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<div>Alan, well done!</div><div>Hank</div><div><br></div>
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On Thursday, January 10, 2019, 2:52:43 PM MST, Alan via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
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<div><div dir="ltr">Hi all,<br></div><div dir="ltr">Bolted my brushless thruster on a Minn kotta outboard bracket & took<br></div><div dir="ltr">it for a run on the back of my inflatable yesterday.<br></div><div dir="ltr">Photo shows 48V battery pack in battery box, with an oil compensator, speed<br></div><div dir="ltr">controller in plastic box & red servo tester ( speed input ) on top of it.<br></div><div dir="ltr">The servo tester is wired to the speed controller & turns the pot input into a 2.4ghz signal. I knew this would be the weak link as it was a cheap unit that I had<br></div><div dir="ltr">previously had trouble with. Possibly the loose pin connection in to it.<br></div><div dir="ltr">I had trouble from the start & swapped to my backup which was a radio control<br></div><div dir="ltr">transmitter & receiver. <br></div><div dir="ltr">I was running the brushless motor on sensorless mode. This means the commutation<br></div><div dir="ltr">is sequenced based on position feedback from the motors back emf.<br></div><div dir="ltr">This wasn't working well on high speeds & was jumpy or stopping completely<br></div><div dir="ltr">as it lost it's sequence. All my motors (11) have hall sensors for sensored control<br></div><div dir="ltr">but I had problems setting that up in the computer program so ran without it<br></div><div dir="ltr">as I wanted to get on the water. The speed controller operates on both so the<br></div><div dir="ltr">"not so good" sensorless control is a back up if a sensor fails.<br></div><div dir="ltr">Speed controller temperature got up to 75C, it has an over temperature function<br></div><div dir="ltr">that backs off the power at 80C, so I stopped to let it cool. I did have heat sinks<br></div><div dir="ltr">glued to the top of my battery box to mount the controller on, but when I set up<br></div><div dir="ltr">at the beach I found I couldn't reach that position as the wires weren't long <br></div><div dir="ltr">enough :( . Highly recommend that any motor controllers have good heat sinks<br></div><div dir="ltr">or are heat sinked to the hull as it will increase their life or save them from failing.<br></div><div dir="ltr">Was followed by a small stingray for a while so am thinking the motor may put out<br></div><div dir="ltr">an attractive vibration to them!<br></div><div dir="ltr">The thrust was good & I am intending to have 4 horizontal thrusters, so should<br></div><div dir="ltr">speed along.<br></div><div dir="ltr">A few things to work on before my next outing.<br></div><div dir="ltr">Alan</div><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a ymailto="mailto:Personal_Submersibles@psubs.org" 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><br></div>
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