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Deployment problems on Giant Leap Rocketry's Vertical Assault

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Neilw

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*Disclaimer: not GLR's fault*

This summer, I flew to try to get my L3 (Canadian L3). The going up part of the flight was good, but coming down, the main parachute got stuck in the body. Anyways, the rocket was undamaged but the failure to deploy lost me the L3. In the end, only my pride was hurt. Here's a video of the launch just for fun:

[video]https://www.facebook.com/neil.woodcock.5/videos/10210966164736116/[/video]

The main parachute had been a bit of a snug fit on the ground, but I was able to pull it out easily enough to make me confident it would work in flight. The main in this case is a 48 inch nylon parachute. Post flight, I noticed 2 things:

  1. The folded parachute had rolled on its side and had become jammed at the mouth of the body tube
  2. The kevlar parachute protector, which was already full of pyrodex residue from previous tests, felt sticky to the touch and had a pretty high friction coefficient with the FG body tube

Based on these observations I have come up with some possible solutions. Of course, I'm looking for feedback from the experienced people on this very forum.

  1. Try a new folding technique. Preferrably one that folds the parachute into a longer, slimmer package. As well, the shockcord may need to be folded better, as it looks like it had a role in jamming the parachute in the tube
  2. Get a smaller parachute. If it landed fine with only a drogue, who says it needs a parachute as big as 48 inches?
  3. Clean the kevlar parachute protector between flights. I've already done this
  4. Maybe wrap the parachute and protector in a sabot of some kind. Cardstock might work.

Any help is appreciated!
 
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Bat-mite

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Things I would do:
  1. Z-fold your harness
  2. More BP
  3. Smaller chute (with that premade fin can, you can take a harder landing, like you said)
  4. Don't be afraid to wash your chute protector and harness (but don't do it with another load of laundry or the clothes might turn gray)
 

FMarvinS

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1+ Bat-mites suggestions. Also ground test, ground test after performing steps 1 to 3 above.
Good Luck!!

Fred,
L2, ROSCO member
KG4YGP
 

Neilw

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Things I would do:
  1. Z-fold your harness
  2. More BP
  3. Smaller chute (with that premade fin can, you can take a harder landing, like you said)
  4. Don't be afraid to wash your chute protector and harness (but don't do it with another load of laundry or the clothes might turn gray)
I did a z-fold, but that may have been part of the problem. It was still jammed up in the body with the tape intact. Maybe I should try a weaker tape? I was using white masking tape but maybe I should have gone with green.

1+ Bat-mites suggestions. Also ground test, ground test after performing steps 1 to 3 above.
Good Luck!!
I'll try to get some testing time. It gets a bit hard to test for me, though, since I live in the city.
 

Bat-mite

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Regarding ground testing, if you don't do it, then you take what you get at the field. If your rocket crashes, you could be out significant $$$. If it works on the ground, it will work in the air.
 

bill2654

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I keep a bottle of baby powder in my chute box. Makes stuff slide a lot better. Put a gob in the chute when you pack it for better visibility when it pops opens.
 

Mr Rocket

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Maybe I should try a weaker tape? I was using white masking tape but maybe I should have gone with green.
I was having the same problem, and one of the guys at our field suggested putting a few starter cuts in the tape with an x-acto knife. Have not had any problems since.

YMMV:wink:
 

Onebadhawk

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Things I would do:
  1. Z-fold your harness
  2. More BP
  3. Smaller chute (with that premade fin can, you can take a harder landing, like you said)
  4. Don't be afraid to wash your chute protector and harness (but don't do it with another load of laundry or the clothes might turn gray)
Please don't ask me how I know this,, lol..

Teddy

( and don't mention it if my wife is with me )
 

Onebadhawk

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I had a tight fit in my 54 mm minimum D "Altitude Seeker"...

1-- Clean the BP residue from the inside of the airframe..
2-- Lot's of baby powder all over everything..
3-- It's super important that when you use a masking tape restraint on a Z folded harness
that the tape be put on the end of the Z folds where both tails come into the fold package..

Teddy
 

Buckeye

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Harness is taped together and not opening? Umm, don't tape the harness?
 

Handeman

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Harness is taped together and not opening? Umm, don't tape the harness?
+1 on this. I know it sounds like it was kind of tongue in cheek, but it really is the best suggestions. If you are z-folding your harness and taping, and it doesn't open, then you don't have enough force on your ejection to warrant needing the z-folds. Don't try to correct one perceived problem by creating another and using a larger charge. Just don't do the unneeded taping.
 

dixontj93060

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Before selling, I had flown my VA many times without a failure. The main compartment is fairly long. On the flight...

What brand 48" chute?

How much BP?
 

Mr Rocket

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Harness is taped together and not opening? Umm, don't tape the harness?
Agreed, but sometimes my OCD just wants to keep everything neat and organized.

Sorry, I must get back to washing my pencils now.
 
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