<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>Tim,</div><div>I had been interested in making my own brushless underwater thruster as there</div><div>wasn't anything cheap on the market around the 2hp size I wanted.</div><div>Brushless have more torque are more economical & better suited to oil</div><div>compensating than brushed, & I am wanting them for a 500ft depth.</div><div>I have used 6374 (dimensions in mm) brushless hobby motors wound to 60kv </div><div>( rpm per volt ) for higher torque. I wanted to avoid gearing. </div><div>There is a major manufacturer ( Sunny Sky ) that I approached.</div><div>I started with a product they made that was a bit more substantial, having a </div><div>can bearing on it. I had previously trialed another 6374 motor without can </div><div>bearing & decided it needed one.</div><div>They put a 316 stainless shaft in it to my specs with Circlip groves cut in it.</div><div>They machined the back of the motor to let the wires comes straight out the</div><div>back rather than top. They also put a hall sensor board in so I could run it</div><div>sensored. And as mentioned wound it with thinner wire. Cost less than $100 each.</div><div>I have bearings in my housing that take the axial load. Am compensating with</div><div>5cst silicone oil so should be good for the motor bearings.</div><div>In tests it was above average with regards to commercial motors as far as thrust </div><div>per Watt was concerned.</div><div>Have more tests to do, but I have a video of it powering my inflatable on my</div><div>Facebook page somewhere.</div><div>Cheers</div><div><br>On 18/01/2020, at 2:06 PM, T Novak via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="Generator" content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Thanks, Alan.<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">It would be interesting to hear the specifications under which your new motors were manufactured. Could they be something we could all use as a source?<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Tim<o:p></o:p></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p><div><div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Personal_Submersibles [<a href="mailto:personal_submersibles-bounces@psubs.org">mailto:personal_submersibles-bounces@psubs.org</a>] <b>On Behalf Of </b>Alan via Personal_Submersibles<br><b>Sent:</b> Friday, January 17, 2020 3:44 PM<br><b>To:</b> Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b>Subject:</b> Re: [PSUBS-MAILIST] Acrylic Dome<o:p></o:p></span></p></div></div><p class="MsoNormal"><o:p> </o:p></p><div><p class="MsoNormal">Tim,<o:p></o:p></p></div><div><p class="MsoNormal">some of those young girls know their stuff but communication looks like<o:p></o:p></p></div><div><p class="MsoNormal">It may be difficult in this case.<o:p></o:p></p></div><div><p class="MsoNormal">With regard to an acrylic dome, you would have to be pretty specific &<o:p></o:p></p></div><div><p class="MsoNormal">see material certification & question them about the process first. Then<o:p></o:p></p></div><div><p class="MsoNormal">check the dome with a spectrometer for any stress after forming & then<o:p></o:p></p></div><div><p class="MsoNormal">pressure test it.<o:p></o:p></p></div><div><p class="MsoNormal">It would almost pay to visit first.<o:p></o:p></p></div><div><p class="MsoNormal">I had 11 motors built in to my specs, with a 316 shaft etc & the manufacturer did<o:p></o:p></p></div><div><p class="MsoNormal">a really good job.<o:p></o:p></p></div><div><p class="MsoNormal">Alan<o:p></o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal" style="margin-bottom:12.0pt"><br>On 18/01/2020, at 10:38 AM, T Novak via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<o:p></o:p></p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Whoever made her t-shirt can't spell. But she is just the "teenaged girl across the counter", not the seasoned technician. You don't know the quality until it's on your bench.</span><o:p></o:p></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Tim</span><o:p></o:p></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"> </span><o:p></o:p></p><p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Personal_Submersibles [<a href="mailto:personal_submersibles-bounces@psubs.org">mailto:personal_submersibles-bounces@psubs.org</a>] <b>On Behalf Of </b>Alan James via Personal_Submersibles<br><b>Sent:</b> Friday, January 17, 2020 12:40 PM<br><b>To:</b> <a href="http://psubs.org">psubs.org</a> <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b>Subject:</b> [PSUBS-MAILIST] Acrylic Dome</span><o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p><p class="MsoNormal">Looked on Alibaba to see what China offered in the way of cast acrylic domes. <o:p></o:p></p><div id="yMail_cursorElementTracker_1579293424676"><p class="MsoNormal">Was contacted as they track your search history. <o:p></o:p></p></div><div id="yMail_cursorElementTracker_1579293449291"><p class="MsoNormal">Have doubts about the firm already as below is a picture of my contact! <o:p></o:p></p></div><div id="yMail_cursorElementTracker_1579293493752"><p class="MsoNormal">Alan<o:p></o:p></p></div><div id="yMail_cursorElementTracker_1579293501037"><p class="MsoNormal" style="margin-bottom:12.0pt"> <o:p></o:p></p><div id="ymail_android_signature"><div><p class="MsoNormal"><image001.jpg><o:p></o:p></p></div><p class="MsoNormal"><br><a href="https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature" id="ymail_android_signature_link">Sent from Yahoo Mail on Android</a><o:p></o:p></p></div></div></div></blockquote><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal">_______________________________________________<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">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><o:p></o:p></p></div></blockquote></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Personal_Submersibles mailing list</span><br><span><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a></span><br><span><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br></div></blockquote></body></html>