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Thread: Electric Rudder

  1. #1
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    Default Electric Rudder

    I would like to add electric propulsion to a traditional rowing skiff. A friend told me that there was an article and/or plans for modifying a trolling motor to incorporate it into a traditional rudder in Wooden Boat.

    The idea is to hide/disguise the fact that the boat has electric power. Additionally, I don't want to modify the boat significantly. The idea is to build a new custom rudder that has a trolling motor base on the bottom.

    Any help finding the article or getting pointed in the right direction would be appreciated.

    -Darin

  2. #2
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    Default Re: Electric Rudder

    Here ya go:

    WB#112, p.70. A Motorized Rudder for MAIA

  3. #3
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    Default Re: Electric Rudder

    Thanks much!

  4. #4
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    Default Re: Electric Rudder

    There are various ways to do it. One of the boats on this year's SF Gunkholing trip had one and it worked very well.

    When they didn't want electric power or to drag the prop, they sailed the boat with the rudder pulled up horizontal to the waterline. Like my dory skiff, the rudder works fine in this orientation and theirs only showed the aft edge and the motor and prop when sailing.

    When they wanted power they released the uphaul and the weight of the motor pulled the rudder blade down into position. Running the motor them pulls it further forward.





    He had the rudder blade set up so that it could be lifted completely out of the water for towing or rowing as you can see in the second photo above == a clever idea.

    Biggest trick seems to be dealing with the wires. I've seen various methods to hide them coming from the rudder (or transom-mounted motor) over the transom and down into the boat. You also don't want the weight of the deepcycle battery in the stern, so you have the thick wires lead forward.

    I've also read that you need to take care to not over-insulate the motor bulb, as that exposed metal is how the motor gets rid of heat into the water, but the fellow who rigged the boat shown above scoffed at the idea of it being an issue.
    Last edited by Thorne; 11-26-2008 at 04:21 PM.
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  5. #5
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    Default Re: Electric Rudder

    Dunno if this would help but it's worth a look.Check the addition specs and photos.You should be able to get enough of an idea to copy it.

    https://www.boatdesigns.com/products.asp?dept=474

    Oh yea.Trolling motors do use water to remove heat from the motor case.

  6. #6
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    Default Re: Electric Rudder

    If you don't want to go the rudder route, you could make one that mounts separately on the transom, but removes completely when you don't want to use it. Here's a rough concept illustration that I came up with -



    Here's another method -

    Last edited by Thorne; 11-26-2008 at 05:05 PM.
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  7. #7
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    Default Re: Electric Rudder

    I was just about to post a similar question! My ebay habit has got the better of me, and I've just scored a 24v 80lb thrust watersnake trolling motor, which I'm intending to power my Oughtred Acorn Skiff with. I suspect 80lb is overkill, but there you go.

    The plan is to make up a rudder, basically 2 cheeks with a channel in each (a vertical tube when they are glued together). The down tube of the outboard will effectively be sandwiched between the rudder cheeks. Then the control head/tiller of the outboard just sits on top of the rudder-the control head is a bit of a lump, hard to disguise in a normal tiller. maybe just paint it brown so you'd only notice if you really looked.
    I haven't done it yet, and I'm a bit nervous about cutting into the outboard down tube (which will need to be shortened). I'd hate to get water in the innards in use, that would kill it in short order.

    Might just use it as is, clamped to the transom for a while, before i do major surgery.
    Phil

  8. #8
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    Default Re: Electric Rudder

    PS-My other thought was to somehow mount the bottom end under the boat, slotted into the centreboard slot. Steer with the normal rudder-really invisible power. Only drawback would be the motor and prop somewhat exposed, sticking down 6" or so below the bottom of the boat-might get wrecked in a grounding, or coming ashore. maybe I could build them into a really short centre board for protection-but it woud still be a nuisance coming into shallow water.

  9. #9
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    Default Re: Electric Rudder

    On most trolling motors you don't need the head at all -- the controls can be removed or a remote can be used. So as you can see in the photos, the above conversions just cut the vertical pipe, leaving the wires intact, and used the lower part of the motor.

    Before any of you folks "go there", be sure to try hoisting a big deepcycle battery in and out of your boat a few times, and figure out how you'll secure same in the boat. Py will need to hoist two of 'em...

    ;0 )

    Until you've got a bad back and battery acid holes in your clothes, you don't really know what you are getting into...
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  10. #10
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    Default Re: Electric Rudder

    if you are willing to spend the money you can buy a trolling motor that is built into a transom mounted trim tab. its already made for just what you want. there are also some made that are intended for attaching to the cav plate of an outboard that would also be a natural chioce ffor what you are wanting.

    look around at cabelas.com and youw ill find something that will work.

    jerry

  11. #11
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    Default Re: Electric Rudder

    Here is something else some of you might wanna have a look at.

    http://www.glen-l.com/designs/special/etm.html

  12. #12
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    Default Re: Electric Rudder

    My motor came with 4 sealed AGM batteries, so yes, the back strain is an issue, but at least i shouldn't get acid burns! I'm figuring on rather nice timber boxes either side of the centrecase, weight bearing on the floors, and with a level interior base for the batteries to sit on. I kinda like the idea of mounting little solar panels on the lids. Have to go look on ebay a bit more I guess.

  13. #13
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    Default Re: Electric Rudder

    Unless your boat lives in the water or on the trailer by a ramp or sling-launch, you won't be able to leave the batteries aboard -- they will probably break or warp a hull like the Acorn if trailered very far. So that means you'll need to load & unload them every time you use the boat.

    That setup does sound like overkill for an Acorn (what size?) -=- too much power and too many batteries unless you intend to use it as a powered launch. Those AGM batteries are what, 40-50lbs each?

    It might work well in a design with a stronger hull, or something purpose-built to handle that much ballast near the keel. I suspect that a single large battery and a 12-v 45lb thrust trolling motor is all you would need for auxiliary power for a 14' Acorn....
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  14. #14
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    Default Re: Electric Rudder

    Re-enforce the floor under the batteries and invest in an on board battery charger.That's what we do when we convert Jon boats to bass boats.The batteries will split the aluminum over time,so we build a second floor to spread the load out.

  15. #15
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    Jun 2005
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    Default Re: Electric Rudder

    I have a 32lb minkota bought brand new. It has been used to move a fiberglass 22ft oday sloop just fine to get in and out of the anchorage, out to where the wind is blowing. So 80 lbs is way too much.

    I had the minkota on my Buccaneer 18 when we capsized, and it ran while completly submerged, sealed batteries (more on those in a min), while I motored the swamped boat closer to shore so we could bail it while standing on the bottom. I have since added more flotation so I can climb in without putting the gunwales under. There was no damage to the motor, the water does not enter into the houseing from the tube. The throttle control is a sealed reostat. So don't be afraid to disassemble. Just take a photo of the wiring connections as the wires connect to the throttle so you make em up correctly.

    For day trips I was using a Husky brand portable power unit, from home depot. It is a jump starter, tire pump, led work light and 400w 12v to 120v inverter, cigarette lighter plug in,with a built in charging jack and nice carrying handle. The guts is a sealed 19amp hr 12v battery. Light enough to carry in and out of the boat everytime I went sailing, small enough that I could bungie it in in case of capsize, sealed battery so no acid spilled when we did capsize. Of course all the electronic parts were ruined when we capsized but the battery still worked.

    So I took that battery and had a second cheaper version of the portable jump starting units I was not using. No inverter, pulled both batteries, permently mounted them so I have 28 amp hours in two batteries (sealed style no leaks), mounted the motor permantly to the transom, tiltable for sailing, with the head relocated and made a quick connect to plug in a RV style flecible solar panel for when sitting on the dock or trailer to charge between trips.

    My Bucc weights 450 lbs. and this weakly powered system pushes it to 3.3mph on GPS, into a 6mph wind for 1 mile. Which is the longest I have had to motor it. Then I plugged it in to the solar panel and she is charged up ready for the next use.

    You can buy the sealed batteries directly from a motor cycle shop as well. Or go get an Optimist brand deep cycle. But they are heavy. So you can go lightweight on your batteries IF you don't have far to go.

    Sorry for admitting that I have a fiberglass, go fast daysailer, but I can get the Bucc to plane at 6mph with me solo in about 8 mph breeze. Lots of smiles for the miles.
    Jimmy
    __________
    Loving Living on Lake Bacalar.

  16. #16
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    Aug 2004
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    Florida
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    Default Re: Electric Rudder

    Here is a photo I took a couple of years ago:

    http://s165.photobucket.com/albums/u...tricrudder.jpg




    Thanks,
    Barry
    Last edited by Otto49; 12-05-2008 at 10:23 PM.

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