The 2015 Spline on Surface can be initially drawn more quickly and with better initial control, but I'm afraid that it is (and will be) forever plagued by the SW 3D solver (not to be confused with the 2D D-cubed solver.) For instance, create a simple revolved shape using a conic (like shown below.) Now create an SOS on it manually spiraling up round it. Now start constraining the beginning and end points - I guarantee you will soon over constrain it. This is an important sketch element that I've wanted to use for a long time - especially since it has the capability to split surfaces but I'm finding that it is no better improved over the previous (<2015) version.

Mark

Hi Mark

As you know, 3D sketches could add up to 6 degrees of freedom for any rigid

piece of geometry. Constraints remove one

or moredegrees of freedom ina model. Splines add a complex form of control to the curve. Coincidence to

complex surfaces will pose challenges to applying a coherent constraint scheme.

That does not change in SOLIDWORKS 2015.

Even with these considerations, SW2015 is a significant upgrade to spline on

surface. Users have requested that we add functionality to support split

surfaces.

http://help.solidworks.com/2015/English/SolidWorks/sldworks/c_Splines_on_Surfaces.htm

- You can drag points along the surface.

- You can span

multiple faces regardless of continuity.I modeled a solid similar to the one you describe. I was able to fully define

the spline using a series of dimensions. While I was working, the spline never

became unsolvable or over defined. The key for me was to remove degrees of

freedom in a step by step approach to each dimension. That may not work for all

designs. I have attached an image of the model below.

Best Regards

Ditmars VEINBACHS

R&D SOLIDWORKS, Modeling Applications Director