Appropriate settings during STL export in old version of NX

Discussion in 'Technologies and Hardware' started by arra, Mar 14, 2013.

  1. arra
    arra New Member
    I'm a complete newby so my question may sound very trivial to the vast majority of the users here, but since I can't proceed my project at the moment I'll ask anyway and take the risk of people considering me a morron.

    I've created my 3D model in an old version of NX and want to export it to STL for printing purpose. The material I aim for is "Frosted Ultra Detail". There are quite some settings whilst exporting and to avoid using the wrong ones I hope someone here can enlighten me. Of course I searched the Web to find an answer but the picture shown below is the only concrete information I found.

    One thing that strikes me as odd is the fact that the traingle size is fixed. I would have expected that based upon the material used the triangle size would vary because the resolution of the materials are different and I assumed that triangle size has to be adjusted to the resolution of the material?

    If anyone could give me some pointers that would be very helpful. Thanks in advance


    Attached Files:

  2. wiwa
    wiwa New Member
    Hi Veloce Modelli

    In this case the triangle tolerance and agacency tolerance refer to the placement of the vertices and faces of the triangles relative to where they would go on a continuous non-flat surface.

    For example, if you are representing a cylinder as a band of triangles, you would need an infinite number of triangles to perfectly recreate the cylinder. So the tolerance will indicate how far away a triangle's vertex can be from the surface in your design, ultimately determining how many triangles need to be used to represent it. Flat surfaces with corners can always be represented at 0 tolerance, this only applies to curved surfaces like fillets, cylinders and NURBs.

    In this case 0.025 mm will work well for both tolerances, as it will give you a number of triangles that will fit within a fraction of the resolution of the FUD material.

    The other question this raises is what units you are exporting in. It can be assumed that you will be exporting in the default dimension of your part in NX, but you should upload the exported STL and confirm that its bounding box units match the dimensions of your part, and change the units of the STL on shapeways if not.

    Last edited: Mar 15, 2013
  3. arra
    arra New Member
    William, thanks for your reply and your effort to explain me some of the background. Lets see if this will help me proceed. Als thanks for warning me about the bounding box. I made a model in the scale I want to have it printed so I should be careful the scale doesn't change during conversion.

    Thanks again, nice to see that community members are willing to help out newbies with advise.
  4. arra
    arra New Member
    Even though UG shows about 8 error messages during the conversion to STL the model shows only a very small red coloured area in NETFAB. The red coloured area disappears with the default repair method.

    After the default repair method in NETFAB some questions rise;
    1. The "invalid orientations" as defined in the design rules does not appear in my default analysis, am I doing something wrong?
    2. The model has 19 shells. According to the design rules it should be 1 shell, how to do that? Executing the default repair method apparently does not resolve the matter.
    3. The analysis shows that "the surface is not orientable" in red coloured font. How to make it orientable?

    Any reply is highly appreciated, I'm completely clueless at the moment.

    Attached Files:

    JACANT Well-Known Member
    It may be worthwhile to try
    It will repair the file, union the shells into one and orientate the model correctly.
  6. arra
    arra New Member
    JACANT/Rob, Thanks for the reply and suggestion. I just installed the freeware version as suggested in the tutorials on the Shapeways website. Unfortunately the result is a non orientable file. I had a brief look on the cloud version of NETFAB you suggested, but to be honest I'm just here for the hobby and not my profession so I guess paying for repair of a file is quite difficult to keep the printing cost under control somehow.

    I was wondering if I can avoid having a non orientable file by changing the STL export options from NX for example? The attached picture shows some of the settings available during STL export. I highlighted the "Normal display" and "Triangle display" during my previous export. Although I can't imagine this has a negative infleunce on the orientation you never know.

    Attached Files:

    JACANT Well-Known Member
    The netfabb Cloud Services offer a free and easy-to-use solution for anyone.
    Just enter your email, upload your file. You will get an email with a link so you can download the repaired file.
    All free.
    Last edited: Mar 24, 2013