<div dir="ltr">I haven't posted in ages and can't seem to post a new thread for some reason so am attaching this to Sean's last post.<div>I am planning on attaching a VHF antenna on top of my hatch and was wondering what I need to do to water tight where the co-axle cable goes into the antenna?</div><div><br></div><div>Rick</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Mar 25, 2016 at 5:06 PM, Sean T. Stevenson 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"><div><p dir="ltr">The counter rotation is a function of the design of the gearbox. It is possible to do it either way, but having e.g. one right handed prop on the forward shaft and one left handed prop rotating in the other direction on the after shaft counters wasted energy from discharge thrust that is circumferentially accelerated. Of course, there is some wasted energy associated with the gearbox, so it's not all positive, but I think I'll come out ahead in my specific application.</p>
<p dir="ltr">I wasn't going to vector one big thruster through a large range of motion, but rather have thrusters mounted on either side, with some degree of movement in order to selectively optimize the thrust direction depending on commanded ahead/astern, lateral, or rotary movement.</p>
<p dir="ltr">Any such scheme has to carry all of the thrust through to the vessel, so it requires some thought on how to best arrange.</p>
<p dir="ltr">Sean<br>
</p><div><div class="h5">
<br><br><div class="gmail_quote">On March 25, 2016 8:36:11 PM MDT, hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px"><div dir="ltr"><span>Autorotate, maybe wrong word, I meant both props turn opposite directions. Are you thinking of vectoring in multiple directions or rotating 360 degrees.</span></div><div dir="ltr">I was once working on a single thruster design. The thruster could point in any direction so the sub only needs one thruster. </div><div dir="ltr">Hank</div> <div><br><br></div><div style="display:block"> <div style="font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px"> <div> <div dir="ltr"><font size="2" face="Arial"> On Friday, March 25, 2016 5:12 PM, Sean T. Stevenson via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<br></font></div> <br><br> <div><div><div><div dir="ltr">It will be similar to a surface vessel bow thruster, only instead of a thruster tunnel in a hull, it will be housed in a symmetric nozzle which itself can be vectored with an actuator. I'm designing the gearbox from scratch - a few off-the-shelf spiral miter gears, tapered roller combined load bearings, shafts, seals and ports for oil circulation. Not sure what you mean by autorotate? They will not freewheel, if that's what you mean. Zero output on the hydraulic servovalve will lock off fluid flow (and thus lock out motion), although the gearbox will still be pressure compensated from the discharge side.</div>
<div dir="ltr">Sean</div>
<br clear="none"><br clear="none"><div>On March 25, 2016 3:59:31 PM MDT, hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>> wrote:<blockquote style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div><div style="color:#000;background-color:#fff;font-family:HelveticaNeue,Helvetica Neue,Helvetica,Arial,Lucida Grande,sans-serif;font-size:12px"><div>Hi Sean,</div><div dir="ltr">It sounds like you are going for something like a hydraulic bow thruster, I am not sure if the props autorotate.</div><div dir="ltr">Hank</div></div></div><div style="margin-top:2.5em;margin-bottom:1em;border-bottom:1px solid #000"></div><pre></pre><hr><br clear="none">Personal_Submersibles mailing list<br clear="none"><a href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br clear="none"><a rel="nofollow" shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></blockquote></div></div></div><br><div>_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" href="mailto:Personal_Submersibles@psubs.org" target="_blank">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div><p style="margin-top:2.5em;margin-bottom:1em;border-bottom:1px solid #000"></p><pre><hr><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></pre></blockquote></div></div></div></div><br>_______________________________________________<br>
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