HFJY34

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  • 08 Oct 2019 19:08
    Reply # 7923235 on 7155071

    I know where to find you Tony...

  • 08 Oct 2019 08:44
    Reply # 7922376 on 7155071

    Good luck with the build Frederik

  • 07 Oct 2019 11:10
    Reply # 7920814 on 7155071

    Hi Annie. The same here...

  • 06 Oct 2019 21:30
    Reply # 7920231 on 7919223
    Frederik wrote:

    Here we go...


    Fantastic to see the work starting, Frederik.  I am so looking forward to seeing your boat take shape.
  • 06 Oct 2019 17:38
    Reply # 7919990 on 7155071

    Hi Arne. Behnke epoxy. From 5 celcius up. 

    When it gets too cold, I’ll do the frame glueing indoors. 

    Last modified: 06 Oct 2019 17:39 | Anonymous member
  • 06 Oct 2019 15:46
    Reply # 7919871 on 7155071
    Anonymous member (Administrator)

    Hem, Frederik,

    that tent doesn’t look like a warm place during winters in Denmark. Have you found a glue that will work down to frost temperatures?

    Arne


  • 05 Oct 2019 21:33
    Reply # 7919223 on 7155071

    Here we go...

    Last modified: 05 Oct 2019 21:35 | Anonymous member
  • 11 Feb 2019 02:16
    Reply # 7157082 on 7156352
    Anonymous wrote:

    Taking the maximum rightning moment of the boat as starting point of the mast calculations  makes the most sense to me.  Times 3 as safety factor. Eric Sponberg does the same.

    Then again... what about the mizzen mast....


    Sponberg's article on designing free standing masts:

    https://www.ericwsponberg.com/wp-content/uploads/design-engineering-masts.pdf

    Last modified: 11 Feb 2019 02:21 | Anonymous member
  • 10 Feb 2019 15:24
    Reply # 7156352 on 7155071

    Taking the maximum rightning moment of the boat as starting point of the mast calculations  makes the most sense to me.  Times 3 as safety factor. Eric Sponberg does the same.

    Then again... what about the mizzen mast....


    Last modified: 10 Feb 2019 15:24 | Anonymous member
  • 10 Feb 2019 13:07
    Reply # 7156219 on 7155556
    Anonymous member (Administrator)
    Anonymous wrote:

    Thanks for the replies.

    Arne. 

    Are you using modulus of rupture in your calculations? For a 310/62 mm hollow spruce that would be 72 Mpa with a breaking strength of approx. 16300 kpm...



     I picked the strength of spruce from Ian Nicholson's Boat Data Book.

    There were three numbers to pick from, tearing force, crushing force and breaking force. Not knowing what to choose, I picked the 'weakest' one, the crushing force at 45MPa. If I had chosen 71MPa instead, then the breaking moment would rise from 11600kpm to around 18500. I have later looked up data about wood, and my 45MPa are most probably on the low side. However, I have just used local trees for masts, not knowing how good quality they were, so I my thinking was 'Better safe than sorry'...

    Arne

    PS:
    As early as in 2006, I had a go on finding the strength of wooden masts. I have later 'refined' the way to guess the righting moment of the boat, but apart from that, the write-up still makes some sense, hopefully. 
    The uncertain factor is the strength of the wood material.

    Last modified: 10 Feb 2019 13:37 | Anonymous member (Administrator)
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