<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:10pt"><div><span>Thanks Alec,</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>I was intending to also mention your experience as a balance to the negatives</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>but got distracted.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>The problem is that I am hearing a lot of
conflicting stories.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color: transparent;">Even with air compensation there are problems. Greg told me he had a problem</span><br></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>with moisture getting in through the exhaust valves of a second stage regulators.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>I have put extension tubes around the exhaust manifolods of my ambient sub's
compensating</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>regulators to try & stop this.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>I dive mostly in sea water, which is not as forgiving as fresh, so want to get it right.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>Emile was telling me about repeated problems with one of his sub's thrusters, & he is now using</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue,
'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>expensive rim thrusters. I will </span><span style="background-color: transparent;">leave it up to him if he feels like sharing the details.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>The guys at Fugu sub with 30 years commercial experience are saying go with air, there are too many hasles with oil. All commercial oil compensating units have about 5psi overpressure which your system </span><span style="background-color: transparent;">doesn't have. So who is right? </span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal;
background-color: transparent;"><span>Cheers Alan</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span><br></span></div><div><br></div> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;
font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Private 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> Sunday, July 27, 2014 2:43 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Air compensating thrusters<br> </font> </div> <div class="y_msg_container"><br><div id="yiv1107933689"><div><div>Alan, honestly you're over-analyzing this one. I would summarize it thus; air and oil compensation both work just fine, pick either one.</div><div><br clear="none"></div><div>I've run Snoopy with both air and oil compensation, using the same motors. I could not tell the difference, either in power or even in sound. I do agree the motors must
in theory lose some efficiency with oil, but it was not in the least noticeable to me. </div><div><br clear="none"></div><div>Personally I prefer oil because the system has no moving parts and therefore in my book is simpler and more reliable, but again... both work just fine. </div><div><br clear="none"></div><div>As for all the stuff about dissolving plastics and brushes, I finally overhauled the thrusters last year for the first time. All I had to do was change the seals and brushes, and I turned the commutator on the lathe because the copper had some wear. These parts had lasted a decade. </div><div><br clear="none"></div><div><br clear="none"></div><div>Best,</div><div><br clear="none"></div><div>Alec<br clear="none"><br clear="none"><div><br clear="none"></div></div><div class="qtdSeparateBR"><br><br></div><div class="yiv1107933689yqt3000388336" id="yiv1107933689yqt11333"><div><br clear="none">On Jul 26, 2014, at 8:41 PM, Alan
James 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="color: rgb(0, 0, 0); font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt; background-color: rgb(255, 255, 255);"><div id="yiv1107933689"><div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt; background-color: rgb(255, 255, 255);"><div id="yiv1107933689yui_3_16_0_6_1406415491611_4"><span id="yiv1107933689yui_3_16_0_6_1406415491611_17">Hi Vance,</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica,
Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_20">I'm still plugging away on this one, looking at the pros & cons. </span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_26">If I wrote a white paper everyone that read it would end up more confused
than when they started.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14618" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span>But this is a summary of what I've learned so far. Others may want to add or comment on this.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_29">The main cause of electric motor failure is overheating. So there is a plus for oil compensation here</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family:
HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_36">in that it transfers the heat to the casing. Most</span><span id="yiv1107933689yui_3_16_0_1_1406415491611_3793" style="background-color:transparent;"> electric motors rely on air cooling which we can't </span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_40" style="background-color:transparent;">achieve underwater. Brushless motors disipate heat to the casing easier but are normally geared.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14622" id="yiv1107933689yui_3_16_0_6_1406415491611_4"
style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Emile has a 2hp protruar brushless motor but said it was noisy.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_44" style="background-color:transparent;">The Minnkota motors must be a robust design that can handle the heat build up while submerged.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal;
background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_48" style="background-color:transparent;">Although I am wondering if there is heat transferance up the tube from the thruster to the control box,</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_98" style="background-color:transparent;">with air circulation caused by the rotating motor.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_52"
style="background-color:transparent;">The air compensation may work with
trolling motors designed for high temperatures, but fail with other</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_56" style="background-color:transparent;">motors. Or fail if the props are too large & put too much strain on the motors causing them to overheat.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_60" style="background-color:transparent;">In oil compensating the oil can lift the brushes, but this has been countered by using heavier
spring tension on the brushes.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_64" style="background-color:transparent;">The wear of the carbon brushes causes the oil to become more conductive & cause arcing.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_68" style="background-color:transparent;">I have read of recomendations to change the oil every 10-20 hrs.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14638"
id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Oil causes the motor to run more slowly & less economically.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14638" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Greg mentioned that his compensating oil (I think WD40) was causing seals & other plastics to harden.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14638" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px;
font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">I experimented with WD40 & found it destroyed some plastics in hours.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14638" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Carsten & Emile moved to a thin expensive silicone oil. Emile then moved to rim thrusters.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color:
transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_75" style="background-color:transparent;">Commercial oil compensating units have a 4-5 psi overpressure. However Carsten says that his units without</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_79" style="background-color:transparent;">overpressure other than being mounted above the motor, can leak when out of water. But this brings in the </span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span
id="yiv1107933689yui_3_16_0_6_1406415491611_83" style="background-color:transparent;">other part of the
equation which
is the motor seals.(Don't know much about these, have to learn)</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_87" style="background-color:transparent;">Another thing that Carsten mentioned was that the cooling of the oil can suck in water past the seal. However</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_91" style="background-color:transparent;">I would have thought the system would remain ambient & his oil reservoir would release oil back
in to the motor,</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_102" style="background-color:transparent;">also a system with overpressure would stop this.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_106" style="background-color:transparent;">He also said that you can get water ingress into an oil filled motor & it survives, but one drop of salt water in </span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color:
rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_110" style="background-color:transparent;">an air compensated motor can wreck it.</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_114" style="background-color:transparent;">Which brings me to Hugh's air comp suggestion of using a pressure relieving regulator with back pressure relief</span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande',
sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_118" style="background-color:transparent;">& setting it with an overpressure. I think this is a great idea & want to experiment with the stainless one he found</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;"> I have pulled 2 other types of these relieving regulators to bits & they look </span><span style="background-color:transparent;">a good option. I am just not sure how </span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0);
font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">much flow the releiving function can handle & what pressure fluctuations </span><span style="background-color:transparent;">there would be in the motor. Probably only a few psi. </span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Karl'</span><span style="background-color:transparent;">s motors would have 500 psi at 1000 ft to force out through </span><span style="background-color:transparent;">his thruster </span><span
style="background-color:transparent;">shaft seals on his
ascent.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Ladies turned up, got to go.</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;">Alan</span></div><div class="yiv1107933689yui_3_16_0_1_1406415491611_14658" id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica,
Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span style="background-color:transparent;"><br clear="none"></span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_95" style="background-color:transparent;"><br clear="none"></span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_72" style="background-color:transparent;"><br clear="none"></span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_4" style="color: rgb(0, 0,
0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-style: normal; background-color: transparent;"><span id="yiv1107933689yui_3_16_0_6_1406415491611_24"><br clear="none"></span></div><div id="yiv1107933689yui_3_16_0_6_1406415491611_16"><br clear="none" id="yiv1107933689yui_3_16_0_6_1406415491611_6"></div> <div class="yiv1107933689yui_3_16_0_6_1406415491611_8" id="yiv1107933689yui_3_16_0_6_1406415491611_9" style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt;"> <div class="yiv1107933689yui_3_16_0_1_1406415491611_2941" id="yiv1107933689yui_3_16_0_1_1406415491611_3079" style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div class="yiv1107933689qtdSeparateBR"><br clear="none"><br clear="none"></div><div class="yiv1107933689yqt8872015775"
id="yiv1107933689yqt09768"><div dir="ltr" id="yiv1107933689yui_3_16_0_1_1406415491611_3078"> <hr id="yiv1107933689yui_3_16_0_1_1406415491611_3599" size="1"> <font id="yiv1107933689yui_3_16_0_1_1406415491611_3080" size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> 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>><br clear="none"> <b><span style="font-weight:bold;">To:</span></b> <a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> <br clear="none"> <b><span style="font-weight:bold;">Sent:</span></b> Sunday, July 27, 2014 2:08 AM<br clear="none"> <b id="yiv1107933689yui_3_16_0_1_1406415491611_3792"><span
id="yiv1107933689yui_3_16_0_1_1406415491611_3791" style="font-weight:bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Air compensating thrusters<br clear="none"> </font> </div> <div class="yiv1107933689y_msg_container" id="yiv1107933689yui_3_16_0_1_1406415491611_3081"><br clear="none"><div id="yiv1107933689"><div id="yiv1107933689yui_3_16_0_1_1406415491611_3084"><font id="yiv1107933689yui_3_16_0_1_1406415491611_3083" color="black" size="3" face="Arial, Helvetica, sans-serif"><font class="yiv1107933689Apple-style-span" id="yiv1107933689yui_3_16_0_1_1406415491611_3082" size="3">The voice of experience. I knew about the brush problems, having fought those carbonizing issues with Hymak oil compensated thrusters (Pisces and Aquarius). Perhaps someone will develop this further and generate a white paper for the psubs archives? Air compensation certainly works for Karl S. and could well be a viable and inexpensive alternative for those in the planning/building
stages.</font>
</font><div id="yiv1107933689yui_3_16_0_1_1406415491611_3085"><font class="yiv1107933689Apple-style-span" size="3">Vance<br clear="none">
</font><br clear="none">
<br clear="none">
<div class="yiv1107933689yui_3_16_0_1_1406415491611_2948" id="yiv1107933689yui_3_16_0_1_1406415491611_3090" style="font-family: helvetica, arial; font-size: 10pt; color: black;">-----Original Message-----<br clear="none">
From: Alan James 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>><br clear="none">
To: <a rel="nofollow" shape="rect" target="_blank" href="http://psubs.org/">psubs.org</a> <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none">
Sent: Fri, Jul 25, 2014 6:35 pm<br clear="none">
Subject: [PSUBS-MAILIST] Air compensating thrusters<br clear="none">
<br clear="none">
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<div class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2952" id="yiv1107933689yui_3_16_0_1_1406415491611_3086" style="color: rgb(0, 0, 0); font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt; background-color: rgb(255, 255, 255);">
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style="">Hi psubbers,</div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style="">in an attempt to get more information on the compensating issue</div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style="">I contacted fugu subs, who I remembered used air compensation.</div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style=""><u class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_3021" style=""><a rel="nofollow" shape="rect" class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_3024" target="_blank" href="http://www.fugusub.com/" style="">http://www.fugusub.com/</a></u><br clear="none" style=""></div>
<div id="yiv1107933689yui_3_16_0_1_1406326496253_2839">They operate small semi dry ambients probably to a max of 100ft. </div>
<div id="yiv1107933689yui_3_16_0_1_1406326496253_2839">One thiught is that they operate in the warm waters of Florida where you would think</div>
<div id="yiv1107933689yui_3_16_0_1_1406326496253_2839">oil compensation would be an advantage in cooling the motors.</div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style="">This is their reply.....</div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style=""><span class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2962" style="font-family: monospace;">Hello Alan,</span><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2963" style="font-family: monospace;"><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2964" style="font-family: monospace;"><span class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2965" style="font-family: monospace;">I seldom respond to technical letters, but I thought it best to save you
some headaches. Over the last thirty years, we have tried several types of oils for filling motors with, as some "authorities" had recommended. Here's what happens: On motors with brushes, the centrifugal force and pressure of the oil passing between brushes and rotors causes the brush to "lift off" of the rotor, causing power loss. The motor slows down dramatically from internal fluid frictions as well. Another issue is that some of these oils can wreck the vinyl insulate on wires and possibly o-rings. On brush motors, </span><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2966" style="font-family: monospace;"><span class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2967" style="font-family: monospace;">oil is a failed prospect. Stick with an air system. Good luck with your project!</span><br clear="none" class="yiv1107933689
yiv1107933689yui_3_16_0_1_1406415491611_2968" style="font-family: monospace;"><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2969" style="font-family: monospace;"><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2970" style="font-family: monospace;"><span class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2971" style="font-family: monospace;">Kind
regards,</span><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2972" style="font-family: monospace;"><br clear="none" class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2973" style="font-family: monospace;"><span class="yiv1107933689 yiv1107933689yui_3_16_0_1_1406415491611_2974" style="font-family: monospace;">Russell J. Canfield</span><br clear="none" class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2955" style=""></div>
<div class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2839" style=""><br clear="none" class="yiv1107933689" id="yiv1107933689yui_3_16_0_1_1406326496253_2955" style=""></div>
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