tilt or slide for outboard in a well

Discussion in 'Sailboats' started by CBTerry, Jun 11, 2017.

  1. CBTerry
    Joined: Jun 2017
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    CBTerry Junior Member

    Hello! I have a 30 foot Pearson Wanderer and a 15 horsepower Johnson sailmaster which I am trying to get together by building a well aft of the cockpit. It is an extra long shaft and I just received a 10 inch diameter four blade 5 inch pitch prop to push it about with. The decision I'm having trouble with is whether or not to have a vertical slide, which would require the building of a bit of a box on the aft deck for the motor to raised up into, or to have the motor tilt. Having the motor tilt would require slotting the transom as well as the bottom of the boat and the motor would be exposed and that could cause problems. The box I'm not too worried about building because I will probably be adding a mizzen mast to make her into a yawl. Getting the control cables to articulate the 30 inches or so might be problematic but I have a couple quite long cables so I think I can pull this off. I would love to hear opinions regarding the motor tilting or the motor traveling vertically (or anything else, such as dark matter, which I still think is a bit of a sketchy idea). Getting the motor to travel vertically I can easily have a bomb door for smooth, quiet sailing.
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    Is the engine to have a steering function ? That will potentially affect the room required.
     
  3. CBTerry
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    CBTerry Junior Member

    I would like it to swing thru 90 or so degrees if possible. If I make the cut out large enough for the prop and the anti aeration plates to go through then there will be enough room for it to turn approximately that much or just a tad less. This is my measurements for the vertical slide arrangement. I am leaning heavily towards the vertical slide arrangement but wondering if I have forgotten one aspect or another or haven't thought of one characteristic or another. If I wanted to put davits off the back at some point to lift a dinghy out not having the foot of the outboard protruding aft would be a nice thing also
     
  4. Barry
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    Barry Senior Member

    [​IMG]There are lots of these types of lifts on the market, most often there is a spring that aids in lifting the weight of the motor. From here if you want you can tilt the motor for more clearance between the prop and the water. The bracket can be lowered to different heights.
     
  5. CBTerry
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    CBTerry Junior Member

    One of the reasons I am going too an outboard in a well instead of an inboard is for ease of docking and maneuverable thrust.
     
  6. PAR
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    PAR Yacht Designer/Builder

    There are good and bad things to consider with both approaches. With a slide, you'll need more height than commonly seen in a well box, but the cutout in the hull can be pretty small which is good for sailing. With a tilt up arrangement, you'll save some height on the box, but the hole will need to be long enough to let the lower leg swing up, which isn't good for sailing. I've also found slides tend to jam if any dirt, salt, etc. gets in them. The spring loaded transom mounts take a pretty big swing, but is a bit less than just the stock pivot mechanism.

    Rather than using a traditional steering setup, I used a simple link to my tiller to turn my outboard. It was little more than a piece of 3/8" rod, bent to go in a fitting on the rudderhead and the engine's tiller. It does have to be popped off, to tilt the engine up, but does permit vectored steering with the engine. My setup was offset to port permitting this simpler approuch.
     
  7. CBTerry
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    CBTerry Junior Member

    Thank you for your response. I had an outboard on one of those previously and the motor wood aerate the prop in short choppy Seas. It was only a long shaft and not an extra long shaft. By putting the motor in a well I will be moving it forward almost 2 feet. This will reduce the ark of the prop going up and down and so in Seas . hopefully it will not aerate as easily. Also being in the well the motor will be protected in heavier Seas and it will also look a lot better as well.
     
  8. CBTerry
    Joined: Jun 2017
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    CBTerry Junior Member

    Thank you for your reply. I am thinking of going with the slide arrangement for the benefits you've already mentioned. For some reason I am a bit fearful of having the foot of the motor stick out the back of the boat with a tilt-up Arrangement. It is an extra long shaft Johnson sailmaster. The Tilt app Arrangement would prohibit need from having a set of davits later if I so wish. Better sailing is important with the bomb door closed it will be nice and quiet. I like your idea of tying the tiller to the motor. Offsetting the motor is a good idea for me as well. I have been trying to come up with a fitting which the motor will engage when it slides down all the way that will be tied through solid Rod linkage to the tiller. It may wind up being a Rube Goldberg Affair though haha one of the reasons I am going to an outboard is so that I can have vectored thrust. I rarely motor sale and so primarily I motor off of a dock and so the outboard seems the better animal for me. Plus I have two of these motors complete and pieces parts to another one or two and I know a good bit about them and parts are plentiful. A short shaft for the dinghy and a long shaft for the Mothership. Same spares Etc if I ever do go extended cruising I can have a complete spare powerhead freshly rebuilt in a garbage bag tucked away somewhere. A complete rebuild is less than $500.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    How much elevation from the run position is required ? Can't be much more than a foot, unless you want it clear of the waterline, which would be somewhat more, presumably. You rather fancy a custom made vertical slide with Teflon or HDPE , and a coarse-threaded rod you could turn with a removeable hand crank, or even a pump-up air ram would give the narrowest slot.
     
  10. CBTerry
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    CBTerry Junior Member

    Yes I would like the prop clear of the water. Dragging stuff through the water bothers me psychologically haha part of the reason I am going with an outboard is because dragging a big problem a diesel through the water gives me nightmares. I will need to raise the motor approximately two and a half feet. I intend to use pulleys and a short bit of rope. I intend to have a bomb door that will close after retraction so that water doesn't slosh about in the well well sailing. The bomb door is just aft of the water line as the hull sweeps up out of the water. If I can attach the line such that it is pulling on the center of mass and parallel to the slides it should greatly reduce any problems of the slides catching. Standing on the ground the motor is 4ft tall and the power head is not very tall it is a Johnson 9.9 that is low profile.
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    2.5 feet is a helluva lift, you can't get away with less ? I'd say you will have to make your own device.
     

  12. CBTerry
    Joined: Jun 2017
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    CBTerry Junior Member

    Oh yes I already understand that. I actually took the clamps, that typically hold the outboard motor to the transom, off of the motor and will bolt on two plates which have an 8 inch "T" to fit the top of the T into the track . The eighth inch measurement is vertical. In other words there will be two 8-inch long slides that will be captured in the tracks I build. The tracks will be 2 inches wide as the top of the T is a shade less than 2 inches. By sanding ( relieving) the leading edges of the T just so I should be able to prohibit a lot of sticking in the mechanism. also pulling parallel to the slides and at the center of mass, or just a little bit towards the track side of the Center of mass will alleviate sticking problems I hope.
     
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