11 Replies Latest reply on Jun 25, 2008 11:55 PM by Balic Dalibor

    Spline to arcs

    Balic Dalibor
      Hi guys,
      does anyone could give some tip, on how to convert a spline into line and tangent arcs without redraw them, i am having about 15 surfaces and sheetmetal per file to cut, and the cut machine not work good with spines.
      Some, trick, macro, add-in, whatever? Possible without exiting from SolidWorks
        • Spline to arcs
          Matt Lombard
          In general, no, there is no way to convert general splines into general lines and arcs.

          But, if a sheet metal flat pattern results in splines, you can use the "simplify bends" option in the Flat Pattern feature to convert flat pattern edge splines into flat pattern lines and arcs.
            • Spline to arcs
              Balic Dalibor
              Hi, the Simplify bends option do not help
              mu sheet is pretty complex, it is curved (by spline redrawed to arcs) and it is cutted by a complex surface (also made by splines)
              to explain my problem, my new customer is producer of yacht glasses (curved)
              i have to calculate unbanded 3 glasses and send to them a DXF profile (in carcs)
              then also i have to design a mold for curving glass (its like a contour offseted by curved glass profile)
              On immage you can see one of 4 sheet metal wich compose the mold, you can see that its curved by spline and cuted by spline.
              With a lot of windows/glasses a lot of profiles, i can't lose all time to redraw splines.

                • Spline to arcs
                  Chris Dordoni
                  Hi Balic,

                  If you have AutoCAD, there are a few freely available scripts to convert splines to arcs from a DWG or DXF file. Just Google on "spline to pline". There are a few stand alone converters that work with DWG or DXF files to create arcs from splines, although these must be purchased, they could save a lot of time.

                  The DWGEditor that comes with SolidWorks unfortunately is not compatible with any of the spline to pline scripts I have tried to date.

                  Another user here, Dean Williamson, made the following suggestion in the DWGEditor, although I have not had a chance to try it for myself:

                  1.) Copy picture to another location
                  2.) In command line type "bpoly"
                  3.) A box pops up "Boundary" click on "Boundary Set"
                  4.) Select entities that need to be created as a poly-line.
                  5.) After all entities are selected hit "Enter"
                  6.) Box re-appears, click on "Select Area"
                  7.) Click anywhere on the inside of the selected entities.
                  8.) Hit Enter
                  9.) Box re-appears, click "Ok"

                  NOTE: I have opened a SPR for a condition that when you complete the "BPOLY" command, the editor will create a whole other splined part on top of the other file you copied. What I do is create a layer with a different color, then I take the dwg that I created and make it that color. After I create my POLY, I can then hide my newly created poly and delete my old. Solidworks is now aware of this issue.

                  Solidworks 2007 SP2.1
                  2GB Ram

                  Dean Williamson
                  Ace Manufacturing & Parts
                  300 Ramsey Street
                  Sullivan, Missouri 63080


                    • Spline to arcs
                      Balic Dalibor
                      I've readed that Chris, but
                      problem is that i have a LOOT of splines, so i don't want to export import, and again, and again, and lossing relations i would like (if possibile) do that right in SW Sketch, like: select spline, convert to arcs, job done
                      am i asking to much?
                      i've seen that logopres have some feature for that, but i never seen it in use, and also, logopress has a price wich is much over my budget
                        • Spline to arcs
                          Piyush Agarwal
                          Hi Balic,

                          You can use a SW API to get the tessellation. Look at this API Curve::GetTessPts(). Here is what it does...

                          Hope that helps,

                          This method gets a set of points that represent the tessellation of this curve.

                          Syntax (OLE Automation)
                          retval = Curve.GetTessPts ( chordTolerance, lengthTolerance, startPoint, endPoint )

                          Input: (double) chordTolerance Chord tolerance to be used in tessellation (meters); this is the maximum permitted distance from a cord to the curve between the cord endpoints
                          Input: (double) lengthTolerance Length tolerance to be used to filter out very short segments (meters); this method does not return tessellated segments shorter than this value
                          Input: (VARIANT) startPoint SafeArray containing the start point of the curve
                          Input: (VARIANT) endPoint SafeArray containing the end point of the curve
                          Return: (VARIANT) retval SafeArray of doubles containing the tessellation points (see Remarks)

                          The array returned contains the x, y, z location of the tessellation points:
                          [ x1, y1, z1, x2, y2, z2, ... ]
                          For the COM implementation, use Curve::IGetTessPtsSize to determine the size of the array needed to contain the return values from this method.
                  • Spline to arcs
                    Roland Schwarz
                    In SW, I've only ever done this the hard way: sketch a series of tangent arcs & lines over a spline.

                    I've considered programming something, but the time:Profit ratio makes it a no-go.

                    I seem to remember this functionality existing in UG a long time ago. Maybe just wishful thinking.
                      • Spline to arcs
                        Balic Dalibor
                        I have tried different AutoCAD macros, and diferent ways, but they are creating a line segments over the spline but not arcs.
                        It seem that at today, there is no way to convert spline into arcs, if not redrawing arcs above, i have spoken with an programer, so maybe i will pay him to make my one Spline to arcs macro.
                        Or maybe i will take more masohistic solution i will learn VBA API by my self then i will make my macro and sell it to the world
                      • Spline to arcs
                        Jon Vacura
                        Our machining software won't interpret splines either. When I export my flat sheet metal DXF parts out I change the options so that Solidworks exports splines as polylines. This breaks up the splines into short line segments. This way I can still use splines in my models.

                          • Spline to arcs
                            Balic Dalibor
                            there is also one problem
                            i have to cut glass, its cutted buy diamont ... (small weel, sorry bad english) with line segments, cut take multiple directions, so when you brake glass (after cutting) it brakes erroneusly.