Delftship framing problem

Discussion in 'Software' started by NTGeorge, Apr 22, 2013.

  1. NTGeorge
    Joined: Jan 2010
    Posts: 15
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    Location: Darwin

    NTGeorge Junior Member

    Hi guys

    I normaly leave the hull modeling to my navel architect but alas he has been beyond flat out lately and has not had time to take on the small hull projects I have.
    I have nearly finished my hull design, and have been going over it before I convert it to DXF to cut. One problem that has cropped up is that frames I have put into the model seem to flow through my chines (reverse chines) in a bit of a radius rather than comforming to the shape of the chine and bottom sheet.
    I've tried attaching a pic but it wants a URL address, I'm assuming I'd need to load it to photobucket or something?
    I'll be the first to admit I don't fully understand the softwares capabitity or all it's functions, as it feels like it takes me longer to do things than it should.
    I'm a builder so I know what I want and need just need a little help with getting the software side of things sorted.

    Cheers

    Ah, got the pic sorted the purpley top sheet is the rear transom frame, you can see the point within the surface where the chine and bottom sheet meet the transom.
     

    Attached Files:

  2. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Very shortly: as far as I know, you can't create internal frames with Delftship.

    That software has been created for hull shape design and hydrostatic (and some hydrodynamics) calculations.
    As soon as you try to insert frames, bulkheads etc, your hull surface will get plagued with deformations, kinks, discontinuities of every type. You might try to correct them, but it's a hell of a work. My advice is to create the hull shape you want with Delftship, and then do the framing work with some other software (Autocad, Rhino, whatever).

    You might check this old thread where I had asked the same questions: http://www.boatdesign.net/forums/de...ated-masses-etc-freeship-delftship-38103.html

    Cheers
     
  3. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    Hmmm, bummer. See we do learn somthing new every day. I can see how my NA earns his money.
    All a bit dissapointing, I'll have to look into Rhino and see if it's echanomicaly viable for me.
    Your not wrong though, as soon as I added a couple frames and bulkheads the poop started hitting the fan.

    Thanks for your time mate
    Cheers
     
  4. lewisboats
    Joined: Oct 2002
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    Location: Iowa

    lewisboats Obsessed Member

    If you want to create a frame the best way to do it is to create a panel, assign it to a separate layer then work with it from there. To create a panel you need to extrude an edge. I usually take an open bit of shear (say two highlighted sections) then extrude the line upwards by say 1. Then you extrude upwards again by say 2. Right click and deselect all. Then turn on interior edges and highlight the mesh from your first extrusion. Delete it using edit/delete. This will leave a panel floating in mid air. Create a new layer and assign the panel to that layer. Now you can start shaping your panel to match your hull. Find your perspective panel and change the mode to shade. Use transform/move to move the panel to the correct position and start manipulating it to fit into your hull.

    From what I see in your picture you have a crease line running down the middle of your hull but you don't have a hard point to match on your frame shape (if I am seeing things correctly). Even if you have selected corner... sometimes you have to create additional lines between points to straighten out the mesh more. Add an additional point on the top of the frame and connect the bottom and top points with a line. Make sure that the corners boxes are checked in the point properties.
     
  5. daiquiri
    Joined: May 2004
    Posts: 5,371
    Likes: 258, Points: 93, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    If you want to go low-cost (no cost in this case), another option could be DraftSight - an AutoCAD clone from Dassault Systems (folks who made the Solidworks): http://www.3ds.com/products/draftsight/overview/
    It is a very well-done and valid CAD software for 2D drafting. Frames and bulkheads are anyways made of 2D entities, so you don't really need a 3D software to get the job done.

    So, in Delftship, delete all the existing stations (if you have any), and create longitudinal and/or transverse stations in positions where you want your bulkheads and frames to be placed. Then export your project to DXF file, and open it with Draftsight. You will see the outlines of your boat's hull at the points where the stations have been placed.

    Detract the hull thickness and you'll get the shape of the internal framings. From there on you can continue your design work on framing in 2D, with DraftSight.

    Cheers!
     
  6. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    Thanks guys, your legends, I'll give your ideas a go this evening.

    Also, at what point or percentage dose a section of UN-developpable plate really become un-developpable? I have a couple small sections at the bow that are in the 2-8% mark. I'm building in 4mm plate ally.

    Cheers
     

  7. NTGeorge
    Joined: Jan 2010
    Posts: 15
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    Location: Darwin

    NTGeorge Junior Member

    Adding some more points directly above the problem on the respective frame and adding a new edge solved the issue, thanks a heap guys.

    I'm realising that I can't fight having to buy some software to do the internal framing and nesting. I'm having a bit of a look around, is there one that will do the internals and unfold to nest?

    Cheers
     
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