I have just started the expedition 3. How far did people have to go to find enough copper to make chromatic metal for the base computer. I feel I have been wandering far and no sign of any except a small secondary deposit near where I started
You get plenty of chromatic metal as reward for early milestones, as far as I remember. I mined a little bit of copper (like one or two deposits) somewhere at the middle of the expedition, and that’s it. In general, most of the trick for this expedition is to check requirements and rewards for milestones, and figure out the most efficient order to do them in, because many rewards of certain milestones can be used to achieve another milestone, though they’re not always listed in the convenient order.
You can make chromatic metal in your refiner from copper, cadmium, emeril and/or indium if you can mine some of those around. Hope this helps and enjoy the game !