Exporting SBC Designs
From Space Engineers Wiki
You can save/export a ship/station/mesh designed in-game as a .sbc file by:
- Load the world with your design in Creative mode with copy/paste enabled
- Copy the design (looking at the design so that the mesh is active, press Ctrl+C)
- Press Escape to stop the copying
- Press F11 to open the debug menu
- Press "Export clipboard to file"
You can now find your design as "shipname.sbc" in your AppData\Roaming\SpaceEngineers\Export folder. If you want to rename it, make sure to change its <SubtypeId> by editing the .sbc file using a text editor as well as the file's name.