Model Boat Mayhem
Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: rathikrishna on March 10, 2012, 11:35:21 am
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Friends..at morn, i was deeply thinking about a new propultion systems, for my oncoming submarine projects..and was thinking and refering about many motor systems for a good under water propultion..suddenly, i cam eon one thing..a brushless motor is not commutated by any means of mechanical link..so, it must induce the EMF, between the magnets and sator..through water..so, i tried to run many motors under water..and amazingly it workes perfectly..so, i made a test bed, with motor under water, holding a prop on it..the only thing that i done is insulating the three wires, from motor to ESC with epoxy..it works like a dream..so i took the craft to canal, and lake, worked well..and the motor is in coolest position as it submerged in water..so, i replaced some ball bearings from motor to brass bushes, to avoid rusting..it made even more versatile..now, i am coated the winding in PU paint, for further water proofing..here some test results..
this motor is from a VCR, and i reworked it for my new big tug boat..it is far powerful..here we are taking a test with it..
you can see the reworked winding..
now dipping in water and powering the ESC..as no pulses back to ESC it trips..still nothing wrong is happened..
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now the out runner back..can see the insulation on wire junctions with Epoxy glue..
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now..time to check out..
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will it work..? have any video..? sure see here my first test video..more videos follows even in salt water...SEE VIDEO..
http://www.youtube.com/watch?v=3S0xpp7DvPE
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Like they said in Jaws "We're gonna need a bigger boat", you're gonna need a BIG propeller for that one Krishna, about 6" (150MM) diameter. Otherwise the body is going to mask the waterflow.
Regards Ian.
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yes..you are true..but not..the motor in first test video, is meant for a big tug, still waiting to fix inside..it used here only for test purpose..now, working on two crafts, one is using a 1200 RPM/Volt outrunner from a reputed company, and one, using a reworked CD motor..on both crafts motor will be fixed directly under the curved area of transom, driving a 1.5 inch pro, and 1 inch prop..will add all and still testing more about this..and also making a submarine, with same idea.. :-))
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I found out by accident that brushless runs ok submerged. I flipped my airboat and proceeded to drive it back to shore with a 6" aero prop on it! Turned it back over, back on the water and away it went - still ok a year on, with no modifications.
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Great..great...inspiring.. :-)) :-)) :-))
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no more 6 inch props,,but works scaled props..here with a cd drive motor..all reworked and fixed a scale prop, is tiny from a ship kit..
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and with a commercially available motor..it will works..because all we know why..and will it drive a craft..? please wait a little..i am making a destroyer with this idea, and later an ARCHERFISH sub..
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more test results..
http://www.youtube.com/watch?v=NZ6kKt3ZH7A
:-))
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The magnets will rust heavily if they are not sealed.
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hi krishna could you post up a buld ans cerket diogram for just a bec cerket please whant to use some larger baterys to pawer my recever on my petrol boats using big servo and would like to buld them myself
thanks :-))
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GW..its very easy to make a BEC circuit our own..and yes ESCs also..i already posted an article in our forum..here is the link..still i have to add many more stuffs there but still the BEC is complete..here the link..http://www.modelboatmayhem.co.uk/forum/index.php?topic=34614.0
please use 7806, instead of 7805, and two TIP 3055, instead of one, because a 6 volt regulator will gives us a good voltage stability in heavy duty applications..and yes two power transistors because in a extra heavy application, there must be a chance of over heating so, some loss..by using two, you can avoid such loses..and please add a 2 Ohms resistor, to the Base lead of transistor, and must connect each to each transistor, means, you must use two, 2 Ohms resistor, to the each Base lead of each transistor..this works well..and was using these circuits even on my big competition sail boats one uses ultra heavy duty servos.. :-))total cost of this circuit costs here as mere 80 Rs/-but works for a life time..can feed it from 6 volts to 14 volts..and if you have a chance to buy a low drop, 78XX series, it will be more satisfying.. :-)