[SS-VehDev] Re: casing

[Lakestake Rocketry]

Good evening Bill,

To which plug do you refer below?

The makeup of the composite should be discussed. I agree that
should be several layers running both at 45' and 90'. We should
probably use Aramid layers for toughness as well as the CF
for strength. CF alone may be too brittle for this application.

Once we have a design I, or someone else, can easily lay up
a 1' square section that can be run through the ringer as needed
to verify the design empirically.

Those with Composites experience toss out ideas!

Matt C

On 9/29/05, william colburn <space1space at sbcglobal.net> wrote:
>
> 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>
> > <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
> > >
> > >
> > > _______________________________________________
> > SS-VehDev mailing list
> > SS-VehDev at sugarshot.org
> > http://www.exrocketry.net/mailman/listinfo/ss-vehdev
> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.exrocketry.net/pipermail/ss-vehdev/attachments/20050929/28506910/attachment.htm