Daggerboards, how to modify to adjust when loaded

Discussion in 'Multihulls' started by Dave_S, Sep 15, 2018.

  1. BrianJ
    Joined: Oct 2018
    Posts: 6
    Likes: 0, Points: 1
    Location: Redlands,( Bayside brisbane Qld. Aust.)

    BrianJ Junior Member

    I heard of someone who uses a strong holdown on the back of the board and winches tension so board comes up (hopefully) on impact, but I digress. Perhaps nylon or teflon rod like previously mentioned instead of synthetic rope,(it's fun to theorize).
     
  2. Nick91
    Joined: Nov 2018
    Posts: 1
    Likes: 0, Points: 1
    Location: Newcastle, NSW, Aus

    Nick91 New Member

    Hi Dave,

    Keen to keep track of what solution you come up with. I'm currently building an Arrow 1200 down in Newcastle, (only done the Carbon fore-beam and working on the Dagger-boards at the moment).

    I'm considering building rectangular cases with some sort of bespoke low friction plastic inserts to transfer the loads on the board and allow me the option of stiffer moulded boards in the future if I so desire. It seems to be the way most higher performance applications are going based on my research.

    I floated this idea with the designers and it was met with a bit of hesitation and a recommendation against, but a few others I've spoken to on similar designs have told me that they wish they'd gone that way for some of the exact reasons your looking for a solution now. Re moulded boards, it's definitely where I'll go in the future, but circumstance has driven me to build my own, the problem I reckon you'll have is going to be the cases being bespoke to their current dagger boards will be fitment all over again, even if made 100% to plan, hence my interest in a rectangular case with removable inserts.

    Another option could be to run a few thin strips of acetal or similar down the length of the case secured some how, potentially even to the boards themselves and see if that frees them up a bit loaded.

    How big of a problem do you find this in your use of the boat? Keen to understand as I'd love to avoid building myself into a problem later!

    Cheers

    Nick
     
  3. Dave_S
    Joined: Sep 2018
    Posts: 10
    Likes: 0, Points: 1
    Location: Brisbane Australia

    Dave_S Junior Member

    Hi Nick

    For me it is a PITA, I usually just pick a setting for the boards and leave them like that for the trip and that aggravates me.

    I haven't found a good solution yet but if I were building I wouldn't go any further until I found out how it's done properly. The big boys foils run beautifully so I assume they run on rollers in the casing so I'd be thinking along those lines. It shouldn't cost much in materials if you make it yourself but it will be more work.

    I must admit for now it is in the too hard basket until I have to take the boat out, then I can have a good look but I do wake up in the night with cunning plans...

    Dream solution
    I have good/reasonable access to the casings from inside and I have thought about fitting sprung adjustable rollers to the casing from inside the boat (above the waterline :)). Nice "U and V" shaped rollers to match the leading and trailing edges of the boards. Access to fit lateral rollers to the outward side of the case is too hard so the wrap idea sounds like a winner to counter lateral loads.

    More realistic solution 2.
    Just wrap the boards and see how well that works. I think it will be good enough that I can winch them up and down and I'll be happy with that.

    Regards
    Dave
     

  4. waynemarlow
    Joined: Nov 2006
    Posts: 399
    Likes: 31, Points: 28, Legacy Rep: 134
    Location: UK

    waynemarlow Senior Member

    Its always the rear section that seems to wedge into the case and prevent lifting out, I had wondered about a location section mounted on a linear bearing, on a shaft, at the rear within the case.
     
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