[SS-VehDev] Re: casing

[Lakestake Rocketry]

Richard,

I think Bill is the right person, as head of the VehDev group, to open
this discussion up to the group when he feels that either:
a) we have reached a proposed design ready for group presentation
b) we have reached a point where we need more group input

Bill, do you concur with these two statements?
Richard, does this fit with your understanding of 'group procedure'?

Richard, my suggestion is that you put together a 'topic starter' email
letter including your take on what specific questions we should open
up for group comment and forward that to Bill for revision and posting
as he sees fit.

Bill, I agree with Richard, we could gain a lot from the experience
the group brings to the table. As with everything on the Internet we
will have to separate the wheat from the chaff...

Matt C

On 10/3/05, Richard Nakka <richard.nakka at aero.bombardier.com> wrote:
>
> Gents,
> Why don't we discuss this side-study on the ss-main list?
> It'd be a good way to help re-establish interest & communication in the
> SStS Project?! We've been sadly failing in this regard, in my opinion.
>
> Richard
> -------
>
>
> william colburn wrote:
> >
> > Matt,
> >
> > We can propose a mandrel diameter. We won't know the
> > actual wall thickness we will ultimately require until
> > be do more testing.
> >
> > The nozzle is being made with an OD of 9.873 +.005
> > -.005 inches. 9.881 would be the OD of the mandrel
> > assuming a minimum clearance of .003 inch for "O" ring
> > and a slip fit. With a tolerance stack-up we could end
> > up with a diametral clearence of .013.
> >
> > At a level of 41KSI, the tubing fabricator (who has
> > not yet quoted!) is using a wall thickness of .188.
> > The materials are E-glass and epoxy.
> >
> > Even with hand-layup, we should be able to match that
> > tensile yield number. This means that our wall
> > thickness will be in the same ball-park as .188.
> >
> > If so, we are in-like-Flynn. If not, then no-go as the
> > casing weight will be too great for making our mass
> > ratio.
> >
> > So with a relatively simple experiment, we will know
> > if we can hand-layup our own casing.
> >
> > If we are successful in hydro, this sample or one like
> > it could be used for the short-stack test.
> >
> > BC
> >
> > --- Lakestake Rocketry <lakestake at gmail.com> wrote:
> >
> > > Hi Bill,
> > >
> > > I was getting ready to acquire the mandrel, I wanted
> > > to get your
> > > feedback/requirements soon so I could move forward
> > > on it. If the SS2S
> > > project does not have a hard size requirement I can
> > > make the other
> > > project to spec. If that won't work for us I can
> > > work on changing the
> > > other spec to match SS2S. I just need to know which
> > > way to jump.
> > >
> > > The current M-100B design calls for a 250mm O.D.
> > >
> > > I understand and can follow your approach below, but
> > > I don't want
> > > to change the other project to adhere to SS2S
> > > requirements unless
> > > it has been determined that this is the way SS2S
> > > will be going. It
> > > does not make sense to purchase one mandrel for
> > > testing, then
> > > another for the final project.
> > >
> > > I see Richard has posted a follow up, more comments
> > > once I have
> > > read that.
> > >
> > > Matt C
> > >
> > > On 10/1/05, william colburn
> > > <space1space at sbcglobal.net> wrote:
> > > >
> > > > So the mandrel is 250 mm? Or is the finished part
> > > 250
> > > > mm OD?
> > > >
> > > > Here is a plan:
> > > >
> > > > Use your existing mandrel to make a short stack
> > > casing
> > > > to best procedure using carbon fiber, kevlar,
> > > glass
> > > > where appropriate.
> > > >
> > > > We will develop end closures and hydrotest the
> > > sample.
> > > >
> > > > From there we will make a decision to go forward
> > > or
> > > > move to another casing source.
> > > >
> > > > We can talk about the exact procedure when you are
> > > > ready to go. It would likely involve an initial
> > > room
> > > > temperature cure with shrink wrap, removal of the
> > > > shrink wrap followed by a two stage cure at
> > > increasing
> > > > temperatures.
> > > >
> > > > No gel coat, it adds weight and no increase in
> > > > strength. No sanding, weakens the outer layre
> > > which
> > > > them becomes dead weight also.
> > > >
> > > > BC
> > > >
> > > > --- Lakestake Rocketry <lakestake at gmail.com>
> > > wrote:
> > > >
> > > > > Hi Bill,
> > > > >
> > > > > The M-100B has a 250mm airframe. It doesn't
> > > really
> > > > > *need* to
> > > > > be 100% scale, but it would be nice. I can fudge
> > > > > either project to
> > > > > match the other as needed. I would need to know
> > > soon
> > > > > though...
> > > > >
> > > > > Matt
> > > > >
> > > > > On 9/30/05, william colburn
> > > > > <space1space at sbcglobal.net> wrote:
> > > > > >
> > > > > > Plug=mandrel over which you are applying the
> > > > > composite
> > > > > > material. The ultimate ID of the part.
> > > > > >
> > > > > > BC
> > > > > >
> > > > > > --- Lakestake Rocketry <lakestake at gmail.com>
> > > > > wrote:
> > > > > >
> > > > > > > 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>
> > >
> > === message truncated ===
>
>
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