[SS-VehDev] Re: casing

Mon Oct 3 22:14:54 PDT 2005

Hi Richard,

You are right, communication within each group and with the group at
large is of utmost importance.

Bill does make a good point that the groups were formed to take some
of the discussions off of the main list.

I think each group should have its own list, and that members of the
main group should be able to subscribe to those lists on a read-only
basis as their interest dictates. That way everyone has access to
any information that they are interested in, yet we don't get bogged
down with rehashes of already-decided design considrations.

There should also be a weekly 'news letter' to the group from one of
the project leads which includes a note from each group lead of what
progress has been made. That way people interested in the project
can have a weekly summary update and feel in touch with the project
without having to wade through the dozens of emails going back and
forth.

I also agree with Bill's statements about group leads bringing up
topics as needed with the main group list, and both of you as project
leads being able to raise any topic needed to further the project.

All good ideas.

Matt C

On 10/3/05, Rich Nakka <richnakka at rogers.com> wrote:
>
> Gents
> I partly agree with Bill, but.... I feel communication is critically
> important to keep all project members interested and so that they feel they
> are a part of the project. Often, feeling as part of a project simply means
> reading postings on various topics. Being informed of "what's happening".
> Personally, I like reading about dipole antennas even if I would not know
> one from a fishing pole. If one is not interested, thats what the delete key
> is for.
>
> I truly feel there is key value added in discussing topics "at large" on
> the ss-main list .
>
> Well, guys? Let's have other project members give their own opinions. Is
> there value-added in discussing topics at large on the ss-main list (I may
> be out to lunch here ,after all ;-)
>
> Richard
>
>
>
> william colburn wrote:
>
> Generally; but I think that Rich should bring motor
> discussions to the group directly and as a co-leader
> should bring whatever he feels important to discuss to
> the group at large. I will bring items of interest to
> the vehicle design group specifically and also to the
> group at large when it is of general interest.
>
> I was involved in the grit of the case composite
> question. It could have been brought up with the
> larger group earlier or later as I see it, so long as
> it was shared at some point. That actually is the
> purpose of having separate groups so the mailing list
> does not get bogged down with rehashing of already
> determined or decided design features or directions.
> (already happening, incidently)And the reporting of
> the groups to the list is that communication we all
> desire. For instance, I don't want to be involved in
> the slightest in choosing a patch, helix, dipole,
> dielectric slot or any other antenna for the vehicle.
> I prefer not to be in those discussions. I do want to
> hear the report after the decision has been made,
> however.
>
> Where I or others have special expertise, we would be
> missing the point of the group effort not to
> contribute in those specific areas.
>
> I apologize for the length of my reply. It clears some
> of the points I wanted to make.
>
> BC
>
> --- Lakestake Rocketry <lakestake at gmail.com> <lakestake at gmail.com> wrote:
>
>    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> <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> <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> <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> <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...
>
>                  === message truncated ===
>
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>
>
>
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