Homemade Outboard (Electric) - Help!

Discussion in 'Propulsion' started by MrLknowles2, Jul 26, 2012.

  1. MrLknowles2
    Joined: Jul 2012
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    Location: Newmarket

    MrLknowles2 Junior Member

    Hi there, The name is Lee, (intro first) I have been looking through the forums and im ready to make a post, i see you all have extensive knowledge of boats and designs so i would love some advise on a small project im putting together!

    Im 21, And from The Home of world horse racing of Newmarket in England. Im a keen fisherman and have been visiting my grandads various boats since i can remember, Im very keen on the idea of having my own project boat stripped and rebuilt (which im currently looking into) Its a lovely lovely boat that i have had my eye on since i was around 10 years old, its been out of the water now since i can remember and has a big chance of carrying osmosis so im getting that checked out before i start obviously but has a reconditioned engine that has been in storage by the old owner (who passed and whose wife has kept paying for the mooring but never managed - Even though its out of water!) But i will possibly start a thread on the boat if we every come to an agreement (if it passes the osmosis test and other various age based tests!) but all in all would be a shame to see this boat never put back to its former glory!


    Introduction over, I need some advice!

    As i mentioned i am a keen fisherman, and have been carp fishing for a few years after switching from traditional course fishing since i can remember! For all uk fisherman you may be local or have fished on the river cam in Cambridgeshire, there are some fantastic fish in there but is notourious for horrendous weed, I have finally decided to use a boat to my advantage!


    I have bought myself a dinghy to rake my favorite spots right the way across the river to bait up some key areas!

    Aswell as buying myself a dinghy i have also accepted my fate as a lazy sod and decided i do not want to row! Therefore have purchased an outboard electric motor for the boat which will be perfect for the job, However i have always enjoyed taking things apart and messing about with things and have decided as a small project to build my own electric outboard motor aswell!
    I have decided to follow this simple principal model outboard which seems to work very well! http://www.youtube.com/watch?v=bRjoUdG2oKs It looks good but as stated in the video he only reaches 1000 metres.. (0.6miles) Which is no good for anything really unless i take 5 batteries which i suppose i could do! but would prefer not too!





    So after this essay my question is this!

    1.Would it be viable to attach 12v gel battery (slow cycle - better for the job) to the drill to obviously last longer, but would the drill burn out quicker as obviously a 12v gel batter for an electric scooter, or a car batter give out different internal resistance and other things, so will this make a difference??

    Also the next question,
    2.if you have any other ideas about a setup i could build... could you share?? :D


    Hope i have not bored you too much and look forward to hearing your ideas soon!

    Take care,
    Lee
     
  2. multiHen
    Joined: Jul 2012
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    multiHen Junior Member

    If the original drill battery 12volts or higher you will not burn it out no matter how big the the 12volt battery is. The drill will only take as much power as it needs the battery does not force more power in.. If use a 7.2 drill with a 12 volt battery it will burn very fast.
     
  3. MrLknowles2
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    MrLknowles2 Junior Member

    Thanks alot MultiHen, So by those terms an 18v drill and a 12v battery will have what outcome?? Thanks alot!
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The drill won't last long. They are designed and built for short uses. There are electric motors for continuous use available. The cheapest solution is to buy an electric trolling motor.
     
  5. MrLknowles2
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    MrLknowles2 Junior Member

    Thanks gonzo, i stated that i had already bought one, but just fancied making one myself, make me feel i achieved something ;)
     
  6. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Drills have bushings instead of bearings so they will overheat and wear out if run for too long.
     
  7. MrLknowles2
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    MrLknowles2 Junior Member

    I thought as much, I was thinking of obviously using a drill with different torque settings so i could get the most efficient set up, and in most cases the drill will not be used for long periods, and i can easily use it in bursts as if using it for domestic purpose rather than one long continuous press?? What about silly little changes like the grill where the suction is on the side of the drill to open that out for better ventilation? Unfortunately i did not pass my drill exams :p
     
  8. multiHen
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    multiHen Junior Member

    It will run but slower, more voltage will increase its RPMs, less voltage will decrease the RPMs.

    Run the battery down to 12 volts on the drill and see how slow it goes.

    You could use a 12volt and a 6 volt battery together it will create a 18 volt battery if u really want to play around. the batteries should be the same amperage or "amp hours" in battery terms... Or one will die before the other.
     
  9. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    These types of home brews, are novelty items at best. They don't have any power and they don't last long. They tear themselves apart relatively quickly and frankly aren't much more then a joke, compared to alternative approaches. I love the comments of the inventors of these things; "Works great", "Super simple", etc. Okay, how great does it work after 6 hours of continuous operation? How melted are the bushing holders in the motor case, after a couple of afternoons fishing? How many times have you had to fix your super simple contrivance, after a dozen hours of operation?

    Simply put, if the life span of the device is single digit or low double digit hours of operation, then it's toy and you should stay close enough to shore to swim back when the time comes.

    There's several very good reasons electric outboards aren't being marketed and those that try, cost twice as much as a gas outboard, with a fraction of the run time. I hate to burst your bubble, but some research into the assorted issues will reveal the usual suspects of problems associated with these and other electric outboards.

    You're much better off with a bank (a half a dozen or much more) of batteries and a washing machine motor, driving a straight shaft, then a tinker toy drill motor outboard.
     
  10. Frosty

    Frosty Previous Member

    Twice you have been told about bushings verses bearings.

    W'eve all been 21, all made a device to turn a prop, and all swam home.

    If only we had hereditary intelligence.
     
  11. MrLknowles2
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    MrLknowles2 Junior Member

    Very negative comments for somebody who has already stated they have an electric outboard already... and are doing this for a "bit of fun"... Thanks for the advice anyway! but i think i may accept defeat on all of your past experiences in the fact that yes im not fussed about spending alot of money making something that may work well or not at all... but i dont want to throw the money down the drain on something that will last hours if i do get it working!!

    Thanks for the advice, Take Care.

    Lee
     
  12. CDK
    Joined: Aug 2007
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    CDK retired engineer

    This I made a dozen years ago, it still works.
    Inside is a slow revving brushless motor I bough through Ebay for almost nothing. The motor has ball bearings, I just added a neoprene seal and poured in some silicone oil in case it shouldn't be watertight, but now I'm sure it is.

    If you bought a Makita drill for your project, you may expect a decent life expectancy.
     

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  13. boatindad
    Joined: Feb 2014
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    boatindad Junior Member

    I threw together a motor today its a weedeater shaft 11x7 air prop and a 12v black and decker cordless drill I took it to the river and could only go in circles. My kayak doesn't track well it had some power, it would pull harder than i could paddle 20140424_140331.jpg

    20140424_140343.jpg

    20140424_140356.jpg
     
  14. FAST FRED
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    Best thing you can do IF your looking for a hobby is to work on the other side,, the battery.

    The electric cars are getting old enough to need replacement batts , and all these are is piles of small batts stuck in tubes and wired together.

    Toss the dead ones , rewire for 12 or 24V get a charger and GO FISHING !
     

  15. boatindad
    Joined: Feb 2014
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    boatindad Junior Member

    I have looked into that Fred the cheapest way i found to come by batteries is through computer recyclers you can buy old laptop batteries at 2bucks a pound. Using the same method toss the old and rewire. For this i used a 7ha agm.
     
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