Delftship station spacing and chine plot

Discussion in 'Software' started by stevee, Jan 3, 2015.

  1. stevee
    Joined: Feb 2011
    Posts: 7
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: scotland

    stevee Junior Member

    Delftship cheat

    Tansl, thanks for your input, am going through your manual.
    Re Delftship, what about the following cheat for chine boats. Copy lines drawing into program, then adjust control point values for sheer chine and rabbet numerically by hand to offset table values. Fair these three control lines, export out the resulting hull values, and note the faired control values. Substitute the latter into the exported offset table, and reload into Delftship. If the export and inport values have the same meaning, then what should be generated is a representation of the original hull now faired, with a new set of control curves to match? Might this also work for round hulls? This would allow use of the fairing process, and station subdivision when this is needed
  2. TANSL
    Joined: Sep 2011
    Posts: 7,039
    Likes: 569, Points: 123, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Sorry, I can not answer your question, I have never worked with DELFTship. The problem, in my opinion, is that the surfaces never go exactly by these control points. You should check whether the degree of approximation is sufficient or not for the goals you want to achieve.
  3. frank smith
    Joined: Oct 2009
    Posts: 980
    Likes: 14, Points: 28, Legacy Rep: 185
    Location: usa

    frank smith Senior Member

    Nope, no control points on the surface, but the more control points, the closer they are to the surface.
  4. DCockey
    Joined: Oct 2009
    Posts: 5,122
    Likes: 568, Points: 113, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    In general if the hull surface passes through a set of offset points, control points will not be on the surface.

  5. mick_allen
    Joined: Dec 2005
    Posts: 46
    Likes: 5, Points: 8, Legacy Rep: 59
    Location: vancouver, b.c.

    mick_allen -

    Since this thread applies to free/delftship and its nomenclature:

    Is it possible to place stations for the SURFACES of a chine boat at predetermined points
    One can derive from the F/Dship model a station or buttock or waterline or chine at any point from their respective origins. Use intersections to place the station, buttock or waterline exactly as desired. Those lines and chine offsets will lie on the surface (and you can export the offsets from those items).

    Nomenclature again:
    There seems little point in entering the offset table if it generates the control curves and not the actual hull . . .
    is there any way to force the control curves of a chine boat to lie on the surface . . . does fairing a critical curve, ie sheer, chine, and fairbody, automatically align the surface with the control curve?

    Free/Delftship manual section 9.7.1 - control curves are always exactly embedded in the surface.
    [Control lines in delftship are applied to surface 'edges' or other edges after modelling and for 2 reasons – one of which is to display a curvature analysis tool.]

    nor can I see any way to see the HULL values in real time
    are you turning the control net off? And/or are the hull layers being turned on?

    adjust control point values for sheer chine and rabbet numerically by hand to offset table values
    In general, control point locations in modelling have nothing to do with station offset point locations – they relate more to the surface or surface edge shapes. Of course one can use whatever is desired like putting them in-line with stations, but are stations good locations for defining a hull or shape with control points? Sometimes gigo.

    Fair these three control lines
    But this has to change their (longitudinal as well as all other) locations and number – not desired in your ‘stations’ scenario?

    note the faired control values
    I don’t think either program records (notes) control values – and you sure wouldn’t do it one by one in a program that doesn’t record them (no point).

    Or am I missing something.
    might be . . . but you know what they say . . . rtfm.
    Humour aside, it's tough: one needs to really play around with the progam(s) for 50 hrs or so in order to see what it can and what it cannot do and maybe what you can game it do. There's lots it cannot do, but then again for free, simply amazing what it can.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.