Some of the features:
- One combinator per requester chest
- A single requester chest can supply multiple furnaces
- A single control circuit with simple control signals
- Can be beaconed and tiled
What is it:
It's a simple logistics based furnace that will smelt all appropriate vanilla raw resources based on a control circuit. The same smelter can be used to make iron plate, copper plate, steel plate, and brick as needed.
How does it work:
It takes advantage of the least common multiple of the raw material counts needed for each type of product outputted.
1 Iron Ore -> 1 Iron Plate
1 Copper Ore -> 1 Copper plate
5 Iron Plate -> 1 Steel Plate
2 Stone -> 1 Brick
The least common multiple of 1, 2, and 5 is 10. If the inserter putting raw materials into the furnace has its stack size overridden to 10 and only activates when there is at least 10 of a resource in it's requester chest, the furnace will consume all the resources put into it and then be available to make another product.
Implementation:
There are two parts to the design, the furnace and the control. The furnace portion can be repeated as many times as needed, while only one control circuit portion is needed.
Furnace:
The furnace decider combinator reads the contents of the request chest and outputs to the stack filter inserter a signal of 1 for all items with quantities 10 or greater. The stack filter inserter has its stack size overridden to 10 and sets it's filter according to the output of the combinator. The requester chest is set to request each raw material. The requested quantities of each resource is implementation dependent, how many logistic robots in your network, how fast are the logistic robots, and how far are the robots from the source of the materials. For this demonstration I have it set to a stack of each raw material. If you notice that raw materials are available and your furnaces are ideal, you may want to increase the requested quantities.
Control:
For this demo, I have the control setup to trigger production if product quantities in the logistic network fall below 10,000 units, but you can adjust this to your needs. If you leave the furnace as described above it will make all the product as raw material is delivered to the requester chest. In order to stop this, a constant combinator applies a -1 signal for each raw material, this will counter act the 1 applied by the decide combinator. Now the furnace will never make anything until another 1 is applied. Using the roboport to get logistic quantities, the 4 decider combinators check how much finished product is in the the network and applies a 1 on the appropriate raw material signal. The 1 enables the furnace to make product if the requisite amount of raw materials are available in its requester chest.
Beyond the basics:
To optimize the design, it's helpful to feed multiple furnaces from the same requester chest. To do this, it is necessary to change the furnace decider combinator to Each >= N * 10 where N is the number of furnaces feeding off the chest. This ensures that none of the inserters can grab a stack less than 10. As an example, if the value was left at 10 and two furnaces where feeding from a chest, if the chest had 13 ore in it, both inserters would be activated, one would get 10 ore as designed, the other would get 3. If the material it picked up was stone or iron plate, the furnace would stall.
Image below is how we run our smelter stacks. The blueprint can be tiled and includes buffer chests to store finished product. The buffer chests are all tied together so we can use one constant combinator to set their contents.
Feedback welcome, enjoy!
Omni Smelter Stack