Re: Heat-PROOF engine mount tubing?

The ejection charge is not roasting the stuffer tube - the delay afterburn is roasting it. bad on all motors but worst on special composite motors. Also the most vulnerable tubes are those with thin walls like standard Estes BT-5, 20 and 50. BT-55 thickness is a bit more. MRC tubes were the thinnest ever.

Google Hibachi Effect.

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLR,GGLR:2005-41,GGLR:en&q=hibachi+effect

http://www.apogeerockets.com/education/newsletter28.asp

-Fred Shecter NAR 20117
http://search.ebay.com/_W0QQfgtpZ1QQfrppZ25QQfsooZ1QQfsopZ1QQsassZshreadvector

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"Gordon S. Hlavenka" <nospam@xxxxxxxxxxxxx> wrote in message news:lZXIg.12849$1f6.854@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I've been experimenting with a no-wadding chute packing/deployment method and run into a snag.

What I've done is to run a stuffer tube all the way up to the nosecone, then pack the shock cord and chute around the stuffer. The nosecone has a plug attached to the center that mates to the stuffer. So the ejection gases pop off the nose, and it pulls the chute out after itself. The shroudlines are wrapped around the chute so that it gets completely out of the body before opening.

This scheme has worked nicely, with one problem: I'm using Estes BT20 for the stuffer, and it burns completely through after 4 or 5 flights. Apparently the BP is hanging around too long and frying the tube. I still get a recovery under 'chute, but the bird has to be rebuilt to fly again. This puzzles me, since I have other models with stuffer tubes (albeit not all the way to the nose) and they don't burn through even after dozens of flights :-/

I coated the stuffer with CA on the first rebuild but that burned through also. So I guess I need a stuffer tube made out of something that just plain doesn't burn. Or some way to get the hot stuff out before it starts burning the stuffer. It seems to me this problem must have come up with baffle designs also, so there should be some useful wisdom out there.

Suggestions?

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Gordon S. Hlavenka http://www.crashelectronics.com
If your teacher tells you to Question Authority
Should you do it?

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Relevant Pages

  • Re: Heat-PROOF engine mount tubing?
    ... The ejection charge is not roasting the stuffer tube - the delay afterburn is roasting it. ... then pack the shock cord and chute around the stuffer. ...
    (rec.models.rockets)
  • Re: Heat-PROOF engine mount tubing?
    ... Keep in mind that the flame path is coming up to temperature at about ... What I've done is to run a stuffer tube all the way up to the nosecone, ... then pack the shock cord and chute around the stuffer. ...
    (rec.models.rockets)
  • Re: Heat-PROOF engine mount tubing?
    ... What I've done is to run a stuffer tube all the way up to the nosecone, ... then pack the shock cord and chute around the stuffer. ...
    (rec.models.rockets)
  • Heat-PROOF engine mount tubing?
    ... What I've done is to run a stuffer tube all the way up to the nosecone, then pack the shock cord and chute around the stuffer. ... So I guess I need a stuffer tube made out of something that just plain doesn't burn. ...
    (rec.models.rockets)
  • Re: Heat-PROOF engine mount tubing?
    ... What I've done is to run a stuffer tube all the way up to the nosecone, ... and it pulls the chute out after itself. ... plain doesn't burn. ...
    (rec.models.rockets)