Snap swivel on chutes?

[stratos283]

Back in the eighties we always attached the shroud lines with a snap swivel. I don't remember why, we just did it. Are there any advantages to using a swivel, such as more dependable chute deployment, or will it make the rocket spin excessively on descent?

Thanks,

Kelly

[Ironnerd88]

Snap swivels help prevent shroud line tangling, and allow you to quickly, and easily change chutes.

[Marlin523]

Adding a swivel helps keeps shroud lines from wrapping and makes changing chutes simple. I have many times changed chutes at the launch site to accommodate for winds.

[Micromeister]

Back in the eighties we always attached the shroud lines with a snap swivel. I don't remember why, we just did it. Are there any advantages to using a swivel, such as more dependable chute deployment, or will it make the rocket spin excessively on descent?

Thanks,

Kelly

Kelly:
Like you I've always used swivels on my chutes and streamers for sport flying. makes it so much easier to set up models for the flying conditions on the field.
As many have said they can reduce the amount of tangle in your should lines as well.
sized I've found most helpful small models and streamers #14, chutes in models up to 1lb #10, and chutes up to 36" in MPRs #2.

[MarkII]

In addition to allowing you to change parachutes to suit the wind conditions, using snap swivels allows you to store your parachutes separate from your rockets. If the parachute is permanently attached to the rocket, then you have to fold it up and keep it stuffed inside the airframe in between launches. This is not good for the parachute, because it creates creases and "memory." When I get home after a launch, I take my parachutes out and hang them upside down by their swivels/links on hooks and leave them like that until I pack them up again to take to another launch. This allows the material in each canopy to "relax" in its natural, open configuration. When I prepare to go to a launch, I fold and pack each parachute into its own plastic baggy and put them all in a separate tackle box, along with wadding, some spare snap swivels and my bottle of talcum powder, that I refer to as my recovery device box. When I prepare a rocket at the launch field, I go into the recovery box and pick out a parachute to use with it. After I recover the rocket, I bring it back to my prep area and detach the parachute and place it back in the box. It is not unusual for me to use the same parachute several times with different rockets on launch day.

I use snaps that have the "coastlock" design, rather than the more familiar "safety pin" design, because they are more secure. Even if they are severely overstressed, they are much less likely to pull open; instead, the coastlock-style snap usually just cinches down like a noose or slip knot as it becomes deformed (stretched out) by the strain, but it does not open up.

Spinning around while it is dangling under the parachute during descent does not cause any problems at all for the rocket. In rare circumstances, if the parachute is directly connected to a screw eye in the base of the nose cone, a great deal of spinning can cause the hook to unscrew out of the nose cone. But since most people lock the screw eye into the nose cone base with epoxy, this would be a very rare scenario. Even in those "once in a blue moon" circumstances, having the parachute attached by a swivel allows everything to rotate freely without putting a strain on the parachute's attachment to the rocket and without causing the shroud lines to twist up.

MK

[karlbaum]

In addition to allowing you to change parachutes to suit the wind conditions, using snap swivels allows you to store your parachutes separate from your rockets. If the parachute is permanently attached to the rocket, then you have to fold it up and keep it stuffed inside the airframe in between launches. This is not good for the parachute, because it creates creases and "memory." When I get home after a launch, I take my parachutes out and hang them upside down by their swivels/links on hooks and leave them like that until I pack them up again to take to another launch. This allows the material in each canopy to "relax" in its natural, open configuration. When I prepare to go to a launch, I fold and pack each parachute into its own plastic baggy and put them all in a separate tackle box, along with wadding, some spare snap swivels and my bottle of talcum powder, that I refer to as my recovery device box. When I prepare a rocket at the launch field, I go into the recovery box and pick out a parachute to use with it. After I recover the rocket, I bring it back to my prep area and detach the parachute and place it back in the box. It is not unusual for me to use the same parachute several times with different rockets on launch day.

I use snaps that have the "coastlock" design, rather than the more familiar "safety pin" design, because they are more secure. Even if they are severely overstressed, they are much less likely to pull open; instead, the coastlock-style snap usually just cinches down like a noose or slip knot as it becomes deformed (stretched out) by the strain, but it does not open up.

Spinning around while it is dangling under the parachute during descent does not cause any problems at all for the rocket. In rare circumstances, if the parachute is directly connected to a screw eye in the base of the nose cone, a great deal of spinning can cause the hook to unscrew out of the nose cone. But since most people lock the screw eye into the nose cone base with epoxy, this would be a very rare scenario. Even in those "once in a blue moon" circumstances, having the parachute attached by a swivel allows everything to rotate freely without putting a strain on the parachute's attachment to the rocket and without causing the shroud lines to twist up.

MK

I had a "safety pin" style snap swivel come undone so I recommend the "coast lock" style.

[Bone Daddy]

At our last DARS launch at the Panther Creek site, I flew 5 different rockets some more than once using the same 12" estes chute with a spill hole. Gotta love snap swivels.

[Trident]

I had a "safety pin" style snap swivel come undone so I recommend the "coast lock" style.

Dittos on that. You can find a pretty good assortment of snap swivels with the fishing gear at Walmart. I also buy the steel leaders that have a snap swivel, and use these for shock cord mounts. You can embed one end in a centering ring, or even epoxy it to the wall of the body tube. Makes it easy to add a Kevlar cord, or just the shock cord itself. With the shock cord, I tie it to a small ring, and then it is simple to undo and replace. I've seen the leaders up to 12" long most recently at Walmart, but I'm sure I've found them up to 18" in length. It may have been at a sporting goods store.

Here is one at the top end of the clustered motor tubes for my Astron Cobra. The snap swivel is out of the picture. I wanted to show how it was mounted into the rocket when I took the picture. A little off topic, but the other end has a 4-40 bolt going into a piece of threaded tube. Keeps the motors in, using a washer. When on display, no unsightly motor hooks (which were not used on the Cobra).

[SteveA]

Love 'em...for the same reasons as everyone else mentioned.