Quick and Daring design/build/race challenge this weekend

Discussion in 'Sailboats' started by Petros, Jul 4, 2013.

  1. hoytedow
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    hoytedow Carbon Based Life Form

    There are people(even wives) in the Michigan-Ontario-Ohio region who wish their homes had 8 boats right now.
     
  2. lewisboats
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    lewisboats Obsessed Member

    I preferred the other option... I got shed of the wife...
     
  3. Petros
    Joined: Oct 2007
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    Petros Senior Member

    this years Quick and Daring build/race contest is this weekend, Seattle

    All of you in the Puget Sound area may want to check out the wooden boat show at the Center for Wooden Boats at the south end of lake Union in Seattle Washington. free sailing, wooden boats on display, live music, maritime heritage museum displays, food, etc.

    My building partner and I have again entered the contest. We will be building our entry at the event on Friday July 4th, and Saturday, July 5th. Than the boats and teams race on lake union on Sunday july 6th at 3 pm.

    The contest is based on a max of 24 hours build time, and completing a three legged race where at least one leg is mandatory sail power, one leg is muscle powered, and third leg is crews option.

    total score is based on the time to build, the weight of the tools used, the cost of the materials, the workmanship, design and of course the race results. No testing is allowed before the race, the first time the boat goes in the water is at the race. Consequently as many as half the entries sink.

    It is always a blast to watch. We will be there in a boat which is a further development of my own design, A small trimaran that has a wood frame and polyester skin. over the last three years we have won the race several times, but came in second on the points total twice, and also sank one year! Hopefully we can win this year.

    It would be great to meet any local forum members, come by and say hello. Saturday is the best time to come chat. Or after the race on sunday afternoon.
     
  4. Skyak
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    Skyak Senior Member

    Good luck! If memory serves last year you built 'disposable' and got docked lots of points on utility despite winning the competitions. The judges are obviously offended by boats not made to last.

    Can you tell us anything about change in strategy? Maybe this year you could give the boat to someone willing to photo-document the build!
     
  5. messabout
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    messabout Senior Member

    We'll be rooting for you Petros. Go fast, build fast, use lightweight tools......but you already figured that out, didn't you?

    I'm a little bit jealous because we have not had a fun event of that sort in Florida. Our events are more nearly suicidal like the Everglades Challenge.
     
  6. Petros
    Joined: Oct 2007
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    Petros Senior Member

    WE are going back to traditional skin on frame construction, I made a great deal on some "closeout" polyester fabric, suitable as a durable and permanent skin, so fabric costs will only be about $25. vs. the more typical $75 for retail price.

    All solid swan stringers and frame material (doug fir) and one sheet of 1/4" ac plywood that I bought for $11 because one corner was damaged. that is for gussets, rudder, floor and seats, plus paddle blades. will use plated deck screws (lifetime guaranteed not to rust or corrode) to assemble it.

    There are a few tweaks to the design to reduce time to build, but it should make a decent boat. since "paint and decoration time" is not counted towards the build, we just have to get it to the point of being able to float and sail it, so there are many nice features we decided are just "decorations" since they are not necessary to float and sail it.

    One thing I am still working out, perhaps someone here could offer some suggestions. we have a 18-19 ft narrow kayak-like center hull, with a simple 2x6 cross beam with two sharp keel amas or floats to offer both stability and some lateral resistance in place of a dagger board or keel. the hull usually builds and covers fairly fast, but these floats double the building time so I have considered various ways to make them fast and easy to make. We have built simple frames and covered with fabric, than painted to seal it. we have to build two, and it has to have fairly sturdy frames to attach to the beam ends (longs screws are fastest, but we might consider other means such as lashing, or wood dowels through a simple double shear bracket). They have been triangular in cross section and about 3 or 4 ft long, so they act like a keel, it works well, fairly low drag too. We have also used cardboard and than covered with light fabric and water proof glue (Tightbond III), and painted it, makes a nice rigid "all natural" shell, but eventually water logged from minor leaks (because of the fast build). I found some cheap imported marine plywood for $11 a sheet (3 mm), and thought about using it the same way the cardboard was used (stitched the edges with wire and used adhesive-caulk to seal the edges-takes more time that it would seem), but both build methods took more time than we wanted. When we have to build three hulls, even if two are small, we are at a big time disadvantage.

    I have been considering finding something cheap, hollow, and shaped about what we need, or even torpedo shaped (so we would have to add a keel, no biggy if it saves build time). something like a 2 liter beverage bottle, but much larger. I could not think of any thing. Our current plan is to use a single layer of 1/4" plywood vertially, and glue on each side 3" rigid foam insulation from a big box hardware store, and than give it a "quick" shaping with a bread knife into an approx foil shape. good enough to float and sail, and than we can "decorate" it by going back over it to smooth it out and either paint it, or even glue on a layer of light fabric and than paint it to give it a tough skin and an attractive finish. It must be attached to the beam in a way so it will not fold inboard when on a reach, but I think several 1x4 diagonal braces part way down should be good enough (and hopefully will not drag in the water). My only concern is this may not be any faster than just building a simple wood frame and covering it with fabric.

    The primary structure has to be wood, but we can use any other material for skin or other features, I am assuming the foam as a float (with the wood center layer for strength) would not violate this rule.

    Any thoughts on what else I could use for a fast build ama? we have build wider mono-hulls but they are more difficult to paddle, the fine narrow hull moves the fastest, and with the small outriggers allows us to put all our efforts into paddling without worry of going for a swim (and lose, which we have also done in previous years), and allows us a larger sail that does not need to be countered with weight shifting. Remember, it is triangular coarse with one leg is mandatory muscle power only, one leg is mandatory sail power only, and one leg "free style". with a stable hull we can both paddle and sail for best speed on the last leg, and with a very narrow hull we move the fastest. This configuration has won us the race three times, but the build time bumped us to 2nd total points. So the narrow hull with out riggers is a proven way to get around the course fastest, now we have to find a way to make the boat faster to build, with the outriggers as a primary way to do this. If we can find something the right size and shape, that is cheap (cost of materials is part of the score), it could just be duct taped or screwed to the end of the beam (and than made "pretty" after the build time clock is stopped). but I could not think of any thing.

    Any ideas or suggestions?
     
  7. Skyak
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    Skyak Senior Member

    You are the expert, but I will throw out some ideas I have had.

    The first question is what is good and bad about prior design
    good -works, saves a keel
    bad -takes too much work/volume, poor lift/drag

    My opinion is that SOF is more difficult fitting higher curvature -so go to a much higher length to beam. The second trick is only put curvature on one side (the inside) and have the outside just be flat plywood. The last trick would be to build the floats back to back for skinning and sealing -the forces are balanced -then cut them apart with a razor. If you use foam for stringers and cut two at a time with a hot wire it should go very fast.

    If the boat was for me I would do two crossbeams -you could make it with no additional wood by making triangular akas using the timings from the front for the aft. Then with long slender floats that are only enough to keep the hiked weight of the crew out of the water you could have some serious sail area from the hiked crew with very little drag.

    I think a serious light wind super low drag boat would be appealing to Pacific north west judges.

    PS -is there any of that cheap fabric left? I could show you how.
     
  8. Petros
    Joined: Oct 2007
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    Petros Senior Member

    good thoughts skyak,

    I had considered two beams and a longer narrower amas. might add extra build time. keeping the part count low, even if at the sacrifice of weight, usually saves build time, which is the big challenge.

    attached is this years design, though I have already made a few tweaks to it (move beam and ama forward a little). So it can be revised some as we build it. notice the amas.
     

    Attached Files:

  9. sharpii2
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    sharpii2 Senior Member

    Here's an idea on how to make the amas (see attachments).

    Here the amas are of the submersible kind and have a scow like shape. Their outer sides double as long keels.

    The outer side/keel could be made of plywood.

    The hulls, themselves, could be made of layers of construction foam, bonded to this plywood.

    In fact, if I ever build this design, I will make the amas this way. Being made of foam, they will not flood if pushed under. They also serve as emergency flotation.
     

    Attached Files:

  10. Petros
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    Petros Senior Member

    thanks Sharpii,

    that is actually a great idea, I would improve on it further by bonding half of the foam on one side of the plywood and the other half on the other side. this way the keel will come out of the center of the ama, and it will give you a little more beam and righting moment. I think it might also make the ama a bit stronger to have the plywood in the center of the foam floatation.

    Good thinking, I might use a variation of the idea. I have already decided to cut the size of the amas down from 2x4' to 1x4'. This is because two layers of 2" foam (4" total), 1'x4' gives me 416 ft lbs of righting moment (at full immersion), and the most the sail could generate is 260 ft lb in a really stiff breeze (more than I think most would want to be in a small boat). This is neglecting any contribution from the plywood center, the hull and from weight shifting of the crew. So smaller amas means less cost, less build time, less weight. but by adding a small fin or skag to just the plywood part of the ama would give me a very efficeint keel, simple and very easy to incorporate.

    Most excellent contribution.

    Interesting: I see there have been 14 views of my plans, but only a few comments on the forum. Feel free to use the plans everyone, I will have more details/refinements if you want after we build it (improvements we discover during the build and sailing of it). Feel free to comment, good or bad now, only a day and half before we start the build.

    Also, if you should make it to the Center for Wooden Boats during Firday, Saturday, or sunday afternoon, make sure you drop by and say hello! It is fun to meet other forum members.
     
  11. lucdekeyser
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    lucdekeyser Senior Member

    why not go tacking proa: less parts ?
    Just keep the design and eliminate one ama; lengthen beam some.
    Good luck.
     
  12. sharpii2
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    sharpii2 Senior Member

    I think the reason most haven't commented on your design is because they can't find anything wrong with it. We designer really should be more supportive of one another.

    It is quite a sweet concept, even for a not so quick and dirty boat.

    I absolutely love the idea of a double outrigger (which this really is).

    The amas can be quite small, simple and light. And, since the amas don't have enough buoyancy to lift the main hull out of the water, the load on the rig is limited, no matter how much weight you put on the main hull.

    The only problem I see with your plan to put the foam on both sides of the plywood and making it quite deep is having to fair the foam.

    The scow like amas I drew only require cutting the profiles out of the foam sheet and gluing them together in layers.

    I drew (see attachment in earlier post) the plywood keel on the outside in hopes of getting less turbulence around the outer chines.

    Also, the scow shape requires only one cutting template. Then just glue and fair a little bit and you're done.

    An alternative would be to stack the cut outs vertically.

    In that case, I wouldn't even bother with curves. I would just cut long trapezoid with sharp points at each end. Then the cut outs could nest with little or no waste of foam.
     
  13. Petros
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    Petros Senior Member

    I had considered the proa, one team even entered one one year. I have never been in one and it seems like a shuttle would be way more work than a simple tack, one where likely you could end up in the water if something gets caught or tangled. I want to be able to turn both ways without having to think about it too much.

    I can not think of a single example of a good performing high performance proa (although attempts have been made), all of the fastest boats are either catamaran or tri maran (symmetrical). Besides, with a cat or tri you can always put a fabric deck (trampoline) between the hulls and have a nice place to stretch out.
     
  14. sharpii2
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    sharpii2 Senior Member

    I think what he meant by a "tacking proa" was really a single outrigger.

    Set up much like a double outrigger but with only one ama.

    The bow stay the bow and the stern stays the stern.
     

  15. Petros
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    Petros Senior Member

    unless the out rigger can swing to the other side, I can see myself going for an unplanned swim in a "tacking proa". I guess I have heard of them, but not sure how you can get that to work when the outrigger is up wind.

    there is something just uncomfortable about a boat that is not symmetrical about the center line.
     
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