Parachute in the Nosecone

[babp1011]

I am trying to save space on a minimum diameter project I'm working on and I was thinking about housing the main parachute in the nosecone. The recovery harness would attach by a loop of kevlar that is epoxied to the base of the nosecones. My concerns lie with making sure the parachute will get out. The parachute can fit pretty easily within the nosecone and I have been debating covering it with talc powder as well as using a small drogue chute to help pull it out. Would these work or is there anything addition I should do?

Phil

 

[garmtn]

Interesting idea. Talc couldn't hurt but, u need to do more. Use lightest, thinnest material u can find; install a "baffle", w/small eye screw to attach shock cord. Now u have something to stop hot gasses from burning up chute, and a good deploy cause gases will pass through baffle and push nose cone off. (I would attach nC on separate line. TTY:blush:

 

[GrossApproximator]

I've never tried this before, but I have a few thoughts: If you tie you 'chute to the shock cord, somewhere near the middle of the cord, the inertia of the nose cone should carry it to the full extent of the shock cord, while the parachute remains near its attachment point. Make sure to keep the kevlar loop (that you glued to the nose cone) small to minimize the chances of tangling.

+1 on thin, light material.

 

[tfish]

I've been using the nose cone for the main for awhile now. I add a short section of body tube to the nose cone shoulder to make it long enough to hold the main chute.

Also, you need to put the ejection charge in the tip of the nose cone to blow the main out.

Tony

 

[babp1011]

I've been using the nose cone for the main for awhile now. I add a short section of body tube to the nose cone shoulder to make it long enough to hold the main chute.

Also, you need to put the ejection charge in the tip of the nose cone to blow the main out.

Tony

What do you do to ensure the parachute isn't scorched by the ejection gasses in the tip of the nosecone? Kevlar? My original thoughts were to place the charge below the nosecone and use a piston to eject everything forward and, as was mentioned above, utilize the inertia to pull the chute out.

 

[tfish]

It all depends on how much room I have. I like to use nomex. I've also just used a plug of dog barf. I've also just used my kevlar shock cord in limited space setups. I placed the charge below the chute one time. It blew everything up into the tip of the nose cone. Just ground test your set up before the flight.

Here is a photo of a reefed/line cutter chute in a deployment bag.

Tony

 

[babp1011]

It all depends on how much room I have. I like to use nomex. I've also just used a plug of dog barf. I've also just used my kevlar shock cord in limited space setups. I placed the charge below the chute one time. It blew everything up into the tip of the nose cone. Just ground test your set up before the flight.

Here is a photo of a reefed/line cutter chute in a deployment bag.

Tony

Tony, based on your picture it looks like when you wrap the parachute with nomex the nomex is attached at the peak (top) to the shock cord to help pull it away from the parachute as it gets unfurled. Do I have that right?

 

[tfish]

Don't let that photo be any bases for the proper use of deployment bags. It was solely to illustrate..that a deployment bag could be used. What I was doing was playing around with reefed-line cutting recovery systems. They work but have lots of "key" points to work properly.

Tony

 

[babp1011]

I was using it for ideas to help develop my overall plan of attack. And as you said before, ground testing is key. How did attach the recovery harness to the nosecone? Another idea I had was to epoxy an eyebolt as an attachment point near the tip of the nosecone so that way there was nothing on the side that could tie up the parachute from getting out.

Phil

 

[tfish]

I layup my own nose cones and epoxy in, a doubled up loop...and the do a loop to loop concetion. That makes my shock cord replaceable..If you're using a fiberglass nose cone make sure it's very smooth inside. Otherwise things will hang up inside.

Tony

 

[UhClem]

I have put the parachute in the nosecone of several space challenged projects ranging in size from BT-55 to 6". I always attach the shock cord to the nosecone by drilling through the tip. These projects have also required nose weight and the extra inertia probably helps a bit in getting the parachute out.

 

[babp1011]

Thanks everyone for your comments and suggestions. I'll definitely keep them in mind as I further develop my space saving measures.

Phil

 

[GDJ]

I've been considering this for my daughters latest acquisition: Quest Cobalt.

I thought of dumping the end cap, epoxying a hook at the very inside tip of the cone, and giving the little rocket some breathing room for a longer streamer/small parachute.

Besides, getting more mass up there bumps up the stability for hotter engines.

 

[Eric1]

Make sure shock cord in nose cone first! last is nomex wrapped chute. I have no problem with my charge going last. To each his own!

 

[babp1011]

Make sure shock cord in nose cone first! last is nomex wrapped chute. I have no problem with my charge going last. To each his own!

What's size nosecones (diameter wise) have you used this method for?

 

[Eric1]

What's size nosecones (diameter wise) have you used this method for?

I do this in my Mach-N-Byrd, It's a 29mm kit!

 

[babp1011]

I do this in my Mach-N-Byrd, It's a 29mm kit!

That's great to know. Definitely gives me more confidence in my idea. I would never have thought to use it in such a small set up, but as you mentioned, putting the Kevlar in front of the parachute will definitely help pull it out.

 

[Coop]

Interesting thread. I've run across the same question on a build I'm doing --not minimum diameter, just really short.

The solution I was going to try was to place a bulkhead up inside the nosecone, with a larger, albeit slide-fitted, bulkhead near the NC base--with stops on the NC wall, creating a parachute compartment inside the NC, pretty much the same way you'd make rear-ejection.

Deployment would be as follows: ejection (from bottom) blows off assembly. Bottom bulkhead is only permitted to travel a short distance, but the NC/parachute keeps going, letting the 'chute unfurl and keeping the whole thing together.

I figure this would remove the need for a baffle (gases would hit bottom bulkhead), or any wadding, as the recovery system is pretty much self-contained inside the NC.



Later!

--Coop

 

[j-blueridge]

I ran across this thread while looking for something else.

I have been thinking of this sort of parachute storage/deployment for my 4" V2 kit. It needs weight in the nose anyway so I thought a baffle and then making a chute compartment in the nose cone might be a smart move.

Anyone tried something like this?

Jamie

 

[jmattingly13]

I've found that a small drogue works well to pull a main out of a nosecone.

 

[hcmbanjo]

On short LPR models I've put parachutes into nose cones where the base has been removed.
Put the shock cord into the nose cone first followed by the parachute.
At ejection the shock cord (on top of the parachute) helps pull out the parachute.

Easy enough to test -
Pack the shock cord in first, then the chute. Pull the nose cone and body tube sections apart
and the parachute should come out of the nose cone.

 

[j-blueridge]

Great, thanks for the responses guys! I was going to cut away the base of the nose cone as mentioned above and load the chute in there. I'll have to take care to sand rough plastic smooth.

Would the drogue chute be attached to the top of the main, or just somewhere along the shock cord?

 

[mperegrinefalcon]

I attach the parachute to a point lower on the shock cord when storing parachutes in nosecones and make the charges a little hotter than they probably should be. The shock cord will pull the parachute out as the nosecone is shot further away from the rocket.

 

[ArchitectOfSeven]

I put the charge in the tip of the nose cone, have the cone shoulder external, and have a flat top end. As long as it ignites hypothetically the parachute stays put and the cone flies off, exposing the chute to the air stream which should do it's magic. I only put the drogue in there though because the GPS tracker is taking up the front half of the cone.

 

[JonathanOtt]

I'm cobbling together a Madcow Cricket(ish) or, if you wish, an up-scaled Estes Swift(ish) rocket (nose cone is wrong, but it's what I have) with some spare parts I have. I'm planning on putting the 'chute in the nosecone something like this:

 

[Keisling]

I haven't had a problem with the parachute getting stuck in the nosecone with my Madcow Avalanche and that chute was packed in tight. I wish I still had the slomo video to show of my deployment testing where the nosecone blew completely free of the chute bundle before the chute even started moving forward. I do have a pic that @timbucktoo snapped at deployment where you can see the chute bundle completely free of the nosecone before the Kevlar was even pulled taut

 

[David Schwantz]

I just built a short, stubby rocket. Low and behold, I did not leave enough room in main tube for chute and wrap. Took a couple of your ideas and cut bottom of NC off, made a ply ring that went inside, aeropoxy is curing. When dry I will countersink several flat heads around the outside through the NC. Drilled a couple of holes in ring and tied in a 1000 # kevlar loop. Now chute will fit in both NC and main tube, tied third loop in kevlar cord for chute attachment, this should pull chute free of NC.

 

[Event Horizon]

Sorta curious here about the chute in the nose cone concept. I've experienced several chute deployments that when the chute fully opened the recoil from the shock cord caused the nose cone and the airframe to impact each other, putting a nice crease in the open end of the tube. Does the nose cone chute method offer less chance for that to occur?

 

[David Schwantz]

Do not know how you have yours setup, but I do not make the shock cord the same length from chute to NC as it is from chute to air frame. If it is the same distance between the two, this can allow them to hit. I tie a third loop in my shock cord near the NC, depending on rocket size, anywhere from a couple inches to a couple of feet. This way the NC is far above the air frame.