<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1481929631290_2683"><span>Thanks Alec.</span></div><div id="yui_3_16_0_ym19_1_1481929631290_2682" dir="ltr"><span id="yui_3_16_0_ym19_1_1481929631290_2681">I am aiming for a couple of hundred hours run time before I will be happy.</span></div><div id="yui_3_16_0_ym19_1_1481929631290_2743" dir="ltr"><span>Will keep working through this.</span></div><div id="yui_3_16_0_ym19_1_1481929631290_2800" dir="ltr"><span>Alan</span></div><div id="yui_3_16_0_ym19_1_1481929631290_2690"><span><br></span></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1481929631290_2638"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1481929631290_2680" style="display: block;"> <div id="yui_3_16_0_ym19_1_1481929631290_2679" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1481929631290_2678" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1481929631290_2677" dir="ltr"> <font id="yui_3_16_0_ym19_1_1481929631290_2676" face="Arial" size="2"> <hr size="1" id="yui_3_16_0_ym19_1_1481929631290_2675"> <b><span style="font-weight: bold;">From:</span></b> Alec Smyth via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Saturday, December 17, 2016 2:59 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Thruster Test Fail<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1481929631290_2801"><br><div id="yiv5032161689"><div id="yui_3_16_0_ym19_1_1481929631290_2803"><div id="yui_3_16_0_ym19_1_1481929631290_2802" dir="ltr">Congrats Alan, that sounds like a very effective test with actionable conclusions. My suggestion would be to change only one thing at a time in the next iteration. For instance, if you changed the Morlina to silicone AND the sheathing material at the same time, you wouldn't really know whether the issue was the oil or the plastic. Thirty hours strikes me as pretty good endurance for a first run!<div id="yui_3_16_0_ym19_1_1481929631290_2804"><br clear="none"></div><div>Best,</div><div><br clear="none">Alec</div></div><div class="yiv5032161689gmail_extra" id="yui_3_16_0_ym19_1_1481929631290_2809"><br clear="none"><div class="yiv5032161689gmail_quote" id="yui_3_16_0_ym19_1_1481929631290_2808">On Fri, Dec 16, 2016 at 4:29 AM, Alan James via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank" rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>></span> wrote:<br clear="none"><blockquote class="yiv5032161689gmail_quote" id="yui_3_16_0_ym19_1_1481929631290_2807" style="margin: 0px 0px 0px 0.8ex; padding-left: 1ex; border-left-color: rgb(204, 204, 204); border-left-width: 1px; border-left-style: solid;"><div class="yiv5032161689yqt2758549003" id="yiv5032161689yqt12562"><div id="yui_3_16_0_ym19_1_1481929631290_2806"><div id="yui_3_16_0_ym19_1_1481929631290_2805" style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);"><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2425"> My home made brushless thruster failed after 30hrs of in pool run time.</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2430">The Kelly controller was flashing an error sequence indicating the</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2424" dir="ltr">hall effects sensors had failed. There are hall effect sensors on a </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2516" dir="ltr">board at the end of the motor that send information on the position</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2517" dir="ltr">of the motor. The board is held on by a large flat nut & had come</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2518" dir="ltr">loose so the sensors were out of position. Also the sheath of the wires</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2519" dir="ltr">to the sensor board had melted. </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2563" dir="ltr">Possibly the fact that oil was being thrown out of the thruster housing</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2562" dir="ltr">& up the wiring tube by centrifugal force, caused the motor to over heat &</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2889" dir="ltr">melt the sheathing. </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2566" dir="ltr"> The outer can of the motor that rotates (out-runner motor) is only supported</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2676" dir="ltr">where it is press fitted on to the propeller shaft at one end. Some out-runner</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2677" dir="ltr">motors have a large bearing that supports the cup like other end of the can. </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2744" dir="ltr">Due to the fact I didn't have a very snug press fit, the can was pulling off center when</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2675" dir="ltr">the motor stopped, so that the outer can with the magnets on it was touching</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2695" dir="ltr">the stator. This caused it to start roughly. It would center when running.</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2778" dir="ltr"> The sheathing on the wires running out of the motor, to protect them from</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2815" dir="ltr">abrasion, were softened & breaking up a bit. The Shell Morlina S2 BL oil I was</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2858" dir="ltr">using must be breaking them down. I can replace this rubber sheath with a heat</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2890" dir="ltr">resistant sheathing (as my other motors have) but can't be sure that this oil won't </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2976" dir="ltr">break down the coating on the motor windings. Maybe I'll change to 10 cst silicone.</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3007" dir="ltr"> On the positive, the general design of the thruster worked well, the motor performed </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3107" dir="ltr">with comparable or better thrust per Watt than most commercial thrusters . The outside of the </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3118" dir="ltr">can never heated up. One day it ran continuously for 13hrs. It started well initially, & could </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3123" dir="ltr">run at slow speeds.</div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3130" dir="ltr"> Am thankful that I could identify a number of issues with just the one test & will </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3194" dir="ltr">have a good think about this over Christmas.</div><span class="yiv5032161689HOEnZb"><font color="#888888"></font></span><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3166" dir="ltr">Alan </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_3095" dir="ltr"> </div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2941" dir="ltr"><br clear="none"></div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2859" dir="ltr"><br clear="none"></div><div id="yiv5032161689m_-7024532040618191012yui_3_16_0_ym19_1_1481877529024_2722" dir="ltr"> </div></div></div></div><br clear="none">______________________________ _________________<br clear="none">
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