It looks like the Official 3DR CAD files are corrupt. I might be doing something wrong, but I'm a fairly experienced CAD user, and I've tried to be thorough. I have access to a CNC laser cutter, and I decided to cut my own Arducopter frame. I tried multiple approaches to open the files (as listed below).
Every single one of the files seems to be corrupt. Can anyone help me to:
What I did that resulted in the errors:
Issue solved. I was doing things incorrectly. For whatever reason, you cannot simply download individual files from the github repository. That will give you corrupt CAD files.
Instead, download the entire repository as a ZIP. To do so, go to https://github.com/3drobotics/3D-Robotics-Products and click the "Zip" button. I've attached a screenshot with the button highlighted in yellow. You could also use Git client to make a local version of the repository, as is described here: http://stackoverflow.com/questions/2751227/how-to-download-source-f....
Cool thing for me to learn, and I hope it helps someone else. Now it's time to arrange all of the DXF files on one sheet so that I can laser CNC cut the frame out of Lexan.