Aug 8, 2009, 6:08 PM
Post #1 of 84
I made a 2-stow main d-bag that uses a pouch to hold the lines. The pouch is held closed and a 'channel' for the lines to play out by magnets. I have only made one jump with it, but it was a soft, snivelly opening. The canopy was an Icarus Crossfire1 104.
I was always wondering when they would get this product on the market. I was told buy a dealer that they were very high maintenance and he never gave me a solid answer to anyting other than that. I think it would probably cut time on packing and reduce the chance of a bag lock. I would like to see if these take hold. Very cool.
edited for spelling
(This post was edited by 2shay on Aug 8, 2009, 6:57 PM)
looks good, but it's not too new. i've been jumping a system that is the same to that since 2004 and have probably 2000 jumps on it. i personally love mine and think you'll really enjoy yours. again, looks good...enjoy it!
Side note: if it's a truly not-yet-patented design, strongly consider applying for a patent.
I'm no patent lawyer, but if you substitute the rubber bands for a safety stow, and the magnets for velcro (holding the line pocket mouth partly closed) then it looks a lot like a reserve freebag. That idea has been around for a long time.
I like the idea - baglocks would be minimized, but packing the lines neatly takes more time than rubberband stows.
Note - Hooknswoop didn't claim it was an original idea, and I'm not criticizing the design. I think it's a good one.
I'm pretty sure those magnetic fields will alter the path of cosmic rays near you, and also cause neurological problems due to their interaction with natural electrical currents in your nervous system. Also you can no longer jump with others who have pacemakers, or sit near the cockpit as it will interfere with the GPS system, and cause all spots to be off. Your AAD will probably be adversely affected too, depending on which magnetic pole is nearest it, and it will cause your AAD to fire too high if you are in the northern hemisphere, and too low if in the southern.
Probably the worst thing though is that red blood cells, with all of their iron, will collect close to the bag, and you will get gian blood clots there, plus you'll be anemic everywhere else in your body.
The good news is that for solar flares, you get some protection.
Neither am I. It may or may not be important to Derek; but if it is, then the best source of advice on whether it's a patentable design is, in fact, a patent lawyer, in conjunction with his own expertise (he's a senior rigger) and knowledge of the industry.
Cool bag. Did you base the pattern on something or make it from scratch?
Made it from scratch. I wanted a 2-stow bag and was trying to find one to buy and couldn't. So I made my own. Used the old d-bag as a pattern, a few strong magnets from my slider keeper supply and a couple of hours later.... It is easier to pack than rubber bands. I didn't want flaps or velcro because of bulk and wear issues. I figure magnets worked great for riser covers and slider keepers, why not for a line pouch?
Not a new concept at all, free bags have been around a long time with 2 stows and a pouch. I just thought that this was a neat twist on the concept and easy to make.
Some people believe that this type of bag causes hard openings, I hope that people will see this bag and the soft openings and realize that is not the case.
I was able to sew the line stowage pouch right onto the existing bag's seams. Although it seems friction holds the lines in place, there are two tabs to secure the mouth (ballistic cloth inside the tabs). I do have the compromise of a velcro closure part-way "up" the pouch, so it opens up easier to stow the lines inside. 500 jumps on it, no problems, velcro is still good enough (since it is only opened for packing, and not suddenly sheared open like some riser cover velcro used to be.)
There may be better ways to implement a line stow pouch, but what I have works.
I understand that he might be able to obtain the patent even with all of the obvious prior art in existence. I wasn't saying it would be a hard sell to the USPTO -- nothing is really a hard sell with them.
I just can't imagine it being worth the trouble and legal expense. As I'm sure you know, patents are not even close to free.
The idea to have that kind of design to stow the lines in the deployment bag pouch is not new. GQ Security a parachute manufacturer of California had it as soon as in the seventies with its UNIT main parachute. When Paraflite designed its first square reserve, the Safety Star in the late seventies the stowing of the lines in the free bag was pretty similar and is still the way square reserve have generally their lines stowed. The idea to have a more "resistant" line stowing using rubber bands on a deployment bag is to insure a good sequence of the line deployment. PD people told me that people shouldn't hesitate to double their rubber bands on the DB to avoid an out of sequence line unstowing. I have some hesitation with the idea to use such a line deployment way for some specific canopies known to be a slammer once in a while. But continue to find out how it works hopefully with different parachutes and tell us about the results. The Crossfire is quite fully elliptical and will deploy anyway softly.
Sabre1 can have some openings you will remember. Same for the Triathlon. As long as you stay with highly elliptical canopies that should work with not too much problem since they generally open in a soft way (I have a Katana). What you have to avoid absolutely is a line dump when the canopy starts to inflate before the full line stretch. In that case at full line stretch you will experience an very important force: the canopy will be inflated first and slowing down while you are still at full speed then at full line stretch you will get the force of accelerating a fully open canopy. That's why doubling the rubber bands on the DB can help. It will make sure you will get not line dump. Be very cautious anyway since you can "be hurt" before the canopy will.
Sabre1 can have some openings you will remember. Same for the Triathlon. As long as you stay with highly elliptical canopies that should work with not too much problem since they generally open in a soft way (I have a Katana).
I would be willing to put a Sabre1 or Triathlon into this d-bag. Those canopys are sensitive to the slider grommets being against the slider stops during deployment.
What you have to avoid absolutely is a line dump when the canopy starts to inflate before the full line stretch.
The only way that can happen is for the locking stows to come undone before the canopy gets to line stretch. Not sure how that could happen with this d-bag.
I have heard of bag strip and have asked several times if anyone, anywhere, in all the thousands and thousands of canopy deployments of video, for video of bag strip. No one has ever shown video of bag strip to me.
I have seen a lot of videos of hard openings, but in none of those was the canopy out of the d-bag before line stretch.
I do expect an increase in initial opening shock (snatch force) as the canopy is re-accelerated to my speed at line stretch, but I doubt if I will even be able to notice the difference.