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Friday, November 28, 2014

Why You Need Wadding . . .


I haven't seen this one for a while, it's worth a re-visit:
CLICK HERE

This is another video from Roger Smith - He explains:
"This video shows what happens inside a rocket when the ejection charge fires. Captured at 1200 frames-per-second, this high-speed video illustrates dramatically why you need recovery wadding (or some other system) to protect the rocket's parachute."

Roger has other videos to see: CLICK HERE

5 comments:

  1. WOW ....that's quite a bit of fire and heat......its a wonder plastic chutes work at all....

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    Replies
    1. Hi Metalhead,
      I use plastic "parasheets" in about all of my LPR rockets and rarely see any melting. If you use a bit of a wadding wrap at the bottom:
      http://modelrocketbuilding.blogspot.com/2014/11/wadding-wrap-tip.html
      it helps quite a bit.
      The weird thing is, I've had some shroud lines get hot and stick together preventing the parachute from fully opening!
      I usually use #10 all cotton crochet thread now.

      Delete
  2. The static tests show quite a bit of thrust vectoring too....

    ReplyDelete
  3. I have had good luck so far with chutes.....gonna try dog barf one day

    ReplyDelete
    Replies
    1. Hi Metalhead,
      I don't like the dog barf. It is cheap, but the pieces are very small and there is better chance for blow-by especially in larger tubes.
      Some people wrap the dog barf in a piece of wadding so it blows out like a one-piece piston.

      Delete