You cannot use the crafting menu for anything other than constructing a vehicle, IF you find all the parts. Rules: You can scrap stuff, you can repair stuff, you can place and upgrade blocks that exist or that you find/buy. But I want to get this challenge out there more so others can experience it and enjoy it.
I presented this idea to Josh Aka Jawoodle(Check him out he's awesome) and he ran with it and is doing quite well with it. Hello folks, Quite some time ago I had this idea(I'm sure a few others have had it too I'm not trying to claim full credit) to play the game with only what you find.