Developable surfaces in Rhino - Plywood

Discussion in 'Software' started by IMSACAD, May 5, 2012.

  1. IMSACAD
    Joined: May 2012
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Stockholm, Sweden

    IMSACAD New Member

    Hi, does anyone have experiance how to set "Twist tolerance" in DevSrf when modelling for plywood.

    I realize that it depends on the thickness/type of the plywood and the size of the surface and I know that plywood doesn´t tolerate much twist -- beeing new to this it would be great with some general direction.

    For instance the topside surfaces for a "typical" 30 ft hull in 12 mm plywood.

    -----------

    For reference I´ve been looking at a french boat "Fox 10.20"

    http://www.fox-tech.fr/f1020gallery.html

    It seems to me that the chine/second surface from the top has some twist towards the bow - in comparison with the topsides and bottom surfaces which seems to have more constant angles. Moreover - by looking at these pictures it does not feel like there is much convexity in the bow sections of this surface. In Rhino I get this kind of flat developable surface with 1)* DevSrf having the "Alignment" option set to "Shortest".

    -in comparence with 2) an extended DevSrf with alignment set to "Least twist" or 3) a Lofted developable surface -which both - produces convexity in twisted regions.

    -------------

    I am currently working on a multichine hull with similar division of surfaces as the Fox 1020 and also with a plumb bow and it is the plumb bow that dictates that this surface has to end with a straight section/edge rather than a convex shape in this part of the stem -- I get a satisfactoy surface here with metod 1)* with a twist tolerance of 5.0.

    - but can I trust this result?
    - is the tolerance value to high?
    - would 12 mm plywood conform to this?

    Many questions and hard to put in writing, I´d be happy to submit Rhino models if someone experianced understands my problem and would help me.

    Thanks and Best Regards
    Christian Wallgren
     
Loading...
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.