with dangerous junk and tell people that they can't fly with anything that hasn't come from the display case it won't make any difference.

"Tried and true" is anything flooding the market regardless of how obviously dangerous it is and how many people it's killed.

And change is approached with skepticism by these brain damaged scumbags because nothing's tried and true until it's had fifty thousand flights on it. And it won't get fifty thousand flights on it 'cause these brain damaged scumbags won't let it go up at all.

Catch-22 hell.

We need to have one of these outfits - preferably Ridgely - sued out of existence to get anything better in circulation in a larger community.

A late thought... With your aeronautical engineering credentials and bearing in mind that last month we killed somebody on Davis's configuration who wouldn't have died on mine or a Koch two stage, would you consider endorsing my complaint to the FAA (and, with me, run the risk of being thought of as one of a couple of faggots - neither one of whom is worth being taken seriously)? (San DIEGO, right? Not Francisco?)

One letter beyond that and we've got a movement.
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