<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_1_1438258701459_4105"><span id="yui_3_16_0_1_1438258701459_4106">Tim,</span></div><div id="yui_3_16_0_1_1438258701459_4105" dir="ltr"><span id="yui_3_16_0_1_1438258701459_4874">I learned a lot yesterday, I repositioned my test thrusters from strait ahead to angled almost 45 degrees. My concern was the forward speed would suffer greatly. In fact the forward speed is still very good, and the turning performance is also good. I am now thinking I will use 4 thrusters. I am not sure about the DW set up because the DW is a short wide machine compared to Gamma. I am thinking the same for the vertical thrusters, but the forward thrusters might be in the front on an angle. I will test with the thrusters in the rear before I commit. If the forward thrusters are in the front, I can see them and it is easier to make them jettisoning .</span></div><div id="yui_3_16_0_1_1438258701459_4105" dir="ltr"><span id="yui_3_16_0_1_1438258701459_8477">The viz in Premier lake is still 15 feet and I am still struggling with my compass. I think I will have to go electronic because what I have is useless.</span></div><div id="yui_3_16_0_1_1438258701459_4105" dir="ltr"><span>Hank</span></div> <br><div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"> <font size="2" face="Arial"> On Tuesday, July 28, 2015 9:26 PM, T Novak via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br> </font> </div> <br><br> <div class="y_msg_container">Hey Hank,<br clear="none"><br clear="none">Take note of the DW configuration.<br clear="none">Four fixed reversible thrusters, two horizontal and two vertical but canted<br clear="none">out by 45 degrees.<br clear="none">The two horizontal control surge (both powered forward or in reverse) and<br clear="none">yaw (one powered forward, the other in reverse).<br clear="none">The two vertical control heave (both powered up or down) and translate (one<br clear="none">powered up, the other down).<br clear="none">There is no roll or pitch control, the ballast block (batteries and lead)<br clear="none">keep the vehicle level on those axis (slight roll during translate<br clear="none">operation).<br clear="none"><br clear="none">Some ROV's have four fixed reversible horizontal thrusters, one on each<br clear="none">corner, with the front two pointed 45 degrees inward and the aft two pointed<br clear="none">45 degrees outward, and one vertical reversible thruster.<br clear="none">The four horizontal control surge (all powered forward or reverse), yaw (one<br clear="none">side forward the other side reverse), and translate (one aft thruster<br clear="none">forward, the other reverse, and one front thruster forward and the other<br clear="none">reverse).<br clear="none">The vertical thruster controls heave.<br clear="none"><br clear="none">Minimum two axis control is one steerable reversible thruster to control<br clear="none">surge and yaw. Control heave with buoyancy or dive planes which really is<br clear="none">pitch control rather than true heave.<br clear="none">Minimum three axis control is two independent rotating non-reversible<br clear="none">thrusters, one on each side, to control surge, heave and yaw by the<br clear="none">direction they are pointed (the SportSub has this but they must rotate<br clear="none">together and are therefore reversible). If they are also canted out 45<br clear="none">degrees then you also get to control translate.<br clear="none"><br clear="none">Pitch and roll are necessary in airplanes, but not in personal submarines<br clear="none">(okay sometimes pitch is useful for powered ascent and descent). <br clear="none"><br clear="none">I think three reversible thruster do the trick, the primary in the stern<br clear="none">that is steerable for surge and yaw, and one canted reversible rotatable on<br clear="none">each side for heave, translate, surge redundancy, and yaw redundancy. Place<br clear="none">those two on the sides just forward of hydrodynamic centre and you also get<br clear="none">a bit of powered pitch.<br clear="none"><br clear="none">What configuration were you thinking about with six thrusters? Eight? Are<br clear="none">you looking for redundancy or only non-reversible thrusters?<br clear="none"><br clear="none">Tim<br clear="none"><br clear="none">-----Original Message-----<br clear="none">From: Personal_Submersibles [mailto:<a shape="rect" ymailto="mailto:personal_submersibles-bounces@psubs.org" href="mailto:personal_submersibles-bounces@psubs.org">personal_submersibles-bounces@psubs.org</a>]<br clear="none">On Behalf Of hank pronk via Personal_Submersibles<br clear="none">Sent: July-28-15 1:38 PM<br clear="none">To: <a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a><br clear="none">Subject: [PSUBS-MAILIST] thruster positioning<br clear="none"><br clear="none">I am trying to figure out the thruster position for all my thrusters before<br clear="none">I take Gamma apart. I have tested with two thruster pointing strait ahead.<br clear="none">That worked well, now I have the same two thruster on angles opposing each<br clear="none">other. I notice on some commercial subs that the thrusters are vectored,<br clear="none">in fact four forward facing thrusters, one at each corner. I assume the way<br clear="none">it works is, all four thrusters are turned on, two in forward and two in<br clear="none">reverse. To go strait ahead all four turn on in the same direction. I am<br clear="none">trying to keep it at 6 thrusters but may need 8.<br clear="none">Hank <br clear="none">_______________________________________________<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><div class="yqt8236695202" id="yqtfd36645"><br clear="none"><br clear="none">_______________________________________________<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><br><br></div> </div> </div> </div></div></body></html>