Smelters take one input and one output, so the built-in Furnace can work just fine as a base. Although that would allow mixed belts to be smelted through one furnace, that's probably fine. If you really want to do mixed smelting, who am I to judge? Apparently one furnace-type building is required to exist otherwise the game crashes, so might as well do that.
Smelters - and all automated buildings - will have Loaders attached to them. In this case, one input and one output. They will have basically infinite speed as they should never be the limiting factor. The input belt determines input speed, craft time determines craft speed, and output belt determines output speed. Loaders conveniently work exactly like Satisfactory already, shovelling a full stack of items into the building before stopping. Loaders should be set to Not Operable.
So completing this task will also lay the groundwork for Constructors, Assemblers and so on.
Smelters take one input and one output, so the built-in Furnace can work just fine as a base. Although that would allow mixed belts to be smelted through one furnace, that's probably fine. If you really want to do mixed smelting, who am I to judge? Apparently one furnace-type building is required to exist otherwise the game crashes, so might as well do that.
Smelters - and all automated buildings - will have Loaders attached to them. In this case, one input and one output. They will have basically infinite speed as they should never be the limiting factor. The input belt determines input speed, craft time determines craft speed, and output belt determines output speed. Loaders conveniently work exactly like Satisfactory already, shovelling a full stack of items into the building before stopping. Loaders should be set to Not Operable.
So completing this task will also lay the groundwork for Constructors, Assemblers and so on.