Hi @mmacia47,
Sorry to hear you are having problems with drawings. What you are seeing is in the PDF is the result of the lineweights assigned to each layer (and object) within the drawing. Generally speaking, we have followed the ISO and ASME drafting standards and assigned 0.5mm lineweights to visible edges within drawing views, 0.35mm to hidden edges within drawing views, and 0.25mm for the majority of annotations (dimension, text, centerlines, etc.). Usually these lineweights work well, but there are cases when they need to be reduced to improve clarity. Unfortunately, there is no way to reduce the lineweights in Fusion 360 Drawings just yet. We do have plans to enhance this, but its still a few months away.
As a workaround (and if you have AutoCAD), you can output the drawing to DWG and use AutoCAD's Layer command to modify the lineweights assigned to each layer. This will allow you to reduce the visible edges from 0.5mm to 0.35mm or less if needed. The PDF output from AutoCAD will then use the reduced lineweights.
15" Retina MacBook Pro (Late 2013), OS X El Capitan (10.11.4), in Sydney Australia
Andrew de Leon
Experience Designer - Fusion 360
MacBook Pro (16-inch, 2019), OSX 10.15.7, in Sydney, Australia