123D Design is an amazing tool for creating custom 3D models. It's totally free, runs on basically anything, and is incredibly simple. When you want to get your 3D models for printed by a service like Shapeways it's exactly what you need.
But the .123DX file is basically useless outside of 123D Design and .STL files only work when you're 3D printing or CNCing your parts. This makes it very difficult to jump from prototype to product within the 123D ecosystem.
Fear not! This is how you extract a .SAT file from your .123DX file.
1. Save Your Project
Mouse over the drop down in the top left of 123D Design, go down to save, and save your model using the "My Computer" option. Remember where you save it. We'll need the file in the next step.
Note: If you have any hidden objects that you don't want to appear in your final .SAT file delete them before saving.
2. Locate the File
Open up a finder or explorer window (depending on whether you're on a Mac or a PC) and navigate to the .123DX file on your computer.
3. Rename the File
Rename the file by adding .zip at the end of the file name. This will trick your computer into treating the file like a .zip file and not like a .123DX file.
4. Use .zip
Your computer will probably confirm with you that you want to change the "extension". Choose "Use .zip".
5. Explore the extracted folder
You should now see a folder with the same name as the .zip version of your 3D model.
6. Locate the .smt file
In my case the .smt file is location in Fusion[Active]/Breps.BlobParts/. It's probably the same for your 3D model.
7. Rename your .smt file to .sat
You can choose any file name you like as long as it ends with .sat.
8. Delete the garbage
Copy your new .sat file somewhere else on your computer and feel free to delete the folder and .zip file that we created.
Now you're ready to move your product into manufacturing with a company like Protolabs!