24" Parachute in tiny space?

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sailmike

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I'm looking for a 24" parachute for my 32" 29mm high flier. I need the chute to pack into a very tiny space, about 2" long by maybe 24mm in diameter to fit part way into the nosecone. Does anybody know about the flame-resistant octagonal parachutes from Mile High Rockets? If it's flame resistant, I won't have to use any protection thereby saving space. It's just that I need space for the tracker. Or, how about the mylar parachutes from JonRocket.com?

Thanks,
Mike
 

DAllen

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I don't know if I would trust with what I assume is an expensive project to a $3 mylar chute no matter how well it is made. If it is dual deploy the main deployment is going to be 80-100 fps and I just don't think mylar could hold up to that. Maybe I'm wrong? Have you tried a 24"
thin-mil chute from TopFlite with lots and lots of talcum powder? Also, how long of a section do you have to work with?

-Dave
 

sailmike

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Have you tried a 24"
thin-mil chute from TopFlite with lots and lots of talcum powder? Also, how long of a section do you have to work with?
-Dave
I saw that, but don't know how much space they take up. There is about 6.25" of space plus the conical nosecone. I thought I designed it with enough space. I think I can make it work if only I can get a chute to fit.

Thanks,
Mike
 

nh4clo4

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Are you sure you need a 24" chute? On lightweight rockets it is often OK to go with a slightly smaller chute. Maybe an 18" chute would fit better and still provide a reasonable landing speed.

Don't do anything unsafe, obviously, but sometimes it is better to have a smaller chute that will come out of the rocket and deploy easily, rather than a big one that gets stuck in the airframe.

I know of some people who use streamers for rockets of that size... :rolleyes:
 

DaveHein

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I use a 14" nylon chute in my 29mm minimum diameter rocket. It descends at a rate of 23 fps, and I haven't had any problems with it.
 

Adrian A

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I'm looking for a 24" parachute for my 32" 29mm high flier. I need the chute to pack into a very tiny space, about 2" long by maybe 24mm in diameter to fit part way into the nosecone. Does anybody know about the flame-resistant octagonal parachutes from Mile High Rockets? If it's flame resistant, I won't have to use any protection thereby saving space. It's just that I need space for the tracker. Or, how about the mylar parachutes from JonRocket.com?

Thanks,
Mike
You can use a 24mm chute holder with a piston made from a 24mm coupler for good protection with almost no volume required for the protection. That's what I do for my 38mm carbon bird. I made a minimalist nylon chute that's 24" across the top (about 18" inflation diameter) and it fits in about 2.5"-3" of 24mm tube. I second the opinion that 24" sounds pretty big for a 32", 29mm rocket.
 

blackjack2564

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FYI.....
....... My little 29mm min diam. only uses a 12in. Topflite. No problems yet after many flights, it's 34in long.
 

sailmike

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Alright, I rechecked and added the weight of a 29/360 case and it now shows 22 ft/s descent on a 18" chute. I tried fitting an 18" chute from Top Flight in, but it took up a bit too much space. For some reason I thought I remembered Rocksim saying 24". The rocket weighs 13.0421 ounces with electronics and the motor case, and about 7.93 ounces without the motor case. Estimated altitude on a I200 is 10,160 ft. Has anyone tried the flame-resistant octagonal parachute from Mile High Rockets?

Thanks,
Mike

Here's the Rocksim file:

View attachment Jasmine 29V2.rkt
 

blackjack2564

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Again I must say try a 12in. Unless you are flying on a really hard surface [playa?] you should be okay.
Mine weighed more than yours by 3oz and has also flown on an I-200.
You can always soak the chute and risers in a borax laden solution of water.[Borax soap powder] That will give it great fire resistant properties . Maybe use carefully folded Estes type tissue wadding. [which happen to be treated with borax]
You may also find it easier to pack 2 small 12in chutes over 1 larger if you are stuck on that notion. Or a 12 with a streamer on the canopy.
 

als57

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The thin mil chutes from Top Flight pack considerably smaller than their standard chutes.


Al
 

sailmike

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Adrian, could you explain the chute holder you are talking about?

Thanks,
Mike
 

Adrian A

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My chute holder is a Kevlar-reinforced 24mm cardboard airframe tube that's attached to my av-bay. The rocket airframe has a 38mm coupler glued into the end of it, and the nosecone slides over the coupler. The av-bay is mounted inside the coupler and the chute holder sticks out past the end of the coupler and deep into the nosecone.



The harness for the chute has a piston and an endcap for the chute holder.
My apogee charge is located at the front end of the chute holder at the end of a wire from the av-bay, and the main deployment charge is at the bottom of the chute holder behind the piston. The shock cord for the nosecone is folded accordion-style and taped around the chute holder. At apogee, the charge at the front of the chute holder blows the nosecone off of the rest of the airframe, and the chute holder endcap protects the chute. The shock cord for the nosecone is attached exterior to the chute holder, at its base, so that it's out of the way when the main chute charge blows at low altitude. The rocket descends nosecone-first, with the nosecone harness stretched out. That harness is long enough that the chute won't get mixed up with the nosecone if it's fully deployed.
 

sailmike

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That is an interesting setup. Thanks for sharing.

Mike
 

BearMan

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My chute holder is a Kevlar-reinforced 24mm cardboard airframe tube that's attached to my av-bay. The rocket airframe has a 38mm coupler glued into the end of it, and the nosecone slides over the coupler. The av-bay is mounted inside the coupler and the chute holder sticks out past the end of the coupler and deep into the nosecone.



The harness for the chute has a piston and an endcap for the chute holder.
My apogee charge is located at the front end of the chute holder at the end of a wire from the av-bay, and the main deployment charge is at the bottom of the chute holder behind the piston. The shock cord for the nosecone is folded accordion-style and taped around the chute holder. At apogee, the charge at the front of the chute holder blows the nosecone off of the rest of the airframe, and the chute holder endcap protects the chute. The shock cord for the nosecone is attached exterior to the chute holder, at its base, so that it's out of the way when the main chute charge blows at low altitude. The rocket descends nosecone-first, with the nosecone harness stretched out. That harness is long enough that the chute won't get mixed up with the nosecone if it's fully deployed.
Adrian,
This setup is very similar to my Mariah...... except my chute holder cap is attached to the booster cord. Can you explain more how the cap works and how the nose cone cord comes out from the tape? Also not sure which piece is the piston and how it slides effectively.... Sorry for pulling up a old thread but I liked this setup....

Barry
 

edwinshap1

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mike, before you use a 24" chute, if you made this thing to break mach, or get near it, i'd recommend a much smaller chute. I launched my 38mm (1.75lb) with a 24" chute dual deploy. came down "fast" but completely safe, and a shorter walk to recovery. I could've gone 18" and been fine.

Use a 12" chute if you're having trouble packing, it shouldn't be an issue if you wanna kill the mach demons:kill:
 

Adrian A

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Adrian,
This setup is very similar to my Mariah...... except my chute holder cap is attached to the booster cord. Can you explain more how the cap works and how the nose cone cord comes out from the tape? Also not sure which piece is the piston and how it slides effectively.... Sorry for pulling up a old thread but I liked this setup....

Barry
The nose cone cord and the main chute cord are tied together and threaded through behind the chute holder. Each can be pulled without pulling on the other. The main chute cord is routed through the chute protector cap and epoxied in place, and the piston is the black piece next to the chute. It was made from the casing of a 24mm single-use motor. It also has a shock cord epoxied to it to form a seal. Some people are dead-set against ever applying any epoxy to kevlar, but I have found that it can be o.k. if done carefully. What you don't want is a skinny epoxy-kevlar composite stick that will break if it gets bent. But if you embed a knot into a puddle of epoxy and are careful to keep the rest of the cord clear of the epoxy, I don't think the epoxy-kevlar knot is much weaker, if any, than a pure kevlar knot.
 

BearMan

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Adrian,
thanks for the help.... still not clear on a couple things. I have studied and starred at your picture. Cant seem to get an order of things in my mind.

Where are the shock cords coming from? outside or inside of chute holder or both?

The piston seems glued on the end..... cant see how it moves free of the cord. Where is the main chute cord when packed?

On my setup..... I have a chute holder with both cords glued in the rear coming out the same tube. The main charge is placed in the bottom..... then barf/nomex.... then main cord..... then main chute.... then 12" of apogee cord slack.... then the chute protector cap..... then the apogee charge taped to the outside of the chute holder tube. I could re-route the booster cord but not sure how to make the chute protector cap work...... does this help? There is a subtle difference here that is making a difference..... your chute looks great..... mine is CHARRED! hehehe:shock: :rolleyes::rolleyes:
 

Micromeister

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You might want to fabricate your own out of Real Silk, I found some light weight silk at a jo-ann fabric. used 13lb kevlar thread for the shrouds on a 24" and 30" needed in my 32nd scale F-104 PMC. it had a BT-55 stuffer tube but only about 2-1/2" long. works just great. Silk crushes down very tightly. I'm sure you can get 1 24" in a BT-50 x 2" with room to spare:)
 

BearMan

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Adrian,

One more question..... looks like both cords are on outside of chute holder.

How do you keep them seperate? Tape? Does the main chute break the tape?
 

Adrian A

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Adrian,
thanks for the help.... still not clear on a couple things. I have studied and starred at your picture. Cant seem to get an order of things in my mind.

Where are the shock cords coming from? outside or inside of chute holder or both?

The piston seems glued on the end..... cant see how it moves free of the cord. Where is the main chute cord when packed?

On my setup..... I have a chute holder with both cords glued in the rear coming out the same tube. The main charge is placed in the bottom..... then barf/nomex.... then main cord..... then main chute.... then 12" of apogee cord slack.... then the chute protector cap..... then the apogee charge taped to the outside of the chute holder tube. I could re-route the booster cord but not sure how to make the chute protector cap work...... does this help? There is a subtle difference here that is making a difference..... your chute looks great..... mine is CHARRED! hehehe:shock: :rolleyes::rolleyes:
They are both attached outside of the chute holder. When packed, the chute holder interior goes: End cap, chute and shock cord, piston (with cord on one end), charge. All of the cord is forward of the piston, and it's attached external to the chute holder.

My chute is not so pristine now, but it's still in pretty good shape. If both of your cords are attached inside of your chute holder (neither of mine are) then I'm having trouble envisioning how it's supposed to work. It seems like you could have at most one cord attached inside, but if you do, it won't be protected from the charge because it would need to be attached on the charge side of the piston.
 

Adrian A

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Adrian,

One more question..... looks like both cords are on outside of chute holder.

How do you keep them seperate? Tape? Does the main chute break the tape?
Both cords are taped down. First I tape down the main chute cord, and then I tape down the longer apogee cord. They are arranged onto different areas of the outside of the chute holder tube so that the main chute cord is still taped down when the nosecone is at full extension.
 

BearMan

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........ It seems like you could have at most one cord attached inside, but if you do, it won't be protected from the charge because it would need to be attached on the charge side of the piston.
You are correct. Both cords are attached to a bulkhead at the rear of the chute holder. The booster is pulled tight as the chute and its cord are packed. Instructions say to place dog barf at the rear of the holder to protect everything. The booster cord seems like it may be hindering the chute from coming out and everything isn't protected well.

This is why I am trying so hard to understand what you are doing here. I think I have it now. Seems MUCH BETTER to me..... Now to see if I can get both cords pulled to the outside of the holder.........:eek:

Any tricks to designing a piston? Free sliding I get.... longer than wide..... how do I prevent it jamming????

Thanks very much for your help so far.
 

RocketManDan

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I'm looking for a 24" parachute for my 32" 29mm high flier. I need the chute to pack into a very tiny space, about 2" long by maybe 24mm in diameter to fit part way into the nosecone. Does anybody know about the flame-resistant octagonal parachutes from Mile High Rockets? If it's flame resistant, I won't have to use any protection thereby saving space. It's just that I need space for the tracker. Or, how about the mylar parachutes from JonRocket.com?

Thanks,
Mike
I make mine out of hefty trash bags and use a 5" spill hole...they work great. I made an extra one if you want I can send it to you..just pay shipping. You have to string it up.
 

Adrian A

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You are correct. Both cords are attached to a bulkhead at the rear of the chute holder. The booster is pulled tight as the chute and its cord are packed. Instructions say to place dog barf at the rear of the holder to protect everything. The booster cord seems like it may be hindering the chute from coming out and everything isn't protected well.

This is why I am trying so hard to understand what you are doing here. I think I have it now. Seems MUCH BETTER to me..... Now to see if I can get both cords pulled to the outside of the holder.........:eek:

Any tricks to designing a piston? Free sliding I get.... longer than wide..... how do I prevent it jamming????

Thanks very much for your help so far.
If the piston is longer than wide, and slides freely, it's very unlikely to jam. Keep the tube it's running in clean, and that's about it. You should be able to blow it out like a blow gun.
 

sailmike

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RocketManDan said:
I make mine out of hefty trash bags and use a 5" spill hole...they work great. I made an extra one if you want I can send it to you..just pay shipping. You have to string it up.
Would you mind posting a picture of it? I wouldn't mind making one for myself.

Thanks,
Mike
 

evil ed

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Greetings Mike!

If you send me a PM with y'all address I'll send you 2 each of my "Thermal Rider" chutes in sizes 18", 20" and 24". Even though they are plastic, they pack pretty tight, and you should have enough room left over for a chute protector. I'll ship them as freebies, so if you choose to go another route, your not out anything.

Evil Ed Hartle

Hartle Engineering, Inc.

"Still Chasing the Demon"
 

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