Fusion consistently crashes when drawing lines off of a spline. Very simple operation.

[autodeskSGP8F]

This is an extremely simple project. I was literally just trying to create a lock lid for a salad lettuce container. The sketch comprises of 2 spline lines, mirrored horizontally and vertically.

When attempting to draw a line off one of the splines, Fusion crashes. I've tried to perform the same operation at least a dozen times and it crashes every single time.

Attached is a video as well as the .f3d file.

Fusion 2603.1.31 x86_64
Windows 11 Pro 24H2 (26100.4652)

[rohit.bapat]

Hello @autodeskSGP8F 

Sorry to know that you are facing this issue. I am able to reproduce this crash easily and have reported to the Development team (Ticket FUS-212960)

Thank you,

Best Regards

Rohit Bapat

[TrippyLighting]

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@autodeskSGP8F wrote:

This is an extremely simple project.

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Yep, and you already made several mistakes in your sketch:

1. Not fully dimensioned and constrained.

2. The above can be difficult or labor intensive to do with fit point splines, but those are hardly needed for this project.

3. You mirrored inadequately constrained and offset splines. Mirroring entire sketch halves / quarters is not a good practice. Outside of using large patterns in sketches,   mirroring inadequately dimensioned and  constrained and offset splines is the best way to kill sketch solver performance.

Two arcs, and extrusion and a solid fillet on the edge makes for a much more efficient workflow that is also a better reflection of the geometry.

[autodeskSGP8F]

Arcs were considered and they were not good enough to contour the shape I was looking for. Nobody wants to deal with splines unless they have to, believe me!

Also this was a quick-and-dirty project to help seal in the freashness of a $3.99 salad box, and it was 2am and I didn't want to spend more than 15m on it.  One time print and I won't ever revisit this project again. Fully constrained and dimensions weren't my priority. 

Lastly, regardless, Fusion should not crash and that's the purpose of this post. The topic of whether there's a better way to design this is out of scope.

[TrippyLighting]

I did not intend to indicate that Fusion should crash. It should not, and a bug was already recorded.

If you take a look at the model I posted, you'll find that my approach is quicker than what you created, but it is also fully constrained.

If you must use splines, then the two arcs can be replaced with  3-degree control point splines.

[TheCADWhisperer]

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@autodeskSGP8F wrote:

The sketch comprises of 2 spline lines, mirrored horizontally and vertically.

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@autodeskSGP8F 

This is not the best way to create splines.

I would not use ANY mirror constraints.

Instead I would use Midpoint constrained Construction Lines to locate the spline nodes before creating continuous spline.

[autodeskSGP8F]

I saw your example. I wanted that graduate curve at the corner rather than a sharp corner.

I must argue my original design, since the splines were surrounded by fully-constrained and tangent to the construction lines, allows me to adjust the width and length of the bowl and the smooth curvature is still maintained. I ended up having to do that because the final product was 2mm too tight. I changed my variables and the splines followed the construction line. I also got around the crashing issue by drawing my lock tabs on a separate projected sketch.

In your example, you used radius to constrain your arcs, making it hard to make adjustment in the future. If the bowl length needs to be increased by 2mm, those radiuses are locked.

Regardless, thanks for introducing me to other options that can be constrained easier in the future.

[TheCADWhisperer]

@autodeskSGP8F 

Fully defined sketch.

Curvature display at the corners, but there will also be abrupt change at the top/bottom and sides.

No Mirror Constraints.

(I accepted the default handles - they could be edited if needed to further control the spline.)

[autodeskSGP8F]

Is it typical to try to blame the users whenever Fusion crashes? I love how I'm getting all these unsolicited advice about how mirror constraints are bad, how splines are bad, so bad that it'd cause Fusion to crash. I'm no expert but if mirrors and splines will cause Fusion to crash, it shouldn't have been made available. 

I think if someone does A and Fusion crashes, people here will tell you A is wrong and do B. If B causes Fusion to crash, people will say you should have done A.

[TrippyLighting]

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@autodeskSGP8F wrote:

Is it typical to try to blame the users whenever Fusion crashes?

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I understand that some users' perception is that they are blamed for the crashes. Our responses could be clearer, as this is not the intention.

No software should ever crash, but respond with intelligible warnings or error messages when stuff goes wrong.

However, none of the software packages I've worked with over the last 30+ years do that perfectly in every situation. 

That direction can be provided by more experienced users. @TheCADWhisperer and I combine 70+ years of professional engineering and CAD experience across multiple CAD software packages (from multiple vendors) and multiple industries. Those directions to avoid such situations are often best practices in any CAD application.

[TheCADWhisperer]

@autodeskSGP8F 

I am trying to help you get around (or avoid altogether) the crash behavior based on my experience.

I am sure Autodesk is taking a look at debugging the issue and they need examples from real users like you to uncover these cases.

[autodeskSGP8F]

@TheCADWhisperer @TrippyLighting Thanks for clarifying the intentions. I was initially taken back a bit because my design was being called out as mistakes. I rarely use splines but I really wanted to create a perfect contour around the edges of the bowl and that's why I resorted to splines initially.

Regardless, I got around the bug by creating a different sketch plane and projected the outline before I drew those lock tabs. Mission accomplished and it keeps my lettuce fresh!