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Dual chutes

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pr_rocket04

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Hello everyone, I'm working on a two stage project, and I want to use dual main chutes. I've never used dual mains, so I was just wondering how they are attached? Do I just attach them both at my center swivel, or will they tangle like that? Thanks for any help.
 

AlexM

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Here is something from Tom Pastrick thta I got from the NARTARC forum...

A little known fact: 2- 18' chutes do not equal 1- 36" chute. It may not sound
right until you see them in action. The air spilling out around the chutes
causes a slight pressure increase between the chutes. Mom Nature doesn't like
this so she moves them apart until the pressure equalizes. This causes the
chutes to angle apart. The angle apart may sometimes be more than 30 degrees,
and depends on the size of the chutes.

Packing the chutes is no different than packing one. If you use the Estes style,
you have the shroud lines wrapped around the folded chute. If you fold
carefully, the 2 chutes should fit side by side inside the rocket. It is best to
have a perforated bulkhead below the chutes so that the 'g' acceleration doesn't
cause them to slide all the way down the tube. The perforations must allow the
ejection gases to push the chutes out. Each chute should have its own attachment
point on the opposite side of the tube. Chutes packed this way seldom tangle
unless the the shroud lengths are not uniform on each chute.

Two identical chutes is probably the best way to go. I have never tried two
chutes of different materials or two different sizes.

Two of the school Teams that I Mentor, have made their first chutes out of
plastic garbage bags. They made them with the shroud lines going over the top of
the chute. This makes a much stronger chute. They also used twice as many shroud
lines as an Estes chute.

Tom Pastrick
 

pr_rocket04

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Thanks for that info. And yes one 36' chute will travel much slower than the two 18' ones will travel simply because of the fact it has a much higher total displacement. But are you saying I should use two shock cords, with a chute on each? I was thinking one, with a swivel near halfway between the two sections and both attached there. I thought I saw that technique used but maybe not. My nose cone will detach at 2000ft to for better quality video (this is where the camera is located), and the chutes will bring down the rest. What do you think?
 
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