<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Hank,</div><div id="AppleMailSignature">you mean like a solenoid with a long stroke?</div><div id="AppleMailSignature">I have been designing a solenoid operated ballast valve but haven't got</div><div id="AppleMailSignature">round to working out how many turns of wire, how much force I need &</div><div id="AppleMailSignature">how many amps it will draw. </div><div id="AppleMailSignature">A lot of solenoids have a short duty cycle, as they heat up pretty quick.</div><div id="AppleMailSignature">I would imagine this could be a problem if you wanted to hold something</div><div id="AppleMailSignature">in position for a long time.</div><div id="AppleMailSignature">Alan</div><div id="AppleMailSignature"><br><br>Sent from my iPad</div><div><br>On 30/09/2017, at 10:32 PM, hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div></div>
<div>Alan,</div><div>I have not taken one apart yet but it sounds like it is a tricky one. I was hoping there was some sort of magnetic rail actuator. I have been Googling around but have not found anything yet. I have had superb results with electro magnets under water (fresh) and figure that could be the answer. I will keep looking.</div><div>Hank</div><div><br></div>
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On Friday, September 29, 2017, 8:07:33 PM MDT, Alan via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:
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<div><div id="yiv2949862173"><div><div>Hank,</div><div>I spent a lot of time investigating oil compensation of linear actuators along</div><div>with Frank.. He was looking at the Lenco trim tab actuators.</div><div>Have several. The motors in them are small & brushed & run rough in</div><div>oil. When the rod extends that leaves a void inside the actuator that needs</div><div>to be filled. So you end up with an external oil reservoir to fill the actuator</div><div>with ambient pressure oil as it extends. ( so why not just push it out with the oil)</div><div>There are micro switches that I drilled with tiny holes, to let ambient pressure</div><div>in so they didn't trigger under pressure. Also there are electronics in some</div><div>actuators that may be effected by pressure. And of course there is the wiring</div><div>going in to the actuator that needs sealing & the seals on the rod that may need replacing.</div><div>Much simpler to use hydraulics. I did see an electric manipulator operating</div><div>at the Underwater Intervention Convention. Can't recall it's name.</div><div> From time to time I have a google on robot sites to see what is new. Or</div><div>Alibaba to see if the Chinese have come up with anything cheap.</div><div>Nearly bought a kids hydraulic arm toy that you assemble, with view to </div><div>scaling up out of aluminium.</div><div>Keep thinking, but the robotics World is big & if there is a new & easier way</div><div>of doing it they'll find it.</div><div>Alan</div><div><br clear="none"><br clear="none"><div>Sent from my iPad</div></div><div class="yiv2949862173yqt3959388798" id="yiv2949862173yqt47678"><div><br clear="none">On 30/09/2017, at 1:08 PM, hank pronk via Personal_Submersibles <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none"><br clear="none"></div><blockquote type="cite"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div>I have been brain storming looking for a less expensive and less complicated means of building manipulators. The obvious choice would be electric liner actuators, oil filled etc. Then I was thinking about a magnetic actuator like a mag lev rail. Is there such a thing? You know, add more voltage and the actuator moves out further. Any ideas? </div><div>Hank</div></div></div></blockquote></div><blockquote type="cite"><div><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span><a rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" target="_blank" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a></span><br clear="none"><span><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br clear="none"></div></blockquote></div></div><div class="yqt3959388798" id="yqt93066">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">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></div>
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