trolling motor on a kayak

Discussion in 'Outboards' started by joco, Dec 1, 2009.

  1. joco
    Joined: Nov 2009
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    Location: ottawa/ontario

    joco Junior Member

    hi all.

    i try this once..but did not work out mabe this time will better.

    i would love to get mr..eddie weeks to guive me some hints on this to. he sher no is stuff in this.

    ok here it goes.

    i got 2 kayak that will be transform in electric.

    i am just using minn kota 17 pound trust motor.

    batterie..not sher yet.


    but is there a way to change that prop to get speed or time on those batterie.?

    i read in few place where those original minn kota prop are not made for kayaks.

    what could i sued to get more efficiensy but not a large cost$.

    any info would be great thanks.

    by the way the kayaka are about 65 pound..plus me..250 plus stuff ok mabe...350 pound in all..and there 14 feet long aprox.

    a sit on top and a sit in kayak both wilderness.

    thanks again.


    joco
     
  2. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    you can look at post an efficient electric boat .

    it is supprising but many change for a model aeroplane propeller ..cheap but not good in weed .
    personally I would like a bigger thrust motor but you must try it to see if its ok for you.

    dont go mad on expensive batteries ,,get cheap car types ...dont go below 10.8v ..charge it immediatly and keep the receipt ..take it back if it fails...telll them you had it on a car but make sure you know which one it fits ....good luck
     
  3. Guest625101138

    Guest625101138 Previous Member

    joco
    There is some data on linked thread at post #252 showing a model plane prop on a Minn Kota:
    http://www.boatdesign.net/forums/boat-design/efficient-electric-boat-27996-17.html

    Marine props are not designed for high efficiency. There are other factors that control their shape. There is no commercial marine prop currently available that is specifically designed to push a canoe. After all these boats are intended to be moved by muscle power not electric or internal combustion.

    Aeroplane propellers are designed for efficiency and they give much higher efficiency than a marine propeller up to limitations on strength and cavitation. These are not of great concern with a little electric motor on a canoe.

    There are photos of the various things that were done to improve the efficiency of the Minn Kota on the referenced post.

    Rick W
     
  4. joco
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    joco Junior Member

    thanks guys.

    now i just to find the right rc plane prop for my little 17 pound minnn kota..it wont be the same as that guy wit is 30 pounder.

    joco
     
  5. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    Try half of the pitch recomended for the 30 pounder ....ie 17/30 of the 30 lb pitch......ie 56 %
     
  6. Guest625101138

    Guest625101138 Previous Member

    The most suitable size RC plane prop to get the highest efficiency may not have the blade strength to push your canoe. The one that Denny used is getting quite small for the required thrust.

    It is common that these RC props do not have the strength to suit marine applications. So be wary of this if you go down in size. There is also the option of getting a larger diameter prop than needed and cutting the blades tips down.

    I get props from here:
    http://www.hobbycity.com/hobbycity/...atname=Propellers&idCategory=265&ParentCat=58

    Mostly I make my own props from stainless steel to get the required strength but these are for low rpm and higher speed so very high P/D ratio compared with model plane stuff.

    Rick W
     
  7. joco
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    joco Junior Member

    There is also the option of getting a larger diameter prop than needed and cutting the blades tips down.

    like that rw

    thanks


    thanks to all.

    joco
     
  8. pistnbroke
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    pistnbroke I try

    As the blades may break off at the hub and given that the central part of the prop is behind the motor why not make a hub for the aero prop same diameter as motor..? simplest would be to cast the prop into a disc of ploy resin and fibre glass cloth ...if you were clever you could make it two part clamping the prop and making a prop change easy.....
     
  9. joco
    Joined: Nov 2009
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    joco Junior Member

    i just taught that i had an old motor in my basement its been there for a long time but never did use it for the past few years.

    a tanaka 120..1.2 ro 1.5hp motor.
    look at some pict..i even took some pict off the prop.beside a 17 pound min kota prop side by side.

    mabe that prop would be more eficient on that minn kota 17 pounder.?

    i do like that tanaka prop

    i even think to get rid off the motor and muffler and keep the leg and lower unti an put a small eletric motor on top off it.



    [​IMG]



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    [​IMG]


    joco
     
  10. narwhal
    Joined: Aug 2009
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    Location: Nashville, TN

    narwhal Junior Member

    Do you know the diameter and pitch of the Tanaka's prop compared to that of the trolling motor? It obviously has more blade area, and might be too aggressive for the Minn-Kota. But if it's an easy swap, why not give it a try?
     
  11. joco
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    joco Junior Member

    i did not measure the shafts and dont no the pitch.

    but i think its bigger so could sleave it if i want to do that.

    but i am thinking to take the motor off and the clamps and the muffler out that would leave me wit just the tube and chaft inside and lower witch are light and put a small eleltric motor on top turn that lower unti..i love that ideal.:D :D .

    the lower is small so not mutch drag compare to my minn kota unit motor in the water.

    joco
     
  12. narwhal
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    narwhal Junior Member

    That might work well, or not. What is the final drive reduction gear ratio of the old outboard? If the electric motor you put on top of the old outboard has an output shaft speed significantly different from that of the old gas engine, you may be disappointed with the results. The Minn-Kota is a direct drive -- the motor itself drive the prop directly with no reduction; this reduces drag, and allows the motor to be cooled by the water flowing around its housing, pretty typical of trolling motors.
     
  13. joco
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    joco Junior Member

    true.

    but its still fun to try good or not.

    i wont spend mutch if any to try...for the fun off it..i do have to find ut some date on those rpm etc.and lower unit gear.

    but i am almost it will work out..but just have to find the right motor for it. something light but still efective and something that wont overheat

    joco
     
  14. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    remember your petrol engine is 1000 watts approx at may be 4000 rpm ......no good trying wiper motors etc too weak ( 60 -100w) an eelectric drill or motor from an electric strimmer powered by a generator might do the trick .....???? !!!
    stick with the min kota
     

  15. joco
    Joined: Nov 2009
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    joco Junior Member

    electric drill or motor from an electric strimmer powered by a generator might do the trick .....???? !!!

    hahahha good one..i want to get rid off that gas..i hate it now..that is why i sold my 2 boats to go fully kayak and canoe no noise and no oil and gas etc.

    eletric i will get a bit off noise..but only a few time a trip the rest will still paddle i love paddling..but for trolling the eltric will be nice.

    i did was thinking about and eltric drill and a few batterie..but the batterie are expensive for those..unles i get a 12vol drill..if there any. and put it on a reg batteerie.

    joco
     
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