5 Replies Latest reply on Jun 16, 2017 2:04 PM by Matt Peneguy

    How do you add dimensions for splines?

    Eric Eubanks

      I traced a picture using splines. Now it won't let me dimension it.

        • Re: How do you add dimensions for splines?
          Kelvin Lamport

          Firstly, you need to attach the model with the drawing. The drawing can be viewed using the Quick view option, but nothing can be selected.


          With the model, you should be able to dimension to the spline points.

          A better method would be to closely match the spline with a series of arcs, and then dimension those.

          • Re: How do you add dimensions for splines?
            Glenn Schroeder

            In addition to dimensioning to the spline points, as Kelvin Lamport said, adding some construction lines and relations can be a big help.


            • Re: How do you add dimensions for splines?
              Steven Mills

              You can only really dimension points on a spline. Not the angle or curve without doing a few more steps, though you can view things about splines by right-clicking on one, and showing 'Control Polygon', 'Curvature Comb' and/or 'Minimum radius'. Also splines are hard to fully define in previous SW versions, they're one of the big exceptions to the 'always fully define a sketch' rule.


              Speaking of which, I remember a feature that placed at every point of a spline two arrows can be made visible, and moving those back and forth caused the spline to change it's curve from that point to the next. But I just tried that on SW2016 and I could not find the function again. Also when I placed two dimensions on all the spline points, the spline became fully defined for once. It used to be that unless you fixed or dimensioned those arrows I was talking about, a spline was never fully defined IIRC. Does anyone know about this?

                • Re: How do you add dimensions for splines?
                  Glenn Schroeder



                  Those are "Spline Handles", and I don't know what happened to them.  I can't seem to make them show in a Part sketch using Search...



                  ...or from the Spline Tools toolbar.



                  ...or in a Drawing.



                  Hopefully someone else will be able to clear it up.  If nothing else, adding construction lines with tangent relations helps.  You can drag them around similar to the handles.

                    • Re: How do you add dimensions for splines?
                      Matt Peneguy

                      Glenn Schroeder,

                      I don't know where your handles went... Strange...  One thing I saw that got updated is they have added better functionality to "Style Spline".  To me, I don't think I'll ever use a regular spline again.  Using that tool you don't have to deal with all of those handles.  Maybe one of the surface gurus will chime in, I'm sure they know how to manhandle those splines better than I do.

                      Here's a screenshot of the 2017 Style Spline:

                      I sure hope they get the stability fixed in 2017.  So, I can use the new functionality.