autocad lt dxf import to fusion issues

[justin_lamoureux]

hi, 

I'm trying to import autocad lt files that mainly contains splines into fusion 360. 

Every file i try to import to fusion comes up with the warning "compute failed", "Some sketch curves cannot be converted to profile edges." The file is one simple outline (but made with splines)

I can't extrude or do anything useful with the file in fusion. 

I'm semi new to fusion, any fixes to this? 

Kind of blown away that there's not an easy import from different autodesk products. especially from the simplest one (LT). 

[jhackney1972]

Zip up your DXF and attach it, let the forum users give it a try.  

[justin_lamoureux]

how do i upload a file? won't let me upload a dxf.. 

[g-andresen]

Hi,

Zip your DXF as @jhackney1972  recommended

günther

[JDMather]

Right click on the *.dxf file name.

Select Send to Compressed (zipped) Folder.

Attach the resulting *.zip file here as suggested by @jhackney1972 .

[justin_lamoureux]

sample  file is attached. can't attach the actual file so this one is a cut down file from what i'm having issues with. it doesn't come up with the actual warning but it can't be extruded.

could the issue be from using fit curves in autocad lt?  

[jhackney1972]

I does give a warning when you import it but on the other hand, it is a complete profile and will Extrude.  

[HughesTooling · Accepted solution]

This error is caused where you have curves that are near tangent overlapping. In this case you have a very bad spline that has loops in in that overlay the spline. You can't see this well in Fusion as you can't zoom in far enough. Below is a screencast of what I see in Rhino.

Mark

[justin_lamoureux]

the loops seem quite strange to me as the drawing came from autocad and is simply 2 segments of a radius (or an ellipse) joined by a fit curve (standard autocad feature). So seems quite odd to me that another autodesk program suddenly loops a drawing from what is essentially the most basic program of all. 

[justin_lamoureux]

hi, 

having played with the file more if you import it with cm, mm or inches you will get different results. 

mm has the warning but will extrude, cm doesn't extrude and inches seems fine!

[g-andresen · Accepted solution]

Hi,

When exporting and importing DXF files, you always have to expect surprises.

günther

[justin_lamoureux]

a few decades of dxf's and we still can't import one from autodesk software to autodesk software without an issue? 

does importing a file as a dwg work better? i'm currently on the home version of fusion.. 

[HughesTooling]

In this case the file is bad as shown in the screencast above so the export is bad. The DXF is bad in Fusion and Rhino, did you try reimporting into AutoCAD and check the spline.

Does AutoCAD have options for how the DXF is exported? Polycurves tend to cause problems, when I export from Rhino I always set the export to explode polycurves.

DWG might work better.

Mark

[HughesTooling]

---

@justin_lamoureux wrote:

the loops seem quite strange to me as the drawing came from autocad and is simply 2 segments of a radius (or an ellipse) joined by a fit curve (standard autocad feature). So seems quite odd to me that another autodesk program suddenly loops a drawing from what is essentially the most basic program of all. 

---

Thinking about this a bit more. It could be DXF doesn't have the features to create this polycurve so it's simplified to a spline on export. See if opening the DXF in autocad gives you the same simple curves you had in the original. I think the individual curves can be represented in a DXF, Ellipse, fit curves etc. But joined might be the problem.

Mark

[justin_lamoureux · Accepted solution]

hi

thanks everyone for the help. it seems to be along the idea of overlapping lines in autocad. I've spent some time with the fusion help crew and we've found some weird bugs through our trials but the root cause may be the blend command in autocad lt (?), which in itself is kind of weird as it's just a fit curve spline and some work totally fine and others don't.

Most of my layers are built off one another, some work and some dont when imported. Also, mirrored versions of the same spline don't work at times. It's been an interesting journey. 

so far the solution is importing a file to fusion, finding the bad layers or sections in a sketch, then going back to autocad and sniping the tiny overlapping sections and reconnecting with, of course, a blend curve. Which seems to work. Also having to rebuild some random mirrored parts which is odd. 

Not nearly as easy as i was hoping to import dxf files into fusion and by far the most issues i've ever had moving files form one program to another. But slowly working it out.