Efficient electric boat

Discussion in 'Boat Design' started by Jeremy Harris, Jun 22, 2009.

  1. portacruise
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    portacruise Senior Member

    The fairing may not work as well when turning the motor is used as a form of steering. I have used "shark fin" adapters with trolling motors before and find steering to be very twitchy, requiring constant correction. The cruising speed on most of these inflatable pontoons is probably closer to 2 mph so the fairing may not be such a factor.

    Still it's incredible what you did with the Cd on the shaft and thrust with the APC!

    Porta
     
  2. Submarine Tom

    Submarine Tom Previous Member

    On the contrary, I think the steering will be great.

    It should take very little angle to produce yaw providing the cowling is coupled to the shaft, otherwise steering will still be good due to directional thrust or vectored thrust, whatever you want to call it.

    Tom
     
    Last edited: Oct 9, 2009
  3. portacruise
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    portacruise Senior Member

    Reference to running 12v troll motors at 24v for double power listed in above responses is listed in "Batteries" section forum posts 279-283. Sorry, cannot return PM directly from this computer.

    Porta



     
  4. MCDenny
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    MCDenny Junior Member

  5. portacruise
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    portacruise Senior Member

  6. MCDenny
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    MCDenny Junior Member

    Porta, I'm using a Castle Creations Mamba Max. There are many others that will work. Just depends on how much power you need.

    Tower Hobbies has a huge selection of brushless controllers and excellent service. You need a controller for a model car if you want forward and reverse.

    The controller will have two input wires to connect to the battery, three power wires to the motor, a three wire flat cable to connect to the receiver (use a servo tester to generate the throttle signal, Tower has an Astro-Flight model for $25) and an off-on switch.

    I'm just selling the motor. I'm keeping the controller for my trolling motor project.
     
  7. Guest625101138

    Guest625101138 Previous Member

    I have been looking at what sort of motor controller combination you would use for a reliable, long-lasting electric drive. Something that has continuous rating rather than the RC burst type motors and controllers.

    I found Kelly Controls are now covering a wider range. They have a nice little PMSM:
    http://www.newkellycontroller.com/product_info.php?cPath=21_63&products_id=509
    Not a lot more expensive than the bigger RC motors. Probably better efficiency and certainly more robust if a little heavier.

    They also have a reasonably priced controller:
    http://www.newkellycontroller.com/product_info.php?cPath=60&products_id=503
    I gather is has reversing switch because there is a reversing alarm.

    Rick W
     
  8. MCDenny
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    MCDenny Junior Member

    The Kelly products are sensored so probably have smoother operation at low speed.

    I have to say, though, my bench tests with the Hyperion motor and Castle controller (sensorless) showed it to be smooth and quiet at very low speeds. These are both high end brands in the RC world so maybe that explains the differences between this and the results Jeremy reported many pages back.
     
  9. Guest625101138

    Guest625101138 Previous Member

    Denny
    I have been asked about an electric outboard equivalent to the smallest ICE outboard - these are 2HP. So I have been looking at what would be used for around 1kW electric swinging a more efficient prop.

    The Hobby City stuff is OK for fiddling with but the durability is suspect. Like Jeremy has found, most users find they have to re-glue magnets and fit more durable bearings to get reliable operation.

    If you look at the better made RC motors then they are typically more expensive than the new Kelly range. Hence for this particular application I am looking at this stuff. There is a weight penalty but it is not excessive for a boat.

    One important factor is the kv of the Kelly motor I linked to. With a 2:1 rightangle gearbox it allows a decent size prop. Other advantages are ability to reverse and a selectable current limit.

    I bought my Mars motors and controllers from Kelly and was very pleased with the service.

    So my interest in the electric drive is a little bigger than you are doing and I would like something more robust as it will be pushing a boat that will have high windage in a good breeze.

    Rick
     
  10. blisspacket
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    blisspacket Junior Member

    A while back I wrote MinnKota and asked why they weren't producing something advanced like the Torqeedo. Now I have to reconsider. Listening to all the motors on UTube, I have to say a submerged brushed motor has the quality of power that I see as essential to electrics: total quiet. Somewhere around the hitech corner there might be an oilfilled brushless that will bring us totally quiet efficient power. I'm waiting...
     
  11. MCDenny
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    MCDenny Junior Member

    Jay, The small Torqeedo motors use two planetary transmissions in series to get an 11:1 reduction ratio. The noise comes from the gears, not the motor. I'm told the new larger Cruise models do not make the noise. I fooled around with a Torqeedo 401 at a boat show running in a barrel. You could hear the gear noise but it was not as bad as I thought it would be from listening to the youtube videos.

    I have a EPIC whisper OB working as a pod motor on my second Harmony 25 launch. It is a brushelss AC motor running at 72v but direct drive to the prop. It is just as quiet as the little MK motors.
     
  12. portacruise
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    portacruise Senior Member

    2 ways I have used to gear down for quiet, low rpm, electric efficiency- cogged belt drive OR overdesigned nylon spur motor gear. Oil fill viscosity causes losses and will not always stop whine which transmits via metal to metal contact.

    Porta


     
  13. joco
    Joined: Nov 2009
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    joco Junior Member

    jeremy harris any new improvement on your project.?

    mabe found something that could be use in that project to.

    i will use it on mine..might or or might not..but its fun to try.

    i founfdin my basement a little tanaka 1.2hp or a 1.5hp outboard.

    i will take the motor off...the muffler that goes down off the boat brakcte off..so the only thig that will be left that alminium tube and the shaft inside and the lower unti/prop that men mabe 4 pound max..mabe even less.

    not sher what kind off motor i will use taugh.

    did like the little motor you post in the first few treads.

    i was thinking eltric drill..but need to many batterie to last at least 4h..unles i get a 12 volt drill and put it on a 12 vold batterie.

    but wen i was looking at the lower end you did wit that drill thing.

    and looking at this lower unti..m sound not to bad.


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    joco
     
  14. wardd
    Joined: Apr 2009
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    wardd Senior Member

    curious here.
    what would be the advantage of a genny connected straight to the motor, no controller?

    with cpp
     

  15. joco
    Joined: Nov 2009
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    joco Junior Member

    there could be a controler..just not on the motor.

    itself...could be a wire that goes to the motor and control frome the seating area.

    no pro here in electricity...

    just a taught

    joco
     
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