Many of us use fusion to design but then cut using machines like fibre lasers, most of these simply use a dxf file in their proprietary software to cut from. Fusion whilst been able to export a sketch as a dxf or going into cam and creating a tool path is very capable the simplest and by far the easiest way I've found is simply project all your sketches on to a new plane then save that as a new sketch so combining all your sketches on one plane then save that as a dxf, its really quick and easy and works a treat, it would be really good if from fusion when you finish a design you could simply click a button to project all sketches onto a new plane and save as a sketch labelled laser contour for example, then you could simply click one button to create this and then one button to export the dxf, 1000's of users would see this as a fantastic addition I'm sure. At the moment you create components then create sketches for all your design its then a long winded process to export all those sketches as one as a dxf ! what you need to do is combine them all into a new sketch that will update if you alter another sketch within the design.