Boat tail/tail Cone Shroud for Mid-Power

Boat tail/tail Cone Shroud for Mid-Power

Post by Rhhick » Sun, 15 Apr 2001 21:46:29



Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA, then
later a couple coatings of epoxy) still be used on rockets powered by E, F, G,
& possibly H engines? I've used sawed-off nosecones in some cases, but paper
shrouds offer more variety (& they're cheaper than sawing down a nosecone).
What are other methods to achieve a tail cone/boat-tail? Thanks, Richard
Hickok.
 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by DesertJe » Mon, 16 Apr 2001 01:33:50


I used a tail cone made of chip board and then wrapped it in a layer of 6oz
fiberglass and then a layer of 2.5 oz fiberglass for my L3 project.  I filled
the  void with expanding foam and placed a centering ring  into the top to snug
the BT between the cone and the centering for stiffness.  The total tail
cone/boat tail was 7" long.  Go to
http://www.uroc.org/gallery/show.cgi?Pic=l850.jpg&cat=12&page=1 to see the
result.   You should be fine

 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by R. J. Talle » Mon, 16 Apr 2001 02:40:12


I haven't tried this myself but have given it much thought. if I needed a
large BT or shroud, I'd make it from card stock and then glue stringers of
balsa to the inside surface. This will give considerable vertical support
and should prevent crushing under load. In addition, if fore and aft balsa
bulkheads were installed, any tendency toward axial deflection should be
lessened as well. A finish coat of thin CA would be good, but a thin coating
of quick-set epoxy on the interior surface would tend to place the stringers
and the cone material into a single plane and would therefore be even
stronger.  Now this is all speculation and I'd be willing to bet that
improvements could be made (Cato, Kaplow, anyone?)but I'm equally certain it
would be  superior to either method you first mentioned.  I've used BTs and
shrouds for A-E models w/o trouble using the CA soaking method you propose.
For heavier loads however, I think the stringer and epoxy method is the way
to go.

--
R. J. Talley
NAR 69594

"To do is to be"...Descartes
"To be is to do"...Voltaire
"Do be, Do be, do"...Sinatra

Quote:
> Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA,
then
> later a couple coatings of epoxy) still be used on rockets powered by E,
F, G,
> & possibly H engines? I've used sawed-off nosecones in some cases, but
paper
> shrouds offer more variety (& they're cheaper than sawing down a
nosecone).
> What are other methods to achieve a tail cone/boat-tail? Thanks, Richard
> Hickok.

 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by Mad Scientis » Mon, 16 Apr 2001 12:54:14


Yes.  This method is used on many TLP kits.  However, I can't say that I
have tried it on anything that would take an H.

--
Mad Scientist
NAR 79010
Happy smoke trails to you!
Take out the garbage to reply by email.


Quote:
> Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA,
then
> later a couple coatings of epoxy) still be used on rockets powered by E,
F, G,
> & possibly H engines? I've used sawed-off nosecones in some cases, but
paper
> shrouds offer more variety (& they're cheaper than sawing down a
nosecone).
> What are other methods to achieve a tail cone/boat-tail? Thanks, Richard
> Hickok.

 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by Christopher Dee » Mon, 16 Apr 2001 10:55:57


I have a 4 inch Bullpup that I made the tail cone out of 1/64th inch
plywood. So far, it's held up to a H242. Or you might try  fiberglassing a
cardstock tailcone.

--
Christopher Brian Deem       NAR 12308 TRA 2256 Level II


Quote:
> I haven't tried this myself but have given it much thought. if I needed a
> large BT or shroud, I'd make it from card stock and then glue stringers of
> balsa to the inside surface. This will give considerable vertical support
> and should prevent crushing under load. In addition, if fore and aft balsa
> bulkheads were installed, any tendency toward axial deflection should be
> lessened as well. A finish coat of thin CA would be good, but a thin
coating
> of quick-set epoxy on the interior surface would tend to place the
stringers
> and the cone material into a single plane and would therefore be even
> stronger.  Now this is all speculation and I'd be willing to bet that
> improvements could be made (Cato, Kaplow, anyone?)but I'm equally certain
it
> would be  superior to either method you first mentioned.  I've used BTs
and
> shrouds for A-E models w/o trouble using the CA soaking method you
propose.
> For heavier loads however, I think the stringer and epoxy method is the
way
> to go.

> --
> R. J. Talley
> NAR 69594

> "To do is to be"...Descartes
> "To be is to do"...Voltaire
> "Do be, Do be, do"...Sinatra


> > Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA,
> then
> > later a couple coatings of epoxy) still be used on rockets powered by E,
> F, G,
> > & possibly H engines? I've used sawed-off nosecones in some cases, but
> paper
> > shrouds offer more variety (& they're cheaper than sawing down a
> nosecone).
> > What are other methods to achieve a tail cone/boat-tail? Thanks, Richard
> > Hickok.

 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by Deave » Mon, 16 Apr 2001 23:02:28


My son and I have made many parts out of poster board to
get the shape and then used fiberglass, carbon or Kevlar to
build up strength. Flew an I161 last weekend in a rocket
with a 12 " long  3.125 to 2.6  transition made this way.
Very strong but used allot of carbon.
Gary Deaver

Quote:
> Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA,
then
> later a couple coatings of epoxy) still be used on rockets powered by E,
F, G,
> & possibly H engines? I've used sawed-off nosecones in some cases, but
paper
> shrouds offer more variety (& they're cheaper than sawing down a
nosecone).
> What are other methods to achieve a tail cone/boat-tail? Thanks, Richard
> Hickok.

 
 
 

Boat tail/tail Cone Shroud for Mid-Power

Post by Jim Kern » Tue, 17 Apr 2001 08:15:01



Quote:
> Can a paper shroud (2 lb. Bristol Board, with an intial soaking of CA,
then
> later a couple coatings of epoxy) still be used on rockets powered by E,
F, G,
> & possibly H engines?

Works for me (without epoxy) for F & G stuff. See no reason why it wouldn't
work for an H...
I've  never seen any sign of stress.

If you are doing a boat tail, the motor mount tube can carry the loads up to
the body tube...

--
/"\  Jim Kerns

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