My CAD journey started in a fabrication shop. I ran a CNC laser, and sometimes parts had a feature in the wrong place, or a hole that was the wrong size. I learned how to make adjustments in Sigmanest, and then learned to make my own 2D cad files. I took a couple of classes in manual drafting (paper and pencils) and another couple of classes in Solidworks. I taught myself autocad after being hired to detail reinforcement in precast concrete parts.