8 Replies Latest reply on Mar 7, 2014 8:25 AM by Raivo Jakovels

    Loft in SW 2009

    Raivo Jakovels

      Hi! I've been facing a problem for a couple days now and i can't find a sloution on my own.. I need to create a loft which would be made from two shapes. The thing is that the loft twists around the center of itself. Why is it hapening? And how could i get rid of that?

      1.bmp

      I am using a simple straight line on one side as guide curve but it still twists for some reason...

      2.bmp

      Any advice?

       

      Thanks in advance

        • Re: Loft in SW 2009
          Bill McEachern

          break the shapes up so they have the same number of segments and line them up accordingly.

            • Re: Loft in SW 2009
              Raivo Jakovels

              Thanks for your quote, Bill, but I didn't quite understand what exactly i had to do - did you meant that I should split the sketch or what? I attached the part here.

                • Re: Loft in SW 2009
                  Bill McEachern

                  Sorry Ravio,

                  I have no ttime to look at your part. However, if you know what twisted looks like then you would know what not twisted looks like. In your not twisted vision you have lines that go from one section to another to ensure it all lines up. Likely these lines in your mind are at the end of specific elements in one sketch. In the other sketch you want to split the sketch so that it has the same number of points in the sketch so that the lines have a point to attach to on the other sketch. As Jerry suggested use the split entities tools to break the entities up so that there are end points on the sketch entites to attach to the end points on the entities in the other sketch. In your case it looks like you have 6 elements in the one sketch, then you need six elements in the other positioned so that lines connecting the two would give you what you want. Currently it looks like you have a single spline entity in the simpler one - just break it up into six at the desired path length positions you want and then pick the sketches in the loft command by picking close to two points you want to be connected. The rest should take care of themselves.

              • Re: Loft in SW 2009
                Jerry Steiger

                Raivo,

                 

                You should probably move this to the SolidWorks/Parts and Features or Surfacing forums.

                 

                Having said that, Bill gave you a critical piece of advice. Another critical piece is to pick your profiles in similar positions, as that can cause twisting. (Try lofting between two rectangles and then pick different corners on one.) You can also play with the Connectors, but if you set them up with the same number of segments (use the Split Entities command under the Right Mouse Button after selecting an element to split) and pick start points that should line up, then the twisting should be easy to eliminate.

                 

                Jerry S.

                • Re: Loft in SW 2009
                  J. Mather

                  and if you still have trouble - attach your *.sldprt file here.

                  • Re: Loft in SW 2009
                    Wouter Van Assche

                    Ravio,

                     

                    Bill has explained quite well what you need to do, but a visual example might be easier to grasp.

                    I don't have 2009 so in image and step-by-step

                    Loft.JPG

                     

                    I did one extra step for an even nicer result that's not mentioned yet. On plane 2 I make a new sketch.

                    tools-spline tools-fit spline and select the four entities in the egg-liked shape. dial in a low tolerance (e.g. 0.01) and you will get a one-entity spline with that shape.

                    Now, as a starting point, draw construction lines from every point in the three leg shape to the left centerpoint.

                    Tools-sketch tools-split entities and split the fit-spline egg where every construction line crosses it. (these split position are not obligatory and can be changed at will, but it gives a good starting point)

                     

                    Redo your loft, you can even play with the "merge tangent faces" option for a result showing the transitions better.

                     

                    Good luck.