Compute failed to generate profile as, curves do not precisely overlap

[griffinXMGJ2]

Hi there, I'm quite new to Fusion 360 and thus this forum, so sorry if this is in the wrong place or anything. Regardless, I've run into an issue when trying to set an offset on part of a sketch. I'm trying to create a 3D-printed marquee sign based off of a tutorial (https://youtu.be/3Mkf67_ZnEM?t=199 [Use subtitles]), and I need to set two offsets for each line of the sketch.

I can add the 8mm offset to the longest/largest line, but when I add a -1.2mm offset to the same line, I get the following error, which eliminates the planes needed for extrusion.

Any ideas?

[g-andresen]

Hi,

The central problem is the amount of control points in your profile.
They cause uncontrolled self-intersections in case of offsets.
Recommendation:

Reduce the number of control points, because not only for fusion:

As many control points as necessary, but as few as possible.

günther

[davebYYPCU]

Yep, same here.  @jeff_strater no logic to this behaviour.

[TrippyLighting]

This is the problems with so many Fusion 360 tutorials. It works in that one case 😉

This is a garbage-in + garbage-out problem.

You imported a DXF of svg file that was originally created in a Adobe Illustrator or any number of other vector graphics applications. The individual spline segments that are used there do not have to comply to the stringent requirements needed for a CAD application, e.g. they don't have to be perfectly tangent. They are near-tangent, but that creates the problem as Fusion 360 does not like that.

So when you offset this one particular chain of splines, Fusion cannot properly trim/shorten the offset curves and profile generation fails.

[jeff_strater]

I created bug FUS-104053 for this issue.  I don't see anything obviously wrong with this sketch, so it should work OK.

[griffinXMGJ2]

Small update: I back-tracked and did the inner 1.2mm offset first, which worked perfectly, but upon doing the outside -8mm offset, it gave me the same error, and while I did get the offset line, I still lost the interior planes, so I'm basically at square one again. Not sure why it can do one or the other, but not both?