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Adding swivels to chutes?

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KHandSons

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Hello again, could someone post a pick and or explanation to adding swivels to chutes? Mine seem to keep getting tangled very badly with the shock cord, the chute still opens and deploys just fine. Its just a pain getting ready for the next launch. thanks in advance:D
 

jj94

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Well first, obtain a swivel. I use snap swivels (some of them are ball bearing snap swivels: they allow the parachute to rotate easier without getting tangled) for LPR and I generally switch over to larger ball bearing swivels that don't have snaps. I connect the ball bearing swivel to the rocket via quick links. So, starting with the parachute, get the shroud lines into two main lines, one on the left and another on the right. The bunched up shroud lines should almost resemble a single thicker one. Then, do this - http://www.animatedknots.com/girth/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com - with the one of the metal loops/rings on the swivel and with the shroud lines from the parachute.
 

FatBoy

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For low power rockets I just use the same swivels used for fishing that you can get from any sporting good store in the fishing department.
 

sandman

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I have a box of chutes each with a swivel. The swivels let you make multiple sizes of chutes and remove them from the rocket when not flying. Just snap on the appropriate chute when time to launch.

You just have to remember to put the chute on...I have forgotten.:eek:
 

Micromeister

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perhaps these drawings will help a little with your line twist problem.
attaching across rather the around the chute helps a bunch.
Adding a #14- #10 snap swivel to the shroud loop does the rest.

Shroud line seperation disc-sm_03-04.jpg
 

luke strawwalker

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perhaps these drawings will help a little with your line twist problem.
attaching across rather the around the chute helps a bunch.
Adding a #14- #10 snap swivel to the shroud loop does the rest.
Yes, I highly recommend building chutes like the yellow one in the graphics, NOT the red one the way Estes always tells you to... no matter what you do, doing it like the red one you WILL have at least one tangled line when you start off! The yellow example will allow all your lines to be parallel with none crossing over the other lines-- far easier to 'cow loop' your shroud lines onto a snap swivel and prevents tangles.

Another trick-- once you have your lines all gathered, hold up the chute and pull it to a point, and even up the lines so the tape dots on the canopy are all at the same level and even, pinch the lines in your fingers where the snap swivel will go, tug them out of your fingers into a little point, and pinch that in half with the fingers of your other hand, making a little 'point' of the shroudlines, pass that through the eye of the snap swivel, and then open the lines up again-- for hex chutes, make sure all three lines are open, then feed the snap swivel through the hole, and pull the snap swivel up to make the 'cow loop' and work the loops down to the line side of the snap swivel away from the swivel barrel to make sure they 'bite' themselves. Make sure the shrouds and tape dots are all still even, and then rub a bit of white glue over the 'cow loop' to make sure the shrouds don't slip and 'tilt' the chute when it snaps open... can't tell you how many chutes I've had 'tilt' before I started doing that... :)

Good luck! OL JR :)
 

BsSmith

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I also use fishing swivels for LPR rockets, it makes things far easier.

Don't use them for Mid Power or higher though, after one early deploy those things will NEVER let go of your chute again. :eek:
 

Gillard

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most my lpr rockets have a "normal" swivel attached to the shock cord.
and then each parahcute has a snap swivel attached to it - works great, easy to swap over to suit the weather conditions, and it means that i'm slowly upgrading all my chute to rip stop nylon, as i only need a dozon or so chutes for low power.
 

mjennings

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What I do is slide the swivel over the shock cord, tie the shock cord off to the NC then clip the chosen chute to the rocket when it's time to fly. I can't remember having a chute fail due to shroud line tangles or ever having to untangle lines.

Not the best view but this shows how I install the swivel
NC-Swivel.JPG
 
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Micromeister

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Here are some of the different Swivels I use on my Standard and LMR Hemi nylon chutes.
#14's for smaller models and streamers.

#10s Yes with our without the locking hook, they both work just fine. I can't remember the last time I straightened out one of these brass/stainless #10 swivels even on a very late ejection in a model up to about 1 pound. The swivels with the locking tab is nice but can also be straightened if your not flying the right motor in your model. High speed deployments are not something to be dismissed, it's just plain poor planning. Match the model to the motor delay and you'll rarely have any recovery failures.

#2's are used on Big Hemi nylon chutes with heavier nylon or Kevlar shrould lines. Generally these are reserved for 30" to 48" chutes in my fleet.
 

Gillard

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I did have one swivel fail on me a few years back. there was a late delay and the swivel broke: it popped at the center. luckily the parachute and rocket recovered fine and without damage - tge chute drifted alot without anything heavy below.
I put this down to one weak swivel - never had a problem since
 

Handeman

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What about a swivel for HPR. Something that will work with about 8 - 10 lbs hanging below the chute. I'm looking for something with little or no rotational resistance with the 10 lb load. I'm looking at flying a parasail type chute and can't have any rotational forces from a spinning rocket hanging below.
 

jj94

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Handeman, a ball bearing swivel should suit you fine. They have very little resistance. I got mine from Wildman.
 

luke strawwalker

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Here are some of the different Swivels I use on my Standard and LMR Hemi nylon chutes.
#14's for smaller models and streamers.

#10s Yes with our without the locking hook, they both work just fine. I can't remember the last time I straightened out one of these brass/stainless #10 swivels even on a very late ejection in a model up to about 1 pound. The swivels with the locking tab is nice but can also be straightened if your not flying the right motor in your model. High speed deployments are not something to be dismissed, it's just plain poor planning. Match the model to the motor delay and you'll rarely have any recovery failures.

#2's are used on Big Hemi nylon chutes with heavier nylon or Kevlar shrould lines. Generally these are reserved for 30" to 48" chutes in my fleet.

Hmmph... I guess not planning for a bonus delay was just stupidity on my part... :rolleyes:

Maybe one day I'll have as much clairvoyance or luck as some people seem to have around here... :eek::D

Yall have a good one! OL JR :)
 

FROB

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What about a swivel for HPR. Something that will work with about 8 - 10 lbs hanging below the chute. I'm looking for something with little or no rotational resistance with the 10 lb load. I'm looking at flying a parasail type chute and can't have any rotational forces from a spinning rocket hanging below.
Just remember that a swivel will have to handle the shock of chute opening, which is usually several times the model's weight, and if the deployment is not exactly at apogee, it can be an order of magnitude higher- If using a swivel, i suggest choosing one with a breaking tensile strength at least equal to your shock cord. For high power models, i have found a variety of swivels in the chain & cable department of good hardware stores that can handle 1000Lbs or more. they don't have ball bearings, but work well enough to keep the chute from spinning itself closed, even with a rapidly spinning rocket. The biggest fishing swivel I've found with low-drag bearings (at a fishing&hunting shop) was rated 400Lbs.
 
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MarkII

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Just remember that a swivel will have to handle the shock of chute opening, which is usually several times the model's weight, and if the deployment is not exactly at apogee, it can be an order of magnitude higher- If using a swivel, i suggest choosing one with a breaking tensile strength at least equal to your shock cord. For high power models, i have found a variety of swivels in the chain & cable department of good hardware stores that can handle 1000Lbs or more. they don't have ball bearings, but work well enough to keep the chute from spinning itself closed, even with a rapidly spinning rocket. The biggest fishing swivel I've found with low-drag bearings (at a fishing&hunting shop) was rated 400Lbs.
Have you seen these?

MarkII
 

Micromeister

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Hmmph... I guess not planning for a bonus delay was just stupidity on my part... :rolleyes:

Maybe one day I'll have as much clairvoyance or luck as some people seem to have around here... :eek::D

Yall have a good one! OL JR :)

Seems to me those comments do not really help the rocketeer trying to learn how to keep their models in one piece for another flight. Flight performance prediction isn't a black art, it's a common basic model rocket skill.

If one doesn't fly APCP they won't have to worry about bonus delays. One of the many reasons I refuse to fly APCP... Delay trains that can't be trusted.

Aside from that; It only takes a little preperation and simple math (or even simpler a sim program) to know and pick the closest delay to any model/bp motor combination in your fleet. A little pre-Launch day preperation...Not clairvoance or luck my friend. Simple Basic Mod-Roc knowledge that should be as much a part of the model rocket certification process as anything.
Taking the time to know you models and motors will avoid most of the silly mismatching mistakes that usually end in stripped chutes and/or crashed models. Failures that are then blamed on malfunctioning swivels or faulty chutes or weak shroud lines when in fact the failure was casued by the same manace that caused most Auto accidents "the Nut behind the wheel" or in these cases the guy who loaded the motor.

Mark:
I've seen some of the Stainless barrel HD swivels used in deepsea trolling, rated at 400lbs. the barrels are about 1/4" in diameter. Very hafty looking swivels way to big for anything i'd ever be flying. Pretty expensive also as I recall.
 
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MarkII

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Well, FROB mentioned that the biggest fishing swivels that he had seen had test weights of 400 lbs. You mentioned that you had also seen some with that test weight and that they were quite large. The SPRO Heavy Duty Swivels that were shown in the link have test weights as high as 1320 lbs. Yes, these would obviously be overkill for low power rockets, but the specific question that I was addressing had to do with fishing-type swivels that would be suitable for mid-power and high power rockets.

In the first attached photo, I am holding a pair of size 7 SPRO HD Swivels. These have a test weight of 860 lbs. As you can see, each one is about the size of an 8 hr. Tylenol pill. Not exactly large or hefty, and yet thay have over twice the strength of the swivels that you and FROB mentioned. In the second photo, I am holding a pair of size 6 SPRO Solid Ring Ball Bearing Swivels. These have a test weight of 300 lbs. Again, they only look dainty. Part of their strength come from the fact that they have solid welded rings at each end rather than split rings. These particular swivels come in sizes up to 8, which has a test weight of 540 lbs. As with the HD swivels, hardware this strong would never be needed in LPR models (sizes 1 and 2 of the Solid Ring swivels have test weights of 40 lbs. and 65 lbs. respectively, though). But if anyone wanted to add a very strong swivel to their mid-power or high power rocket's recovery system without having to go with a big tractor hitch-style unit, they might want to take a look at these.

MarkII
 

Micromeister

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Those in your first pic look like the ones I saw, the break test rating was 400lbs.
Where did you see or obtain the swivels your holding, If they are available and are smaller then the Deep Sea Trolling swivels I mentioned I'm sure they might be of use for mid power models as well as Long as they aren't more the a couple buck apiece.
If your going to Show something share the Where as well.
 

MarkII

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Those in your first pic look like the ones I saw, the break test rating was 400lbs.
Where did you see or obtain the swivels your holding, If they are available and are smaller then the Deep Sea Trolling swivels I mentioned I'm sure they might be of use for mid power models as well as Long as they aren't more the a couple buck apiece.
If your going to Show something share the Where as well.
I ordered them from the Cabela's Web store. All of the links that I have included in my two posts that were about these swivels go to that store.

MarkII
 

Micromeister

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Kewl!
I used to order from Cabela's, I'll have to dig out their catalog again.
thanks.
 

Handeman

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... snip
If one doesn't fly APCP they won't have to worry about bonus delays. One of the many reasons I refuse to fly APCP... Delay trains that can't be trusted.

... snip
I have to disagree with this. I've rarely had bonus delays with APCP. I've had more delay issues with BP. The timing isn't usually the problem, although it does happen, weak or none existent ejection charges have caused the demise of a couple of models.
 

CharlaineC

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For lpr try to use the swivels that have a locking bar I have had some fail upon ejection where the non locking one just pried open from the shock of opening on a payloader.
 

luke strawwalker

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Seems to me those comments do not really help the rocketeer trying to learn how to keep their models in one piece for another flight. Flight performance prediction isn't a black art, it's a common basic model rocket skill.

If one doesn't fly APCP they won't have to worry about bonus delays. One of the many reasons I refuse to fly APCP... Delay trains that can't be trusted.

Aside from that; It only takes a little preperation and simple math (or even simpler a sim program) to know and pick the closest delay to any model/bp motor combination in your fleet. A little pre-Launch day preperation...Not clairvoance or luck my friend. Simple Basic Mod-Roc knowledge that should be as much a part of the model rocket certification process as anything.
Taking the time to know you models and motors will avoid most of the silly mismatching mistakes that usually end in stripped chutes and/or crashed models. Failures that are then blamed on malfunctioning swivels or faulty chutes or weak shroud lines when in fact the failure was casued by the same manace that caused most Auto accidents "the Nut behind the wheel" or in these cases the guy who loaded the motor.

Mark:
I've seen some of the Stainless barrel HD swivels used in deepsea trolling, rated at 400lbs. the barrels are about 1/4" in diameter. Very hafty looking swivels way to big for anything i'd ever be flying. Pretty expensive also as I recall.
Very nice... thanks for the pontification...

Sorry if I confused you using a "HPR" term; but I wasn't aware that the term "bonus delay" was strictly applied to HPR... Not having ever flown APCP, strictly flying BP, I was referring to the D12-3's I've launched that have sometimes been more like a D12-9... (and yes, I know there is no such thing). I've also had C6-5's end up with delays more like C6-8's... (again fictitious motor designation)... When you put a motor that is appropriate for the model in it and it does something it's NOT supposed to do, what can you do about it?? Your earlier statement came across as, "well, if you learn how to put the right motor delay in your model things like that would NEVER happen" when anybody who's flown awhile knows sooner or later you WILL come across a motor that is either a W-A-Y L-O-N-G-E-R delay than what was on the label, or shorter, but that's more rare, or you put a C motor in your model that performs like a wet "A" motor and barely gets it off the pad... Couple subpar performance with even a regular (meaning proper) delay time and that puppy's gonna be moving at a good clip when the chute pops... presuming it pops before it hits the ground. I recently lost a rocket to just such a happenstance.

Also, I've chosen motors with what I thought was the 'proper' delay only to find that the model hits a breeze on the way up or a gust weathercocks it soon after leaving the rod, and the rocket arches WAY more than you figured or intended, and the thing ejects near apogee but still carrying a LOT of horizontal velocity, especially if it's into the wind and a good stiff breeze at altitude which increases the "apparent" wind velocity. I've had a rocket or two strip or nearly shred a chute even though it looked to have little actual 'ground velocity' but was horizontal at apogee into a stiff wind aloft that was ripping past it fast enough to do nasty things.

Now perhaps you didn't mean to come across with this "well, if you knew what you were doing that wouldn't happen" attitude, but it sounded to me like it. I'll presume you didn't intend to come across that way. Perhaps you'll consider your word choice a little more carefully in the future, my friend... :)

Anyhow, yeah, it's still rocket science. Yes, I agree with you that one should ALWAYS endeavor to choose the right motor for the conditions, but sometimes that IS a learned skill, and from bitter experience, as I can attest. Difference between knowledge and WISDOM... (and experience).

However, the unexpected still can and DOES happen sometimes...

Have a good one! OL JR :)
 

luke strawwalker

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For lpr try to use the swivels that have a locking bar I have had some fail upon ejection where the non locking one just pried open from the shock of opening on a payloader.
Yeah, that's been my experience with the plain jane ones too Char... I've had at least TWO fail before I scrapped all of them and replaced them with the locking kind... no failures since.

Oh, and about the motors, I've noticed from my own experiences since I've gotten back into rocketry, that modern motors are a LOT more 'variable' (poorer quality control, BP mixtures off, or something similar IMHO) than the older motors. I've had a few 'back in the day' do something squirrelly, but I've had more instances in a shorter period of time using new motors since I've been back.

Of course your mileage may vary... :) OL JR :)
 

Fly Johnson

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Here's how Johnson Flying Services deals with swivels.
Of course, it has to done before the lines are attached to the canopy.
This would work with Estes type chutes if they aren't preassembled.
 

MarkII

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Here's how Johnson Flying Services deals with swivels.
Of course, it has to done before the lines are attached to the canopy.
This would work with Estes type chutes if they aren't preassembled.
That's pretty slick. I find that passing the chute through the looped ends of the shrouds after those looped ends have been passed through the eye of the swivel is a pretty simple maneuver, though. BTW, that alternative, parallel pattern of shroud line attachment that Micromeister posted awhile back is a great idea - I never would have thought of that! I frequently use TFR chutes, but unfortunately, they don't attach the lines that way.

MarkII
 

Pat_B

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With my FAI streamer rocket I was using the small snap swivels. I ended up using a pair of pliers to crimp the metal over the wire for a permanent attachment. I found that to be the weakest link. I eventually devised a system where I used no swivels at all, but had good luck with the crimped method of keeping everything together.

The problem I noticed was that the shock cord (whether Kevlar or fishing line) was strong enough to open the gate if it got jammed in there during ejection.
 
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