FreeShip/DelftShip tip

Discussion in 'Boat Design' started by lewisboats, Jun 23, 2013.

  1. lewisboats
    Joined: Oct 2002
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    Location: Iowa

    lewisboats Obsessed Member

    If you haven't already figured out this one then here is a tip to find your CE's of your sails. Put your sail on a separate layer and name them and they will show up in Design Hydrostatics at the bottom. Create a new point and assign it the X and Z coordinates for the center. So... no brainer! However... if you then assign All your sails to the same layer... the mainsail... then the combined CE will be listed and you can assign it it's own point. In my case I have 4 center points... the mainsail alone; the whole rig with topsail; the main, mizzen and Jib; and the mizzen and jib together with no main. This allows me to estimate various balances very easily and to plan my appendages accordingly. So far I have a good group with one flyer... the Jib and Mizzen is a bit more forward than the rest but a bit of lee helm might help in tacking... or not... then furling the jib to about 80% would shift it back in line. Note that if you disregard the point indicating the Mainsail alone the other two are within 3 of inches of each other and the Jib/mizzen combo is about 9 inches ahead of the full rig and a foot forward of the rig with no topsail.


    Points in the Gaff Mainsail... top left: Main alone. top right: All sails combined. Point below upper two: No Topsail. bottom point is Jib and Mizzen alone.
  2. kvsgkvng
    Joined: Jan 2012
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    kvsgkvng Senior Member

    Great tip! Thanks for letting people know. Now this daunting task is made easy. This should be a thread dedicated to tips/methods/tutorials like this for all to know. Thank you.
  3. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    I hadn't thought about assigning a point to the CE. I do assign each sail to it's own layer though. I can pull up the Design Hydrostatics page or just the Layers command menu and pull the values for X and Z from those locations. I have a spreadsheet that will calculate the total CE and lead based off of the sail and hull properties. I've built in some shifting mechanisms to offset centers when I'm trying to balance the rig out. When I like the numbers, I go back to FS and apply the shift to the model to keep everything sync'd up. On a split rig and having the mizzen on it's own layer, I can take it's center and apply a custom mizzen factor if the rig warrants something other than a 50% value.
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