I work with Corel Draw for most of my carvings. (profile cuts in particular, imported into LazyCAM). The DXF file format just doesn't work for me. So after many hours of trying different files formats, when exporting them from Corel Draw, I discovered that the Hewlett Packard Graphic Language *.PLT file format is the one to use. As it preserves the correct aspect ratio, and actual dimensions of the drawings. When importing them into LazyCAM. (Instead of just clicking the "open DXF" menu item, click on the "File, Open vector file", and select the HPGL *.PLT file format, then navigate to the folder where your file is stored, and click on it to open). Works great for me. And has for the past 8 years!