7 Replies Latest reply on Mar 24, 2016 6:39 PM by Chris Dordoni

    Exported drawing splines are segmented

    Sean Trainor

      A customer is trying to export a SW drawing as DXF/DWG for cutting but the exported file has many lines segmented. When I open the part file it contains just a sketch (no extruded solid geometry) and the lines which are being segmented are splines or conics.

       

      Changing the export settings does not make any difference so I'd like to know if anyone has any other suggestions on what can be done?

        • Re: Exported drawing splines are segmented
          Leszek Paprota

          Hi Sean,

           

          as you save as DXF you have some extra options:

           

          hope this helps

           

          Leszek

          • Re: Exported drawing splines are segmented
            Dennis Bacon

            Hi Sean,,, I am assuming you are the one who is doing the cutting. What program are you using to open this dxf/dwg file? Is it your cad/cam software? Are you going to need lines and arcs in order to generate code? If you open it in AutoCad or DraftSight and list the entities are they splines, polylines, conics?  Just trying to get a feel for this..

              • Re: Exported drawing splines are segmented
                Sean Trainor

                HI Dennis.

                No i'm not the one cutting. I've just been sent this file to look at because lines are being segmented and it's causing problems for the one who is doing the cutting because the segmented lines are leaving a rough cut. In AutoCad some entities are listed as splines and some polylines.

                  • Re: Exported drawing splines are segmented
                    Dennis Bacon

                    Would we have an NDA issue if you posted the dxf/dwg? Maybe part of it? I'm still guessing.. Are you having the line segment issue when you open in SW? This will happen with polylines (depending on the options in the dxf/dwg). The splines should come into SW as splines (from my experience) Is the goal here to have smooth transitions from lines to arcs for generating code?

                • Re: Exported drawing splines are segmented
                  Feroz Mahomed

                  Sean,

                   

                  We have a similar problem when we open up a SolidWorks part with splines in our cam software (Mastercam).The spline is wire cut as segments instead of a smooth curve. We overcome this by changing the filter settings within the cam software. By playing around with the tolerances the number of segments are reduced. Ask your customer to check if their cam software has any similar settings that have to be changed.

                   

                  Somebody posted a macro here about a month ago that would convert your spline to radii. The macro would create a new sketch and convert the spline to radii. I shall post the macro if I find it.

                   

                  Macro for converting splines to 3pt

                    • Re: Exported drawing splines are segmented
                      Chris Dordoni

                      There's some additional detail about the macro toward the end of this discussion:

                      How to change a SPLINE to a regular curve....?

                       

                      There are several third party tools that can convert splines to a series of tangent arcs, and I believe there is a script for AutoCAD that can do it as well, (may not be a built in function).

                       

                      The majority of CNC waterjet, laser and router still use arcs. The cutting service probably has the software to convert splines to arcs, but then the output might not be what you expect.

                       

                      I have never been able to get consistent spline output from SolidWorks in a 2D DXF/DWG. Turning up the quality settings in the Document Options helps to a some extent, and its definitely better to save from a drawing than to attempt to save directly from a sketch for reasons which I do not understand. Sometimes breaking up the spline into smaller sections can help, but failing that, I have occasionally resorted to using a PDF printer (Not using SolidWork's built in PDF output) instead of DXF/DWG. Then I use an application that can read the splines from the PDF file, and export as DXF/DWG, and convert to arcs if needed.