I am designing a part that uses an Equation Driven Curve spline as one of the surfaces (a gaussian to be exact), rotated about an axis for cylindrical symmetry. The machine shop would normally take my .prt file and export it to .dxf to load it into their CAM software for the CNC lathe. However, when they do so, SW breaks the spline into shorter strainght line segments, with varying length depending on the method in which I export it.

So far we have tried several methods:

1) Exporting the 2D sketch to dxf, which seems to have the worst resolution (about 0.125" line segments).

2) Exporting the 3D part to dxf and removing the extra line segments in the DXF/DWG Cleanup window. Better resolution, but still not quite as fine as I would like (about 0.05").

3) Redrawing the part in the CAM software. Ultimately the best resolution (up to 0.0001" if I wanted), but not ideal for future projects.

So my question is this, is there a way to control the resolution of the dxf export function?

How is SW chosing those short line segments? After playing with a couple of other geometries (I picker a function with tighter curves) SW seems to be able to make shorter lines for tighter radii. How it does it and why it can't use the same segment length throughout, I don't know.

Finally, the CAM software might be able to import file types other than dxf, is there a better format to suit my needs?