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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Alan,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The inside seal will still see full pressure and lip seals have PV ratings (pressure times Velocity) They invented mechanical seals for that reason.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The bearings in the motor are generally only for radial load not axial load. You will need a thrust bearing probably.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The solid nature of the end caps is going to make it too heavy possibly and you could drill a series of holes or other method of hollowing out.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Those motors are reliant on a huge amount of air passing for cooling them so if possible ensure you have better contact area of the motor to the housing <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hugh</span><span lang=EN-NZ style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-NZ style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Personal_Submersibles [mailto:personal_submersibles-bounces@psubs.org] <b>On Behalf Of </b>Alan James via Personal_Submersibles<br><b>Sent:</b> Friday, 25 March 2016 7:34 a.m.<br><b>To:</b> Personal Submersibles General Discussion<br><b>Subject:</b> Re: [PSUBS-MAILIST] MK 2 Brushless Thruster<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div id="yui_3_16_0_ym18_1_1458842538155_2681"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Hank,<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2750"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>thanks for the advice.<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2683"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>I thought that welding would be quicker & cheaper rather than cutting an o-ring groove<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2685"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>& drilling & taping & recessing for 6 bolt holes. Also a more smoother hydrodynamic<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2734"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>finish. I will be welding on the fins for the kort nozzle attachment so can do it all in<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3217"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>one shot.<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2854"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'> I will probably add a fill port in to the top of the seal compartment to aid air<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2869"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>removal. Once there is oil in there the only way you would get air in would be<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2862"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>running it out of water with some sort of reverse pumping action caused by the seal.<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2906"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'> The double seal arrangement I am copying from that military document on<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3081"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>sealing & compensation. However they use face seals. This thruster is so small<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3040"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>that 2 face seals would take up too much space, so have doubled up on 2 low<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3025"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>pressure lip seals. In the pdf it makes a good case for the secondary seal & I<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3055"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>intend to do most of my diving in seawater where it is a more destructive environment.<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3119"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>All the Minnkotas I have seen have 2 seals, I think just lip seals.<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3146"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Cheers Alan<o:p></o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_3092"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div><div id="yui_3_16_0_ym18_1_1458842538155_2699"><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div><div><div><div><div><div class=MsoNormal align=center style='text-align:center;background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><hr size=1 width="100%" align=center></span></div><p class=MsoNormal style='background:white'><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'> hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b>To:</b> Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> <br><b>Sent:</b> Friday, March 25, 2016 1:31 AM<br><b>Subject:</b> Re: [PSUBS-MAILIST] MK 2 Brushless Thruster</span><span style='font-family:helveticaneue;color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p><div id=yiv9315279386><div><div><div id="yiv9315279386yui_3_16_0_1_1458822019452_3535"><p class=MsoNormal style='background:white'><span style='font-size:9.0pt;font-family:helveticaneue;color:black'>Hi Alan,<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_1_1458822019452_3488"><p class=MsoNormal style='background:white'><span style='font-size:9.0pt;font-family:helveticaneue;color:black'>It wouldn't hurt to clamp the end cap tight but you do have a nice shoulder for the end cap to sit on. Any time I make a part that can and usually does warp, I make it oversize and machine it true after welding. I am curious why you want to weld it-that big shoulder has room for an o-ring. I would also ditch the second seal-it is an air trap. Great project!<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_1_1458822019452_3488"><p class=MsoNormal style='background:white'><span style='font-size:9.0pt;font-family:helveticaneue;color:black'>Hank<o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-size:9.0pt;font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div><div><div><div><div id=yiv9315279386yqt39232><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>On Thursday, March 24, 2016 12:27 AM, Alan James via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:</span><span style='font-family:helveticaneue;color:black'><o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p><div><div id=yiv9315279386><div><div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4233"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>This is my latest brushless thruster design for scrutiny.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4199"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>The last thruster I made was 2 piece with one seal.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4332"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>I machined the last version out of aluminum rod, which was expensive & difficult.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4331"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>The end pieces in this design are from solid rod but the mid section is from a stock tube<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4371"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>that I intend to have welded to the propeller end. The back end is bolted on.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4334"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Am I likely to get distortion when welding the two sections together? There is a sleeve<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4333"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>press fitting to help give it some rigidity for welding. Should I make a jig to clamp it in<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4367"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>for welding?<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4372"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>The thruster is for 500ft depth & is oil filled with a slight over pressure above ambient. <o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4490"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Oil filled mainly for cooling purposes, but also as a secondary defense against any leaks,<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4555"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>& for lubrication of bearings & seals. I am using low pressure lip seals & have a double <o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4565"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>seal redundant arrangement. The outboard seal is orientated to keep the oil in & with the<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_4612"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>internal overpressure should keep the water out. The outboard seal should fail first as it is <o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5135"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>exposed to abrasives, especially in sea water. The inboard seal is oriented so that it keeps<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5246"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>any water out that may get past the outboard seal. <o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5265"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>The tube coming out of the seal cavity is for pressurizing it & for collecting any water that<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5247"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>may get through & come out of suspension. I am thinking of putting a water sensor in there.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5383"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Any comments welcome.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5384"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>Alan<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5281"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>p.s. if image isn't big enough keep hitting ctrl & + TO ENLARGE.<o:p></o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5112"><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5539"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5494"><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5541"><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5540"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p></o:p></span></p></div></div></div><div id="yiv9315279386yui_3_16_0_ym18_1_1458793494416_5542"><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div></div></div></div></div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:helveticaneue;color:black'><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><br><o:p></o:p></span></p></div></div></div></div></div></div></div></div><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p><div id=yqt38260><p class=MsoNormal style='background:white'><span style='font-family:helveticaneue;color:black'>_______________________________________________<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><o:p></o:p></span></p></div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:helveticaneue;color:black'><o:p> </o:p></span></p></div></div></div></div></div></div></body></html>