Comment 57 for bug 192923

    yes, I was afraid that this might be the case, the problem is that physical machinery likes to move in a straight line, no curves.
    what I would recommend is that you investigate the Inkscape menu option called :
Effects | Modify Path | Flatten Beziers
    with this effect you can take a Bezier path or a spline and you can convert it into a multiline, and you can specify the precision or the length of each segment. You can also do the same with text if you have previously used the menu option called Path | Object to Path.
    once you have converted the splines into multilines like this, then you can export to dxf and the result will be readable by a CNC machine because it will be all lines, no splines. The choice of precision in the output may be difficult, not quite sure how to do that, best thing is to zoom in and look at it.
   I have no experience with doing this kind of conversion, but I would recommend asking a question at http://www.nabble.com/Inkscape---User-f1927.html
or check out : http://sourceforge.net/mailarchive/forum.php?forum_name=inkscape-user