I 3D-printed a custom threaded barrel nut without ever opening AutoCAD. I use my 3D printer to make parts for various projects, including a pinball machine and a boat, but I struggle with AutoCAD. As an alternative, I described the part to Claude in plain English and asked it to create a `.3mf` file. I opened the file in Bambu Studio and printed the part without using AutoCAD. Step-by-step: 1. I described the custom threaded barrel nut to Claude in plain English. 2. I asked Claude to create a `.3mf` file for the part. 3. I opened the file in Bambu Studio. 4. I printed the part on my 3D printer.