Joining Line Segments
@Anonymous - can you help me understand why you need these curves to be a single object? What operation can you not do in Fusion with them as separate items? This is the thing I have not yet understood about this discussion. Just trying to better understand the request. Thanks.
Jeff Strater
Engineering Director
whoa there... Sketch blocks are a totally different requirement than what I've heard before about "joining line segments". I've always heard this expressed as a kind of "composite curve", and I don't see the need for such a thing in Fusion. Yes, sketch blocks would be useful, in that they can be instanced, etc, but that's different
Jeff Strater
Engineering Director
right. You should be able to extrude that whole shape, regardless of whether it is one curve or 5. The fact that Fusion is not recognizing it as a valid profile is the problem, not the number of curves. If you can share your f3d here, we can take a look at it. Most likely, there is some gap between the curves, or else it is not exactly planar. But, share it, and we'll take a look...
Jeff Strater
Engineering Director
Accepted solution
Thanks, @Anonymous - the problem is what I suspected. There is a break in the geometry from TurboCAD. I used the technique here: find-break-in-sketch-geometry to isolate it:
Zooming in, you can see the break:
Depending on what you want to do, there are several ways to fix this. I would just create a small line segment:
and the profile is recognized:
Then, I noticed that there are two sketches here (presumably 2 layers in the original). There are several ways to deal with that, assuming the result is a single body with cutouts. I would just do 2 extrudes - one of the outer body, and one of the cutouts.
Jeff Strater
Engineering Director
@Claus_J wrote:
Jeff, I would certainly like to give my view, I'm also a TurboCad/ViaCad/Shark user and just used to be able to add, join, edit and convert anything to anything. See an edge you like, convert it to a curve and continue to shape it. Don't like a CV spline, convert it to bezier. It's likely more an artists fuzzy way of creating than an engineers and that whole "I want freedom" habit is what clashes with Fusion and the very opinionated and much appreciated mentors here. I'm sure to get bashed again for writing this. So as an example I may start with a few lines and fillet the corners and in SharkCad I will maybe join those elements and start manipulating the control points of the resulting spline and may end up with something completely different. It will probably make your head explode but it gets me to a result very quickly and with a lot of freedom, it's probably an illustrators approach. So to your question "why" I would like to respond "why not".
fair enough. I actually do see value in a "fit a single spline curve to the selected sketch curves". That, of course, has some limitations (what do we do with sharp corners?), and may require some fit tolerance as input. Perhaps I was assuming too much from other threads, but I've often heard this requirement expressed as some kind of "composite curve" object, which could be composed of lines, arcs, splines, etc. That is the requirement that, in my view, doesn't make sense in Fusion. Given that we can build profiles and paths out of a set of connected curves, I don't see the value that a composite curve would give you.
Finally: The answer to "why not?" is limited resources. We only have so much ability to add things to Fusion. We should bias our priorities around those things that either cannot be accomplished at all today in Fusion (e.g. designing a cam follower), or are otherwise blocking building real-world designs (assembly performance). There's another argument about simply adding too much stuff to Fusion, resulting in a cluttered experience. We've tried (though I feel every day that we are losing this battle) to keep Fusion's "surface area" as small as possible, and still allow our customers to do real design. We've all had experience with software that is just overwhelming in terms of the total number of commands/workspaces/etc that are available. So, if there are entire concepts that we can avoid, I, personally, will push to do so. I don't always get my way... 
Jeff Strater
Engineering Director
