-Fouled Parachute-

[talkin Monkey]

L1 Cert rocket apogees around 1700'(Rocksim) and comes down about 1100'(Google Earth) from the rail down wind on (most of) a 54" PML chute.

I don't recall it flopping around a lot at ejection but that's not saying much, I was at max Q with the L1 jitters most of the morning...and day.

Here's a couple pics of how I got the rocket back and a couple pics demonstrating how it was set up "pre-flight".

...Maybe put swivels on everything that will hold still long enough for me to do so?

Your thoughts?

 

[blackjack2564]

I watched your entire flight. [congratulations on your L-1, once again].

It was snarled the entire way down. Actually a blessing in disguise considering how windy it was that day. You wouldd have been in for a long walk, like many others that day, had the chute inflated properly!

Anyhow..... I see the electrician coming out of you in the daisy chaining of your shock cord [LOL].

There is the possibility that the rocket is not heavy enough to pull the shock cord out of the chain fast enough and cause the undo twisting. I have seen your technique used on large heavy rockets, but not on small light one's. Not that it shouldn't be done.

Next flight you might try ribbon folding the cord, and gently just drop it in on top of the piston. That's the method of cord folding I always use.

That said.... there is always the fluke fouled up chute that has no apparent explanation.
Nice to have met you ......Jim

 

[talkin Monkey]

Yah, no kidding Jim, had the chute inflated as intended, we woulda been wayyyyy deeper into the tree line south of the runway. Absolutely as you described, a blessing in disguise indeed.

 

[ECayemberg]

Scott,

Like Jim, I watched your flight from ignition to touchdown (I had to!). The chute did indeed foul, but not enough to prevent safe recovery nor void the cert.

One thing Jim did not mention was that the nose popped/chute came out a little early. Happens all the time, but it may have contributed to the tangling. If the chute was folded so that it would open quickly (shroud lines z folded within the chute instead of around the chute), the rocket may have "traveled through" the opening chute which usually tangles stuff up.

Lots of people have lots of ways of folding chutes too. For "normal" chutes, I have never done anything but the good ol' low power method of spiking the chute at it's apex, folding it a few times, and wrapping the shrouds around the chute. Many fear that this method causes tangled shrouds, etc. I've never had issues with it, and very much appreciate that I can tightly wrap the chute to help it fit in small airframes. Another advantage of wrapping the chutes as such is that they open more slowly, which IMO lessens the shock of an early/late ejection. I will admit that I do not fold Rocketman and Skyangle chutes in the manner above.

Ditto on the 54" chute not fully opening with the windy conditions; that would've made for an even more exciting adventure

-Eric-

 

[astrowolf67]

In reviewing your pics, you set yours up like I used to, just a loop tied in the shock cord with the chute attached. What I now do, looks the same, but, with the nose and chute location swapped. I put the chute at the top, with a swivel, and the nose attached at the loop, approximately 1/3 of the way from the chute. It has provided some of the most stable descents I've ever experienced. To help reduce the shock during deployment, I fold my shock cord ribbon style, about two feet at a time, and put a wrap of masking tape around each bundle.

David

 

[TWRackers]

In reviewing your pics, you set yours up like I used to, just a loop tied in the shock cord with the chute attached. What I now do, looks the same, but, with the nose and chute location swapped. I put the chute at the top, with a swivel, and the nose attached at the loop, approximately 1/3 of the way from the chute. It has provided some of the most stable descents I've ever experienced. To help reduce the shock during deployment, I fold my shock cord ribbon style, about two feet at a time, and put a wrap of masking tape around each bundle.

David

I concur with that arrangement, although I do one thing a little differently. Instead of masking tape, I use one of those little Goody's elastic ponytail holder things, the "ouchless" variety without the metal splice. They have a round cross-section, so they'll roll off the shock cord when it's put under tension, if you make sure both free ends of the shock cord come out the same side of the loop. I always have some on hand anyway, since I have a ponytail that needs confinement. I also started putting my nose/payload section at the 1/3 point between the chute attachment and the booster attachment. My L3 rocket actually has a short (2 ft) harness between a delta-dhaped quicklink and the payload section, so that the tension from chute to booster doesn't have to lay across the edge of the coupler during descent.

 

[ECayemberg]

Right on Dave and Tom!

Here's a post from the archived TRF about the subject: https://www.rocketryforumarchive.com/showpost.php?p=489783&postcount=7

-Eric-