<div dir="ltr">Hi Jim,<div><br></div><div>No mesh and no flushing system, it just takes about two minutes to remove the outer dome as its a few screws. This BTW has never been in the water, so we'll see and learn when it does. Just off the top of my head, it's probably about 8 inches of separation at the apex and tapers to an inch and a half at the base.</div><div><br></div><div>I don't use Rain-X on the viewports, I use Joy detergent, which is a Dr. Phil recommendation that does wonders. </div><div><br></div><div><br></div><div>Best,</div><div><br>Alec</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 28, 2014 at 6:00 PM, via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div style="FONT-SIZE:10pt;FONT-FAMILY:Arial;COLOR:#000000"><font color="#000000" face="Arial">
<div>Hi Alec,</div>
<div> </div>
<div>What is the average distance between the two domes? Do you have any
type of mesh etc. over the 1/4" holes to keep debris out? Do
you have some type of flushing system for cleaning the surfaces between the
two? Since that's an ambient space I'm guessing it wouldn't take too long
to remove the outer dome when you want to do a thorough cleaning.</div>
<div> </div>
<div>All: Have you been using Rain-X on your view ports and domes? A
while back I saw some ads for another hydrophobic product that claims to be
superior to Rain-X, but I don't recall the brand.</div>
<div> </div>
<div>Best regards,</div>
<div>Jim T.</div><div><div class="h5">
<div> </div>
<div>
<div>In a message dated 10/28/2014 4:30:30 P.M. Central Daylight Time,
<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a> writes:</div>
<blockquote style="PADDING-LEFT:5px;MARGIN-LEFT:5px;BORDER-LEFT:blue 2px solid"><font style="BACKGROUND-COLOR:transparent" color="#000000" face="Arial">
<div dir="ltr">Hi Vance,
<div><br></div>
<div>Actually it starts at 2" thickness, and at the time was the thickest dome
Greg had made. It was an iffy proposition, meaning he didn't know if it would
turn into sub jewelry or just a deformed glob of expensive material. Luckily
it came out virtually perfect. </div>
<div><br></div>
<div>My hull is 31" OD, a little smaller than yours. The window is a 120
degree segment, just under 27" OD. So the trick is how to span the gap between
the 27 inches and the 31 inches. In the original design, this bow window also
acted as a hatch, a la Deep Flight. I made a massive Al ring 31" OD, which
telescoped on linear bearings and four 1.25" bars, driven by rams. With
ensuing redesign, the need for all that disappeared because I now have a
coning tower, so I've dropped the bars and rams, and the seat is now mounted
to the hull very simply with four big bolts. It will make a very handy big
door into the sub for maintenance purposes, but is overkill and the window
could be mounted by using part of your existing endcap and a permanently
welded conventional seat. </div>
<div><br></div>
<div>One big decision is the window seat geometry. I like conical because PVHO
rates it for twice the life of square edge, but it requires fabrication
capabilities that Greg didn't have for the window and I didn't have for the
seat. So its a square edge for the simple reason that we could make it that
way. </div>
<div><br></div>
<div>I should mention the Al ring actually has two domes on it, one inside the
other. The 27" dome is structural, and the outside dome is 31" and only half
an inch thick. The outside one is just for fairing, to protect the structural
dome from abrasion, and to mitigate collision damage. The space between the
two domes is free flooding, and there are 1/4" holes around the edge of the
outer dome to facilitate that. In a collision, the water would squish out
through the little holes, so the thing is basically a shock absorber.</div>
<div><br></div>
<div>As for calculations, I will paste the window calcs below. It is really
just table lookups from PVHO tables, a simple cook book. The seat would have
to be calculated with FEA. I didn't have FEA, so I did like the Greeks and
Romans. You know why the Partenon is still standing? Try to do engineering
calculations using Roman numbers! It was too complex, so they simply made
everything massive. The seat is one integral piece of aluminum of ridiculous
proportions, and it backs into a 516 gr 70 ring on the end of the hull that is
an inch thick and two inches deep. I'm pretty confident that ring isn't going
wobbly before something else does. </div>
<div><br></div>
<div><br></div>
<div>Best,</div>
<div><br>Alec</div>
<div><br></div>
<div><br></div>
<div><br></div>
<div><br></div>
<div>----------------- pasted ------------------</div>
<div>
<h1><span style="FONT-SIZE:14pt">Viewport Depth Rating per
PVHO-1a-1997</span></h1>
<p class="MsoNormal"> </p>
<p>The following calculations and specifications are for a sperical sector
window with square edge, to include an optional O-ring seal.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">1) Determine Conversion
Factor (CF) </span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">Water temperature = 75
</span><span style="FONT-SIZE:10pt;FONT-FAMILY:Symbol">°</span><span style="FONT-SIZE:10pt">F (tropical conditions)</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">From Table 2-2.4, CF = 7
</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">2) Given actual fabricated
dimensions</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">t</span><sub><span style="FONT-SIZE:10pt">min</span></sub><span style="FONT-SIZE:10pt"> =
1.73”</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">D</span><sub><span style="FONT-SIZE:10pt">i</span></sub><span style="FONT-SIZE:10pt"> =
26.847”</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt;FONT-FAMILY:Symbol">\</span><span style="FONT-SIZE:10pt">t/D</span><sub><span style="FONT-SIZE:10pt">i</span></sub><span style="FONT-SIZE:10pt"> =
0.064</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">Entering table 2-2.10 with
STCP, t/Di = 0.064</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">Solving for Critical Pressure
= 3,460 psi</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">Since Short Term Critical
Pressure (STCP) = CF x P = 3,460 psi</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt">Solving for P,
P = 3,460 / 7 = 494 psi</span></p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt"></span> </p>
<p class="MsoNormal"><span style="FONT-SIZE:10pt;FONT-FAMILY:Symbol">\</span><span style="FONT-SIZE:10pt"> Safe operating depth for window = 1,139
fsw</span></p></div>
<div><br></div>
<div> </div></div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Oct 28, 2014 at 3:48 PM, via
Personal_Submersibles <span dir="ltr"><<a title="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT:1ex;MARGIN:0px 0px 0px 0.8ex;BORDER-LEFT:#ccc 1px solid"><font color="black" size="3" face="Arial, Helvetica, sans-serif"><font size="3">Alec,</font>
<div><font size="3"><br></font></div>
<div><font size="3">I hope this is still you.</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">I've been talking to Greg about a major retro-fit on my
K-350--a full hull-diameter dome segment viewport in place of the forward
elliptical head. He mentioned having built yours (the 1000' version) while
we were talking about thickness and whether to try and use something out of
Pete's junk pile.</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">While we were chewing the fat about this, he said that to
the best of his recollection, yours started at 1.5" thickness, and that he
could build it for me (maybe a 150 degree arc segment) for what I thought
was a very reasonable amount.</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">My problem (okay, one of my problems) is that I don't
really know how to do the calculations for these things. That said, I'm
wondering if a partial copy of yours might not do the trick for my
application (it would be tested much shallower, 500 feet or
thereabouts).</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">I don't know how you feel about sharing that kind of
thing, but I have a picture in my head of an acrylic bow K-350 with some
fairings and a Minn-Kota driven Deepworker style propulsion system. I think
it would make a great little boat, and so if I can get the viewport and
frame designed, then it's going to be built.</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">It's time to play if I'm going to. So, what do you
think?</font></div>
<div><font size="3"><br></font></div>
<div><font size="3">Best Regards,</font></div>
<div><font size="3">Vance
Bradley</font></div></font><br>_______________________________________________<br>Personal_Submersibles
mailing list<br><a title="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br><a title="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br><br></blockquote></div><br></div><br><br>_______________________________________________<br>Personal_Submersibles
mailing
list<br><a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></font></blockquote></div></div></div></font></div><br>_______________________________________________<br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
<br></blockquote></div><br></div>