RE: [PSUBS-MAILIST] Acrylic bubble and machining

["Wade Carson" <wacarson@interchange.ubc.ca>]

Hey Suds,

	Ya it's a university project.  Unfortunately, it's nothing so simple as the
front bubble (although I will be making that and had planned on gravity
forming it).  I think I may be lucky enough that we already have an oven
kicking around but I'm not sure if it will be big enough.  THe hatch I'm
looking to build is shaped from the hull and extends from about three feet
forward of midships to 1 foot past.  It will end up being about 48x26x13" in
total (provided this is possible).  Does acrylic break down? is that why the
you specified one time use?  In fact we may want to use the same hull in
future years.  The hull will be built of fibreglass with an aluminum frame.
I've heard a few rumblings about problems with corrosion in the aluminum so
if you know anything there it would be helpful as well.  The hatch will be
attached to the hull with magnetic fasteners (safety issue)as it must be
possible to exit the sub quickly and open it up from inside as well as out.
The hull may be cut to suit the final shape of the hatch and both will be
independent of each other so we can get away with a little on the shape of
the hatch.  There won't be any flanges on the hatch or the hull.  The fit
doesn't have to be watertight but we don't want it to greatly affect the
flow over the sub. The hatch must be transparent enough that divers outside
the sub are able to look in and see both pilots and the pilots don't feel so
much like they are trapped in a very small box.
	Perhaps a little bit of explanation about the project is in order.  The
competition is in June in San Diego.  We are from British Columbia, Canada.
We are resurrecting a program that has been essentially dead at UBC for a
couple of years now.  We started with almost no knowledge of submarine
design or construction and a deficit of just under $2000.  So cost is a
pretty big issue.  Human powered submarines currently run at a top speed of
just over six knots.  Many of the teams have been running for more than ten
years.  Our goal is to build a submarine that works and we can enter in the
race and to work our way towards being contenders in future years.  Our sub
measures in at about fourteen feet in length and has a maximum diameter of
26".  To contend in the races we will have to bring those numbers down
significantly.  Unfortunately, that means that most of us will not be able
to fit in a contending sub so we have chosen fun over competition.  So far
the project has been a lot of fun, but we've had some major hurdles to leap.
I'm seeing a few more coming up shortly and I'm trying to prepare for them
as best I can.  Thank you for your support.

Wade