Diamond Sweepback

Discussion in 'Multihulls' started by catsketcher, Jul 28, 2015.

  1. catsketcher
    Joined: Mar 2006
    Posts: 1,315
    Likes: 165, Points: 63, Legacy Rep: 790
    Location: Australia

    catsketcher Senior Member

    Hello all
    Does anyone have experience with the calculations on sweepback on diamonds on a mast. I am building my mast now and can go out and measure some boats moored nearby but someone may have some numbers.

    I will also be able to have some lowers/intermediates coming from the diamonds to stop forward pumping. The boat is solid and not flexible.

    cheers

    Phil
     
  2. outside the box

    outside the box Previous Member

    Hi Phil
    Have you made any progress?

    The reason for my question being, the guys were discussing this Friday and suggested a GL paper available on masts and rigging, we can scan and email you if you don't already have it.

    We have recently been discussing the same thing with Southern spars, they analised a rig for us, surprisingly they suggested a minimal increase in spreader rake made quite a difference and also suggested we move the rotation point aft this creating a complementary moment to the few degrees extra spreader rake.

    I am sure we have other information in archive I could scan for you also.
    I am available direct on admin@ezifoldyachts.com.

    Brooke and Team Ezifold

    QUOTE=catsketcher;744865]Hello all
    Does anyone have experience with the calculations on sweepback on diamonds on a mast. I am building my mast now and can go out and measure some boats moored nearby but someone may have some numbers.

    I will also be able to have some lowers/intermediates coming from the diamonds to stop forward pumping. The boat is solid and not flexible.

    cheers

    Phil[/QUOTE]
     
  3. catsketcher
    Joined: Mar 2006
    Posts: 1,315
    Likes: 165, Points: 63, Legacy Rep: 790
    Location: Australia

    catsketcher Senior Member

    That would be good to read the article. I used to have one by a Kiwi designer but seem to have mislaid it

    cheers

    Phil

    philthompson67@gmail.com
     
  4. Richard Woods
    Joined: Jun 2006
    Posts: 2,209
    Likes: 171, Points: 63, Legacy Rep: 1244
    Location: Back full time in the UK

    Richard Woods Woods Designs

    Missed this one. I guess your mast is fixed, not rotating, as if so then the genoa leech position will determine sweep back. I generally use between 10-15 deg but rigger seem to do their own thing, whatever I say

    You certainly want some sweepback and of course, balance the stay forces. But I think you know all this anyway.

    Richard Woods

    Richard Woods
     

  5. outside the box

    outside the box Previous Member

    Phil
    Check your in box.

    Regards
    Brooke and Team Ezifold

     
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