Zack,
My own system with the bungee in the basetube is really really cool 'cause it:
- automatically hits the actuation system with a brutal amount of force; and
- keeps what little there is in the airflow tight as violin strings for the duration of the flight.
But it's a LOT of work to build it in - especially with faired tubing. And if I were gonna build another one for myself I'd probably just use a cleat.
No, it's not all that important but it would be nice to keep the upper assembly neat and clean.
Or...
Another idea that just occurred to me that maybe I like better. Just put a cord lock (the little gizmo they use on the drawstrings for stuffbags) on the lanyard, pull the lanyard taut, and jam the cord lock up against the downtube when convenient.
...I'd probably tie a loop in the release end...I know you're not big on loops, but I am (for two fingers anyway...I wouldn't put my whole hand through).
Put a button on the end - like I did. Statistically, there doesn't seem to be an issue doing it the way you're proposing but it still scares me and there's no need to take the chance.
Dunno about that particular release, but you tested another copy pretty rigorously.
No, I didn't. I loaded ONE up to 388 pounds and pulled the cable ONCE. As I've said many times, it WAS a surprisingly light pull. But...
- I never dissected the core mechanism.
- The core mechanism is NOT well designed.
- Cable is problematic. The spinnaker shackle - ignoring the issues of the weak link unfriendly gate - is a beautiful, well engineered piece of hardware but cable - as you and untold hordes know from firsthand experience - can render it inert under normal tow tension.
And after a short time getting to know Matt a little better I had ZERO interest in ever being near him or anything that came out of his shop ever again.
And many people have been using these so they've gotten a good deal of in-flight testing.
And every one I've so far heard about has failed.
That counts for a lot, even if my particular release had never been tested at all.
Noooooooooo. It counts for NOTHING!
The ONLY thing I've EVER learned in the field that I didn't on the bench was "Oh yeah, I can't put that there because that's where the basetube rests on the cart bracket." And I COULD have thunk that through at home.
Releases have EVERYTHING to do with tension and NOTHING to do with aerodynamics. There's NEVER been a release issue that couldn't have been easily predicted on the ground.
The Bailey Release does GREAT as far as in-flight testing is concerned - tens of thousands of consecutive problem free releases. 'Cause:
- Nobody flies with anything heavier than a loop of 130 pound Greenspot.
- Emergency situations hardly ever involve much in the way of tension anyway.
- When somebody DOES have a problem with it he probably won't survive the "landing" in good enough shape to be able report on it.
Please don't ever say that again. It's the tactic Rooney and his adoring zombies use to make sure nothing better ever gets into the air.
http://ozreport.com/forum/viewtopic.php?t=22308
Better mouse trap(release)?
Jim Rooney - 2010/12/16 18:47:05
Oh, I've heard the "everything we do is an experiment" line before. The trouble is, it's not.
I've seen experimentation with towing gear more than anything else in HG.
I've not seen many go out and try to build their own sails for example. When someone does, they're very quickly "shown the light" by the community. Example... the guy that was building the PVC glider in California somewhere.
But for some reason, towing gear is exempt from this.
The difference is what we do has been done by thousands of people already. It's been tested... a lot.
What we do is free of the experimentation part.
It's still dangerous, but not at the level of building new gear is. Not even close.
That's what people fail to realize.
It's no small difference. It's a huge chasm.
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.
I like the idea of improving gear, but the lack of appreciation for the world they were stepping into didn't sit with me.
For example... flying with the new gear in mid day conditions?
Are you kidding me????
Approach it for what it is... completely untested and very experimental gear which will likely fail in new and unforseen ways as it tries it's damndest to kill you... and then we can talk.
- The only way to certify something new is to tow it ten thousand times.
- But you can't tow it because it hasn't been towed ten thousand times.
- So just use the stuff we sell you 'cause it's been towed tens of thousands of times and works almost half the time.
...I'd be worried about the stuff I implemented.
We're talking about running a string around a pulley, up through a tube, and out a hole in the top. It's pretty hard to fuck that up.
Antoine copied your barrel release design and had some issues initially.
Not by any stretch of the imagination did he copy my design. One of his issues is impossible on mine ('cause the Base runs are stitched together) and the other he had to deliberately induce and...
Zack C - 2011/07/21 12:22:09 UTC
I tried it on the releases Tad provided me and I can't do it.
...you tried it on the releases Tad provided you and couldn't do it.
...but it's hard for me to imagine what that kind of pull feels like.
- Get three two liter bottles of Coke.
- Drink a quarter of one and put it back in the bag with the others.
- Tie a string to the bag.
- Use a pulley if you wanna see what it feels like horizontal.
If I built a rope lanyard release into my glider without anything to give a mechanical advantage, could I expect any better?
With my Remote Barrel unboosted you can blow 130 with an eight pound pull. But I use a block and tackle for a two to one mechanical advantage, so half that. (Four.) ((Sorry.))
It would be nice to a) have a release I could be confident in...
Yes.
b) get rid of the draggy cable...
Yes.
c) not have to worry about velcroing and tying the damn thing to my glider every time I tow (which is actually a significant part of the time it takes me to get ready)...
Yes.
d) have an alternative to cable releases I can actually show people...
Good luck. You may do better in an environment in which there's not a lot of flight park scum around telling everybody what an asshole Tad is and to stay the hell away from his dangerous unproven equipment.
...and e) have something to show Steve Pearson when I try to convince him to build releases into their wings.
Steve will know instantly and exactly what he's looking at with my photo set.
Keep at it, Tad...you'll convince me eventually.
I won't be able to claim all the credit - I'll have a big debt of gratitude to Matt.
I've got a few other projects that take precedence right now, though (so long as I have a functioning release...).
I hesitate to mention Joe Street 'cause that'll probably work well enough to make you forget about items b, c, d, and e.
Steve,
But if we do it this way the carbon footprint is lower and everybody gets to follow along with the process and progress.
But there's more to it than that, such as securing and tensioning the upper assembly. And can the string go straight to the assembly from the top of the downtube without any additional routing? What addresses the friction/abrasion between the string and the drilled hole (which will occur if the string isn't pulled in line with the downtube)?
Even if you're right, you said yourself it's a lot of work to build and he may not be interested in implementing something that complex for a limited segment of the market. Maybe showing him something easy to implement initially will have more of an impact.