Hedley Nicol Trimaran Plans

Discussion in 'Multihulls' started by oldsailor7, Mar 12, 2010.

  1. taow
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    taow Junior Member

    yes agree having the plans would make life a little easier, thankfully i will have a full set of them in the future. unlike the full set of plans that was said to come with the boat. it was a piece of unreadable faded torn paper.
    i'd like to just tap them bolts through, cut the keel back to its original size and put some new bolts back in and glass it over.
    thanks on the paint, does look good, looks even better from a distance. :p
     
  2. cavalier mk2
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    cavalier mk2 Senior Member

    I'd make it at least as deep as the Cavalier keels, check out the photos and sail plans I posted way back. The stock Wanderer keels are pretty shallow as you can see on the pdf of Hawk.
     
  3. taow
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    taow Junior Member

    yeah i think ill be leaving them pretty close to what they are now, especially if the bolts go all the way through. i think with all the new info and renewd hopes in the old girl, i was thinking way ahead of my self. so for now a patch up, maybe take the squared edge of the leading edge for a better flow, remove the S/S boot crap and any flat bar or bolted on steel and further down the track when my knowledge as grown ill make some bigger and better changes, it would seem keel design has come along way since 1965. im going cross eyed reading about it haha.

    on that note. a question:
    are the side hull(ama) keels curved on bother sides or just the outside? for is it the side way lift out ward, that is wanted?
    does this make any sense? let me know your thoughts.
     
  4. cavalier mk2
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    cavalier mk2 Senior Member

    They were designed flat with a rounded front and tapered back edge. I think you are talking about a asymmetric keel. In that case the curved side would be inboard and the flat side out. Since both foils are often in the water at once a symmetrical foil would probably work as well. Did Glenn have a set of plans? Alan Nicol said they still have transparencies for Wanderer and others, hopefully they will make them available to restorers.
     
  5. oldsailor7
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    oldsailor7 Senior Member

    It's funny how some sailors have very fixed ideas about asymmetric foils.

    John Hitch (for whom I have a great respect for his innovative designs), once gave me a right ticking off for sailing his Spindrift 45 with both asymmetric daggerboards down at the same time. He was convinced that one would cancel out the other. I couldn't convince him that biplanes, with their very asymmetric wing sections, can fly perfectly well upside down. :eek:
     
  6. taow
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    taow Junior Member

    i dont know if glenn does or not sorry, and the full set of plans that was said to come with the boat, turned out to be an unreadable faded out, torn and glued pieces were glued like a jigsaw puzzle to a piece of carboard, but then you could hardly read them as half was missing any way.

    and the curve would be to the inside ay, well that throws my thoughts out the window,
    QUOTE=cavalier mk2
    They were designed flat with a rounded front and tapered back edge.
    ok well mine look to be squared front and very little tapered off if any tapering off the the back at all
     
  7. taow
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    taow Junior Member

    see i understand how a wing works, i use to work as a TA to an aircraft engineer and did some flying in my time, what im having trouble getting around is the curve being inboard on the keel as would this not want to pull that side hull downwards? should the boat ever go fast enough for such a small wing area to create any real lift in the first place. or maybe you want that downward pull to lift the other side higher, im really still just getting my head around it, and although i have plenty of other things to take care of first im keen to hear this explained
    cheers
    and does any one have a pic or 2 of the ideal or what they see as the ideal shape even just a few shape ideas, cheers
     
  8. cavalier mk2
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    cavalier mk2 Senior Member

    Round the fronts and taper the backs and you have one improvement right there. The curved side in is the lifting section of the wing counteracting the leeway....
    Fixed ideas about fixed foils eh Oldsailor? Your right in that the drag wouldn't be much and according to Rudy Choy theory might help offwind tracking. It only takes a few degrees of heel to lift the ama out so by 8-10 degrees most of the windward foil would be out too. Using foam section add ons it would be easy to make up your own mind, asymmetric one year symmetric the next.
     
  9. cavalier mk2
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    cavalier mk2 Senior Member

    It actually would lift the whole boat up a imperceptible amount. The foil guys are using radical lifting foils to more obvious effect for comparison. The windward keel if it pulled down would take away heel. In reality you get into what John Hitch was telling Patrick which is a small amount of drag.
     
  10. taow
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    taow Junior Member

    hmmm ok ,
    well i was planing to round the leading edge once i removed all the steel crap, so theres a start, thanks for that cavalier little clearer now cheers.
     
  11. cavalier mk2
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    cavalier mk2 Senior Member

    I should also say Oldsailor was right in his example in that having both boards down increased the area for leeway resistance. The windward asymmetric foil would add a slight drag penalty for the amount of lift. I think John Hitch forgot to take into account the angle of attack as the boat making leeway would make the windward foil operate like Oldsailor's upside down wing instead of canceling out the leeward foil. The only way to really check is with the instruments, GPS and knotmeter to see if everything is helping or knot. It gets confusing as you plot boat leeway versus speed drag....If the boards were built towed in a few degrees to offset leeway the windward board should have been up.
     
  12. taow
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    taow Junior Member

    well i don't think i'll be getting much time to do any real shaping. i'm going to shape the leading edge as best i can and reglass over it.
    (speaking of that, in what you saying in prev' post, should the leading edge be equal curve on both side, say the bi-plane, of or cured with the curve leading outboard? some ideas guys)
    and I installed a bilge pump into each side hull last time i was up, but have only put a plug on the ends where when needed i run a wire from the cockpit, didnt want them swinging on the deck and duck tape and anti slip doesn't hold for long. so be good to come up with something to do with that while we are playing with the glass.
    i'll try to post a pic or 2 along the way, if any ones interested, and i do thank every one for there input, power to knowledge.

    any more thoughts or ideas on something i should think about taking care of while i'm doing this work on the keels, put it up, might be something i haven't thought on yet.
    cheers
     
  13. cavalier mk2
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    cavalier mk2 Senior Member

    Hello Taow, I think you should round the fronts the same on each side and keep things symmetrical. You could do an ellipse rather than a half circle but I don't think it really matters that much on those keels. Taper the back edge to about 1/4 in starting at least 6 inches in and you'll be stock.
     
  14. taow
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    taow Junior Member

    thanks cavalier,
    i was planing an ellipse shape, but wasn't to sure on the trailing edge, so tapper to about 1/4, tapering from around 6in in, well if that's stock then there's very little stock about these keels, wonder why who ever did the work didn't take care of it like that, rather then just pretty much just put 2 x 2 to 3in thick flat boards on each side, amazing. anys
    cheers
     

  15. cavalier mk2
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    cavalier mk2 Senior Member

    If you feel inspired start about a foot in (sorry I'm not metric) and taper in a gentle arc or curve to the 1/4 inch edge. They specified a feather edge but the books will tell you anything beyond 1/4 inch won't help and will be fragile.
     
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