Minecraft: How To Make Automated Furnaces
A Basic Auto Furnace
The Basic Principle
The most basic design of an automated furnace is a system where a chest is on the ground, a hopper is placed below it, and above the hopper is where the furnace rests. This design allows the finished products, whether it is cooked meat, smelted ore, or any other smelt-able item is promptly removed from the furnace and placed into the chest, which naturally has a much larger storage area.
Above the furnace, is another hopper facing downward into the furnace. This hopper is the one that will contain the item that you want to cook. In order to have items fall into the hopper to be placed into the furnace, you will have to place a chest onto the top of that hopper. To place a chest onto the hopper you will have to hold down the control button while placing if you are on the computer, and be crouching down to do it on Xbox or Playstation.
The next step will be the row of hoppers that supplies the fuel for the furnace to burn. This hopper can come in from any of the three remaining directions of the furnace not including the front facing part of the furnace that shows whether or not it is cooking. This fuel source can be anything from coal blocks, lava, or wood planks. This hopper should have a chest placed on top of it with a sign labeled "fuel" so you can know what to place into it. Anything placed into this chest will flow into the furnace to burn it.
A word of caution however, if you place an item that cannot be burned, or be used to cook other items in the chests, it will break your automated system and not allow it to continue. To fix this, just remove the incorrect items directly from the furnace and it should promptly start up without any other steps.
Your design should look relatively similar to the design pictured to the right.
Have You Ever Used An Automated Furnace?
A Slightly More Advanced Version
A More Efficient System
One way to make your system even faster is to add a second furnace, This system can share the same top chest, as long as it is a double chest by simply having two hoppers underneath pointing into the furnaces to supply the item being cooked. On the sides, as pictured, or behind you can add the chests to funnel the fuel into the furnaces like described in the instructions above. This system will smelt items twice as fast and can be duplicated down the line with multiple furnaces.
Want To Be More Advanced?
But what if you want 10 furnaces? How about 20?
Very quickly it becomes impracticable to put items in ten or twenty chests to simply smelt things. Well with the more advanced uses or rail hoppers, you can place your fuel in one mine-cart and items you want to be smelted in another and turn on the rail, which runs along hoppers that suck items from the mine-cart while it moves along the array of hoppers.
This design, while more efficient, requires a large amount of resources and a fairly advanced amount of knowledge when it comes to redstone and mine-cart mechanics and is rather difficult to describe via text.
But fear none, there are a vast amount of great tutorials showing how to make it easily by following videos. Below is my favorite design, made by a YouTube Star and Minecraft player Mumbo Jumbo. This video is of his design and i take no credit for it, but advise you to study his design as it is one of the most efficient and easiest to make.