[SS-VehDev] Re: casing

[william colburn]

Excellent guys. Remember to do the fiber orientation
to get 2 x hoop as longitudinal count. When Scaled
Composite did their motor for SpaceShip One, they also
did 45 degree wraps too. We ultimately need two 10
foot pieces and a 42 inch piece for the short stack
motor. We will hydrotest them all also to 10-15% over
MEOP. What is the OD of your plug?

BC

--- Lakestake Rocketry <lakestake at gmail.com> wrote:

> Hi Roman,
> 
> Do you want to take up this challenge with me? I
> think we can
> make better tube for less.
> 
> Matt C
> 
> P.S. I am making a bunch of 10" CF tube now for a
> scale M100
> (russian sounding rocket of course!) As I am tooling
> up I can run
> out a few dozen feet of SS2S tube while I am at it.
> 
> I am looking for your confirmation that this is
> practical as I have
> not finalized my plans for the M100. I would also
> enjoy you
> as a collaborator on the team building the airframe.
> Let me
> know what you think.
> 
> Are you visiting LA any time soon?
> 
> On 9/29/05, Lakestake Rocketry <lakestake at gmail.com>
> wrote:
> >
> > Hi Roman,
> >
> > Do you want to go in on this with me? I think we
> can
> > make better tube for less.
> >
> > Matt
> >
> > ---------- Forwarded message ----------
> > From: william colburn <space1space at sbcglobal.net>
> > Date: Sep 29, 2005 1:08 PM
> > Subject: casing
> > To: "Robert H. Krech" <krech at psicorp.com>, william
> colburn <
> > space1space at sbcglobal.net>, richnakka at rogers.com,
> Lakestake Rocketry <
> > lakestake at gmail.com>, roman.lev at aero.cz, "David
> (Beltsville) Smith" <
> > david.smith2 at perkinelmer.com>
> >
> > At this point, I need some additional help in
> locating
> > our casing material. I should be getting a very
> > belated quote on the composite tubing.
> >
> > The composite tubing is made in standard inch
> ID's. So
> > the closest to our size is 10 inch ID. This makes
> the
> > casing 10.375 OD. It is certainly workable, but
> not
> > compatible with the nozzle which has already gone
> into
> > scheduling. That was designed for a .06 wall with
> a
> > 10.00 inch OD casing, or titanium.
> > The target cost for the composite is $65 a foot.
> > Probably doable with the current membership.
> > Advantages are it will be solid white in color,
> very
> > easily machined, drilled, good rigidity due to
> > additional wall thickness. Drawbacks are: diameter
> is
> > off our spec, attachments require about .5
> Diameters,
> > somewhat more thermally sensitive.
> >
> > The tubing they are quoting is NOT carbon
> composite.
> >
> > Now we could also do a carbon composite layup. The
> > HAH-203 (see Hybriddyne.com
> <http://Hybriddyne.com>) is partially carbon
> > composite, hand layup. With the shrink-wrap
> technique,
> > very good results are gotten with no autoclave or
> > bagging. Possible within our group.
> >
> >
> > We can certainly adapt to the composite if
> necessary.
> >
> > The problem with the Titanium tubing is the cost.
> We
> > need a few 10K's in donations before we can order.
> >
> > In seeking tubing, the material yield strength
> must be
> > above this value: 687,000 x material density in
> > lbm/in^3 = yield strength psi. This will preserve
> our
> > mass fraction. Use this equation to estimate wall
> > thickness:
> >
> > wall thickness = .180 x (41,000)/ material yield
> psi)
> >
> > So 4130 at a high temper of 194 KSI requires a
> wall
> > thickness of .038 inch. Titanium at 123 ksi gives
> a
> > wall of .06 inch.
> >
> > So this is an appeal to research possible casing
> > sources, materials, pricing, donations.
> >
> > Rich, this is more properly in your domain, but I
> got
> > involved due to some tubing sources I had so I am
> > putting this out to the veh dev group.
> >
> > BC
> >
> >
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