OpenSCAD - Getting Started with MakerBot - page 212

We found that it is helpful to perform Boolean operations be-
fore exporting, instead of just stacking shapes on top of each
other.
Using pstoedit
Another alternative to a DXF exporter is pstoedit http://www.pstoedit.net .
Pstoedit is a useful conversion utility that translates PostScript and PDF
graphics into other vector file formats. We found that it was very useful for
converting EPS files exported from Inkscape or other vector drawing pro-
grams to DXF format.
When used in with the following syntax, it will remove all splines and polylines
from the exported EPS file:
pstoedit -dt -f dxf:-polyaslines INFILE.eps OUTFILE.dxf
The easiest way to install on Mac OSX is to use a package manager like
Macports or Homebrew .
Installing on Mac via Macports
sudo port install pstoedit
Installing on Mac via Homebrew
sudo brew install pstoedit
Installing for Windows
Download the Windows binaries and follow the instructions on the
pstoedit page ( http://www.pstoedit.net ).
For more tips on how to format files in Inkscape for DXF conversion using
pstoedit, check out Tony Buser's tutorial on the subject ( http://tonybus
er.com/2d-to-3d ) .
If you don't want to install extensions or use the command line,
there is another option. You can convert all the curved line
segments to straight lines before exporting to DXF via the de-
fault Inkscape DXF exporter. Nudel has written a Inkscape to
OpenSCAD dxf tutorial to help you.( http://repraprip.blog
spot.com/2011/05/inkscape-to-openscad-dxf-tutorial.html )
This works for some drawings, but we found that on traced
bitmaps and complex curves that the results were unpredict-
able and we sometimes ended up with splines and polylines
that caused OpenSCAD errors. Your mileage may vary.