Westerly Pageant conversion!

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  • 25 May 2020 00:24
    Reply # 8990677 on 8987104

    Hi Graeme

    What a brilliant tip!

    Your right of course, I would have thought about it myself.                                 

    Probably about 5 minutes before I'd finished transcribing all the figures manually to the paper sailplan;-)

    Thanks very much...

    Last modified: 25 May 2020 00:32 | Anonymous member
  • 24 May 2020 23:31
    Reply # 8990642 on 8987104

    The use of spreadsheets. You will probably think of this yourself.

    When you are ready to make the spars and the sail, there are an awful lot of numbers that all need to be multiplied by  .9848 or whatever your final scale factor becomes. Easy to get a mistake. 

    I haven’t learnt how to use my CAD progam properly yet, but when I had to apply a scale factor across a whole set of dimensions (as when scaling Slieve’s Amiina sail drawing with its original dimensions) I found it easy to put all the dimensions into an excell spread sheet.

    Once done, apply a scale factor across all of them instantly.

    [Edit: You put the scale factor into your spread sheet at a cell address, say, A3B4 then when you refer to it throughout the rest of the spread sheet, you refer to it not as the relative address A3B4 but as an "absolute address" which you write as $A3$B4.

    After that you have a real working spreadsheet. Your scale factor is now a variable - you can change the value of $A3$B4 - or whatever the cell address is - and instantly get a whole new set of scaled dimensions.]


    Also, if you want to try what it looks like a little larger or a little smaller on your drawing, then you are all set up to instantly get a new set of dimensions. As a bonus, the (scale factor)**2 follows instantly too, so you can keep an eye on the sail area.

    In fact, I found it quite interesting to start with sail area and then inverse the maths,  to find the desired scale facter.

    (Great thread. Its interesting to follow the thinking of these two designers.)

    Last modified: 26 May 2020 10:01 | Anonymous member
  • 24 May 2020 19:11
    Reply # 8990265 on 8987104

    Thanks Arne. I wasn't being lazy ;-) 

    I just thought your CAD just magically gave you everything, including the next lotto numbers...It doesnt...Right ;-)

    Cheers...Paul

  • 24 May 2020 18:33
    Reply # 8990195 on 8987104
    Anonymous member (Administrator)

    Paul.
    I can of course find all the measurements, but they don’t pop up by themselves, so I leave that job to you (..better that you make the errors...)

    This is how you do it:

    ·         Look up my page: https://junkrigassociation.org/arne/

    ·         Up to the left you find ‘the book’  -  The Cambered Panel Junk Rig.

    ·         Open (or better download) Chapter 4 and read it carefully.

    ·         Then print out Sheet 1 and 2 of the Master Sailplan with AR= 1.80

    Now you need a calculator. The AR=1.80 sail I drew for you, has only been scaled down a bit from that master plan.
    The scale factor is F=0.9848.
    Multiply all the measurements on the master sailplan with that factor and write the found numbers onto the printed out sheets. I have double- and triple-checked those numbers, so they are quite reliable. Double-check your own calculations to be sure.

    For quick and rough checks of the measurement of your boat, just print it out. I have added a metre-scale to the right which you can use.

    Cheers,
    Arne

     


  • 24 May 2020 17:11
    Reply # 8990038 on 8987104

    David, Sorry but I missed the comment before the schooner design.

    In fact, I want to install a hatch type companionway similar to Sea Rover on you tube.

    Only a bi-fold version, all this is much later, after the rig is complete of course...

    Cheers...

  • 24 May 2020 16:56
    Reply # 8989985 on 8987104

    Sorry, I was away checking the prices on a big winch ;-)

    Arne,

    You hit the nail on the head. I'm a bit saturated with ideas now. It'll take a few days I guess to come up with a decision, but I do like that monster sail for light conditions...

    Could you make a copy with the measurements in?

    I owe you a dinner next time I'm in Stavanger,

    Wait , Make that a snack!

    Last time in Stavanger, I nearly had to sell my car to pay for the hotel, food and bar bill ;-)

    David, Don't scare me ;-) I'm hoping to not need the bottom panel (or 2) all the time. But It'll sure be nice in calm winds. Regards space available in 23'. Yes it was too tight until I decided to ditch half the v-berth.and the head. They'll be cut back (for'ard) It's only a sea going galley and the head is a portapotti.

    I'll try to draw it out in coming days, but don't expect drawings like you and Arne okay.

    Don't mock the artistically afflicted ;-)

    I still have a ton of questions about mast dimensions and rudders etc.

    But best I give you a break though first. ;-)

    I'll think this whole thing through and ask your further advice later if that's ok...

    Once again, many thanks to all contributors...


  • 24 May 2020 16:55
    Reply # 8989968 on 8987104

    I started to respond with a funny comment but actually .....;-) 

  • 24 May 2020 16:47
    Reply # 8989963 on 8987104
    Any thoughts?
    1 file
  • 24 May 2020 16:13
    Reply # 8989913 on 8987104

    Umm, how about two masts? (has been done in a boat this size, eg Hunter Liberty). Mainmast in the middle of the boat where there is plenty of space, smaller foremast way up forward where it does no harm. Then you might get 18 + 9 m2 in high AR? I'll look at it. [would need a non-sliding main hatch, possibly Mingming-style]

  • 24 May 2020 16:02
    Reply # 8989905 on 8987104

    Whew, that'll take some handling on a 23ft boat! I hope you're built like a rugby second row forward, Paul. I thought the 29m2 had got quite near to being OTT, but this ... will certainly need effective twin rudders (which I don't have on Weaverbird but are an integral part of my SibLim design). It's not relaxed sailing for a pensioner, anyway.

    OK, I think I understand the aim with the accommodation, now. It goes cockpit>>galley>>2 seaberths>> forepeak. But I don't understand how to fit it into 23ft, though I expect you've measured up and found that it will fit if the mast is that far forward.

    Last modified: 24 May 2020 16:05 | Anonymous member
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