Attaching parachute to END of shock cord

[4regt4]

I've always attached the nose cone to the end of the shock cord, and the chute about 1/3 of the way down from there. But I see some (all?) of the LOC kits suggest swapping places - putting the chute on the end, and the nose cone 1/3 of the way down. It looks like either should work. I guess.

Have any of you tried this? How well did it do? Could it possibly reduce chute/cord tangles?

I'm building the little LOC Photon, and I'm thinking of giving it a go.

Hans.

 

[Pinetree]

The instructions for the kit I'm building state the same thing, but I just don't think I can bring myself to attach the shock cord anywhere but the nosecone.

 

[Hobie1dog]

Traditions can be hard to break. But as a guy at work once asked an old guy who said, " I've been doing this longer than you've been alive".. so he asked him...."Did you ever think that you could have been doing it WRONG, all these years?"

 

[4regt4]

Traditions can be hard to break. But as a guy at work once asked an old guy who said, " I've been doing this longer than you've been alive".. so he asked him...."Did you ever think that you could have been doing it WRONG, all these years?"

True that.

I'm going to try it. Small light rocket, even if it goes pear shaped, the rocket will likely survive and I can reconfigure it.

I'm hoping someone has had experience doing it this way, good or bad, and can comment.

Hans.

 

[SolarYellow]

Try calling LOC and asking them to educate you. I bet they’re small enough for someone who knows why they recommend that to explain it to you.

 

[mundayr2]

I have been attaching my chutes to the end of my shock cords for some time now. My reasoning is that when the ejection charge pushes the nose cone off the rocket it pulls the chute out more efficiently than having the nose cone at the end. I have, as of yet, not had a chute fail to deploy using this method. Just my 2 cents.

Bob

 

[jmasterj]

This method was recommended to me by my L1 advisor, and I've used it without issue for all my HPR rockets.

 

[4regt4]

I'm still scratching my head over this. It seems - to me - that having all the goods exit in the order that they are packed is a good idea. That favors having the parachute under the nose cone on the shock cord. But once out and clear of the body tube, all the "goods" are flopping about - especially if you are using a JLCR. So having the chute up top in the column of precious rocket parts during descent seems like a good idea. I don't know.

Hans.

Edit: I think I've got it figured out. Schrodinger's Shock Cord. It doesn't know how it's attached until after it's been deployed......

 

[Onebadhawk]

http://onebadhawk.com/why-a-3rd-loop.html
Teddy

 

[neil_w]

I have also been attaching the parachute down a bit from the nose cone, and have also been tempted to try putting the chute at the end of the shock cord instead.

The big advantage I see is that there doesn't seem to be any way for the nose cone to get tangled up in anything, as it'll be dangling off the middle of the shock cord. The other way, the nose cone is dangling down on a bit of shock cord, admittedly away from the parachute but still swinging around and with the possiblility of getting into some sort of trouble.

 

[Onebadhawk]

I'm sorry for posting that link and not elaborating.
Been busy, Airfest is coming quickly..
It is impossible to not see that attaching the top of the payload harness and the main chute to the hardpoint in the nose cone
greatly reduces the risk of entanglement.
When the nose or main chute is attached anywhere in the middle of the payload harness the nose is swinging around and around the harness.
Every flight.
With the payload harness and the main chute connected directly to the hardpoint in the nose cone this doesn't happen at all, ever.
There is still a small risk of entanglement during separation until the chute inflates and the harness comes taught.
But that risk is no matter how you set up.
The risk of the nose swinging in circles around the harness isn't for the moment of separation, it's all the way down.

To endure / tolerate this greatly increased entanglement risk of putting the chute ( or nose cone ) in the middle of the harness
there must be one or more great upsides / gains / benefits.. Right ??

Please explain them..

( I understand many like increased complexity for its own sake, they think complexity is cool.
No probs, to each his own. But not at the risk of an anomalous flight )..

Me, I like the simplicity of a flawless flight, after all, we all know, that can be easier said than done..

Teddy

 

[Tractionengines]

There is a distinction to be made between Single Deploy, and Dual Deploy.

1) For single deploy I have done the version with parachute on the end and nose cone a little ways down. I LIKE IT and feel it can allow the parachute to stay clear of the shock cord, and give a smoother deployment. The chute takes up the load (weight) of the nose cone. Then as the shock cord is extending and any "bundling" is releasing adding the weight of the fin can over time. When the fin can either reaches the end of the cord, or is slowed to the same speed, the parachute has full load.

2) for dual deploy I DON'T LIKE this arrangement for the drogue chute. (I think, for the same reason Teddy says above.) You can't get an inverted V where the nose is pointing away from the rest of the "stuff" if it is hanging straight down below the chute. [Note, in a dual deploy system this arrangement CAN be used on the Main parachute.]

Just my 2cents. YMMV.

Mike

 

[4regt4]

There is a distinction to be made between Single Deploy, and Dual Deploy.

1) For single deploy I have done the version with parachute on the end and nose cone a little ways down. I LIKE IT and feel it can allow the parachute to stay clear of the shock cord, and give a smoother deployment. The chute takes up the load (weight) of the nose cone. Then as the shock cord is extending and any "bundling" is releasing adding the weight of the fin can over time. When the fin can either reaches the end of the cord, or is slowed to the same speed, the parachute has full load.

2) for dual deploy I DON'T LIKE this arrangement for the drogue chute. (I think, for the same reason Teddy says above.) You can't get an inverted V where the nose is pointing away from the rest of the "stuff" if it is hanging straight down below the chute. [Note, in a dual deploy system this arrangement CAN be used on the Main parachute.]

Just my 2cents. YMMV.

Mike

Thanks.

My original question/comments are oriented around single deploy, motor ejection. So issues about positioning of the deployment charge, etc., as in the article referenced by Ted are to some extent irrelevant to me. I'm using a JLCR most of the time, so the chute spends quite a while bundled.

I have good video of a number of my flights. With the chute attached below the nose cone, I see a vertical column of rocket parts falling with the chute in the middle. So when the JLCR releases, that chute could get tangled with the nose cone. It hasn't happened to me yet, but who knows? I'm going to try attaching the chute on top on this current build (as mentioned, it's a small LOC kit, 24mm motor).

Hans.

 

[waltr]

Single or Dual I read the question as to the MAIN Chute and NOSE cone attachment.

I do have a Chute extension cord on one rocket which does basically the same thing. The chute is way above the nose during descent. Never a problem with deploy or tangling.

I originally did this to keep the chute on top on grass and crops after landing. This has worked well as the rocket sinks into the flora the chute does stay on top and allows it to be seen from a distance, whereas if chute is attached below the nose it get pulled down into the flora and one needs to be very close to see it.

 

[Rschub]

Thanks.

My original question/comments are oriented around single deploy, motor ejection. So issues about positioning of the deployment charge, etc., as in the article referenced by Ted are to some extent irrelevant to me. I'm using a JLCR most of the time, so the chute spends quite a while bundled.

I have good video of a number of my flights. With the chute attached below the nose cone, I see a vertical column of rocket parts falling with the chute in the middle. So when the JLCR releases, that chute could get tangled with the nose cone. It hasn't happened to me yet, but who knows? I'm going to try attaching the chute on top on this current build (as mentioned, it's a small LOC kit, 24mm motor).

Hans.

I had a tangle with the JLCR where the chute got caught under the shock cord, since you need the chute close to the cord to attach the JLCR's short little tether.
I ended up getting a little 2 foot shock cord to attach the chute to the nose, this keeps the chute package away from everything.
This is just due to the specific idiosyncrasy of my JLCR installation. When I start doing DD I will probably use the Jarvis dual shock cord method.
31 minutes in.

 

[pathtouch]

I've been doing chute at the end, above the nose cone on my MPR and HPR flights now too. Last year I had a 7.5" kit with the nose cone at the end and main chute 1/3 the way along the harness. When the chute opened and the nose cone fell down below, then swung back around and right through the main chute shroud lines, collapsing the chute.

Having the main on the end ensures once it opens and all the other parts fall below it they can't swing back up and through... at least in my experience.

 

[Onebadhawk]

I've been doing chute at the end, above the nose cone on my MPR and HPR flights now too. Last year I had a 7.5" kit with the nose cone at the end and main chute 1/3 the way along the harness. When the chute opened and the nose cone fell down below, then swung back around and right through the main chute shroud lines, collapsing the chute.

Having the main on the end ensures once it opens and all the other parts fall below it they can't swing back up and through... at least in my experience.

100%..
I just don't know how better to say it..
There's so much less risk of any probs with the main cute on the hardpoint in the nose cone.

Teddy

 

[86mustang408w]

Can you guys post a few pictures of the chutes at the end of the shock cord? It definitely seems better for HP to have the chute at the end, and the NC down from that. Very interesting I've never thought of that setup.

 

[4regt4]

Can you guys post a few pictures of the chutes at the end of the shock cord? It definitely seems better for HP to have the chute at the end, and the NC down from that. Very interesting I've never thought of that setup.

I don't have pictures off hand, (I'm packing for a launch event) but I find it to be a little awkward/weird stuffing the shock cord in. Hard to describe. But my one and only rocket with that setup has always deployed well.

Hans.

 

[86mustang408w]

I don't have pictures off hand, (I'm packing for a launch event) but I find it to be a little awkward/weird stuffing the shock cord in. Hard to describe. But my one and only rocket with that setup has always deployed well.

Hans.

Ok, was just curious im always looking better ways. Thank you, I have a good idea now how its done after messing around with some stuff here.

 

[4regt4]

Ok, was just curious im always looking better ways. Thank you, I have a good idea now how its done after messing around with some stuff here.

LOL. When you figure it out, let me know!

Hans.

 

[86mustang408w]

LOL. When you figure it out, let me know!

Hans.

I mean, I get the idea about how having the chute at the end of the shock cord, and how it keeps the NC from even coming close to the chute once its all out/opens up. I've always had the nosecone at the end and the shock cord, then about 2/3 up the shock cord the chute. I'll have to try it the other way around.

 

[Crazyrocket]

For single deploy, I always put the chute at the end and the nose cone a little below the chute. In addition to the reason that Teddy and Pathtouch mention, having the chute on the end also helps to prevent the swinging/circling that can happen when the nosecone is at the end. I do not seem to get as much damage to the rocket on landing when the chute is at the end.

 

[Viper3]

I have always attached the shock cord to the nose cone eye bolt/ u bolt. I then attach the main chute to the same nose cone eye bolt/ u bolt.
it works every time for me.

 

[Handeman]

I have always attached the shock cord to the nose cone eye bolt/ u bolt. I then attach the main chute to the same nose cone eye bolt/ u bolt.
it works every time for me.

What size rockets are you flying?

I did the same with all of my LPR. When I moved into MPR and HPR, I started putting the chute about 1/3 down from the nose cone. I'm not sure that was the right thing to do, but it works also. Moving the chute to the end and the nose cone down 1/3 might also be the right move for some or all sized rockets. I free bag the deployment of my L3 so having the chute on the end of the cord certainly works for that.

 

[86mustang408w]

I like the idea and going to start doing it for all mid/high. Thank you guys!!

 

[86mustang408w]

I have always attached the shock cord to the nose cone eye bolt/ u bolt. I then attach the main chute to the same nose cone eye bolt/ u bolt.
it works every time for me.

What size rockets are you flying?

I did the same with all of my LPR. When I moved into MPR and HPR, I started putting the chute about 1/3 down from the nose cone. I'm not sure that was the right thing to do, but it works also. Moving the chute to the end and the nose cone down 1/3 might also be the right move for some or all sized rockets. I free bag the deployment of my L3 so having the chute on the end of the cord certainly works for that.

All of mine from low to high have been the same. The shock cord to the nosecone then the chute about 2/3 of the way up usually with a quicklink or hitch knot along the shock cord 2/3 the way. I've never had an issue this way for smaller chutes and nosecones. But can see how having the nosecone at the end could cause it to tangled or collapse the chute with longer shock cords or bigger chute and heavy NC's. I think its a great idea for high power.

I can see how Viper3 does it, but think having the chute in the NC would tangle maybe?