Minimum wall thickness vs cylinder diameter

Discussion in 'Design and Modeling' started by gibell, Jul 9, 2009.

  1. gibell
    gibell Well-Known Member
    I made a WSF part which is five 9mm diameter spheres joined by cylinders of diameter 2mm. While flexing this piece slightly last night, it broke fairly easily at one of the connections. It seems to me there is a difference between a wall or surface of thickness 2mm and two large volumes which are connected by a cylinder 2mm in diameter. The latter is far weaker.

    Anyway, I would recommend a minimum 3mm diameter for cylinders connecting two larger volume pieces. I have not had this size connection break on me.

    What is the diameter of the wires used to make springs in the 3D parts database? Do these break when flexed?
    Last edited: Jul 9, 2009
  2. joris
    joris New Member
    The springs in the 3D parts database are 3mm. You can download them here:

    Shape influences the strength of your models a lot. The ball I used for this video was 1mm thick but incredibly strong because of the structure:

    If a cylindrical shape is "held fast", hollow or acts as a supporting structure it could break very easily.

    We have these testing things though that we give to people and these are 1mm but solid and they bend in every which way without breaking.
  3. gibell
    gibell Well-Known Member
    I agree 100%. My pieces connected by a 2mm cylinder can lever against one another and easily break.

    Cool video! Is the model for that ball downloadable? I didn't see it in the 3D parts database.