OK, before I comment on your aluminum rod idea, lemme give you some of the history of the evolution of my remote barrel.
1991/08/02-04, a bunch of us locals went down to Currituck to pick up that stop on the Dragonfly promo tour. That was about the most fun I ever had with a glider, I loved everyone and had great hopes for the future, and never in a million years would've believed that what I was seeing were the seeds of an organized crime syndicate and of the destruction of nearly any hope for even holding aerotowing up to the level of safety we had those three days.
We had a cheap panic snap based release:
http://www.flickr.com/photos/aerotowrelease/8319482072/
http://www.flickr.com/photos/aerotowrelease/8319484072/
with a cable loop on the basetube that was clunky looking but worked fine and with which I was pretty happy. The secondary release was on the Dragonfly.
I left with one for thirty-five bucks and snooped around horse shops in vain for a couple of years (pre web) looking for a duplicate of the core mechanism so I could make them myself.
In 1994 at Annapolis Performance Sailing I suddenly found myself riveted to a Wichard 2673 spinnaker shackle thinking, "THIS is an AEROTOW RELEASE!!! I don't know exactly how I'm gonna rig it but I'm gonna take it home and figure that out when I get there."
Thought I was the first person to make this discovery but I recently found a record dating back to 1983.
I was, however, IMMEDIATELY not happy with the gate:
http://www.flickr.com/photos/aerotowrelease/8318769461/
http://www.flickr.com/photos/aerotowrelease/8318781297/
http://www.flickr.com/photos/aerotowrelease/8318845617/
http://www.flickr.com/photos/aerotowrelease/8318846765/
but, after a lot of experimentation, concluded that one would be OK as long as it was used in a halfway sane configuration.
But, of course, give enough shitheaded glider jockeys enough time and they'll eventually figure out a way to translate ANYTHING to a fatality.
Immediately after the promo tour, Bobby replaced the panic snap with the infinitely more elegant but, in some ways, problematic spinnaker shackle, welded it to a cable assembly, replaced the loop on the basetube with a bicycle brake lever velcroed to the downtube, and established the bent pin "backup" release as the gold standard for all eternity. The result was nothing short of sickening - and that was my immediate reaction the first time I laid eyes on one of the contraptions.
http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?
Jim Rooney - 2011/08/26 08:24:31 UTC
And I'm not so arrogant to think that my precious little ideas are going to magically revolutionise the industry.
There are far smarter people than me working this out.
I know, I've worked with them.
(Bobby's a fucking genius when it comes to this shit... for example.)
Ah... Yeah.
Robin DOES get a lot of credit for killing himself on 2005/01/09 but not much more than the douchebags running and present at that competition - including Bobby - who allowed that configuration to get in line - or the douchebags at Ridgely who continued to allow it to go up the next year. (Just don't bother getting in line with a stronglink 'cause Rooney doesn't want to be on the other end of the rope when someone listening to this drivel smashes in.)
For some years prior to Robin's death I had been trying to think how I could configure a straight pin barrel release for use at the keel. On the shoulder it was simple, light, cheap, efficient, and bulletproof. The thing I couldn't figure was that the barrel needed to be pulled straight back and the lanyard would, of necessity, be coming up to it at a REAL unacceptable angle. But Robin's crash kept bugging me enough that by May of the next year I said "Fuckit, I'm gonna start making something and figure out how to do it in the process."
And that's what I did. And in the process I thought, "Do sailboat people have some sort of device to redirect line tension?" "Well DUH!!!" So I just incorporated a Harken pulley as the foundation of the mechanism. (Gee, just how difficult was THAT?)
(Note... I'm still not pulling STRAIGHT back 'cause there's a parallax issue - and the shorter the assembly the more pronounced it is. I DO lose a little efficiency but it's not that B an Fing D.)
OK, for your mechanism you need to be able to pull the barrel straight back. And you can't just duplicate what's being used for a glider's VG system 'cause that's going to stuff OVER the keel and you need to work UNDER. So you're probably gonna need to incorporate a pulley in the aft end and figure out how to connect to the barrel.
...the other for the bungee.
What bungee?
I have and (found out at the cost of an uncommanded release at an altitude at which it was challenging (but not impossible) to work my way up that I) NEED something besides pin pressure to hold the barrel closed. I solved that problem with a tiny diameter bungee.
You mean something like that?
Or are you talking about the Tensioner going to the nose?
If the latter it's a BAD idea to have ANY elasticity in ANY component between the tug and the glider feeling ANY component of the tow tension. In some of my older photos I DO show a Perlon cord being used for the Tensioner. That wasn't really a detectable problem but I subsequently figured that I should be using leechline and replaced it.
It's just a straight pin barrel release but it releases out the bottom, not out the front.
You CANNOT do that. If the pin isn't allowed to rotate fully you WILL bend it and send the mechanism slamming into the keel.
It's AMAZING how much kick/recoil you get in these mechanisms - even at normal tow tensions. If you ever need to blow a shoulder mounted straight pin barrel while towing one point at something approaching weak link you better be wearing leather gloves and willing to accept a blood blister anyway.
Also, even with your pin free to rotate your - or any - mechanism is gonna recoil into the keel. And the more massive it is the more problematic that is.
Also the pin could be shaped like a "P" instead of an "i".
You could do that but you'd be reducing the efficiency of and increasing the stress on your second class lever by offsetting the load away from the fulcrum (pivot point).
Would be nice if a 2 to 1 was not needed but if it was it could be installed in the down tube just like Wills 12 to 1.
The two to one really isn't "NEEDED" but:
- Extra mechanical advantage is never a disadvantage when the shit hits the fan.
- The cost is only the dollars, weight, and drag of an extra pulley in the airflow.
- That arrangement allows you some slack when separating the downtube and basetube if you're using a basetube bungee like I am (which I don't recommend for anybody nowadays anyway).
You can also pick up cheaper, lighter, cleaner mechanical advantage just by using a longer pin than my off the shelf job.
Summary...
I love people thinking, engineering, coming up with new ideas and a working of your concept could go somewhere. BUT...
It has to be better than the spinnaker shackle and the spinnaker shackle ain't that bad - certainly infinitely better than that abortion Matt shoved down everyone's throat a couple years ago.
In hang gliding everyone's perfectly willing to fork out a thousand bucks for a heavy parachute he's never gonna use and has a pretty fair probability of not being of any use if he does. And I'm guessing that there's probably a lot of tedious hand work involved in the manufacture of one of those jobs.
But nobody wants to spend more than twenty bucks on a release which is a critical control/safety system component that one uses and depends on EVERY FLIGHT...
(So, Chuck... Would you rather take this tow minus your parachute or minus your release? Take your time thinking about it before you give me your final answer.)
...and is VERY likely to spell the difference between life and death in the extremely rare emergency situations that the Flight Park Mafia goons are always gambling will never happen.
If you're spending a lot more on your parachute than you are on your release system you're almost certainly misprioritizing your safety resources.
But you can still get a Lamborghini level release system for probably less than a third of the cost of a new top notch parachute - once production is ramped up.
Anyway that little mechanism of mine...
http://www.flickr.com/photos/aerotowrelease/8305993207/
is EXTREMELY powerful, efficient, effective, bulletproof and worth paying someone for the couple of hours of handwork it might take to punch one out when things get going.
So keep thinking but always look at the best EXISTING technology, use that as a base for improvement, and be REAL careful about trying to save a few bucks worth of time/labor and/or materials when you're dealing with something this critical.