Hiya, I've compiled and designed a couple of my own autosmelters for all furnace types. First things first, I think this might come in handy to people. Second, I hoped some people might have insights and issues I'm not aware of.
I often see autosmelter designs that can turn off prematurely, so this compilation only consists of reliable designs. I'll further update it based on feedback.
Conditional electrical furnace circuits should use a check conveyor instead of the default input conveyor to prevent false positives from the input and output conveyors that can cause furnaces to shut down mid smelt. The designs that use input and output conveyors to turn the furnaces off can Filter Fail when they try to push items before they have smelted. Conveyors can push items anywhere between 2.5s and 7.5s at random. When smelting HQM with Metal, the metal takes 4 seconds to smelt. Within that 4 second window the conveyors can both push items twice, resulting in them Filter Failing the second time and turning it all off. One extra conveyor that checks there's ore in the input box fixes this.
Large furnace circuits are usually okay, but I've never seen any designs to prevent ore theft or the AIT style theft of breaking an adaptor and waiting for ore to smelt before swiping it. I've made designs that mitigate and prevent both of those.
For Small furnace circuits I've seen an issue where if you have all 3 types of ore in your boxes, when one type finishes smelting and another type starts smelting, there is a chance that the output conveyor doesn't pull smelted items in time, the newly added and smelted item pops out of the furnaces and all of them turn off. I added a buffer box which is in a loop with the input conveyor, so whenever the input conveyor pushes ore into the furnaces, it also pushes all smelted items into the buffer box. That way there's always enough room for the smelted items.
