I see this thread is a couple of years old now but I have tried the fixes below with changing the extension code and it did not work for me. So in the interest of helping people who are having the same issue I will tell how I got the extension to code correctly. I first downloaded the latest .92 and that's when I discovered the g code output scaling problem. It scaled way too small. After I uninstalled and went to .91 it scaled too large. But I soon discovered that if I left the settings as they were on a new file and made my drawing to the size I wanted and save the file before I sent to generate the code. Select all and set the toolbar size to % and scale it up or down set object to path and then generate. It takes a few times to find the right % but it will correct the scaling issues. Keep your original size file that you saved to use over and remember the percentage for your next project.