Sketch not closed- Please help my student get this to work.

[kmcgheeCMFPG]

So one of my students wants to machine out a belt buckle on the Tormach, and he is a avid fan of the comic book hero the punisher. He drew this up and got it to this point but I can't help him. 

This issue is we want to extrude the skull down to the rest of the body. The issue is there is no profile to extrude. Now I watched him draw this skull and it was done with the spline tool and each point connected to the next when stopping one spline and starting another, yet its acting like there is a gap and not closed. In our old software, Rhino, in this situation we would just join it the two but in fusion I know that command does not exist, and I feel like I need to make the two lines coincidence but if I am right I can't get it to work.

Anyone out there know what I did wrong in my "teaching," well more like the blind leading the blind I think. File attached.

[nstevelmans]

Hi,

This should fix it.

One spline was open I closed it.

[etfrench]

Here's a little screencast of my first attempt to debug it.  I'll add the second one whenever it gets done uploading (It will be the same solution as @nstevelmans)

You'll note the non-closed area is not where the overlapping splines are which is very odd.

[etfrench]

Here's the second screencast:

[kmcgheeCMFPG]

Thank you very much for your time. I am not sure why I did not see the correction in the second video, I guess I did not zoom in enough. What I don't understand is why the edit in the first video was hidden from view, what I mean is that it does not appear to be anything wrong with it, and yet there was. How does one tell when that happens aside from just drawing lines and seeing if it creates a profile or not?

[etfrench]

Having the sketch profiles turned off masks doesn't help when debugging.  I don't know a good reason for turning them off. 

It's usually pretty quick to zero in on the error by dividing the sketch in two with lines.  What's unusual here, is that it did not find the error.

@jeff_strater: Can you take a look at this?

[jeff_strater]

The main reasons for turning off the profiles are 1) clutter and 2) performance.  If you have a large sketch, the time necessary to compute the profiles can be significant.  But, yes, the downside is that you forget to turn them back on when you go to consume the sketch.

I think that the divide-and-conquer method did work here.  But, think about what it is doing.  That technique just finds breaks in the profile.  Which, in your first video did work and helped to correct the initial problem.  The second problem, shown in your second video, was not an open profile problem, it was a set of funky geometry that produced some questionable BRep geometry.  Yes, the divide method will not find those problems.  I'm not sure what sort of tool might exist to find those kinds of problems, to be honest.  I've never seen that one before.

One question:  Where did the geometry in this sketch come from?  Was it imported from an SVG, by any chance?

Jeff

[kmcgheeCMFPG]

The image was drawn using a canvas and the spline tool to trace it on the top plane.

[etfrench]

@jeff_strater: I should have mentioned the two videos are each from fresh downloads of the file.  Replacing the line in the first file made the profiles start working, while in the second it wasn't necessary.

[jeff_strater]

thanks, @kmcgheeCMFPG, that is good information.  Armed with that information, plus some time to think about this, I took a fresh look at this problem, and I understand it better.  The problem is that the spline handles on a couple of those splines have gotten flipped around, making small loops near the ends of the splines.  I'm not sure how that happened.  It could have been a Fusion bug, it could have been that the user inadvertently dragged those spline handles.  In any case, the fix is pretty straightforward - dragging the spline handles back to eliminate the loops.

I would like to sometime understand how these got so tangled, whether there is a bug we should be on the lookout for.

Jeff

[kmcgheeCMFPG]

?There is a very good possibility that the student played with the spline handles to make the spline duplicate the canvass, knowing this is the case I will make sure I instruct students to do that as little as possible.