simple amas for canoe-tri

Discussion in 'Multihulls' started by Owly, Jan 4, 2019.

  1. Aaron_de
    Joined: Jun 2016
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    Location: Avoca Beach, Australia

    Aaron_de Junior Member

    You should definitely check out Gary's book and blog. I built my Wa'apa from his plans which include a really simple ama. I built my amas from 3mm plywood, they are 15cm x 15cm x 4.2m and have 95kg of buoyancy each.

    Here's the boat in some of my YouTube videos...
    First sail with a new Lugsail -
    Boat walkaround with commentary -
    Rigging setup -
     
  2. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    I like the simplicity of those amas........There is not a lot of reason to make them fancy. I have a tendency to over complicate things.

    Thanks for the suggestion.................. H.W.
     
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  3. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    Time, a budget crunch, and other priorities put this project off...... I never got around to building the amas, but had lots of fun building models of them.... I still have two models based on some of the suggestions here sitting on display on my desk...... dreams are free, and models cheap. There always seems to be something more important, and the shop needs to be available for something else...... this week a trailer that needs an axle replaced, next week pulling the transmission out of my '05 F 150 and tearing it down for an overhaul, and currently it's sitting at about 0 F outside air temp....... a lovely calm sunny day though
    2 weeks ago I stumbled upon the "remains" of a Hobie 14........ no mast or sail for $100.......... Two amas for a fraction of what I could build one for, not to mention two excellent rudders and all the hardware........ I'm not pleased with the weight though. It was over 1K miles from home, but not far from where I happened to be going anywhere, and allowed me to route through an area I'd wanted to pass through for years.
    I'm not left with any real excuse for not moving forward now...... even the cross beams for the tramps can be cut in half and used. There is hardly a single component that is not worth what I paid for the whole boat....... The kick up rudders are excellent and well designed, and the entire linkage and tiller handle are there. I'd intended to use a single rudder though, and see little reason to use both of them other than the fact that they are a complete system needing only a longer connecting rod.
    I'm seriously considering the idea of using one rudder on the transom of the canoe, and the other as a leeboard on one side of the canoe hull, perhaps even making it "tuneable" a few degrees each way. It would kick up under one side deck. They are nice foil shaped rudders.

    H.W.
     
  4. thepelell
    Joined: Oct 2019
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    Location: italy

    thepelell Junior Member

    Your idea is basically what I did a couple of months ago to create an outrigged canoe for double paddling on my local lake ( a 3km diameter almost circular lake). My main hull is made out of 4mm okoume , but for the amas I used 4mm poplar that is the only locally available plywood. Total length of each ama is 2m, width at deck is 25cm if I remember correctly. I made them short because I didn't want them to interfere with my paddling. I think you cannot get simpler than this as a construction method. Here are some pics..
    IMG_3679.JPG IMG_3680.JPG IMG_3683.JPG IMG_3687.JPG IMG_3710.JPG
     

    Attached Files:

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  5. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member


    Beautiful job on the amas........... Sorry about the delayed response. There is a considerable difference in mission between your project and mine. Mine is intended for sailing and camping out aboard. I want considerably more displacement in the amas, as the boat will have side decks which will be sleeping / camping / seating decks. Each deck will be somewhere in the 6.5' range......... not set in stone yet, and 24-30" width. A boom tent will make this into a serviceable wall tent allowing you to sit on the side decks, or lay on them. The decks will overlap the original gunnels, reducing interior hull space.... which will no longer be used for much other than flotation and a place to put your feet. the actual distance between the inner edges of the decks will be only around 18" as I currently am envisioning it. and will largely be a footwell. The decks will be well aft, with a spray shield at the forward beam... probably fabric, and one or more grooves in the side decks to act as gutters draining to an outboard gutter on each side with an aft scupper...and needless to say inboard depending on heel angle. I'm planning at this point to make the side decks from blue XPS foam with a layer of epoxy glass top and bottom. They will be glued to the inner beams that cross the boat..... probably just routed common lumber, and to light weight longitudinal member, and tabbed into the sides of the canoe hull. The 6.5' longitudinal distance calls for some stiffening longitudinal members. The inner edge extending into the canoe hull may be thickened downward to add this stiffness, by simply laminating foam on and glassing it.
    The project is gradually taking shape in my mind if nowhere else ;-)

    H.W.
     
  6. thepelell
    Joined: Oct 2019
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    Location: italy

    thepelell Junior Member

    yes I get your idea.. it's actually how I would build my next tri if I had the funds and workshop place.. maybe next year.
     
  7. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    The basic concept is somewhat like Richard Woods Strike 15......... very loosely needless to say............. here are some photos of that boat: Small Trimarans.

    H.W.
     
  8. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Owly,

    Just make your amas longer.
    Taller, wider if need be but the approach and concept are what is of value in thepelell's post.
    Light construction, well made.
    Simple.
    Lather as much reinforcing fiber as you see fit and go sailing.
     
  9. rnlock
    Joined: Aug 2016
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    Location: Massachusetts

    rnlock Junior Member

    Since you have the Hobie, do you really need the canoe any more?
     
  10. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    The project is a trimaran, which will have integrated side decks, and some spray protection. The Hobie is not complete, nor is it what I want. I'm not interested in racing around on a Hobiecat, but in leisurely camping on large remote reservoirs for a few days at a time. To make the Hobie work, I would need to do a considerable amount of work.... if that was what I wanted. This boat will have a junk rig, and the two side decks will be provide a place to sit, with your feet in the center hull, for comfort, and a place to sleep. They will be solid, and built with gutters, and a spray shield at the forward beam, etc. A wall tent hung over the boom will make for comfortable camping. Throw an anchor out in a quiet bay a bit off shore (away from bears). It will have a free standing mast stepped in the canoe hull. The idea is leisurely touring & exploring, not the thrills and hiking out for max speed like a Hobie. If that was what I wanted, I'd invest in a more complete beach cat. The junk rig makes for extremely easy sail management, and instant reefing to whatever amount of sail is needed, which will allow an oversize sail for ghosting in light airs. It's a very different concept. The Hobie hulls just eliminated the need to build hulls. At $100 for the pair, including a great pair of rudders, and all the hardware it was an incredible bargain. I couldn't build ONE rudder for what I paid for the whole package.

    H.W.
     
  11. nwguy
    Joined: Feb 2010
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    Location: Poulsbo, WA

    nwguy Junior Member

  12. thepelell
    Joined: Oct 2019
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    Location: italy

    thepelell Junior Member

    nwguy, I like the ladder beams. Is it robust enough? I imagine you can change width as you wish.
     
  13. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    Very nice job......... but definitely not what I'm building which will as I said, have solid side decks that will extend both outboard and inboard a bit, and be about 6.5 feet long, with the beams at the forward and aft ends of these decks. The idea is to have a tiny sailing camper. These side decks will be for sleeping or sitting on with your feet in the canoe hull, and the beams and amas outboard of these will fold upward for transport. Total width between the outboard edges of the two decks will be about 6', leaving about 2' outboard on each side, a foot of which will be open space between the decks and the amas.... assuming I make the boat 10' wide. The pivot bolts will be above the beams a bit, allowing the two amas to fold up over the decks for transport.
    I love the ladder arrangement in the photo very innovative. A friend of mine built an aircraft using ladder rails for wing spars. The deal on the mast and sail looks like a bargain..... I might have bought it if I'd known about it a month ago, but it's way too far for a special trip.
    I'm not particularly happy with the weight of the Hobie hulls, but they'll do for now..... too cheap to pass up. I still may build amas from thin ply using stitch and glue, at some point..... but that involves money and time. The two flip up rudders on the Hobie 14 were worth at least what I paid for the whole boat! Right now, getting it built and rigged and on the water by next summer is priority over refinements. The idea is to set it up with an oversized cambered split junk rig sail so it will ghost in light airs and can reef instantly as only a junk can. The idea is easy relaxed sailing and camping, a completely different mission than most folks are looking at.
    Here is a photo of a little tri with the sort of sail rig I have in mind. Little Tri
    [​IMG]

    H.W.
     
  14. Owly
    Joined: Oct 2016
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    Location: Montana USA

    Owly Senior Member

    If you look again..... the ladder is not set up to telescope. He has a shortened section below, and a longer section on top.... obviously for strength. Personally my concern would be twisting of the amas. There would be little to keep them parallel along the longitudinal axis with the two mountings so close together.
    H.W.
     

  15. rnlock
    Joined: Aug 2016
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    Location: Massachusetts

    rnlock Junior Member

    I wasn't suggesting you put a Hobie rig on it. If you use smaller sails, you won't be racing around. If the hulls can handle enough weight, you could make a deck, spray protection, etc. where the Hobie trampoline is now. I suspect, though, that it might not handle the weight.
     
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