56" diameter, 16 shroud lines, and 6 hours of work. DONE.

[Neil]

I just finished sewing my dad's L2 chute.... It took me 6 hours of work.

Specs:

diameter: 56"
shroud lines: 16
Panels: 1 piece of ripstop nylon
Result: one heck of a chute! (if I do say so myself... )


I was running through the living room to get an idea of how it would open up, and when it did, I Just about fell flat on my face! It stopped me dead in my tracks! Either I need to stick to smaller chutes, or I need to gain some more weight, cause if I take one of those things outside, im a gonner!

if its windy tomorrow I will tie it to a tree and get a pic. Theres not enough room anywhere in our house to lay it out flat, so I cant give you a pic yet... Tommorow, though, I will clear some space!

 

[rstaff3]

Sounds cool. What did you use for the shroud lines?

 

[Ryan S.]

for soem reason that sounds kinda small, only 4 feet? Maybe I am just used to bigger L2 birds

 

[Neil]

Id say your used to bigger projects

It will bring the 4" diameter 72" long rocket down about 23 FPS. Considering we were in agreement about the 25FPS being the fastest that would be safe for this rocket, I Think its pretty good... I was just taking some pics of the chute, and the camera ran out of batteries. Youll have to go with a folded-up chute pic for now... Ill post it in a sec.

 

[Neil]

Heres the pic! Its next to an 18" ruler for scale. Its about 13" long when folded. I could get it shorter, but why bother. We have plenty of room in the rocket.

 

[Neil]

I just had a merry poppins moment! I was posing for a pic with the chute. I was standing on the build-in bench on the deck, with the chute going over the yard. my mom snapped the pic. SO then I decided it owuld be a good idea to try to simulate a deployment! So I took the chute in my hand, and threw it into the wind, right when a HUGE gust of wind came! It was all Icould do to keep myself on the deck! I almost fell twice before I regaind controll! Scratched up my hand on the quick-link, too!


THATS IT! THATS THE BIGGEST CHUTE I AM EVER MAKING! Well, if I make a bigger one, I wont test it in the wind. Ill fly away!

Heres the best pic my mom got.

 

[Neil]

Heres another view.

 

[Ryan S.]

looks like some panels would be helpful

 

[Neil]

Why? I think its fine the way it is... Especially after I almost lifted off when I was testing it! LOL! :kill:

 

[Ryan S.]

maybe, it still seems small, how much is this rocket gonna weigh?

 

[Neil]

Between 6 and 10 pounds. As I said, it should have a descent rate of between 20 and 25 FPS. Im pretty sure its fine, and if not, I can make another chute for the nosecone and have the two pieces recover seperately.

 

[jetra2]

Neil,

Just a FYI. 13-17 FPS is a "normal" descent rate. You may want to be carefule with this rocket if the fins are swept back at all - they may break with such a fast descent rate. Build the fins strong and they will likely be better off.

Jason

 

[Neil]

We already went through this... They dont have anything hanging over the back of the tube. The tube is glassed. It should be fine.

 

[Ryan S.]

Jason has a good point. Why dont you use dual deployment? This thing is gonna go pretty high, also the back the the tube may get bent up over time from constantly landing so fast

 

[Stones]

Neil...
I made a scratchbuilt ripstop chute of 40". I use it to bring down a 25 oz. rocket. Dual deploy sounds like a way better way to go or if you're bound and determined to go with single deploy, use at least an 80" chute which will bring down a 6lb. rocket at about 20fps. Personally, I like to stay at 15fps or lower.

 

[Neil]

This is one stinkin tough tube.... And once I glass it, I bet I could hit it wiht a hammer a few times and hardly make a dent



And, depending on the weight, I might have to make a second 56" chute.


Sure, a 56" chute will bring it down kinda quick (23.2FPS), but I think itll be fine. Should I chuck one of the tubes out a window to see if it dents?

 

[Ryan S.]

you could but remember the real tube will have fins, a motor, a motor mount, etc etc. So it isnt very accurate.

It might be okay the first time but it will probably break after a few flights

 

[Neil]

The fins dont hang over the back, and the motor mount is sunk into the tube a little. And theres good padding where we launch Blueberry bushes! That wont make too much difference, but hey.

My dad doesent like to launch rockets over and over and over. Once or twice a year per rocket is enough for him. As long as it can come down 2 or 3 or 4 times without too much repairwork, hes happy.

 

[Ryan S.]

I see, so you are putting dual deployment in it right?

 

[Neil]

Ummm, no. This is a cert flight, remember?

 

[Ryan S.]

yeah I do what is your point? there is no rule agianst electronics in a cert rocket

 

[Neil]

No written one, but you saw Bill Spadafora's 5 attemps at a L2 flight with electronics. :kill:

Besides, we have 600 acres of blueberry barrens to launch from and recover in. We would really have to try hard to loose a rocket in Cherryfield. THe only rocket that I know of that has ever come close to being lost was a 7" V2 on an M green gorrila. with single stage deployment. and it was a pretty windy day. That should give you an idea of how big Cherryfield is.

 

[Ryan S.]

yeah, bill simply overcomplicated his rocket, using electronics is so easy and is a smart idea, try it in your L1 rockets first to test it.

you can lose a rocket within the feild and it is just a pain to walk. I would use electronics or go low and slow....at least use them for motor back up

THis is just what I would do, this way you have a better chance of finding the rocket and it can land easier, it is an L2 so dont chance anything.

BTW the way I heard the story about steve boy's V2 (from Nikita) was it went up and they lost it but they had a radio tracker in it, so they went for a drive and found it a couple miles away

 

[n3tjm]

The problems Bill had with his Level 2 Certs had nothing to do with the electronics.

First Flight - Nose SEP
Second - Fin Broke
Third - Body Damage?
Forth - Shock Cord to short, did not pull chute all the way out. Damage to fins and Body
Fifth time was the charm

Each time the electronics worked perfectly.

 

[Neil]

Really? I heard the electronics had something to do with it...

But still, its just one more uncertainty, and my dad has never used any electronics, and I dont think his L2 flight is really the place to start... :kill:

 

[havoc821]

Nice chute! THe only thing is 16 lines is WAAAAAAAY overkill. My 8ft Military chute had 16 lines and I took a couple off to reduce tangeling. If a 5 foot chute is pulling you around, you need to gain some weight. If you think that is big and you almost got "blown away", youhave no idea what blown away is. Borrow my 25foot chute, walk outside and tell me what "blown away" really is. The wind was less than 5 mph and I had to run to keep up. The only way it stopped was by getting caught in a tree.

 

[BlueNinja]

Where can you get military chutes?

 

[havoc821]

My 8 foot chute was given to me but you can find similar at military surplus stores. I got my 25foot military chute at a gun show for only $35 bucks!

 

[Neil]

Well, I was standing on a bench when this happend, and I caught a big gust.

16 lines is fine if you ask me.... I havent had any problem with tangling, and if one breaks for some reason, it will still work fine.

 

[Ryan S.]

but have you put it in a rocket and flown it yet? 16 shroud lines does seem like a lot, but if it works I would think it would make the chute more efficient