Hi Paul, I tested reading your DXF files into MoI, Rhino, and ViaCAD and they seemed to come in fine in all of these.

It may be possible that both LibreCAD and Inkscape are not able to figure out what unit system the DXF file is supposed to be in - there is "sort of" a setting in DXF files for units but it's fairly obscure and so some programs don't know what units the coordinates in the file are supposed to be in. There may be some option in those programs that you can set to tell them that your DXF file is in millimeter units.

Does an incorrect unit system being used explain the weird results that you're seeing?

Maybe you'll need to include a screenshot of the weird results as well since I cannot get any bad results over here with those same files...

If it looks like you're getting squashed shapes in places where there should be circular arcs, then that means that the program does not support reading full spline information from the DXF file, it's ignoring one piece of the spline information called "weights" that can be set on splines that are arc or ellipse segments.

If that's what you're seeing you can set the option in MoI for "Write curves as: Cubic splines", which will rebuild any curve that has weights in it with a non-weighted curve for the export, and that should avoid the type of spline data that those programs are not handling properly. When weighted splines are read in but with the weights ignored it can kind of mutate the shape. If that is the problem then you may want to report it as a bug in both of those programs, if they read in spline entities they should be reading in all the data including the weights, they shouldn't just be ignoring the weight values or else you get weird results like you have seen.

If the "weight values just being ignored" is the problem then you should also have seen ok looking shapes with either the "Write curves as: cubic splines" or the "Write curves as polylines" options set at export time from MoI though, and from your original description it sounded like you were also seeing problems with these options set though is that correct or do those options make ok looking results for those programs?

- Michael