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tangle-less parachute

 

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jaredmt

Aug 12, 2012, 8:30 AM
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tangle-less parachute Can't Post

I am wondering if anyone knows why we don't do this. they could make a canopy that is attached from webbing rather than using just rope. this would prevent from ever getting tangled. there could be 4 ropes in addition just to control/steer it. an example is here:
http://cullytechnologies.com/...hutes_tangleless.php
http://cullytechnologies.com/...ess/web/PC180365.jpg

That is an example with a webbed parachute used on a model rocket. i had a toy with an army soldier using that exact same parachute. it didn't matter how u folded the parachute. u could TRY to tangle everything up and it would still unravel and open perfectly if given enough time to open.

Does anybody know if they have tried this on a full scale? Yes, it might be more expensive but a LOT safer

edit: its called a mesh parachute. its only used on rockets/toys. why not skydivers??


(This post was edited by jaredmt on Aug 12, 2012, 9:11 AM)


dragon2  (D 101989)

Aug 12, 2012, 8:45 AM
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

You're not a jumper, are you?


Our parachutes do not "tangle" all that much actually.


Modern parachutes (square parachutes) are made out of 2 layers of fabric with ribs in between, open in front and closed in the back. This design generates lift and forward speed.

Lift is something we use to land softly, and can be used to create a lot of forward speed, which a lot of jumpers like. In fact it is the whole purpose of the jump for a number of jumpers.

The forward speed you get from just normal square flight is very helpful in landing exactly where you want to land, ie being less dependant on the winds.

Round canopies, like yours, do not generate lift and have little forward speed. They are used purely to slow down your descent. Helpful in certain situations, like cargo dropping or certain types of military jumps. But not nearly as much "fun" as flying a square canopy is.

Look up pictures of tandem drogues, they are the little break parachutes a tandem uses in freefall. This comes close to your design I would think.

But other than that, 99.999% of jumpers will stick with squares Wink


jaredmt

Aug 12, 2012, 9:14 AM
Post #3 of 51 (3620 views)
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Re: [dragon2] tangle-less parachute [In reply to] Can't Post

In reply to:
You're not a jumper, are you?


Our parachutes do not "tangle" all that much actually.


Modern parachutes (square parachutes) are made out of 2 layers of fabric with ribs in between, open in front and closed in the back. This design generates lift and forward speed.

Lift is something we use to land softly, and can be used to create a lot of forward speed, which a lot of jumpers like. In fact it is the whole purpose of the jump for a number of jumpers.

The forward speed you get from just normal square flight is very helpful in landing exactly where you want to land, ie being less dependant on the winds.

Round canopies, like yours, do not generate lift and have little forward speed. They are used purely to slow down your descent. Helpful in certain situations, like cargo dropping or certain types of military jumps. But not nearly as much "fun" as flying a square canopy is.

Look up pictures of tandem drogues, they are the little break parachutes a tandem uses in freefall. This comes close to your design I would think.

But other than that, 99.999% of jumpers will stick with squares Wink

thanks for the reply. I didn't say that it had to be a round parachute. it could still be square. just using a mesh to prevent from tangling.


airtwardo  (D License)

Aug 12, 2012, 9:16 AM
Post #4 of 51 (3614 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

It would fly just like a regular square...PIZZA! Wink


Andy9o8  (D License)

Aug 12, 2012, 9:18 AM
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

In reply to:
I didn't say that it had to be a round parachute. it could still be square. just using a mesh to prevent from tangling.

To repeat: "Tangling" of modern ram-air parachutes is really not much of an issue. If it was, it would have been proactively addressed via design engineering long ago.

Learn first; advise later.


excaza  (C License)

Aug 12, 2012, 9:21 AM
Post #6 of 51 (3601 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

In reply to:
I am wondering if anyone knows why we don't do this.
It's a solution to a problem that really doesn't exist, canopies don't really tangle too often.

I'd rather run my lines than try and make heads or tails of a suspension system made entirely out of mesh. Not to mention it would be a nightmare to inspect and repair.


(This post was edited by excaza on Aug 12, 2012, 9:21 AM)


mark  (D 6108)

Aug 12, 2012, 9:22 AM
Post #7 of 51 (3597 views)
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In reply to:
Does anybody know if they have tried this on a full scale?

Depends on what you mean by "full scale." This is similar to what we already do for main pilot chutes.

We could do mesh instead of suspension lines on ram-air canopies. There would be a lot more drag, as well as greatly increased pack volume. My guess is that the increase in drag would result in ram-air performance being very similar to rounds, and the pack volume would triple or more. The malfunction rate might go down, but the landing injury rate would, uh, skyrocket.

Mark


airtwardo  (D License)

Aug 12, 2012, 9:25 AM
Post #8 of 51 (3593 views)
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Re: [mark] tangle-less parachute [In reply to] Can't Post

 
Just imagine all the fish ya would catch in the swoop pond though! Cool


riggerrob  (D 14840)

Aug 12, 2012, 12:25 PM
Post #9 of 51 (3522 views)
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In reply to:
Just imagine all the fish ya would catch in the swoop pond though! Cool

....................................................................

Hah!
Hah!
Hah!


riggerrob  (D 14840)

Aug 12, 2012, 12:47 PM
Post #10 of 51 (3512 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

You are making sense.
That model-rocketry example closely resembles the small pilots-chutes (french "extractor") that skydivers toss out to start the inflation process. The pilot-chute drags the main (or reserve) parachute canopy to line stretch, where wind completes the inflation process.

The primary reason skydiving pilot-chutes are meshed is to reduce the cost of manufacturing. One piece of mesh and a couple of reinforcing tapes are way simpler (less labour-intensive) than trying to manage the eight tiny suspension lines used on first-generation (pre-1970s) pilt chutes. Mesh simplifies the process of packing pilot-chutes and reduces the risk of them inverting during inflation or tangling with toes, fingers, etc.

Similarly, all tandem drogues are meshed. Drogues are just over-grown pilot-chutes, with the increased risk of entangling with feet and arms (eight in total).

Large round parachutes often (5 percent per Poynter) entangle during opening. After they are dragged to line-stretch, sometimes a part of the skirt (the seam where mesh or suspension lines are sew to the solid fabric) will blow across the skirt and try to inflate "outside" the canopy. This might cause a "brassiere" (aka. partial inversion of line-over) type malfunction. Often the canopy only briefly inverts, but as the canopy blows back into the correct configuration, the fabric is burned by high-speed rubbing. Those burns are time-consuming to patch.

Ergo, during the 1960s, the British Army invented anti-inversion netting (a stip of wide mesh 2 feet deep) sewn around the suspension lines, just below the skirt. Most modern military, static-line parachutes (T-10, TAP 30, etc) use anti-inversion netting to reduce their malfunction rate to almost zero.
The disadvantage of anti-inversion netting is that it increases cost, weight and bulk. Military jumpers burdened with 170 pounds of light-weight, high-tech gadgets don't seem to mind the extra weight, but civilian skydivers whine loudly. Back during the 1980s, a British company tried to introduce a skydiving reserve with an anti-inversion net, but they only sold a handful.

Modern square parachutes rarely entangle during inflation, so mesh would only add weight, pack-volume and drag.


nitrochute  (D License)

Aug 12, 2012, 5:37 PM
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

umm we dont use "rope"


jaredmt

Aug 12, 2012, 6:04 PM
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In reply to:
Modern square parachutes rarely entangle during inflation, so mesh would only add weight, pack-volume and drag.

thanks for the reply, very informative! so in summary it is a better design and would save more lives but it wouldn't sell because its more expensive,heavier, and takes up more room.

just wondering, how do you know all this? did you serve in the military?



In reply to:
It's a solution to a problem that really doesn't exist, canopies don't really tangle too often.
key word: "too often". I know its unlikely. but my point is that tangling would not exist. ever.

In reply to:
Depends on what you mean by "full scale." This is similar to what we already do for main pilot chutes.

We could do mesh instead of suspension lines on ram-air canopies. There would be a lot more drag, as well as greatly increased pack volume. My guess is that the increase in drag would result in ram-air performance being very similar to rounds, and the pack volume would triple or more. The malfunction rate might go down, but the landing injury rate would, uh, skyrocket.

Mark
interesting. my solution would be to mesh everything except the very top. maybe only a foot of rope? or who knows maybe drag won't be an issue. good point and I would consider this if I were to design it.


In reply to:
umm we dont use "rope"
i admit i haven't thoroughly studied every detail of how parachutes work yet. i do plan to do it but for now i am taking a basic concept. a toy with a mesh always works. a toy with strings will get tangled sooner or later. the concept makes sense.


(This post was edited by jaredmt on Aug 12, 2012, 8:04 PM)


jaredmt

Aug 12, 2012, 6:10 PM
Post #13 of 51 (3376 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

to clarify, it wouldn't be just a straight mesh. i would make a square-shaped parachute that uses the mesh to prevent tangling and still has a way to steer and use "brakes".


airtwardo  (D License)

Aug 12, 2012, 6:31 PM
Post #14 of 51 (3367 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

to clarify, it wouldn't be just a straight mesh. i would make a square-shaped parachute that uses the mesh to prevent tangling and still has a way to steer and use "brakes".

In reply to:

Go for it! Cool

You'll make MILLIONS i tell ya ~ M I L L I O N $ !


jaredmt

Aug 12, 2012, 6:58 PM
Post #15 of 51 (3354 views)
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Re: [airtwardo] tangle-less parachute [In reply to] Can't Post

In reply to:
to clarify, it wouldn't be just a straight mesh. i would make a square-shaped parachute that uses the mesh to prevent tangling and still has a way to steer and use "brakes".

In reply to:

Go for it! Cool

You'll make MILLIONS i tell ya ~ M I L L I O N $ !
lol no i won't cus no one will buy it because it's too expensive/big/heavy. but i might make a small model version just for fun :) and if it generates interest then why not?


(This post was edited by jaredmt on Aug 12, 2012, 7:00 PM)


davelepka  (D 21448)

Aug 12, 2012, 7:00 PM
Post #16 of 51 (3352 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

 
Ok Einstein, quit your bitching about everyone shooting holes in your idea, and build a proof-of-concpet prototype, and doucment some real-world deployments on the thing. Until you do that, you can expect the masses to tell you it can't be done.

Also, fill out your profile. Then let us know your qualifiactions for designing anything parachute related. Until you do those two things, you can expect very little respect for you or your ideas.

I'm an experienced jumper with many years of high performance parachute flying, testing, and maintaining. To me, your idea sounds like bullshit, and not something that would come for anyone with any practical experience with sport parachutes. Prove me wrong.


wildcard451  (D License)

Aug 12, 2012, 7:41 PM
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Re: [davelepka] tangle-less parachute [In reply to] Can't Post

In reply to:
Ok Einstein, quit your bitching about everyone shooting holes in your idea, and build a proof-of-concpet prototype, and doucment some real-world deployments on the thing. Until you do that, you can expect the masses to tell you it can't be done.

Also, fill out your profile. Then let us know your qualifiactions for designing anything parachute related. Until you do those two things, you can expect very little respect for you or your ideas.

I'm an experienced jumper with many years of high performance parachute flying, testing, and maintaining. To me, your idea sounds like bullshit, and not something that would come for anyone with any practical experience with sport parachutes. Prove me wrong.

If you put the word "brakes" in quotes.....well, you're sticking your nose into a real you know NOTHING about.

Equivalent of me calling up an F1 team telling them I know more about nosewing design.


jaredmt

Aug 12, 2012, 7:42 PM
Post #18 of 51 (3320 views)
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In reply to:
Ok Einstein, quit your bitching about everyone shooting holes in your idea, and build a proof-of-concpet prototype, and doucment some real-world deployments on the thing. Until you do that, you can expect the masses to tell you it can't be done.

Also, fill out your profile. Then let us know your qualifiactions for designing anything parachute related. Until you do those two things, you can expect very little respect for you or your ideas.

I'm an experienced jumper with many years of high performance parachute flying, testing, and maintaining. To me, your idea sounds like bullshit, and not something that would come for anyone with any practical experience with sport parachutes. Prove me wrong.

you're right. And i'm an engineer. I'm on here because YOU guys are the skydiving experts/enthusiasts. I want to know what is already out there that is similar to this. Any info is helpful.
Riggerrob had some great information, Id like to know if there is an article on anything he said. And I dont mind criticism if it is helpful


airtwardo  (D License)

Aug 12, 2012, 8:02 PM
Post #19 of 51 (3303 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

In reply to:
In reply to:
Ok Einstein, quit your bitching about everyone shooting holes in your idea, and build a proof-of-concept prototype, and document some real-world deployments on the thing. Until you do that, you can expect the masses to tell you it can't be done.

Also, fill out your profile. Then let us know your qualifications for designing anything parachute related. Until you do those two things, you can expect very little respect for you or your ideas.

I'm an experienced jumper with many years of high performance parachute flying, testing, and maintaining. To me, your idea sounds like bullshit, and not something that would come for anyone with any practical experience with sport parachutes. Prove me wrong.

you're right. And i'm an engineer. I'm on here because YOU guys are the skydiving experts/enthusiasts. I want to know what is already out there that is similar to this. Any info is helpful.
Riggerrob had some great information, Id like to know if there is an article on anything he said. And I dont mind criticism if it is helpful

You do understand that when we say square parachute we are not talking about a 'square shaped' parachute but instead describing a rectangular flying wing?

I don't see any practical application to your idea regarding the types of canopies we 'fly'...your mesh idea would do little more than inhibit the performance characteristics we pay lot$ for.

You may want to do some research regarding the inherent malfunction rates for the wings we utilize in comparison to the military round type parachutes...

That may give you some insight as the the friction you are encountering here.


stayhigh  (F 111)

Aug 12, 2012, 8:09 PM
Post #20 of 51 (3297 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

they open fine.
http://www.youtube.com/watch?v=i16HryVyRaI


jaredmt

Aug 12, 2012, 8:10 PM
Post #21 of 51 (3296 views)
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In reply to:
You do understand that when we say square parachute we are not talking about a 'square shaped' parachute but instead describing a rectangular flying wing?

I don't see any practical application to your idea regarding the types of canopies we 'fly'...your mesh idea would do little more than inhibit the performance characteristics we pay lot$ for.

You may want to do some research regarding the inherent malfunction rates for the wings we utilize in comparison to the military round type parachutes...

That may give you some insight as the the friction you are encountering here.

Yes I do understand it is rectangular. That is another good point of why no one would buy it, thank you. And I will research that when I get a chance.


airtwardo  (D License)

Aug 12, 2012, 8:10 PM
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In reply to:


mr2mk1g  (C 103449)

Aug 13, 2012, 5:18 AM
Post #23 of 51 (3216 views)
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Re: [jaredmt] tangle-less parachute [In reply to] Can't Post

Mesh wont work on a rectangular parachute. The way modern parachutes work is that they conform to a "ram air" design. I'll try and simplify the way things work these days for you.

Imagine an inflatable camp bed with one side cut off it. The jumper is suspended below on lines which spread the weight of the jumper evenly across the whole of the bed. The weight of the jumper pulls the inflatable bed through the air and air is forced into the open side of the bed by the motion of the bed through the air. This inflates the bed causing it to be rigid. The shape of the rigid bed is like that of a wing on an aeroplane. Thus, as it flies through the air, the inflatable bed-wing generates lift just like on a plane.

The wing remains rigid because the air pressure inside the wing is greater than the air around it. The pressure remains greater because there's constantly air being "rammed" into the open front buy the wing's movement through the air and the material the wing is made of a non-porous construction. Ie, once the air has gone in, it can't leak out through the skin of the wing.

If you start making part of the parachute wing from mesh, all that air leaks out and you are left with a simple drag device like the old-style round parachutes we no longer use. The wing would no longer be rigid and would no longer fly forward or generate lift like a plane's wing. It would simply flap behind you causing drag.

You can't replace the lines connecting the jumper to the wing with mesh as that would cause so much parasitic drag that the whole thing would not move forward through the air. A lot of development has happened in the last 10-20 years in skydiving to reduce the thickness of the lines we use to connect the parachutist to the wing. The thinner the lines the faster and more efficiently the wing flys and thus the more lift it can generate. The "rope" we use these days can be very high tech and ranges from cutting edge nylons and aramids to things like kevlar. Replace that with mesh and everything stops working.

To top all this, you're trying to prevent a problem that simply doesn't exist. Occasionally a tangle will occur or a parachute will have problems with it's lines. This is a very low order of probability however. Despite that, skydivers have a back up system and can easily jettison a problematic parachute and use a second one in its place.

What you have linked to has been arround in skydiving for decades. It works fine for what it does and is still used in certain applications in modern skydiving. As a technology for main parachute design however, it is litterally 30-40 years behind the technology employed in modern skydiving.

1) Yes you could build it.
2) If you did you would probably find copyright issues with someone else who already invented it more than half a centry ago.
3) It would suck by comparison to everything else on the market today.


(This post was edited by mr2mk1g on Aug 13, 2012, 5:22 AM)


piisfish

Aug 13, 2012, 5:30 AM
Post #24 of 51 (3209 views)
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In reply to:
Mesh wont work on a rectangular parachute. ...
If you start making part of the parachute wing from mesh, all that air leaks out and you are left with a simple drag device like the old-style round parachutes we no longer use.
this is the way you interpret it.
Quote:
Ie, once the air has gone in, it can't leak out through the skin of the wing.
it actually does Tongue not exactly through the skin, but through the pinholes of the seams Angelic


mr2mk1g  (C 103449)

Aug 13, 2012, 5:47 AM
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Re: [piisfish] tangle-less parachute [In reply to] Can't Post

yeah yeah, I know - the whole post is vastly dumbed down for a whuffo. Everything in it is a vast generalisation that can have holes picked in it.

Imagine a hybrid canopy only instead of F111 you have mesh. Crazy That's several orders of magnitude over even a shagged out old F111 canopy and not even in the same ball park as the pin-hole leaks from a seam of a ZP canopy.

At best the thing's going to fly something like a paradactyl, if at all, or if you're lucky it'll work like a round rather than just spinning up into a ball of crap.

I'm trying to help the guy out with some low level explanation rather than baffle him with science. Tongue


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