Create 3d cross sections from separate dxf files

[Anonymous]

I'm trying to create an STL file for a 3D printer in AutoCAD. I have 12 separate dxf files, that I'd like to combine into cross sections, each layered directly above one another from 1 - 12 (have included 1-3 as attachments).

I can't work out how to combine the images as cross sections. I can import them into one file as blocks, but I don't think I can use LOFT with blocks? I'm totally new to AutoCAD. The images were originally raster, that I fed through inkscape and saved as dxf. I'm using the student AutoCAD in Windows 10.

[tboehler]

each file:

DXFIN

PEDIT all splines to polylines and join them. (this will add many verticies  - you can weed of needed)

SAVEAS dwg

You can loft or change the elevation of the poylines in the individual files or when inserted together.

INSERT them into one file.  @0,0,0

Do your stuff.

I think that should work - If I understand it correctly.  I just did that with those 3 files in a matter of minutes.

[Anonymous]

Thanks for the advice. I can get to the point where I insert them into one file, specifying different elevations for each, but when I try the LOFT command, I get: "selected cross section is not a valid type".  Also, if I hover my cursor over the shapes, instead of coming up as polylines, it says "Block Reference". I definitely saved them as polylines, so I'm not sure why it's importing them as blocks. Am I missing an option somewhere?

Also I realised my images have an internal cut out section, so would I need to use REGION to make the hole, then back to polyline, save then insert?

[tboehler]

You need to explode them after insert.  Or during insert.  Just the blocks - careful not to explode any of the shapes twice - you'll get tiny line segments.

Hopefully that allows to loft and do what you need.  I'm not familar with Loft.

[maratovich]

Maybe this will help ...

[Anonymous]

That works, and I can select the first cross section fine, but when I select the second, AutoCAD crashes!

Is there an alternative I can use to LOFT? Or am I overloading the program by specifying z: 10 for the elevation? (I didn't think that was extreme? And my images aren't that complex.)

[tboehler]

Maybe there are too many verticies on the polylines?  You could try to "WEED" some the verticies.

I did just look at the help file and tried LOFT.  I'm guessing there are to many verticies in your polylines.

-and it looks like you can use splines - i think your original dxf files were splines?

I guess i would weed the polylins or try using the splines  - test 2 of the original dxf's files.

I use Civil 3D - that would create a surface model quite easily from those polylines.