I've been trying to remember the name of this horror film I saw quite a while ago (likely made in the 80's) which involved a group of people in a futuristic and seemingly post-apocalyptic world trying to survive among these small subterranean machines that looked similar to a circular saw blade (one you might find on a mitre saw, for instance). I know this sounds really odd but I can't remember much more than that other than at the beginning the people were hiding out in a fortified bunker-like building with window slots for their guns and blah blah blah, and eventually one or a few of them have to venture out for some reason and thus the story continues. Any ideas?? I've tried searching on imdb with various keywords and whatnot but I can't seem to find anything. It's driving me nuts!