Motorizing a Sunfish...

Discussion in 'Sunfish Talk' started by Light and Variable Winds, Jan 26, 2014.

  1. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    I was intrigued by the video that appeared here a while ago. In Turkey, a boater had a portable drill, chucked a long shaft into it, and added a small propeller to power his rowing dinghy—and it worked very well. :cool:

    Even though I continually watch the skies for bad weather, I still got caught in a "cell", which tore my racing sail, and bent my mast beyond 90°. :( From a ½-mile out, just another two minutes would have had me in the lee of protection. :confused: Since I've accumulated two small propellers, I'm considering running a small hollow shaft diagonally through one side of the transom, and trimming the (mounted) propeller so it's not dragging.

    One of my spare propellers is off a 4-HP outboard, and the other is a spare impeller for an "Ice-Eater". (Too big or too small?) :oops:

    'Course, in my state, that'll add $10 to the annual registration fee! :rolleyes: Hmmm...maybe.... ;)

    Anyone considering such a "permanent" device? :)
     
  2. greenskeeper

    greenskeeper Member

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    electric trolling motor with 12v deep cycle battery would be plenty to push a little sunfish safely to port. A lot of extra weight to carry though.
     
  3. oldfish

    oldfish Member

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    how about some oarlocks and collapsible oars.?
     
  4. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Once, when I had 1½-miles from launching-point to home port, I used a heavy 12-v auto battery and my tiniest electric outboard. (Clamped to the rudder cheeks). I had 1½-miles to cover—"threatening" weather and no wind. :confused: The cord was 'way too short, so battery and tiller fought for space :mad:. At that time, a portable drill would have been too little, and the automobile battery was 'way too much.

    But now I'm thinking, I can "steal" a suitable propeller from one of the other electric motors I own. :) Maybe paint a similar propeller on the opposite side of the transom? :p

    When I had a wind that could just fill the sail :oops: and an approaching cell :eek: ANY help would have been of critical value.

    (Once, I accepted a tow from a Jet-Ski!) :confused:
     
  5. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Well, a 12-volt motorcycle battery or one of those smaller gel-batteries might do the trick.

    If you can find the time, a new site (to me) that features really endless scrolling :confused: features this "paddle":
    Water Sports, Sporting Goods

    Meanwhile, somebody in China must have seen that Turkish "outboard drill" video, 'cause they've come out with this device, for less than $50:

    Microsoft Edge 12132015 80708 PM.bmp.jpg
    Reading up on it, some have said that a Jacobs chuck will eventually loosen its grip. :(

    Hmmm...Still thinking of a permanent mount...remove the foam handle...¾" PVC pipe as a dripless "stuffing-box"...feathering the prop...?

    Now, will my Makita fit through a 6" inspection port (?) and if I actually do this, I'll need to remember to bring my portable drill along—and to keep it charged ! :rolleyes:


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  6. Webfoot1

    Webfoot1 Active Member

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    If there is enough wind to bend the mast the drill is not going to have enough poop to do anything. Will not go very far on a calm day. There was a thread 5 year ago where someone wanted to get his Sunfish through a channel out to a lake. The consensus was to pull the Sunfish with a 12 foot boat and outboard, then anchor the 12 foot boat and switch to the Sunfish. I'd try this in calm conditions first and work my way up to windier conditions. If you do try to motorize the Sunfish, let me know how it goes. It was an I idea I tossed out originally and I got a "you can't be serious" reaction. My inclination is that people have fun making all sorts of modifications to Sunfish. If you're really serious I think it would take a Brush-less electric motor/ speed control and Lithium-Ion battery's to make it work. This is going to cost some money unless you can scavenge the parts somewhere.
     
  7. jaas75

    jaas75 Member

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    well i motorized my sea snark and it works great!! when no wind or im to tired to tack and tack to get back to port ,the only problem i see is that my trolling motor is super efficient in the lowest speed (can run for 2 hours no stop and still enough battery to get you out of trouble) but thats super slow!!!!!! for my taste, BUT as soon as you speed up the battery goes to %^$^%$%^$ and last for 15 minutes :confused::confused::confused: (but better than rowing back 1 mile ;))
    so your choice is getting a cheap old trolling motor and getting a nice small battery. (mine cost me like 10dls because i got it from a radio shack store closing)

    check out my setup IMG_0008.JPG
     

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  8. jaas75

    jaas75 Member

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    BTW i took the mounting idea from the kayakers so theres a lot of ideas of how to mount the motor!!
    i also said the motor is super slow on low setting but the "torque" is quite good:confused::confused: i feel i can troll a truck and the motor would pull but it doesnt go any faster
    (my guess is the shape of the props are more for torque thn for speed
     
  9. Webfoot1

    Webfoot1 Active Member

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    I think I have it figured out, which may be dangerous coming from me. Think of a Sunfish with a removable outrigger unit. All the stuff like batteries and motors would be attached to the removable outrigger unit. The outrigger could be attached to Sunfish with line and almost no modification. When its time to sail simply slide the Sunfish out from under the outrigger, reattach when you're done sailing. The whole thing could be made from PVC pipe and even simpler, a 2 hp Johnson outboard could be attached to the outrigger instead of batteries and electric motors.
     
  10. jaas75

    jaas75 Member

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    pictures pictures:p:p:p

    that sound cool but honestly having trouble visualizing
     
  11. Webfoot1

    Webfoot1 Active Member

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    I'll draw a sketch this weekend. It would sort of look like a Sunfish stuck under a Catamaran. Objective would be to make something a cheap a possible yet sturdy enough to last the whole season. The trick is to find something in the junk pile that would work as pontoons. If I did not think it would be stolen I'd say mount the motor on the rudder bracket and when you are ready to sail, remove it and place the motor in a water-proof container with a bicycle flag on top and let it float till retrieval. Perhaps mounting the motor in a foam cooler chest with the lower unit stuck through hole in the chest and strapping the chest to the Sunfish? That's about as simple as I can think of.
     
  12. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    All good thinking! :) Actually you'd need only one pontoon, and could construct it out of inexpensive PVC pipe.

    Microsoft Edge 12172015 92819 AM.bmp.jpg

    You could also rig a minimal outboard bracket and mount it as far aft as possible. (Tilt the motor while sailing—shorten the shaft at its top with a pipe-cutter). A small "gel" battery container could be cut and bonded under the tiller, but made deep enough so the secured cables don't interfere with tiller operations. Or make the container well-sealed, covered, secured—but removable—as an inspection port and allow inside access to the gudgeon- and traveler- area.

    I once bought a Hobie 16 catamaran with a perfect hull bottom. The previous owner lived on a freshwater canal, kept this Hobie in a huge boathouse with the mast up, and had fabricated a tiny trolling-motor bracket (with aluminum pipe, a wooden door stop—and duct tape (!) to get a ½-mile to the ocean. :confused:

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  13. fhhuber

    fhhuber Member

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    I would look into a mount to the rudder for the motor/prop.
    Kind of stealing the idea of one of the modern high end trolling motors that mounts to an outboard...
    Engine Mount

    And I'd go with RC model aircraft LiPos for power (because I have a lot of them and they are VERY light.)

    Use of a common RC electronic speed control and a "servo tester" as the throttle control would allow use of a modern brushless motor (small, light and inexpensive.. and they do fine running underwater in fresh water if you dry them out afterward)

    Some creativity and I could rig this all up and be lighter than that drill rig and have more power... (I have up to 5000 watt or 6 hp motors available..)

    the expensive part of all this is the batteries if you were to go out and buy everything needed.

    And easy to install/remove...
     
  14. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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  15. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    To save money on LiPo batteries, let's say I start with my 9.7 volt Makita portable drill battery. I have several 9.7 Makita drills to part out and 9.7 volt Makita chargers I can scavenge for wiring it up. To keep this venture simple, I won't insist on variable speeds.

    Googling around, I found 9-volt brushless motors. Would a 9-volt brushless motor be compatible with my 9.7 volt Makita batteries? (This would be a freshwater application).
     
  16. fhhuber

    fhhuber Member

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    The motor should work with the batteries.

    A brushless motor requires a brushless electronic speed control and that would need a method to operate the throttle.
     
  17. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Would the application still make sense if I only needed "full speed ahead"?

    Online, I can buy a 9-volt brushless motor. If I walked into Radio Shack with my 9.7 Makita battery, what electronic speed control part should I be asking for?
     
  18. fhhuber

    fhhuber Member

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    Radio Shack probably wouldn't have the speed control. The place that carries the brushless motor you are looking at would have one.
     
  19. danpal

    danpal Active Member

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    That and Radio Shack is pretty much out of business...
     
  20. jaas75

    jaas75 Member

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    go to a hobby store, get a ESC of at least 60amps.
    theres several online stores like hobbyking and banggood (just add www and .com)
     

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