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mast rake

  • 12 Jun 2015 20:12
    Quote
    Reply # 3384780 on 3202326
    Deleted user

    Hello, 

    Thanks for the input, I have decieded on a location for the mast, based on " jester" as I am replacing the deck and coach roof on my own folkboat I don't need to worry about existing woodwork, and the mast will come down into the forepeak area, which is only to be used for light storage, as long as I can access the forward keelbolt, job done, I can always juggle the sail around a bit, if needed.
  • 11 Jun 2015 13:38
    Quote
    Reply # 3382832 on 3202326
    Anonymous member
    For what it's worth I plan to alter Tammy Norie to make her mast rake adjustable. It's possible that you could do something similar and therefore have less worry about getting it right first time.

    Tammy Norie's mast step is a glassed-in block of wood with a steel bracket on top that connects with the mast fore and aft. There's a long bolt that goes through the bracket and the mast to hold it in place.

    My idea is simple: extend the "jaws" of this bracket further aft and have several wooden blocks of padding along the bolt that I can use to fill in the gap.  To adjust the mast rake I'll move some blocks around (and of course, I'll need to fiddle with the other blocks at the partners).

    There's more background on my blog.


    Last modified: 11 Jun 2015 13:39 | Anonymous member
  • 17 Jan 2015 10:38
    Quote
    Reply # 3202673 on 3202326
    Deleted user
    Hello David Thank you for the reply, I noticed in your profile the reference to "David Thomas" as well as the folkboat, i own a 25.5ft bolero, (which is for sale to fund the JR folkboat ), and I also used to live in Cumbria ( Appleby ) but I digress ! I have various reference books, and between them I should be able to sort things out with relative ease, but as an example it took me about 3 yrs to figure out " ohms law " so I do struggle with mathematics. My folkboat is about 400 miles away in Glasson dock, Lancaster, so I don't have the luxury of nipping outside to make various measurements, or looking at the accommodation etc, although there won't be much of an impact internally, as the mast will be entering the forepeak area, which was used to house all the various sails. I have basic measurements of Haslers boat "jester" but not sure if he raked his mast forward. Struggerling along trying to figure the maths out is my biggest challenge, so hopefully people will tolerate my posts, until the penny drops ! Thanks
  • 16 Jan 2015 23:40
    Quote
    Reply # 3202490 on 3202326
    Anonymous member

    Roger,

    This isn't really something that can be considered in isolation.

    1. First, the centre of area of the sail must be placed correctly relative to the centre of lateral area of the hull. Not an exact science, but usually about 9% of the waterline length ahead of it.
    2. Then you can begin to consider the position of the mast line relative to the sail. Fig 6.28 in PJR gives the practical limits of the mast line.  
    3. Then you can begin to consider where, within those practical limits, you can place the mast in the boat, taking into account possible positions of the partners in the deck, possible positions of the heel near the keel, and possible positions of the mast line relative to the accommodation. 
    4. Having taken into account all of that, we can then say that angles of forward rake between 2 and 6 degrees have been found satisfactory, and indeed desirable in some cases. But to start with the rake angle first is to put the cart before the horse :-)
  • 16 Jan 2015 21:38
    Quote
    Message # 3202326
    Deleted user
    Hello I am in the process of trying to figure out a lot of issues before altering my folkboat. I wish to rake the mast forward, but by how much ? I am thinking 2 or 3 degrees, but not being very good with maths, I struggle generally trying to work out the mathematical implications. On a 26ft folkboat, could I leave the mast where it is, and simply rake it forward, or would it need to be moved forward before raking ? Thanks
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