15 Replies Latest reply on Jul 18, 2008 3:14 PM by Mark Matthews

    Looking for any tricks to save a surface as .stl filetype

      I have a surface that I'd like to save into a .stl filetype for use with another application. SW2008 sp3.0 doesn't like this and says that the operation cannot be performed. "The file could not be saved because the part's geometry is not valid for this type of save operation." Any way around this? I also have Rhino surface modeling software that can import my SW surface and export it as a .stl but this is very cumbersome to export, then import then export for every face/surface that I'm interested in. This is rediculous that SW can't do this. Any help would be appreciated.
        • Looking for any tricks to save a surface as .stl filetype
          Charles Culp
          I don't believe it is a "rule" but generally STL files infer a closed solid. I can only assume this is what the problem is in Solidworks. If the "other application" is known to handle non-solid STL files, then maybe make your surface-body a solid, with only 6 triangular faces to close the surface body. Then you can delete those in the "other application" or even hand-edit the STL file to remove them (any text editor will do).
          • Looking for any tricks to save a surface as .stl filetype
            Matt Lombard
            I don't think it's ridiculous that SW can't do it, I think you're using SW for something it's not intended to do. In SW stls are meant to transfer data for making a prototype, which can only be a solid. Stl is not meant as a general shape transfer tool.

            Rhino is a completely different kind of tool.

            Vrml works if you're desperate. It's still a mesh format. Maybe your mesh modeler can read it.

            Or you could make the surface into a solid and that will save out as stl.

            Maybe you should wonder why your mesh modeler software doesn't read NURBS data from say iges.
              • Looking for any tricks to save a surface as .stl filetype

                matt lombard wrote:

                 

                I don't think it's ridiculous that SW can't do it, I think you're using SW for something it's not intended to do. In SW stls are meant to transfer data for making a prototype, which can only be a solid. Stl is not meant as a general shape transfer tool.

                I am using SolidWorks in an unconventional manner, you're right about that and its not nearly as rediculous to me as it is cumbersome to deal with a capability that exists in one mode (part files) but not in another mode (assembly files). It would just make life easier if I could do this. That's why I was hoping for some advice.

                For the record. I'm not a huge advocate for Rhino but it has some slick tools that really come in handy from time to time. But it is developed for other uses.
                  • Looking for any tricks to save a surface as .stl filetype
                    Chris Kamery
                    Just a thought, and it may not help your end result, but depending on your surface could you just thicken it by a small amount? I am new to surfaces but my understanding is that a surface has 0 thickness. If you thicken it, the stl may see it as a solid and therefore export.
                      • Looking for any tricks to save a surface as .stl filetype

                        Chris Kamery wrote:

                         

                        Just a thought, and it may not help your end result, but depending on your surface could you just thicken it by a small amount? I am new to surfaces but my understanding is that a surface has 0 thickness. If you thicken it, the stl may see it as a solid and therefore export.

                        I'm starting with a solid so that step wouldn't be necessary but you would be correct in thickening a surface to save an .stl but only in part mode. I started another thread about saving multi-body surfaces parts out but have been limited in SolidWorks capability there too.

                      • Looking for any tricks to save a surface as .stl filetype
                        Mark Matthews
                        Seriously, try the vrml fomat. It is based on the image quality you have set for the display of your model in the graphics window; the smoother your model looks, the more triangles will be in the mesh.
                          • Looking for any tricks to save a surface as .stl filetype
                            Thanks Mark, VRML format does very well. Additionally it takes care of another problem that I was having-saving an assembly of surfaces as a .stl file. I can save an assembly of surfaces as VRML all I have to do now is rewrite my filetype converter to now include VRML files which get converted to a another format which SolidWorks doesn't support.



                            Mark Matthews wrote:

                             

                            Seriously, try the vrml fomat. It is based on the image quality you have set for the display of your model in the graphics window; the smoother your model looks, the more triangles will be in the mesh.

                              • Looking for any tricks to save a surface as .stl filetype
                                Mark Matthews
                                Thank Matt Lombard. He's the one who suggested it first.
                                    • Looking for any tricks to save a surface as .stl filetype
                                      VRML works to save out my faces however, SolidWorks cannot open the VRML file that it just saved This

                                      Sketch a 2d box with dimmensions 2000x1000 inches. Surface Fill and save as VRML. Now try to open the VRML you just saved. SW says "Model exceeds dimensional limits..."
                                        • Looking for any tricks to save a surface as .stl filetype
                                          Mark Matthews
                                          What might be happening is that the VRML file has no unit type associated with it. It has units, but doesn't know wether they are inches, mm, or miles. The parasolid kernel that is the geometry engine for SW is based in meters, so it's translating one unit of your VRML to one meter. SW has a size limit of 1000 meters. Your VRML model therefore is too big to hold.

                                          You don't want to work with a mesh in SW anyway. It has no ability to do anything with it other than use it for reference. If you want to work with the mesh, use Rhino, or 3D Max, or Modo, or one of the other good mesh modelers out there.
                                            • Looking for any tricks to save a surface as .stl filetype
                                              I understand the units issue now but one other concern is the import options within solid works that allows the user to select the units. I can select the units as inches and I get the same result. 2000 inches is only about 50meters, well under the 1000m envelope. Is this a software bug? I'm also wanting to use the VRML files for reference like you mentioned.


                                              Mark Matthews wrote:

                                               

                                              What might be happening is that the VRML file has no unit type associated with it. It has units, but doesn't know wether they are inches, mm, or miles. The parasolid kernel that is the geometry engine for SW is based in meters, so it's translating one unit of your VRML to one meter. SW has a size limit of 1000 meters. Your VRML model therefore is too big to hold.



                                              You don't want to work with a mesh in SW anyway. It has no ability to do anything with it other than use it for reference. If you want to work with the mesh, use Rhino, or 3D Max, or Modo, or one of the other good mesh modelers out there.

                                                • Looking for any tricks to save a surface as .stl filetype
                                                  Mark Matthews
                                                  Well I tried various units exports of VRML on a simple box, and all I can say is that it is broken. All other units except mm came in too small. This is independent of the part file's units. The part file can be in any unit, the only VRML export unit that came in the correct size is mm. Export in inches comes in too small, export in meters comes in 100 times too small. SW imports all VRML's in mm regardless.

                                                  So this does not answer your question of why your's are coming in too large? If you exported in inches they should be coming in 25.4 times too small, not larger.