9 Replies Latest reply on May 12, 2017 11:57 AM by Maha Nadarasa

    Lofted / Boundary Surface

    Maha Nadarasa

      In this video Boundary Surface has been used to loft. I used Lofted Surface instead of Boundary Surface but the result is same.

       

      SolidWorks Tutorial #268 : advanced screwdriver bit (PZ2) - YouTube

      Time 12.52  

      1.png

      Is there any differences between using these two tools?

       

       

        • Re: Lofted / Boundary Surface
          Paul Salvador

          ..they seem to be the same visually when comparing their isocurves and curvature plots.

          loftx.png

          • Re: Lofted / Boundary Surface
            Dan Pihlaja

            Maha Nadarasa wrote:

             

            In this video Boundary Surface has been used to loft. I used Lofted Surface instead of Boundary Surface but the result is same.

             

             

            Is there any differences between using these two tools?

             

             

             

            From the help files:

            The boundary surface feature lets you create surfaces that can be tangent or curvature continuous in both directions (all sides of the surface). In most cases, this delivers a higher quality result than the loft tool. Consumer product designers and others who require high quality surfaces with curvature continuity can use this tool.

            2015 SOLIDWORKS Help - Boundary Surface

             

            This would mean that the boundary surface can probably do things that the loft tool cannot do.

            I am guessing that in this case, the user knows that and uses the boundary surface all the time instead of the loft.

            • Re: Lofted / Boundary Surface
              Mike Price

              I have found that lofted surfaces are much more stable than boundary surfaces.  Therefore, I always default to a loft.  With that said, there are sometimes that a loft will work and a boundary will not or vice versa, so you want to be comfortable with using both, but I always counsel to use a loft when possible unless more control is necessary.

               

              Also another thing to keep in mind is that, for example, when you select one edge and then another, if you select an edge on one end and then select the other edge on the opposite end, you get a "bowtie", which can be corrected by dragging the balloon.  However, SW sometimes likes to put the balloon back to its default position and not remember that you had dragged it in times past.  If you have a 1000+ feature model, that is wonderful fun   So, my counsel would be to deselect the edge and then reselect it rather than dragging the balloon.

                • Re: Lofted / Boundary Surface
                  Maha Nadarasa

                  If a blue sketch turn into black I can say it is stable. I am unable to understand what is meant by “stable” here.

                   

                  Second one is an important information. I had to struggle with this problem many times. Thank you for sharing this information.

                    • Re: Lofted / Boundary Surface
                      Dan Pihlaja

                      Maha Nadarasa wrote:

                       

                      If a blue sketch turn into black I can say it is stable. I am unable to understand what is meant by “stable” here.

                       

                       

                       

                      "Stable" and "Unstable" are different than "defined" and "Undefined" which is what you are referring to.

                       

                      As an example, in the case of assembly mates, a "stable" constraint would be a concentric mate.  And "unstable" constraint would be a tangent mate, in which it has a tendency to "flip" to the other side of the arc.  Especially when things aren't fully defined.

                      So, "Stable" here refers to "having less errors" or "able to predict easier"